ILO Content Manager

ILO Content Manager

Tuesday, 25 January 2011 20:15

Prevention

Occupational exposures account for only a minor proportion of the total number of cancers in the entire population. It has been estimated that 4% of all cancers can be attributed to occupational exposures, based on data from the United States, with a range of uncertainty from 2 to 8%. This implies that even total prevention of occupationally induced cancers would result in only a marginal reduction in national cancer rates.

However, for several reasons, this should not discourage efforts to prevent occupationally induced cancers. First, the estimate of 4% is an average figure for the entire population, including unexposed persons. Among people actually exposed to occupational carcinogens, the proportion of tumours attributable to occupation is much larger. Second, occupational exposures are avoidable hazards to which individuals are involuntarily exposed. An individual should not have to accept an increased risk of cancer in any occupation, especially if the cause is known. Third, occupationally induced cancers can be prevented by regulation, in contrast to cancers associated with lifestyle factors.

Prevention of occupationally induced cancer involves at least two stages: first, identification of a specific compound or occupational environment as carcinogenic; and second, imposing appropriate regulatory control. The principles and practice of regulatory control of known or suspected cancer hazards in the work environment vary considerably, not only among different parts of the developed and developing world, but also among countries of similar socio-economic development.

The International Agency for Research on Cancer (IARC) in Lyon, France, systematically compiles and evaluates epidemiological and experimental data on suspected or known carcinogens. The evaluations are presented in a series of monographs, which provide a basis for decisions on national regulations on the production and use of carcinogenic compounds (see “Occupational Carcinogens”, above.

Historical Background

The history of occupational cancer dates back to at least 1775, when Sir Percivall Pott published his classical report on scrotal cancer in chimney-sweeps, linking exposure to soot to the incidence of cancer. The finding had some immediate impact in that sweeps in some countries were granted the right to bathe at the end of the working day. Current studies of sweeps indicate that scrotal and skin cancer are now under control, although sweeps are still at increased risk for several other cancers.

In the 1890s, a cluster of bladder cancer was reported at a German dye factory by a surgeon at a nearby hospital. The causative compounds were later identified as aromatic amines, and these now appear in lists of carcinogenic substances in most countries. Later examples include skin cancer in radium-dial painters, nose and sinus cancer among woodworkers caused by inhalation of wood dust, and “mule-spinner’s disease”—that is, scrotal cancer among cotton industry workers caused by mineral oil mist. Leukaemia induced by exposure to benzene in the shoe repair and manufacturing industry also represents a hazard that has been reduced after the identification of carcinogens in the workplace.

In the case of linking asbestos exposure to cancer, this history illustrates a situation with a considerable time-lag between risk identification and regulatory action. Epidemiological results indicating that exposure to asbestos was associated with an increased risk of lung cancer were already starting to accumulate by the 1930s. More convincing evidence appeared around 1955, but it was not until the mid-1970s that effective steps for regulatory action began.

The identification of the hazards associated with vinyl chloride represents a different history, where prompt regulatory action followed identification of the carcinogen. In the 1960s, most countries had adopted an exposure limit value for vinyl chloride of 500 parts per million (ppm). In 1974, the first reports of an increased frequency of the rare tumour liver angiosarcoma among vinyl chloride workers were soon followed by positive animal experimental studies. After vinyl chloride was identified as carcinogenic, regulatory actions were taken for a prompt reduction of the exposure to the current limit of 1 to 5 ppm.

Methods Used for the Identificationof Occupational Carcinogens

The methods in the historical examples cited above range from observations of clusters of disease by astute clinicians to more formal epidemiological studies—that is, investigations of the disease rate (cancer rate) among human beings. Results from epidemiological studies are of high relevance for evaluations of the risk to humans. A major drawback of cancer epidemiological studies is that a long time period, usually at least 15 years, is necessary to demonstrate and evaluate the effects of an exposure to a potential carcinogen. This is unsatisfactory for surveillance purposes, and other methods must be applied for a quicker evaluation of recently introduced substances. Since the beginning of this century, animal carcinogenicity studies have been used for this purpose. However, the extrapolation from animals to humans introduces considerable uncertainty. The methods also have limitations in that a large number of animals must be followed for several years.

The need for methods with a more rapid response was partly met in 1971, when the short-term mutagenicity test (Ames test) was introduced. This test uses bacteria to measure the mutagenic activity of a substance (its ability to cause irreparable changes in the cellular genetic material, DNA). A problem in the interpretation of the results of bacterial tests is that not all substances causing human cancers are mutagenic, and not all bacterial mutagens are considered to be cancer hazards for human beings. However, the finding that a substance is mutagenic is usually taken as an indication that the substance might represent a cancer hazard for humans.

New genetic and molecular biology methods have been developed during the last 15 years, with the aim of detecting human cancer hazards. This discipline is termed “molecular epidemiology.” Genetic and molecular events are studied in order to clarify the process of cancer formation and thus develop methods for early detection of cancer, or indications of increased risk of the development of cancer. These methods include analysis of damage to the genetic material and the formation of chemical linkages (adducts) between pollutants and the genetic material. The presence of chromosomal aberrations clearly indicates effects on the genetic material which may be associated with cancer development. However, the role of molecular epidemiological findings in human cancer risk assessment remains to be settled, and research is under way to indicate more clearly exactly how results of these analyses should be interpreted.

Surveillance and Screening

The strategies for prevention of occupationally induced cancers differ from those applied for control of cancer associated with lifestyle or other environmental exposures. In the occupational field, the main strategy for cancer control has been reduction or total elimination of exposure to cancer-causing agents. Methods based on early detection by screening programmes, such as those applied for cervical cancer or breast cancer, have been of very limited importance in occupational health.

Surveillance

Information from population records on cancer rates and occupation may be used for surveillance of cancer frequencies in various occupations. Several methods to obtain such information have been applied, depending on the registries available. The limitations and possibilities depend largely on the quality of the information in the registries. Information on disease rate (cancer frequency) is typically obtained from local or national cancer registries (see below), or from death certificate data, while information on the age-composition and size of occupational groups is obtained from population registries.

The classical example of this type of information is the “Decennial supplements on occupational mortality,” published in the UK since the end of the nineteenth century. These publications use death certificate information on cause of death and on occupation, together with census data on frequencies of occupations in the entire population, to calculate cause-specific death rates in different occupations. This type of statistic is a useful tool to monitor the cancer frequency in occupations with known risks, but its ability to detect previously unknown risks is limited. This type of approach may also suffer from problems associated with systematic differences in the coding of occupations on the death certificates and in the census data.

The use of personal identification numbers in the Nordic countries has offered a special opportunity to link individual census data on occupations with cancer registration data, and to directly calculate cancer rates in different occupations. In Sweden, a permanent linkage of the censuses of 1960 and 1970 and the cancer incidence during subsequent years have been made available for researchers and have been used for a large number of studies. This Swedish Cancer-Environment Registry has been used for a general survey of certain cancers tabulated by occupation. The survey was initiated by a governmental committee investigating hazards in the work environment. Similar linkages have been performed in the other Nordic countries.

Generally, statistics based on routinely collected cancer incidence and census data have the advantage of ease in providing large amounts of information. The method gives information on the cancer frequencies regarding occupation only, not in relation to certain exposures. This introduces a considerable dilution of the associations, since exposure may differ considerably among individuals in the same occupation. Epidemiological studies of the cohort type (where the cancer experience among a group of exposed workers is compared with that in unexposed workers matched for age, sex and other factors) or the case-control type (where the exposure experience of a group of persons with cancer is compared to that in a sample of the general population) give better opportunities for detailed exposure description, and thus better opportunities for investigation of the consistency of any observed risk increase, for example by examining the data for any exposure-response trends.

The possibility of obtaining more refined exposure data together with routinely collected cancer notifications was investigated in a prospective Canadian case-control study. The study was set up in the Montreal metropolitan area in 1979. Occupational histories were obtained from males as they were added to the local cancer registry, and the histories were subsequently coded for exposure to a number of chemicals by occupational hygienists. Later, the cancer risks in relation to a number of substances were calculated and published (Siemiatycki 1991).

In conclusion, the continuous production of surveillance data based on recorded information provides an effective and comparatively easy way to monitor cancer frequency by occupation. While the main purpose achieved is surveillance of known risk factors, the possibilities for the identification of new risks are limited. Registry-based studies should not be used for conclusions regarding the absence of risk in an occupation unless the proportion of individuals significantly exposed is more precisely known. It is quite common that only a relatively small percentage of members of an occupation actually are exposed; for these individuals the substance may represent a substantial hazard, but this will not be observable (i.e., will be statistically diluted) when the entire occupational group is analysed as a single group.

Screening

Screening for occupational cancer in exposed populations for purposes of early diagnosis is rarely applied, but has been tested in some settings where exposure has been difficult to eliminate. For example, much interest has focused on methods for early detection of lung cancer among people exposed to asbestos. With asbestos exposures, an increased risk persists for a long time, even after cessation of exposure. Thus, continuous evaluation of the health status of exposed individuals is justified. Chest x rays and cytological investigation of sputum have been used. Unfortunately, when tested under comparable conditions neither of these methods reduces the mortality significantly, even if some cases may be detected earlier. One of the reasons for this negative result is that the prognosis of lung cancer is little affected by early diagnosis. Another problem is that the x rays themselves represent a cancer hazard which, while small for the individual, may be significant when applied to a large number of individuals (i.e., all those screened).

Screening also has been proposed for bladder cancer in certain occupations, such as the rubber industry. Investigations of cellular changes in, or mutagenicity of, workers’ urine have been reported. However, the value of following cytological changes for population screening has been questioned, and the value of the mutagenicity tests awaits further scientific evaluation, since the prognostic value of having increased mutagenic activity in the urine is not known.

Judgements on the value of screening also depend on the intensity of the exposure, and thus the size of the expected cancer risk. Screening might be more justified in small groups exposed to high levels of carcinogens than among large groups exposed to low levels.

To summarize, no routine screening methods for occupational cancers can be recommended on the basis of present knowledge. The development of new molecular epidemiological techniques may improve the prospects for early cancer detection, but more information is needed before conclusions can be drawn.

Cancer Registration

During this century, cancer registries have been set up at several locations throughout the world. The International Agency for Research on Cancer (IARC) (1992) has compiled data on cancer incidence in different parts of the world in a series of publications, “Cancer Incidence in Five Continents.” Volume 6 of this publication lists 131 cancer registries in 48 countries.

Two main features determine the potential usefulness of a cancer registry: a well-defined catchment area (defining the geographical area involved), and the quality and completeness of the recorded information. Many of those registries that were set up early do not cover a geographically well-defined area, but rather are confined to the catchment area of a hospital.

There are several potential uses of cancer registries in the prevention of occupational cancer. A complete registry with nationwide coverage and a high quality of recorded information can result in excellent opportunities for monitoring the cancer incidence in the population. This requires access to population data to calculate age-standardized cancer rates. Some registries also contain data on occupation, which therefore facilitates the monitoring of cancer risk in different occupations.

Registries also may serve as a source for the identification of cases for epidemiological studies of both the cohort and case-control types. In the cohort study, personal identification data of the cohort is matched to the registry to obtain information on the type of cancer (i.e., as in record linkage studies). This assumes that a reliable identifying system exists (for example, personal identification numbers in the Nordic countries) and that confidentiality laws do not prohibit use of the registry in this way. For case-control studies, the registry may be used as a source for cases, although some practical problems arise. First, the cancer registries cannot, for methodological reasons, be quite up to date regarding recently diagnosed cases. The reporting system, and necessary checks and corrections of the obtained information, results in some lag time. For concurrent or prospective case-control studies, where it is desirable to contact the individuals themselves soon after a cancer diagnosis, it usually is necessary to set up an alternative way of identifying cases, for example via hospital records. Second, in some countries, confidentiality laws prohibit the identification of potential study participants who are to be contacted personally.

Registries also provide an excellent source for calculating background cancer rates to use for comparison of the cancer frequency in cohort studies of certain occupations or industries.

In studying cancer, cancer registries have several advantages over mortality registries commonly found in many countries. The accuracy of the cancer diagnoses is often better in cancer registries than in mortality registries, which are usually based on death certificate data. Another advantage is that the cancer registry often holds information on histological tumour type, and also permits the study of living persons with cancer, and is not limited to deceased persons. Above all, registries hold cancer morbidity data, permitting the study of cancers that are not rapidly fatal and/or not fatal at all.

Environmental Control

There are three main strategies for reducing workplace exposures to known or suspected carcinogens: elimination of the substance, reduced exposure by reduced emission or improved ventilation, and personal protection of the workers.

It has long been debated whether a true threshold for carcinogen exposure exists, below which no risk is present. It is often assumed that the risk should be extrapolated linearly down to zero risk at zero exposure. If this is the case, then no exposure limit, no matter how low, would be considered entirely risk-free. Despite this, many countries have defined exposure limits for some carcinogenic substances, while, for others, no exposure limit value has been assigned.

Elimination of a compound may give rise to problems when replacement substances are introduced and when the toxicity of the replacement substance must be lower than that of the substance replaced.

Reducing the exposure at the source may be relatively easily accomplished for process chemicals by encapsulation of the process and ventilation. For example, when the carcinogenic properties of vinyl chloride were discovered, the exposure limit value for vinyl chloride was lowered by a factor of one hundred or more in several countries. Although this standard was at first considered impossible to achieve by industry, later techniques allowed compliance with the new limit. Reduction of exposure at the source may be difficult to apply to substances that are used under less controlled conditions, or are formed during the work operation (e.g., motor exhausts). The compliance with exposure limits requires regular monitoring of workroom air levels.

When exposure cannot be controlled either by elimination or by reduced emissions, the use of personal protection devices is the only remaining way to minimize the exposure. These devices range from filter masks to air-supplied helmets and protective clothing. The main route of exposure must be considered in deciding appropriate protection. However, many personal protection devices cause discomfort to the user, and filter masks introduce an increased respiratory resistance which may be very significant in physically demanding jobs. The protective effect of respirators is generally unpredictable and depends on several factors, including how well the mask is fitted to the face and how often filters are changed. Personal protection must be considered as a last resort, to be attempted only when more effective ways of reducing exposure fail.

Research Approaches

It is striking how little research has been done to evaluate the impact of programmes or strategies to reduce the risk to workers of known occupational cancer hazards. With the possible exception of asbestos, few such evaluations have been conducted. Developing better methods for control of occupational cancer should include an evaluation of how present knowledge is actually put to use.

Improved control of occupational carcinogens in the workplace requires the development of a number of different areas of occupational safety and health. The process of identification of risks is a basic prerequisite for reducing exposure to carcinogens in the workplace. Risk identification in the future must solve certain methodological problems. More refined epidemiological methods are required if smaller risks are to be detected. More precise data on exposure for both the substance under study and possible confounding exposures will be necessary. More refined methods for description of the exact dose of the carcinogen delivered to the specific target organ also will increase the power of exposure-response calculations. Today, it is not uncommon that very crude substitutes are used for the actual measurement of target organ dose, such as the number of years employed in the industry. It is quite clear that such estimates of dose are considerably misclassified when used as a surrogate for dose. The presence of an exposure-response relationship is usually taken as strong evidence of an aetiological relationship. However, the reverse, lack of demonstration of an exposure-response relationship, is not necessarily evidence that no risk is involved, especially when crude measures of target organ dose are used. If target organ dose could be determined, then actual dose-response trends would carry even more weight as evidence for causation.

Molecular epidemiology is a rapidly growing area of research. Further insight into the mechanisms of cancer development can be expected, and the possibility of the early detection of carcinogenic effects will lead to earlier treatment. In addition, indicators of carcinogenic exposure will lead to improved identification of new risks.

Development of methods for supervision and regulatory control of the work environment are as necessary as methods for the identification of risks. Methods for regulatory control differ considerably even among western countries. The systems for regulation used in each country depend largely on socio-political factors and the status of labour rights. The regulation of toxic exposures is obviously a political decision. However, objective research into the effects of different types of regulatory systems could serve as a guide for politicians and decision-makers.

A number of specific research questions also need to be addressed. Methods to describe the expected effect of withdrawal of a carcinogenic substance or reduction of exposure to the substance need to be developed (i.e., the impact of interventions must be assessed). The calculation of the preventive effect of risk reduction raises certain problems when interacting substances are studied (e.g., asbestos and tobacco smoke). The preventive effect of removing one of two interacting substances is comparatively greater than when the two have only a simple additive effect.

The implications of the multistage theory of carcinogenesis for the expected effect of withdrawal of a carcinogen also adds a further complication. This theory states that the development of cancer is a process involving several cellular events (stages). Carcinogenic substances may act either in early or late stages, or both. For example, ionizing radiation is believed to affect mainly early stages in inducing certain cancer types, while arsenic acts mainly at late stages in lung cancer development. Tobacco smoke affects both early and late stages in the carcinogenic process. The effect of withdrawing a substance involved in an early stage would not be reflected in a reduced cancer rate in the population for a long time, while the removal of a “late-acting” carcinogen would be reflected in a reduced cancer rate within a few years. This is an important consideration when evaluating the effects of risk-reduction intervention programmes.

Finally, the effects of new preventive factors have recently attracted considerable interest. During the last five years, a large number of reports have been published on the preventive effect on lung cancer of consuming fruits and vegetables. The effect seems to be very consistent and strong. For example, the risk of lung cancer has been reported as double among those with a low consumption of fruits and vegetables versus those with high intake. Thus, future studies of occupational lung cancer would have greater precision and validity if individual data on fruit and vegetable consumption can be included in the analysis.

In conclusion, improved prevention of occupational cancer involves both improved methods for risk identification and more research on the effects of regulatory control. For risk identification, developments in epidemiology should mainly be directed toward better exposure information, while in the experimental field, validation of the results of molecular epidemiological methods regarding cancer risk are needed.

 

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Tuesday, 25 January 2011 20:13

Environmental Cancer

Cancer is a common disease in all countries of the world. The probability that a person will develop cancer by the age of 70 years, given survival to that age, varies between about 10 and 40% in both sexes. On average, in developed countries, about one person in five will die from cancer. This proportion is about one in 15 in developing countries. In this article, environmental cancer is defined as cancer caused (or prevented) by non-genetic factors, including human behaviour, habits, lifestyle and external factors over which the individual has no control. A stricter definition of environmental cancer is sometimes used, comprising only the effect of factors such as air and water pollution, and industrial waste.

Geographical Variation

Variation between geographical areas in the rates of particular types of cancer can be much greater than that for cancer as a whole. Known variation in the incidence of the more common cancers is summarized in table 1. The incidence of nasopharyngeal carcinoma, for example, varies some 500-fold between South East Asia and Europe. This wide variation in frequency of the various cancers has led to the view that much of human cancer is caused by factors in the environment. In particular, it has been argued that the lowest rate of a cancer observed in any population is indicative of the minimum, possibly spontaneous, rate occurring in the absence of causative factors. Thus the difference between the rate of a cancer in a given population and the minimum rate observed in any population is an estimate of the rate of the cancer in the first population which is attributable to environmental factors. On this basis it has been estimated, very approximately, that some 80 to 90% of all human cancers are environmentally determined (International Agency for Research on Cancer 1990).

Table 1.  Variation between populations covered by cancer registration in the incidence of common cancers.1

Cancer (ICD9 code)

High-incidence area

CR2

Low-incidence area

CR2

Range of variation

Mouth (143-5)

France, Bas Rhin

2

Singapore (Malay)

0.02

80

Nasopharynx (147)

Hong Kong

3

Poland, Warsaw (rural)

0.01

300

Oesophagus (150)

France, Calvados

3

Israel (Israeli-born Jews)

0.02

160

Stomach (151)

Japan, Yamagata

11

USA, Los Angeles (Filipinos)

0.3

30

Colon (153)

USA, Hawaii (Japanese)

5

India, Madras

0.2

30

Rectum (154)

USA, Los Angeles (Japanese)

3

Kuwait (non-Kuwaiti)

0.1

20

Liver (155)

Thailand, Khon Khaen

11

Paraguay, Asuncion

0.1

110

Pancreas (157)

USA, Alameda County (Calif.) (Blacks)

2

India, Ahmedabad

0.1

20

Lung (162)

New Zealand (Maori)

16

Mali, Bamako

0.5

30

Melanoma of skin (172)

Australia, Capital Terr.

3

USA, Bay Area (Calif.)(Blacks)

0.01

300

Other skin cancers (173)

Australia, Tasmania

25

Spain, Basque Country

0.05

500

Breast (174)

USA, Hawaii (Hawaiian)

12

China, Qidong

1.0

10

Cervix uteri (180)

Peru, Trujillo

6

USA, Hawaii (Chinese)

0.3

20

Corpus uteri (182)

USA, Alameda County (Calif.) (Whites)

3

China, Qidong

0.05

60

Ovary (183)

Iceland

2

Mali, Bamako

0.09

20

Prostate (185)

USA, Atlanta (Blacks)

12

China, Qidong

0.09

140

Bladder (188)

Italy, Florence

4

India, Madras

0.2

20

Kidney (189)

France, Bas Rhin

2

China, Qidong

0.08

20

1 Data from cancer registries included in IARC 1992. Only cancer sites with cumulative rate larger or equal to 2% in the high-incidence area are included. Rates refer to males except for breast, cervix uteri, corpus uteri and ovary cancers.
2 Cumulative rate % between 0 and 74 years of age.
Source: International Agency for Research on Cancer 1992.

There are, of course, other explanations for geographical variation in cancer rates. Under-registration of cancer in some populations may exaggerate the range of variation, but certainly cannot explain differences of the size shown in table 1. Genetic factors also may be important. It has been observed, however, that when populations migrate along a gradient of cancer incidence they often acquire a rate of cancer which is intermediate between that of their home country and that of the host country. This suggests that a change in environment, without genetic change, has changed the cancer incidence. For example, when Japanese migrate to the United States their rates of colon and breast cancer, which are low in Japan, rise, and their rate of stomach cancer, which is high in Japan, falls, both tending more closely towards United States’ rates. These changes may be delayed until the first post-migration generation but they still occur without genetic change. For some cancers, change with migration does not occur. For example, the Southern Chinese retain their high rate of cancer of the nasopharynx wherever they live, thus suggesting that genetic factors, or some cultural habit which changes little with migration, are responsible for this disease.

Time Trends

Further evidence of the role of environmental factors in cancer incidence has come from the observation of time trends. The most dramatic and well-known change has been the rise in lung cancer rates in males and females in parallel with but occurring some 20 to 30 years after the adoption of cigarette use, which has been seen in many regions of the world; more recently in a few countries, such as the United States, there has been the suggestion of a fall in rates among males following a reduction in tobacco smoking. Less well understood are the substantial falls in incidence of cancers including those of the stomach, oesophagus and cervix which have paralleled economic development in many countries. It would be difficult to explain these falls, however, except in terms of reduction in exposure to causal factors in the environment or, perhaps, increasing exposure to protective factors—again environmental.

Main Environmental Carcinogenic Agents

The importance of environmental factors as causes of human cancer has been further demonstrated by epidemiological studies relating particular agents to particular cancers. The main agents which have been identified are summarized in table 10. This table does not contain the drugs for which a causal link with human cancer has been established (such as diethylstilboestrol and several alkylating agents) or suspected (such as cyclophosphamide) (see also Table 9). In the case of these agents, the risk of cancer has to be balanced with the benefits of the treatment. Similarly, Table 10 does not contain agents that occur primarily in the occupational setting, such as chromium, nickel and aromatic amines. For a detailed discussion of these agents see the previous article “Occupational Carcinogens.” The relative importance of the agents listed in table 8 varies widely, depending on the potency of the agent and the number of people involved. The evidence of carcinogenicity of several environmental agents has been evaluated within the IARC Monographs programme (International Agency for Research on Cancer 1995) (see again “Occupational Carcinogens” for a discussion of the Monographs programme); table 10 is based mainly on the IARC Monograph evaluations. The most important agents among those listed in table 10 are those to which a substantial proportion of the population is exposed in relatively large amounts. They include particularly: ultraviolet (solar) radiation; tobacco smoking; alcohol drinking; betel quid chewing; hepatitis B; hepatitis C and human papilloma viruses; aflatoxins; possibly dietary fat, and dietary fiber and vitamin A and C deficiency; reproductive delay; and asbestos.

Attempts have been made to estimate numerically the relative contributions of these factors to the 80 or 90% of cancers which might be attributed to environmental factors. The pattern varies, of course, from population to population according to differences in exposures and possibly in the genetic susceptibility to various cancers. In many industrialized countries, however, tobacco smoking and dietary factors are likely to be responsible each for roughly one-third of environmentally determined cancers (Doll and Peto 1981); while in developing countries the role of biological agents is likely to be large and that of tobacco relatively small (but increasing, following the recent increase in the consumption of tobacco in these populations).

Interactions between Carcinogens

An additional aspect to consider is the presence of interactions between carcinogens. Thus for example, in the case of alcohol and tobacco, and cancer of the oesophagus, it has been shown that an increasing consumption of alcohol multiplies manyfold the rate of cancer produced by a given level of tobacco consumption. Alcohol by itself may facilitate transport of tobacco carcinogens, or others, into the cells of susceptible tissues. Multiplicative interaction may also be seen between initiating carcinogens, as between radon and its decay products and tobacco smoking in miners of uranium. Some environmental agents may act by promoting cancers which have been initiated by another agent—this is the most likely mechanism for an effect of dietary fat on the development of breast cancer (probably through increased production of the hormones which stimulate the breast). The reverse may also occur, as, for example, in the case of vitamin A, which probably has an anti-promoting effect on lung and possibly other cancers initiated by tobacco. Similar interactions may also occur between environmental and constitutional factors. In particular, genetic polymorphism to enzymes implicated in the metabolism of carcinogenic agents or DNA repair is probably an important requirement of individual susceptibility to the effect of environmental carcinogens.

The significance of interactions between carcinogens, from the point of view of cancer control, is that withdrawal of exposure to one of two (or more) interacting factors may give rise to a greater reduction in cancer incidence than would be predicted from consideration of the effect of the agent when acting alone. Thus, for example, withdrawal of cigarettes may eliminate almost entirely the excess rate of lung cancer in asbestos workers (although rates of mesothelioma would be unaffected).

Implications for Prevention

The realization that environmental factors are responsible for a large proportion of human cancers has laid the foundation for primary prevention of cancer by modification of exposure to the factors identified. Such modification may comprise: removal of a single major carcinogen; reduction, as discussed above, in exposure to one of several interacting carcinogens; increasing exposure to protective agents; or combinations of these approaches. While some of this may be achieved by community-wide regulation of the environment through, for example, environmental legislation, the apparent importance of lifestyle factors suggests that much of primary prevention will remain the responsibility of individuals. Governments, however, may still create a climate in which individuals find it easier to take the right decision.

 

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Tuesday, 25 January 2011 19:15

Occupational Carcinogens

The control of occupational carcinogens is based on the critical review of scientific investigations both in humans and in experimental systems. There are several review programmes being undertaken in different countries aimed at controlling occupational exposures which could be carcinogenic to humans. The criteria used in different programmes are not entirely consistent, leading occasionally to differences in the control of agents in different countries. For example, 4,4-methylene-bis-2-chloroaniline (MOCA) was classified as an occupational carcinogen in Denmark in 1976 and in the Netherlands in 1988, but only in 1992 has a notation “suspected human carcinogen” been introduced by the American Conference of Governmental Industrial Hygienists in the United States.

The International Agency for Research on Cancer (IARC) has established, within the framework of its Monographs programme, a set of criteria to evaluate the evidence of the carcinogenicity of specific agents. The IARC Monographs programme represents one of the most comprehensive efforts to review systematically and consistently cancer data, is highly regarded in the scientific community and serves as the basis for the information in this article. It also has an important impact on national and international occupational cancer control activities. The evaluation scheme is given in table 1.


Table 1.  Evaluation of evidence of carcinogenicity in the IARC Monographs programme.

1. The evidence for the induction of cancer in humans, which obviously plays an important role in the identification of human carcinogens is considered. Three types of epidemiological studies contribute to an assessment of carcinogenicity in humans: cohort studies, case-control studies and correlation (or ecological) studies. Case reports of cancer in humans may also be reviewed. The evidence relevant to carcinogenicity from studies in humans is classified into one of the following categories:

  • Sufficient evidence of carcinogenicity: A causal relationship has been established between exposure to the agent, mixture or exposure circumstance and human cancer. That is, a positive relationship has been observed between the exposure and cancer in studies in which chance, bias and confounding could be ruled out with reasonable confidence.
  • Limited evidence of carcinogenicity: A positive association has been observed between exposure to the agent, mixture or exposure circumstance and cancer for which a causal interpretation is considered to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence.
  • Inadequate evidence of carcinogenicity: The available studies are of insufficient quality, consistency or statistical power to permit a conclusion regarding the presence or absence of a causal association, or no data on cancer in humans are available.
  • Evidence suggesting lack of carcinogenicity: There are several adequate studies covering the full range of levels of exposure that human beings are known to encounter, which are mutually consistent in not showing a positive association between exposure to the agent and the studied cancer at any observed level of exposure.

2. Studies in which experimental animals (mainly rodents) are exposed chronically to potential carcinogens and examined for evidence of cancer are reviewed and the degree of evidence of carcinogenicity is then classified into categories similar to those used for human data.

3. Data on biological effects in humans and experimental animals that are of particular relevance are reviewed. These may include toxicological, kinetic and metabolic considerations and evidence of DNA binding, persistence of DNA lesions or genetic damage in exposed humans. Toxicological information, such as that on cytotoxicity and regeneration, receptor binding and hormonal and immunological effects, and data on structure-activity relationship are used when considered relevant to the possible mechanism of the carcinogenic action of the agent.

4. The body of evidence is considered as a whole, in order to reach an overall evaluation of the carcinogenicity to humans of an agent, mixture or circumstance of exposure (see table 2).


Agents, mixtures and exposure circumstances are evaluated within the IARC Monographs if there is evidence of human exposure and data on carcinogenicity (either in humans or in experimental animals) (for IARC classification groups, see table 2).

Table 2.  IARC Monograph programme classification groups.

The agent, mixture or exposure circumstance is described according to the wording of one of the following categories:

Group 1— The agent (mixture) is carcinogenic to humans. The exposure circumstance entails exposures that are carcinogenic to humans.
Group 2A— The agent (mixture) is probably carcinogenic to humans. The exposure circumstance entails exposures that are probably carcinogenic to humans.
Group 2B— The agent (mixture) is possibly carcinogenic to humans. The exposure circumstance entails exposures that are possibly carcinogenic to humans.
Group 3— The agent (mixture, exposure circumstance) is not classifiable as to its carcinogenicity to humans.
Group 4— The agent (mixture, exposure circumstance) is probably not carcinogenic to humans.

Known and Suspected Occupational Carcinogens

At present, there are 22 chemicals, groups of chemicals or mixtures for which exposures are mostly occupational, without considering pesticides and drugs, which are established human carcinogens (table 3). While some agents such as asbestos, benzene and heavy metals are currently widely used in many countries, other agents have mainly an historical interest (e.g., mustard gas and 2-naphthylamine).

Table 3. Chemicals, groups of chemicals or mixtures for which exposures are mostly occupational (excluding pesticides and drugs).
Group 1-Chemicals carcinogenic to humans1

Exposure2 Human target organ(s) Main industry/use
4-Aminobiphenyl (92-67-1) Bladder Rubber manufacture
Arsenic (7440-38-2) and arsenic compounds3 Lung, skin Glass, metals, pesticides
Asbestos (1332-21-4) Lung, pleura, peritoneum Insulation, filter material, textiles
Benzene (71-43-2) Leukaemia Solvent, fuel
Benzidine (92-87-5) Bladder Dye/pigment manufacture, laboratory agent
Beryllium (7440-41-7) and beryllium compounds Lung Aerospace industry/metals
Bis(chloromethyl)ether (542-88-11) Lung Chemical intermediate/by-product
Chloromethyl methylether (107-30-2) (technical grade) Lung Chemical intermediate/by-product
Cadmium (7440-43-9) and cadmium compounds Lung Dye/pigment manufacture
Chromium (VI) compounds Nasal cavity, lung Metal plating, dye/pigment manufacture
Coal-tar pitches (65996-93-2) Skin, lung, bladder Building material, electrodes
Coal-tars (8007-45-2) Skin, lung Fuel
Ethylene oxide (75-21-8) Leukaemia Chemical intermediate, sterilant
Mineral oils, untreated and mildly treated Skin Lubricants
Mustard gas (sulphur mustard)
(505-60-2)
Pharynx, lung War gas
2-Naphthylamine (91-59-8) Bladder Dye/pigment manufacture
Nickel compounds Nasal cavity, lung Metallurgy, alloys, catalyst
Shale-oils (68308-34-9) Skin Lubricants, fuels
Soots Skin, lung Pigments
Talc containing asbestiform fibers Lung Paper, paints
Vinyl chloride (75-01-4) Liver, lung, blood vessels Plastics, monomer
Wood dust Nasal cavity Wood industry

1 Evaluated in the IARC Monographs, Volumes 1-63 (1972-1995) (excluding pesticides and drugs).
2 CAS Registry Nos. appear between parentheses.
3 This evaluation applies to the group of chemicals as a whole and not necessarily to all individual chemicals within the group.

An additional 20 agents are classified as probably carcinogenic to humans (Group 2A); they are listed in table 4, and include exposures that are currently prevalent in many countries, such as crystalline silica, formaldehyde and 1,3-butadiene. A large number of agents are classified as possible human carcinogens (Group 2B, table 5) - for example, acetaldehyde, dichloromethane and inorganic lead compounds. For the majority of these chemicals the evidence of carcinogenicity comes from studies in experimental animals.

Table 4. Chemicals, groups of chemicals or mixtures for which exposures are mostly occupational (excluding pesticides and drugs).
Group 2A—Probably carcinogenic to humans1

Exposure2 Suspected human target organ(s) Main industry/use
Acrylonitrile (107-13-1) Lung, prostate, lymphoma Plastics, rubber, textiles, monomer
Benzidine-based dyes Paper, leather, textile dyes
1,3-Butadiene (106-99-0) Leukaemia, lymphoma Plastics, rubber, monomer
p-Chloro-o-toluidine (95-69-2) and its strong acid salts Bladder Dye/pigment manufacture, textiles
Creosotes (8001-58-9) Skin Wood preservation
Diethyl sulphate (64-67-5) Chemical intermediate
Dimethylcarbamoyl chloride (79-44-7) Chemical intermediate
Dimethyl sulphate (77-78-1) Chemical intermediate
Epichlorohydrin (106-89-8) Plastics/resins monomer
Ethylene dibromide (106-93-4) Chemical intermediate, fumigant, fuels
Formaldehyde (50-0-0) Nasopharynx Plastics, textiles, laboratory agent
4,4´-Methylene- bis-2-chloroaniline (MOCA)
(101-14-4)
Bladder Rubber manufacture
Polychlorinated biphenyls (1336-36-3) Liver, bile ducts, leukaemia, lymphoma Electrical components
Silica (14808-60-7), crystalline Lung Stone cutting, mining, glass, paper
Styrene oxide (96-09-3) Plastics, chemical intermediate
Tetrachloroethylene
(127-18-4)
Oesophagus, lymphoma Solvent, dry cleaning
Trichloroethylene (79-01-6) Liver, lymphoma Solvent, dry cleaning, metal
Tris(2,3-dibromopropylphosphate
(126-72-7)
Plastics, textiles, flame retardant
Vinyl bromide (593-60-2) Plastics, textiles, monomer
Vinyl fluoride (75-02-5) Chemical intermediate

1 Evaluated in the IARC Monographs, Volumes 1-63 (1972-1995) (excluding pesticides and drugs).
2 CAS Registry Nos. appear between parentheses.

Table 5. Chemicals, groups of chemicals or mixtures for which exposures are mostly occupational (excluding pesticides and drugs).
Group 2B—Possibly carcinogenic to humans1

Exposure2 Main industry/use
Acetaldehyde (75-07-0) Plastics manufacture, flavors
Acetamide (60-35-5) Solvent, chemical intermediate
Acrylamide (79-06-1) Plastics, grouting agent
p-Aminoazotoluene (60-09-3) Dye/pigment manufacture
o-Aminoazotoluene (97-56-3) Dyes/pigments, textiles
o-Anisidine (90-04-0) Dye/pigment manufacture
Antimony trioxide (1309-64-4) Flame retardant, glass, pigments
Auramine (492-80-8) (technical-grade) Dyes/pigments
Benzyl violet 4B (1694-09-3) Dyes/pigments
Bitumens (8052-42-4), extracts of
steam-refined and air-refined
Building material
Bromodichloromethane (75-27-4) Chemical intermediate
b-Butyrolactone (3068-88-0) Chemical intermediate
Carbon-black extracts Printing inks
Carbon tetrachloride (56-23-5) Solvent
Ceramic fibers Plastics, textiles, aerospace
Chlorendic acid (115-28-6) Flame retardant
Chlorinated paraffins of average carbon chain length C12 and average degree of chlorination approximately 60% Flame retardant
a-Chlorinated toluenes Dye/pigment manufacture, chemical intermediate
p-Chloroaniline (106-47-8) Dye/pigment manufacture
Chloroform (67-66-3) Solvent
4-Chloro-o-phenylenediamine (95-83-9) Dyes/pigments, hair dyes
CI Acid Red 114 (6459-94-5) Dyes/pigments, textiles, leather
CI Basic Red 9 (569-61-9) Dyes/pigments, inks
CI Direct Blue 15 (2429-74-5) Dyes/pigments, textiles, paper
Cobalt (7440-48-4)and cobalt compounds Glass, paints, alloys
p-Cresidine (120-71-8) Dye/pigment manufacture
N,N´-Diacetylbenzidine (613-35-4) Dye/pigment manufacture
2,4-Diaminoanisole (615-05-4) Dye/pigment manufacture, hair dyes
4,4´-Diaminodiphenyl ether (101-80-4) Plastics manufacture
2,4-Diaminotoluene (95-80-7) Dye/pigment manufacture, hair dyes
p-Dichlorobenzene (106-46-7) Chemical intermediate
3,3´-Dichlorobenzidine (91-94-1) Dye/pigment manufacture
3,3´-Dichloro-4,4´-diaminodiphenyl ether (28434-86-8) Not used
1,2-Dichloroethane (107-06-2) Solvent, fuels
Dichloromethane (75-09-2) Solvent
Diepoxybutane (1464-53-5) Plastics/resins
Diesel fuel, marine Fuel
Di(2-ethylhexyl)phthalate (117-81-7) Plastics, textiles
1,2-Diethylhydrazine (1615-80-1) Laboratory reagent
Diglycidyl resorcinol ether (101-90-6) Plastics/resins
Diisopropyl sulphate (29973-10-6) Contaminant
3,3´-Dimethoxybenzidine (o-Dianisidine)
(119-90-4)
Dye/pigment manufacture
p-Dimethylaminoazobenzene (60-11-7) Dyes/pigments
2,6-Dimethylaniline (2,6-Xylidine)(87-62-7) Chemical intermediate
3,3´-Dimethylbenzidine (o-Tolidine)(119-93-7) Dye/pigment manufacture
Dimethylformamide (68-12-2) Solvent
1,1-Dimethylhydrazine (57-14-7) Rocket fuel
1,2-Dimethylhydrazine (540-73-8) Research chemical
1,4-Dioxane (123-91-1) Solvent
Disperse Blue 1 (2475-45-8) Dyes/pigments, hair dyes
Ethyl acrylate (140-88-5) Plastics, adhesives, monomer
Ethylene thiourea (96-45-7) Rubber chemical
Fuel oils, residual (heavy) Fuel
Furan (110-00-9) Chemical intermediate
Gasoline Fuel
Glasswool Insulation
Glycidaldehyde (765-34-4) Textile, leather manufacture
HC Blue No. 1 (2784-94-3) Hair dyes
Hexamethylphosphoramide (680-31-9) Solvent, plastics
Hydrazine (302-01-2) Rocket fuel, chemical intermediate
Lead (7439-92-1) and lead compounds, inorganic Paints, fuels
2-Methylaziridine(75-55-8) Dyes, paper, plastics manufacture
4,4’-Methylene-bis-2-methylaniline (838-88-0) Dye/pigment manufacture
4,4’-Methylenedianiline(101-77-9) Plastics/resins, dye/pigment manufacture
Methylmercury compounds Pesticide manufacture
2-Methyl-1-nitroanthraquinone (129-15-7) (uncertain purity) Dye/pigment manufacture
Nickel, metallic (7440-02-0) Catalyst
Nitrilotriacetic acid (139-13-9) and its salts Chelating agent, detergent
5-Nitroacenaphthene (602-87-9) Dye/pigment manufacture
2-Nitropropane (79-46-9) Solvent
N-Nitrosodiethanolamine (1116-54-7) Cutting fluids, impurity
Oil Orange SS (2646-17-5) Dyes/pigments
Phenyl glycidyl ether (122-60-1) Plastics/adhesives/resins
Polybrominated biphenyls (Firemaster BP-6) (59536-65-1) Flame retardant
Ponceau MX (3761-53-3) Dyes/pigments, textiles
Ponceau 3R (3564-09-8) Dyes/pigments, textiles
1,3-Propane sulphone (1120-71-4) Dye/pigment manufacture
b-Propiolactone (57-57-8) Chemical intermediate; plastics manufacture
Propylene oxide (75-56-9) Chemical intermediate
Rockwool Insulation
Slagwool Insulation
Styrene (100-42-5) Plastics
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) (1746-01-6) Contaminant
Thioacetamide (62-55-5) Textile, paper, leather, rubber manufacture
4,4’-Thiodianiline (139-65-1) Dye/pigment manufacture
Thiourea (62-56-6) Textile, rubber ingredient
Toluene diisocyanates (26471-62-5) Plastics
o-Toluidine (95-53-4) Dye/pigment manufacture
Trypan blue (72-57-1) Dyes/pigments
Vinyl acetate (108-05-4) Chemical intermediate
Welding fumes Metallurgy

1 Evaluated in the IARC Monographs, Volumes 1-63 (1972-1995) (excluding pesticides and drugs).
2 CAS Registry Nos. appear between parentheses.

Occupational exposures may also occur during the production and use of some pesticides and drugs. Table 6 presents an evaluation of the carcinogenicity of pesticides; two of them, captafol and ethylene dibromide, are classified as probable human carcinogens, while a total of 20 others, including DDT, atrazine and chlorophenols, are classified as possible human carcinogens.

Table 6. Pesticides evaluated in IARC Monographs, Volumes 1-63(1972-1995)

IARC Group Pesticide1
2A—Probably carcinogenic to humans Captafol (2425-06-1) Ethylene dibromide (106-93-4)
2B—Possibly carcinogenic to humans Amitrole (61-82-5) Atrazine (1912-24-9) Chlordane (57-74-9) Chlordecone (Kepone) (143-50-0) Chlorophenols Chlorophenoxy herbicides DDT (50-29-3) 1,2-Dibromo-3-chloropropane (96-12-8) 1,3-Dichloropropene (542-75-6) (technical-grade) Dichlorvos (62-73-7) Heptachlor (76-44-8) Hexachlorobenzene (118-74-1) Hexachlorocyclohexanes (HCH) Mirex (2385-85-5) Nitrofen (1836-75-5), technical-grade Pentachlorophenol (87-86-5) Sodium o-phenylphenate (132-27-4) Sulphallate (95-06-7) Toxaphene (Polychlorinated camphenes) (8001-35-2)

1 CAS Registry Nos. appear between parentheses.

Several drugs are human carcinogens (table 9): they are mainly alkylating agents and hormones; 12 more drugs, including chloramphenicol, cisplatine and phenacetin, are classified as probable human carcinogens (Group 2A). Occupational exposure to these known or suspected carcinogens, used mainly in chemotherapy, can occur in pharmacies and during their administration by nursing staff.

Table 7. Drugs evaluated in IARC Monographs, Volumes 1-63 (1972-1995).

Drug1 Target organ2
IARC GROUP 1—Carcinogenic to humans
Analgesic mixtures containing phenacetin Kidney, bladder
Azathioprine (446-86-6) Lymphoma, hepatobiliary system, skin
N,N-Bis(2-chloroethyl)- b-naphthylamine (Chlornaphazine) (494-03-1) Bladder
1,4-Butanediol dimethanesulphonate (Myleran)
(55-98-1)
Leukaemia
Chlorambucil (305-03-3) Leukaemia
1-(2-Chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (Methyl-CCNU) (13909-09-6) Leukaemia
Cyclosporin (79217-60-0) Lymphoma, skin
Cyclophosphamide (50-18-0) (6055-19-2) Leukaemia, bladder
Diethylstilboestrol (56-53-1) Cervix, vagina, breast
Melphalan (148-82-3) Leukaemia
8-Methoxypsoralen (Methoxsalen) (298-81-7) plus ultraviolet A radiation Skin
MOPP and other combined chemotherapy including alkylating agents Leukaemia
Oestrogen replacement therapy Uterus
Oestrogens, nonsteroidal Cervix, vagina, breast
Oestrogens, steroidal Uterus
Oral contraceptives, combined Liver
Oral contraceptives, sequential Uterus
Thiotepa (52-24-4) Leukaemia
Treosulfan (299-75-2) Leukaemia

IARC GROUP 2A—Probably carcinogenic to humans
Adriamycin (23214-92-8)
Androgenic (anabolic) steroids (Liver)
Azacitidine (320-67-2)
Bischloroethyl nitrosourea (BCNU) (154-93-8) (Leukaemia)
Chloramphenicol (56-75-7) (Leukaemia)
1-(2-Chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) (13010-47-4)
Chlorozotocine (54749-90-5)
Cisplatin (15663-27-1)
5-Methoxypsoralen (484-20-8)
Nitrogen mustard (51-75-2) (Skin)
Phenacetin (62-44-2) (Kidney, bladder)
Procarbazine hydrochloride (366-70-1)

1 CAS Registry Nos. appear between parentheses.
2 Suspected target organs are given in parentheses.

Several environmental agents are known or suspected causes of cancer in humans and are listed in table 8; although exposure to such agents is not primarily occupational, there are groups of individuals exposed to them because of their work: examples are uranium miners exposed to radon decay products, hospital workers exposed to hepatitis B virus, food processors exposed to aflatoxins from contaminated foods, outdoor workers exposed to ultraviolet radiation or diesel engine exhaust, and bar staff or waiters exposed to environmental tobacco smoke.

The IARC Monograph programme has covered most of the known or suspected causes of cancer; there are, however, some important groups of agents that have not been evaluated by IARC—namely, ionizing radiation and electrical and magnetic fields.

Table 8. Environmental agents/exposures known or suspected to cause cancer in humans.1

Agent/exposure Target organ2 Strength of evidence3
Air pollutants
Erionite Lung, pleura 1
Asbestos Lung, pleura 1
Polycyclic aromatic hydrocarbons4 (Lung, bladder) S
Water pollutants
Arsenic Skin 1
Chlorination by-products (Bladder) S
Nitrate and nitrite (Oesophagus, stomach) S
Radiation
Radon and its decay products Lung 1
Radium, thorium Bone E
Other X-irradiation Leukaemia, breast, thyroid, others E
Solar radiation Skin 1
Ultraviolet radiation A (Skin) 2A
Ultraviolet radiation B (Skin) 2A
Ultraviolet radiation C (Skin) 2A
Use of sunlamps and sunbeds (Skin) 2A
Electric and magnetic fields (Leukaemia) S
Biological agents
Chronic infection with hepatitis B virus Liver 1
Chronic infection with hepatitis C virus Liver 1
Infection with Helicobacter pylori Stomach 1
Infection with Opistorchis viverrini Bile ducts 1
Infection with Chlonorchis sinensis (Liver) 2A
Human Papilloma virus types 16 and18 Cervix 1
Human Papilloma virus types 31 and 33 (Cervix) 2A
Human Papilloma virus types other than 16, 18, 31 and 33 (Cervix) 2B
Infection with Schistosoma haematobium Bladder 1
Infection with Schistosoma japonicum (Liver, colon) 2B
Tobacco, alcohol and related substances
Alcoholic beverages Mouth, pharynx, oesophagus, liver, larynx 1
Tobacco smoke Lip, mouth, pharynx, oesophagus, pancreas, larynx, lung, kidney, bladder, (others) 1
Smokeless tobacco products Mouth 1
Betel quid with tobacco Mouth 1
Dietary factors
Aflatoxins Liver 1
Aflatoxin M1 (Liver) 2B
Ochratoxin A (Kidney) 2B
Toxins derived from Fusarium moniliforme (Oesophagus) 2B
Chinese style salted fish Nasopharynx 1
Pickled vegetables (traditional in Asia) (Oesophagus, stomach) 2B
Bracken fern (Oesophagus) 2B
Safrole 2B
Coffee (Bladder) 2B
Caffeic acid 2B
Hot mate (Oesophagus) 2A
Fresh fruits and vegetables (protective) Mouth, oesophagus, stomach, colon, rectum, larynx, lung (others) E
Fat (Colon, breast, endometrium) S
Fiber (protective) (Colon, rectum) S
Nitrate and nitrite (Oesophagus, stomach) S
Salt (Stomach) S
Vitamin A, b-carotene (protective) (Mouth, oesophagus, lung, others) S
Vitamin C (protective) (Oesophagus, stomach) S
IQ (Stomach, colon, rectum) 2A
MeIQ 2B
MeIQx 2B
PhIP 2B
Reproductive and sexual behavior
Late age at first pregnancy Breast E
Low parity Breast, ovary, corpus uteri E
Early age at first intercourse Cervix E
Number of sexual partners Cervix E 

1 Agents and exposures, as well as medicines, occurring mainly in the occupational setting are excluded.

2 Suspected target organs are given in parentheses.

3 IARC Monograph evaluation reported wherever available (1: human carcinogen; 2A: probable human carcinogen; 2B: possible human carcinogen); otherwise E: established carcinogen; S: suspected carcinogen.

 4 Human exposure to polycyclic aromatic hydrocarbons occurs in mixtures, such as engine emissions, combustion fumes and soots. Several mixtures and individual hydrocarbons have been evaluated by IARC.

Industries and Occupations

Current understanding of the relationship between occupational exposures and cancer is far from complete; in fact, only 22 individual agents are established occupational carcinogens (table 9), and for many more experimental carcinogens no definitive evidence is available based on exposed workers. In many cases, there is considerable evidence of increased risks associated with particular industries and occupations, although no specific agents can be identified as aetiological factors. Table 10 present lists of industries and occupations associated with excess carcinogenic risks, together with the relevant cancer sites and the known (or suspected) causative agent(s).

Table 9. Industries, occupations and exposures recognized as presenting a carcinogenic risk.

Industry (ISIC code) Occupation/process Cancer site/type Known or suspected causative agent
Agriculture, forestry and fishing (1) Vineyard workers using arsenic insecticides Fishermen Lung, skin Skin, lip Arsenic compounds Ultraviolet radiation
Mining and quarrying (2) Arsenic mining Iron ore (haematite) mining Asbestos mining Uranium mining Talc mining and milling Lung, skin Lung Lung, pleural and peritoneal mesothelioma Lung Lung Arsenic compounds Radon decay products Asbestos Radon decay products Talc containing asbestiform fibers
Chemical (35) Bis(chloromethyl) ether (BCME) and chloromethyl-methyl ether (CMME) production workers and users Vinyl chloride production Isopropyl alcohol manufacture (strong-acid process) Pigment chromate production Dye manufacturers and users Auramine manufacture p-chloro-o-toluidine production Lung (oat-cell carcinoma) Liver angiosarcoma Sinonasal Lung, sinonasal Bladder Bladder Bladder BCME, CMME Vinyl chloride monomer Not identified Chromium (VI) compounds Benzidine, 2-naphthylamine, 4-aminobiphenyl Auramine and other aromatic amines used in the process p-chloro-o-toluidine and its strong acid salts
Leather (324) Boot and shoe manufacture Sinonasal, leukaemia Leather dust, benzene
Wood and wood products (33) Furniture and cabinet makers Sinonasal Wood dust
Pesticides and herbicides production (3512) Arsenical insecticides production and packaging Lung Arsenic compounds
Rubber industry (355) Rubber manufacture Calendering, tyre curing, tyre building Millers, mixers Synthetic latex production, tyre curing, calender operatives, reclaim, cable makers Rubber film production Leukaemia Bladder Leukaemia Bladder Bladder Leukaemia Benzene Aromatic amines Benzene Aromatic amines Aromatic amines Benzene
Asbestos production (3699) Insulated material production (pipes, sheeting, textile, clothes, masks, asbestos cement products) Lung, pleural and peritoneal mesothelioma Asbestos
Metals (37) Aluminum production Copper smelting Chromate production, chromium plating Iron and steel founding Nickel refining Pickling operations Cadmium production and refining; nickel-cadmium battery manufacture; cadmium pigment manufacture; cadmium alloy production; electroplating; zinc smelters; brazing and polyvinyl chloride compounding Beryllium refining and machining; production of beryllium-containing products Lung, bladder Lung Lung, sinonasal Lung Sinonasal, lung Larynx, lung Lung Lung Polycyclic aromatic hydrocarbons, tar Arsenic compounds Chromium (VI) compounds Not identified Nickel compounds Inorganic acid mists containing sulphuric acid Cadmium and cadmium compounds Beryllium and beryllium compounds
Shipbuilding, motor vehicle and railroad equipment manufacture (385) Shipyard and dockyard, motor vehicle and railroad manufacture workers Lung, pleural and peritoneal mesothelioma Asbestos
Gas (4) Coke plant workers Gas workers Gas-retort house workers Lung Lung, bladder, scrotum Bladder Benzo(a)pyrene Coal carbonization products, 2-naphthylamine Aromatic amines
Construction (5) Insulators and pipe coverers Roofers, asphalt workers Lung, pleural and peritoneal mesothelioma Lung Asbestos Polycyclic aromatic hydrocarbons
Other Medical personnel (9331) Painters (construction, automotive industry and other users) Skin, leukaemia Lung Ionizing radiation Not identified


Table 10.  Industries, occupations and exposures reported to present a cancer excess but for which the assessment of the carcinogenic risk is not definitive.

Industry (ISIC code) Occupation/process Cancer site/type Known (or suspected) causative agent
Agriculture, forestry and fishing (1) Farmers, farm workers Herbicide application Insecticide application Lymphatic and haematopoietic system (leukaemia, lymphoma) Malignant lymphomas, soft-tissue sarcomas Lung, lymphoma Not identified Chlorophenoxy herbicides, chlorophenols (presumably contaminated with polychlorinated dibenzodioxins) Non-arsenical insecticides
Mining and quarrying (2) Zinc-lead mining Coal Metal mining Asbestos mining Lung Stomach Lung Gastrointestinal tract Radon decay products Coal dust Crystalline silica Asbestos
Food industry (3111) Butchers and meat workers Lung Viruses, PAH1
Beverage industry (3131) Beer brewers Upper aero-digestive tract Alcohol consumption
Textile manufacture (321) Dyers Weavers Bladder Bladder, sinonasal, mouth Dyes Dusts from fibers and yarns
Leather (323) Tanners and processors Boot and shoe manufacture and repair Bladder, pancreas, lung Sinonasal, stomach, bladder Leather dust, other chemicals, chromium Not identified
Wood and wood products (33), pulp and paper industry (341) Lumbermen and sawmill workers Pulp and papermill workers Carpenters, joiners Woodworkers, unspecified Plywood production, particle-board production Nasal cavity, Hodgkin lymphoma, skin Lymphopoietic tissue, lung Nasal cavity, Hodgkin lymphoma Lymphomas Nasopharynx, sinonasal Wood dust, chlorophenols, creosotes Not identified Wood dust, solvents Not identified Formaldehyde
Printing (342) Rotogravure workers, binders, printing pressmen, machine-room workers and other jobs Lymphocytic and haemopoietic system, oral, lung, kidney Oil mist, solvents
Chemical (35) 1,3-Butadiene production Acrylonitrile production Vinylidene chloride production Isopropyl alcohol manufacture (strong-acid process) Polychloroprene production Dimethylsulphate production Epichlorohydrin production Ethylene oxide production Ethylene dibromide production Formaldehyde production Flame retardant and plasticizer use Benzoyl chloride production Lymphocytic and haemopoietic system Lung, colon Lung Larynx Lung Lung Lung, lymphatic and haemopoietic system (leukaemia) Lymphatic and haemopoietic system (leukaemia), stomach Digestive system Nasopharynx, sinonasal Skin (melanoma) Lung 1,3-Butadiene Acrylonitrile Vinylidene chloride (mixed exposure with acrylonitrile) Not identified Chloroprene Dimethylsulphate Epichlorohydrin Ethylene oxide Ethylene dibromide Formaldehyde Polychlorinated biphenyls Benzoyl chloride
Herbicides production (3512) Chlorophenoxy herbicide production Soft-tissue sarcoma Chlorophenoxy herbicides, chlorophenols (contaminated with polychlorinated dibenzodioxins)
Petroleum (353) Petroleum refining Skin, leukaemia, brain Benzene, PAH, untreated and mildly treated mineral oils
Rubber (355) Various occupations in rubber manufacture Styrene-butadiene rubber production Lymphoma, multiple myeloma, stomach, brain, lung Lymphatic and haematopoietic system Benzene, MOCA,2 other not identified 1,3-Butadiene
Ceramic, glass and refractory brick (36) Ceramic and pottery workers Glass workers (art glass, container and pressed ware) Lung Lung Crystalline silica Arsenic and other metal oxides, silica, PAH
Asbestos production (3699) Insulation material production (pipes, sheeting, textiles, clothes, masks, asbestos cement products) Larynx, gastrointestinal tract Asbestos
Metals (37, 38) Lead smelting Cadmium production and refining; nickel-cadmium battery manufacture; cadmium pigment manufacture; cadmium alloy production; electroplating; zinc smelting; brazing and polyvinyl chloride compounding Iron and steel founding Respiratory and digestive systems Prostate Lung Lead compounds Cadmium and cadmium compounds Crystalline silica
Shipbuilding (384) Shipyard and dockyard workers Larynx, digestive system Asbestos
Motor vehicle manufacturing (3843, 9513) Mechanics, welders, etc. Lung PAH, welding fumes, engine exhaust
Electricity (4101, 9512) Generation, production, distribution, repair Leukaemia, brain tumors Liver, bile ducts Extremely low frequency magnetic fields PCBs3
Construction (5) Insulators and pipe coverers Roofers, asphalt workers Larynx, gastrointestinal tract Mouth, pharynx, larynx, oesophagus, stomach Asbestos PAH, coal tar, pitch
Transport (7) Railroad workers, filling station attendants, bus and truck drivers, operators of excavating machines Lung, bladder Leukaemia Diesel engine exhaust Extremely low frequency magnetic fields
Other Service station attendants (6200) Chemists and other laboratory workers (9331) Embalmers, medical personnel (9331) Health workers (9331) Laundry and dry cleaners (9520) Hairdressers (9591) Radium dial workers Leukaemia and lymphoma Leukaemia and lymphoma, pancreas Sinonasal, nasopharynx Liver Lung, oesophagus, bladder Bladder, leukaemia and lymphoma Breast Benzene Not identified (viruses, chemicals) Formaldehyde Hepatitis B virus Tri- and tetrachloroethylene and carbon tetrachloride Hair dyes, aromatic amines Radon

1 PAH, polycyclic aromatic hydrocarbon.

2 MOCA, 4,4’-methylene-bis-2-chloroaniline.

3 PCBs, polychlorinated biphenyls.

Table 9 presents industries, occupations and exposures in which the presence of a carcinogenic risk is considered to be established, whereas Table 10 shows industrial processes, occupations and exposures for which an excess cancer risk has been reported but evidence is not considered to be definitive. Also included in table 10 are some occupations and industries already listed in table 9, for which there is inconclusive evidence of association with cancers other than those mentioned in table 9. For example, the asbestos production industry is included in table 9 in relation to lung cancer and pleural and peritoneal mesothelioma, whereas the same industry is included in table 10 in relation to gastrointestinal neoplasms. A number of industries and occupations listed intables 9 and 10 have also been evaluated under the IARC Monographs programme. For example, “occupational exposure to strong inorganic acid mist containing sulphuric acid” was classified in Group 1 (carcinogenic to humans).

Constructing and interpreting such lists of chemical or physical carcinogenic agents and associating them with specific occupations and industries is complicated by a number of factors: (1) information on industrial processes and exposures is frequently poor, not allowing a complete evaluation of the importance of specific carcinogenic exposures in different occupations or industries; (2) exposures to well-known carcinogenic exposures, such as vinyl chloride and benzene, occur at different intensities in different occupational situations; (3) changes in exposure occur over time in a given occupational situation, either because identified carcinogenic agents are substituted by other agents or (more frequently) because new industrial processes or materials are introduced; (4) any list of occupational exposures can refer only to the relatively small number of chemical exposures which have been investigated with respect to the presence of a carcinogenic risk.

All of the above issues emphasize the most critical limitation of a classification of this type, and in particular its generalization to all areas of the world: the presence of a carcinogen in an occupational situation does not necessarily mean that workers are exposed to it and, in contrast, the absence of identified carcinogens does not exclude the presence of yet unidentified causes of cancer.

A particular problem in developing countries is that much of the industrial activity is fragmented and takes place in local settings. These small industries are often characterized by old machinery, unsafe buildings, employees with limited training and education, and employers with limited financial resources. Protective clothing, respirators, gloves and other safety equipment are seldom available or used. The small companies tend to be geographically scattered and inaccessible to inspections by health and safety enforcement agencies.

 

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Tuesday, 25 January 2011 19:12

Introduction

Magnitude of the Problem

The first clear-cut evidence of cancer causation involved an occupational carcinogen (Checkoway, Pearce and Crawford-Brown 1989). Pott (1775) identified soot as the cause of scrotal cancer in London chimney-sweeps, and graphically described the abysmal working conditions, which involved children climbing up narrow chimneys that were still hot. Despite this evidence, reports of the need to prevent fires in chimneys were used to delay legislation on child labour in this industry until 1840 (Waldron 1983). An experimental model of soot carcinogenesis was first demonstrated in the 1920s (Decoufle 1982), 150 years after the original epidemiological observation.

In subsequent years, a number of other occupational causes of cancer have been demonstrated through epidemiological studies (although the association with cancer has usually first been noted by occupational physicians or by workers). These include arsenic, asbestos, benzene, cadmium, chromium, nickel and vinyl chloride. Such occupational carcinogens are very important in public health terms because of the potential for prevention through regulation and improvements in industrial hygiene practices (Pearce and Matos 1994). In most instances, these are hazards which markedly increase the relative risk of a particular type or types of cancer. It is possible that other occupational carcinogens remain undetected because they involve only a small increase in risk or because they simply have not been studied (Doll and Peto 1981). Some key facts about occupational cancer are given in table 1.

 


Table 1. Occupational cancer: Key facts.

 

  • Some 20 agents and mixtures are established occupational carcinogens; a similar number of chemicals are highly suspected occupational carcinogens.
  • In industrialized countries, occupation is causally linked to 2 to 8% of all cancers; among exposed workers, however, this proportion is higher.
  • No reliable estimates are available on either the burden of occupational cancer or the extent of workplace exposure to carcinogens in developing countries.
  • The relatively low overall burden of occupational cancer in industrialized countries is the result of strict regulations on several known carcinogens; exposure to other known or highly suspected agents, however, is still allowed.
  • Although several occupational cancers are listed as occupational diseases in many countries, a very small fraction of cases is actually recognized and compensated.
  • Occupational cancer is-to a very large extent-a preventable disease.

 


 

Occupational causes of cancer have received considerable emphasis in epidemiological studies in the past. However, there has been much controversy regarding the proportion of cancers which are attributable to occupational exposures, with estimates ranging from 4 to 40% (Higginson 1969; Higginson and Muir 1976; Wynder and Gori 1977; Higginson and Muir 1979; Doll and Peto 1981; Hogan and Hoel 1981; Vineis and Simonato 1991; Aitio and Kauppinen 1991). The attributable cancer risk is the total cancer experience in a population that would not have occurred if the effects associated with the occupational exposures of concern were absent. It may be estimated for the exposed population, as well as for a broader population. A summary of existing estimates is shown in table 2. Universal application of the International Classification of Diseases is what makes such tabulations possible (see box).

Table 2.  Estimated proportions of cancer (PAR) attributable to occupations in selected studies.

Study Population PAR and cancer site Comments
Higginson 1969 Not stated 1% Oral cancer
1-2% Lung cancer
10% Bladder cancer
2% Skin cancer
No detailed presentation of exposure levels and other assumptions
Higginson and Muir 1976 Not stated 1-3% Total cancer No detailed presentation of assumptions
Wynder and Gori 1977 Not stated 4% Total cancer in men,
2% for women
Based on one PAR for bladder cancer and two personal communications
Higginson and Muir 1979 West Midland, United Kingdom 6% Total cancer in men,
2% total cancer
Based on 10% of non-tobacco related lung cancer, mesothelioma, bladder cancer (30%), and leukaemia in women (30%)
Doll and Peto 1981 United States early 1980 4% (range 2-8%)
Total cancer
Based on all studied cancer sites; reported as ‘tentative’ estimate
Hogan and Hoel 1981 United States 3% (range 1.4-4%)
Total cancer
Risk associated with occupational asbestos exposure
Vineis and Simonato 1991 Various 1-5% Lung cancer,
16-24% bladder cancer
Calculations on the basis of data from case-control studies. Percentage for lung cancer considers only exposure to asbestos. In a study with a high proportion of subjects exposed to ionising radiation, a 40% PAR was estimated. Estimates of PAR in a few studies on bladder cancer were between 0 and 3%.

 


The International Classification of Diseases

Human diseases are classified according to the International Classification of Diseases (ICD), a system that was started in 1893 and is regularly updated under the coordination of the World Health Organization. The ICD is used in almost all countries for tasks such as death certification, cancer registration and hospital discharge diagnosis. The Tenth Revision (ICD-10), which was approved in 1989 (World Health Organization 1992), differs considerably from the previous three revisions, which are similar to each other and have been in use since the 1950s. It is therefore likely that the Ninth Revision (ICD-9, World Health Organization 1978), or even earlier revisions, will still be used in many countries during the coming years.


The large variability in the estimates arises from the differences in the data sets used and the assumptions applied. Most of the published estimates on the fraction of cancers attributed to occupational risk factors are based on rather simplified assumptions. Furthermore, although cancer is relatively less common in developing countries due to the younger age structure (Pisani and Parkin 1994), the proportion of cancers due to occupation may be higher in developing countries due to the relatively high exposures which are encountered (Kogevinas, Boffetta and Pearce 1994).

The most generally accepted estimates of cancers attributable to occupations are those presented in a detailed review on the causes of cancer in the population of the United States in 1980 (Doll and Peto 1981). Doll and Peto concluded that about 4% of all the deaths due to cancer may be caused by occupational carcinogens within “acceptable limits” (i.e., still plausible in view of all the evidence at hand) of 2 and 8%. These estimates being proportions, they are dependent on how causes other than occupational exposures contribute to produce cancers. For example, the proportion would be higher in a population of lifetime non-smokers (such as the Seventh-Day Adventists) and lower in a population in which, say, 90% are smokers. Also the estimates do not apply uniformly to both sexes or to different social classes. Furthermore, if one considers not the whole population (to which the estimates refer), but the segments of the adult population in which exposure to occupational carcinogens almost exclusively occurs (manual workers in mining, agriculture and industry, broadly taken, who in the United States numbered 31 million out of a population, aged 20 and over, of 158 million in the late 1980s), the proportion of 4% in the overall population would increase to about 20% among those exposed.

Vineis and Simonato (1991) provided estimates on the number of cases of lung and bladder cancer attributable to occupation. Their estimates were derived from a detailed review of case-control studies, and demonstrate that in specific populations located in industrial areas, the proportion of lung cancer or bladder cancer from occupational exposures may be as high as 40% (these estimates being dependent not only on the local prevailing exposures, but also to some extent on the method of defining and assessing exposure).

Mechanisms and Theories of Carcinogenesis

Studies of occupational cancer are complicated because there are no “complete” carcinogens; that is, occupational exposures increase the risk of developing cancer, but this future development of cancer is by no means certain. Furthermore, it may take 20 to 30 years (and at least five years) between an occupational exposure and the subsequent induction of cancer; it may also take several more years for cancer to become clinically detectable and for death to occur (Moolgavkar et al. 1993). This situation, which also applies to non-occupational carcinogens, is consistent with current theories of cancer causation.

Several mathematical models of cancer causation have been proposed (e.g., Armitage and Doll 1961), but the model which is simplest and most consistent with current biological knowledge is that of Moolgavkar (1978). This assumes that a healthy stem cell occasionally mutates (initiation); if a particular exposure encourages the proliferation of intermediate cells (promotion) then it becomes more likely that at least one cell will undergo one or more further mutations producing a malignant cancer (progression) (Ennever 1993).

Thus, occupational exposures can increase the risk of developing cancer either by causing mutations in DNA or by various “epigenetic” mechanisms of promotion (those not involving damage to DNA), including increased cell proliferation. Most occupational carcinogens which have been discovered to date are mutagens, and therefore appear to be cancer initiators. This explains the long “latency” period which is required for further mutations to occur; in many instances the necessary further mutations may never occur, and cancer may never develop.

In recent years, there has been increasing interest in occupational exposures (e.g., benzene, arsenic, phenoxy herbicides) which do not appear to be mutagens, but which may act as promoters. Promotion may occur relatively late in the carcinogenic process, and the latency period for promoters may therefore be shorter than for initiators. However, the epidemiological evidence for cancer promotion remains very limited at this time (Frumkin and Levy 1988).

Transfer of Hazards

A major concern in recent decades has been the problem of the transfer of hazardous industries to the developing world (Jeyaratnam 1994). Such transfers have occurred in part due to the stringent regulation of carcinogens and increasing labour costs in the industrialized world, and in part from low wages, unemployment and the push for industrialization in the developing world. For example, Canada now exports about half of its asbestos to the developing world, and a number of asbestos-based industries have been transferred to developing countries such as Brazil, India, Pakistan, Indonesia and South Korea (Jeyaratnam 1994). These problems are further compounded by the magnitude of the informal sector, the large numbers of workers who have little support from unions and other worker organizations, the insecure status of workers, the lack of legislative protection and/or the poor enforcement of such protection, the decreasing national control over resources, and the impact of the third world debt and associated structural adjustment programmes (Pearce et al. 1994).

As a result, it cannot be said that the problem of occupational cancer has been reduced in recent years, since in many instances the exposure has simply been transferred from the industrialized to the developing world. In some instances, the total occupational exposure has increased. Nevertheless, the recent history of occupational cancer prevention in industrialized countries has shown that it is possible to use substitutes for carcinogenic compounds in industrial processes without leading industry to ruin, and similar successes would be possible in developing countries if adequate regulation and control of occupational carcinogens were in place.

Prevention of Occupational Cancer

Swerdlow (1990) outlined a series of options for the prevention of exposure to occupational causes of cancer. The most successful form of prevention is to avoid the use of recognized human carcinogens in the workplace. This has rarely been an option in industrialized countries, since most occupational carcinogens have been identified by epidemiological studies of populations that were already occupationally exposed. However, at least in theory, developing countries could learn from the experience of industrialized countries and prevent the introduction of chemicals and production processes that have been found to be hazardous to the health of workers.

The next best option for avoiding exposure to established carcinogens is their removal once their carcinogenicity has been established or suspected. Examples include the closure of plants making the bladder carcinogens 2-naphthylamine and benzidine in the United Kingdom (Anon 1965), termination of British gas manufacture involving coal carbonization, closure of Japanese and British mustard gas factories after the end of the Second World War (Swerdlow 1990) and gradual elimination of the use of benzene in the shoe industry in Istanbul (Aksoy 1985).

In many instances, however, complete removal of a carcinogen (without closing down the industry) is either not possible (because alternative agents are not available) or is judged politically or economically unacceptable. Exposure levels must therefore be reduced by changing production processes and through industrial hygiene practices. For example, exposures to recognized carcinogens such as asbestos, nickel, arsenic, benzene, pesticides and ionizing radiation have been progressively reduced in industrialized countries in recent years (Pearce and Matos 1994).

A related approach is to reduce or eliminate the activities that involve the heaviest exposures. For example, after an 1840 act was passed in England and Wales prohibiting chimney-sweeps from being sent up chimneys, the number of cases of scrotal cancer decreased (Waldron 1983). Exposure also can be minimized through the use of protective equipment, such as masks and protective clothing, or by imposing more stringent industrial hygiene measures.

An effective overall strategy in the control and prevention of exposure to occupational carcinogens generally involves a combination of approaches. One successful example is a Finnish registry which has as its objectives to increase awareness about carcinogens, to evaluate exposure at individual workplaces and to stimulate preventive measures (Kerva and Partanen 1981). It contains information on both workplaces and exposed workers, and all employers are required to maintain and update their files and to supply information to the registry. The system appears to have been at least partially successful in decreasing carcinogenic exposures in the workplace (Ahlo, Kauppinen and Sundquist 1988).

 

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There is a growing awareness among public and private sector employers in the United States that healthy birth outcomes, productivity and the organization’s economic status are connected. Concurrently, there is heightened concern about occupational reproductive health hazards. Never before have employers had better reasons to improve maternal and infant health among employees and their families. Rising health care costs, changing workforce demographics, and increasing evidence that healthy employees lead to productivity gains, are compelling reasons to make maternal and infant health an addition to their health education and promotion programs.

A maternal and infant health strategy is a term broadly used to define any thoughtfully planned employer-sponsored or union-sponsored initiative that promotes the health and well-being of women, before, during, and after pregnancy, and supports the health of infants during the first year of life as well. There is no single solution or approach to improving maternal and infant health. Rather, for most employers, the effort is a combination of the following activities, custom-fit to meet the environment that makes their workplace unique.

Health Care Benefits

It is helpful to view maternal and infant health care benefits as a continuum of care that provides reproductive health awareness and family planning counseling and services throughout the reproductive life span. The benefits listed in table 1 represent those a health insurance plan should cover because of their significance in improving maternal and infant health.

Table 1. Health insurance benefits.

Pre-pregnancy

Pregnancy

Post-pregnancy

Infancy

Annual preconception or interconception care visit (includes family planning services)

Genetic counseling and testing

Prescription drug plan

Substance abuse treatment

Genetic counseling and testing

Prenatal care–should be offered with no deductibles or copayments

Labor and delivery at a hospital or birthing centre should be offered with no deductibles or copayments

  •  Room and board at a hospital or birthing centre
  •  Anaesthesia services
  •  Prescription drug plan (including prenatal vitamins)
  •  Home health care services
  •  Substance abuse treatment

Postpartum care

Prescription drug plan

Home health care services

Substance abuse treatment

Normal newborn nursery care

Neonatal intensive care–no pre-existing conditions exclusions for newborns

Prescription drug plan

Home health care services

Source: March of Dimes Birth Defects Foundation 1994.

Benefits design

While many American health care plans provide coverage for preconception and prenatal care, there are a number of reasons why it may be difficult for some women to obtain high quality, affordable care. For example, some providers require payment in advance for prenatal care and delivery services, yet most insurers will not make payment until after delivery. Other barriers to accessing proper care include high deductible fees or copayments, inconvenient office hours, lack of coverage for dependants, and geographic inaccessibility. Employers cannot eliminate all of these barriers, but it would represent an excellent beginning to help remove the burdens of upfront payments and high deductible fees and to offer assistance to the employee in finding acceptance by a suitable provider of prenatal care.

At Texas Instruments (TI), the goal is to make prenatal care affordable regardless of an employee’s income level or health care provider. Mothers seeking prenatal care inside the TI network pay only 10% of an upfront negotiated fee, a single charge that covers prenatal care services and both uncomplicated deliveries and Caesarean sections.

The Haggar Apparel Company pays 100% of the cost of prenatal care upfront if an employee or dependant accesses prenatal care in the first trimester of pregnancy. The Home Depot (a retailer of builder’s wares and related merchandise) waives the expectant mother’s hospital deductible fee if prenatal care visits begin in the first trimester.

While many plans provide for adequate care for a newborn’s first few days of life, coverage for the infant’s ongoing preventive care after leaving the hospital, frequently referred to as well-baby care, is often inadequate or nonexistent.

At the First National Bank of Chicago, expectant mothers who are enrolled in the indemnity plan and who complete a prenatal education program by the end of their fourth month of pregnancy have the $400 deductible charge waived from their newborn’s first year health insurance coverage. The Monfort Company, a beef packing plant in Greeley, Colorado, totally covers well-baby care up to age three.

Benefits-related Services and Employee Programs

Table 2 lists benefits-related services and programs that are considered important supportive features to a maternal and infant health strategy. These services and programs may be provided directly by the employer, either in the workplace or a nearby location, or under a contract with an outside agency or vendor, depending on the structure, location and size of the organization and may be administered by the benefits, employee health, health promotion or employee assistance department, for example.

Few companies can offer all of these components; however, the more complete and comprehensive the strategy, the better the chance of improving the health of mothers and babies.

Table 2. Other benefits-related services provided by the employer.

SERVICES

Pre-pregnancy

Pregnancy

Post-pregnancy

Infancy

 
  •  Maternity management
    program
  •  Maternity high-risk case
    management (may be part of a
    maternity management
    program)
  •  Maternity disability benefits
  •  Case management services for high-risk newborns
 
  •  Dependant care reimbursement accounts

PROGRAMMES 

Pre-pregnancy

Pregnancy

Post-pregnancy

Infancy

  •  Preconception health promotion
  •  Smoking cessation programs
  •  Prenatal health promotion
  •  Sensitivity training for managers
  •  Parenting classes on infant care
    and development
  •  Smoking cessation program
  •  Lactation program
  •  On-site child care facility
 
  •  Referrals to child care services

Source: March of Dimes Birth Defects Foundation 1994.

Pre-pregnancy and pregnancy period

Maternity management programs are gaining popularity because they offer attractive features to both the expectant parents and the employer. While not designed to replace prenatal care delivered by a health care professional, maternity management is a benefit-related service that provides personalized advice and support customized to a mother’s needs and risk levels.

Levi Strauss & Company, one of the nation’s largest clothing and apparel producers, offers a maternity management program administered by an insurance company. Employees are encouraged to access the program as soon as they are pregnant and they will receive $100 cash for calling the toll-free maternity management number. In 1992, costs for newborns whose mothers participated in the program were nearly 50% lower than for those whose mothers who did not.

The First National Bank of Chicago offers the March of Dimes Babies and You prenatal health promotion program as part of its maternal and infant health strategy. This program is described below and in the case study on p. 15.23 above.

Babies and You: A prenatal health promotion program

The March of Dimes’ Babies and You prenatal health promotion program was developed in 1982 in partnership with maternal and infant health care specialists throughout the country. Extensively field-tested by March of Dimes chapters and worksites, the program is continuously updated and enhanced.

Babies and You educates adults about how to practice healthy lifestyle behaviors before and during pregnancy, motivates women to get early and regular prenatal care, and influences employers to implement strategies that support healthy pregnancy outcomes.

Prenatal health promotion activities should be reaching male as well as female employees, partners, other family members and friends. Babies and You is adaptable to the unique needs of any given workforce. Consideration is given to the educational level, culture and language of prospective participants, as well as to any worksite restrictions and available community resources.

Because employers are at different stages in their health promotion activities, Babies and You offers three levels of implementation: an information campaign, educational seminars, and training of health professionals (see box). The most popular topics for informational materials and educational seminars are preconception and prenatal care, fetal development, genetics, the male role in pregnancy, nutrition during pregnancy, and parenting. The topics covered in the prenatal programs of 31 companies surveyed by the New York Business Group on Health found the dominant themes to be understanding what goes on during pregnancy and delivery; timely care by qualified health professionals; practicing healthy behaviors related to pregnancy and avoidance of hazards that might affect mother and/or fetus; care of the newborn; and maintaining satisfactory family and work relationships (Duncan, Barr and Warshaw 1992).


BABIES AND YOU: Levels of Implementation

Level I Informational Campaign is designed to create awareness at the worksite about the importance of early and regular prenatal care. To sustain this level of implementation, a variety of print and audiovisual materials is available from the March of Dimes.

Level II Educational Seminars are delivered at the worksite by March of Dimes volunteer health professionals. Fourteen different seminar topics are available to choose from, including: preconception care, prenatal care, nutrition, exercise and pregnancy, pregnancy after 35, stress and pregnancy, pregnancy complications, well-baby care, male role in pregnancy, and breastfeeding.

Level III Training of Health Professionals allows a worksite to establish Babies and You as an on-going component of its wellness activities. The March of Dimes provides a one-day training on program delivery and implementation to on-site health professionals such as occupational health nurses, benefits managers, medical directors and health promotion specialists.

But no matter what level of Babies and You a worksite chooses to implement, there are eight goals of a successful prenatal health promotion effort that this program strives to achieve:

  • Management commitment
  • Inter-departmental program planning
  • Employee input
  • The offering of incentives
  • Supportive benefits and policies
  • Establishment of communications channels
  • Access to community resources
  • Evaluation

Post-pregnancy and infancy period

In addition to implementing health promotion programs and other services that focus on a mother’s health before and during pregnancy, many employers also offer programs that support parents and infants after pregnancy, during the critical first twelve months and beyond. Maternity disability benefits, lactation programs, dependant care reimbursement accounts (e.g., pre-tax set-asides of earnings that employees may draw on to pay for dependant care expenses), parenting classes and onsite child care are just a few of the benefits and programs now offered.

For example, to maintain goodwill with its employees, Lancaster Laboratories, based in Lancaster, Pennsylvania, and providing contract laboratory research and consulting to the environmental, food and pharmaceutical industries, continues to provide health care insurance benefits during both maternity disability leave and unpaid parental leave whether or not the employee plans to return to work after having given birth. This family-supportive management approach has gotten results: in an industry where a 27% turnover rate is the norm, the rate at Lancaster is only 8% (March of Dimes 1994).

Lactation programs also are easy and beneficial for employers to implement. The health benefits of breastfeeding extend beyond the child’s own. A recent study shows that improving an infant’s health through breastfeeding has a direct effect on employee productivity. Healthier infants mean mothers and fathers miss significantly fewer days of work to care for a sick child (Ryan and Martinez 1989). Offering a lactation program simply requires providing onsite space and equipment for pumping and storing breast milk.

The Los Angeles Department of Water and Power was able to quantify some benefits of its lactation program: for example, 86% of participants state that the program eased their transition back to work; 71% report taking less time off since participating; and program participants have a 2% turnover rate (March of Dimes 1994).

Employer Policies

There are many workplace policies that employers can initiate to create a maternal and infant-health supportive culture. Instituting new policies and changing old ones can send an important message to employees about the company’s corporate culture.

Some policies affect the health of all workers, like creating a smoke-free environment. Others focus on selected groups, such as those that address occupational reproductive health hazards and which are targeted to meet the needs of men and women who are planning to have a child. Still more, including flexible work policies, support pregnant women in scheduling prenatal visits and ease the burden of parents with infants and small children. Finally, policies relating to modifying work assignments when needed during pregnancy and resolving questions of disability and its duration help to protect the health of the pregnant worker while minimizing interference with her work assignments.

When the Warner-Lambert Company, a leader in the pharmaceutical, consumer health care and confectionary products industries, initiated its maternity management and prenatal education programs, the company also introduced comprehensive guidelines for managing reproductive health. The guidelines encourage employees to complete questionnaires assessing the potential of reproductive health hazards in their jobs or worksites. If necessary, a Warner-Lambert safety engineer will conduct an assessment to determine what, if any, control of workplace hazards or job restrictions may be necessary.

In addition to reproductive health hazards policies, a number of employers offer flexible family leave policies. For example, at AT&T, the communications giant, employees can take up to 12 months of unpaid leave to care for a newborn or adopted child. More than 50% of the employees who have taken advantage of this leave policy since 1990 returned to work within three months. Within six months, 82% of the employees were back at work (March of Dimes 1994).

And at PepsiCo Inc., the large beverage and food conglomerate based in Purchase, New York, fathers of newborns can take up to eight weeks of paid leave and an additional eight weeks of unpaid leave with a guarantee of the same or a comparable job when they return (March of Dimes 1994).

Designing a Maternal and Infant Health Strategy to Meet Business Needs

Any sustainable employer-based maternal and infant health strategy, in addition to being acceptable to employees, must meet sound business objectives. Depending on a company’s objectives, different benefits, employee programs, or policies may take priority. The following steps are useful in developing a preliminary strategy:

  1. Document existing benefits, programmes, and policies that support maternal and infant health in order to create the foundation of a formal strategy.
  2. Find out about community resources available to assist the company’s efforts.
  3. Prepare a prioritized list of preliminary maternal and infant health initiatives which includes changes or introductions in benefits, programmes, or policies.
  4. Gain preliminary support from top management before taking the next step.
  5. Assess perceived needs and test proposed strategies with employees to validate preliminary recommendations.
  6. Develop a formal maternal and infant health strategy by articulating a mission, outlining objectives, allocating the resources needed, identifying potential obstacles and key players, preparing an implementation timetable and gaining necessary support at all levels of the company.

 

Implementing maternal and infant health initiatives

The next step is to implement the benefits, programs and policies that are part of the strategy. The implementation process typically includes the following steps:

  1. Assign responsibility for implementation.
  2. Select quality measurements by which to manage the programme.
  3. Evaluate and select vendors.
  4. Review incentives and other methods to increase employee participation.
  5. Communicate initiatives to employees and family members.

 

Managing the success of a maternal and infant health strategy

After implementation, an employer’s maternal and infant health strategy should be reviewed for effectiveness in meeting original objectives and business needs. Evaluation and feedback are essential and help to ensure that the maternal and infant health initiatives are meeting both the employer’s and employees’ needs.


Mother and Child Health in France

Shortly after World War II, France instituted Protection maternelle et infantile (PMI), a nationwide system through which public and private health professionals, in collaboration with social services, provide basic preventive health, medical, social and educational services to pregnant women, infants and children through to the age of six.

For the most part, families and private physicians arrange individually for preconception counseling, family planning, early and regular prenatal care and preventive health examinations and vaccinations for children up to the age of six. Participation in the program is encouraged through 100% reimbursement by national health insurance (in order to qualify for this coverage, women must register their pregnancies by the 15th week of gestation), monthly (family) allowance payments from a woman’s fourth month of gestation through to the child’s third month of life as an incentive for compliance with the national guidelines for preventive care, and a continuing program of information and education.

Women not able to participate in care via the private sector are covered by 96 locally controlled PMI centers, one in each French département. In addition to providing free neighborhood health clinics, these centers identify and target for intervention pregnant women and children at risk, conduct home visits and monitor the progress of all women and infants to ensure that the preventive services called for in the national guidelines are received.

The employers’ role in this system is regulated by law. They provide pregnant women with:

  • Job changes; flexible hours to ease commuting burdens and rest periods in order to reduce the stress and fatigue that may lead to premature delivery
  • Maternity leave with job security for mothers who bear or adopt children to promote bonding and healthy child development (a maternity benefit amounting to 84% of the salary, is paid by social security up to a ceiling)
  • Part-time work arrangements and unpaid parental leave with job security to enable parents to balance child care and work responsibilities (a national parental allowance helps to offset the cost of the unpaid leave) (Richardson 1994)

Conclusion

The need to address maternal and infant health in the American workplace will increase as more and more women enter the labor force and as family and workplace issues become inseparable. Forward-thinking companies have already recognized this and are developing innovative approaches. Employers are in a unique and powerful position to influence change and become leaders in promoting healthy mothers and babies.

 

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This case study describes the mammography program at Marks and Spencer, the first to be offered by an employer on a nationwide scale. Marks and Spencer is an international retail operation with 612 stores worldwide, the majority being in the United Kingdom, Europe and Canada. In addition to a number of international franchise operations, the company owns Brooks Brothers and Kings Super Markets in the United States and D’Allaird’s in Canada and pursues extensive financial activities.

The company employs 62,000 people, the majority of whom work in 285 stores in the United Kingdom and the Republic of Ireland. The company’s reputation as a good employer is legendary and its policy of good human relations with staff has included the provision of comprehensive, high-quality health and welfare programs.

Although a treatment service is provided at some work locations, this need is largely met by community-based primary care physicians. The company health policy emphasizes the early detection and prevention of disease. A number of innovative screening programs have consequently been developed over the past 20 years, many of which have predated similar projects in the National Health Service (NHS). Over 80% of the workforce is female, a fact that has influenced the choice of screening programs, which include cervical cytology, ovarian cancer screening and mammography.

Breast Cancer Screening

In the mid-1970s the New York HIP study (Shapiro 1977) proved that mammography was capable of detecting impalpable breast cancers with the expectation that earlier detection would reduce mortality. To an employer of large numbers of middle-aged women, the appeal of mammography was obvious and a screening program was introduced in 1976 (Hutchinson and Tucker 1984; Haslehurst 1986). At that time there was virtually no access to reliable high-quality mammography in the public sector and that available in private health care organizations was of variable quality and expensive. The first task therefore was to ensure access to a uniformly high quality and this challenge was met by using mobile screening units, each equipped with a waiting area, examination cubicle and mammography equipment.

Centralized administration and film processing allowed continuous checks on all aspects of quality and allowed film interpretation to be undertaken by an experienced group of mammographers. There was, however, a disadvantage in that the radiographer was not able to immediately examine the developed film to verify that there were no technical errors so that if there had been any, the employee could be recalled or other arrangements made for the necessary repeat examination.

Compliance has always been exceptionally high and has remained over 80% for all age groups. Doubtless this is due peer group pressure, the easy availability of the service at or near the worksite and, until recently, a lack of mammography facilities in the NHS.

Women are invited to join the screening program and attendance is entirely voluntary. Prior to screening, short educational sessions are carried out by the company doctor or nurse, both of whom are available to answer queries and give explanations. Common anxieties include concern about radiation dosage and worry that the compression of the breast may cause pain. Women who are recalled for further tests are seen during working hours and fully recompensed for travel expenses for themselves and a companion.

Three modalities were used for the first five years of the program: clinical examination by a highly trained nurse-practitioner, thermography and mammography. Thermography was a time-consuming examination with a high rate of false positives and made no contribution to the cancer detection rate; accordingly it was discontinued in 1981. Although of limited value in cancer detection, clinical examination, which includes a detailed review of personal and family history, provides invaluable information to the radiologist and allows the client time to discuss her fears and other health issues with a sympathetic health professional. Mammography is the most sensitive of the three tests. Cranio-caudal and lateral oblique views are taken at the initial examination with single views only at the interval check. Single reading of films is the norm, though double reading is used for difficult cases and as a random quality check. Figure 1 shows the contribution of clinical examination and mammography to the total cancer detection rate. Of the 492 cases of cancer found, 10% were detected by clinical examination alone, 54% by mammography alone, and 36% were noted by clinical examination and mammography.

Figure 1. Screening for breast cancer. Contribution of clinical examination and mammography to cancer detection, by age group.

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Women aged 35 to 70 were offered screening when the program was first introduced but the low cancer detection rate and high incidence of benign breast disease among those in the 35 to 39 age group led to withdrawal of the service in 1987 from these women. Figure 19 shows the numbers of screen-detected cancers by age group.

Figure 2. Age distribution of screen-detected cancers.

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Similarly, the screening interval has changed from a yearly interval (reflecting initial enthusiasm) to a two-year gap. Figure 3 shows the number of screen-detected cancers by age group with the corresponding numbers of interval tumors and missed tumors. Interval cases are defined as those occurring after a truly negative screen during the time between routine tests. Missed cases are defined as those cancers which can be seen retrospectively on the films but were not identified at the time of the screening test.

Figure 3. Number of screen-detected cancers, interval cancers and missed cancers, by age group.

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Among the screened population, 76% of breast cancers were detected at screening with a further 14% of cases occurring during the interval between examinations. The interval cancer rate will be carefully monitored to ensure that it does not rise to an unacceptably high level.

The survival benefit of screening women under the age of 50 remains unproven although it is agreed that smaller cancers are detected and this allows some women to choose between mastectomy or breast conservation therapy—a choice valued highly by many. Figure 4 shows the sizes of screen-detected cancers, the majority being under two centimeters in size and node negative.

Figure 4. Sizes of screen-detected cancers.

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Impact of the Forrest Report

In the late 1980s, Professor Sir Patrick Forrest recommended that regular breast screening be made available to women over the age of 50 via the NHS (i.e., with no charge at the point of delivery of the service) (Forrest 1987). His most important recommendation was that the service should not start until specialist staff had been fully trained in the multidisciplinary approach to breast care diagnosis. Such staff was to include radiologists, nurse counselors and breast physicians. Since 1990, the United Kingdom has had an outstanding breast screening and assessment service for women over 50.

Coincidentally with this national development, Marks and Spencer reviewed its data and a major flaw in the program became apparent. The recall rate following routine screening was in excess of 8% for women over fifty and 12% for younger women. Analysis of the data showed that common reasons for recall were technical problems, such as malpositioning, processing errors, difficulties with grid lines or a need for further views. Additionally, it was clear that the use of ultrasonography, specialized mammography and fine needle aspiration cytology could cut the recall and referral rate even further. An initial study confirmed these impressions, and it was decided to redefine the screening protocol so that clients who needed further tests were not referred back to their family practitioners, but were retained within the screening program until a definitive diagnosis was made. Most of these women were returned to a schedule of routine recall after the further investigations and this reduced the formal surgical referral rate to a minimum.

Instead of duplicating the service provided by the National Health Service, a policy of partnership was developed which allowed Marks and Spencer to draw upon the expertise of the public sector while company funding is used to improve service for all. The breast screening program is now delivered by a number of providers: about half the requirement is met by the original mobile service but employees at the larger city stores now receive routine screening at specialist centers, which may either be in the private or public sectors. This cooperation with the National Health Service has been an exciting and challenging development and has helped to improve the overall standards of breast diagnosis and care for the entire population. By marrying together both private worksite and public sector programs it is possible to deliver an exceptionally high quality service to a widely distributed population.

 

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Tuesday, 25 January 2011 18:41

Women's Health

There is a common misperception that, outside of reproductive differences, female and male workers will be similarly affected by workplace health hazards and attempts to control them. While women and men do suffer from many of the same disorders, they differ physically, metabolically, hormonally, physiologically and psychologically. For example, women’s smaller average size and muscle mass dictate special attention to the fitting of protective clothing and devices and the availability of properly designed hand tools, while the fact that their body mass is usually smaller than that of men makes them more susceptible, on average, to the effects of alcohol abuse on the liver and the central nervous system.

They also differ in the types of job they hold, in the social and economic circumstances that influence their lifestyles, and in their participation in and response to health promotion activities. Although there have been some recent changes, women are still more likely to be found in jobs that are stultifyingly routine and in which they are exposed to repetitive injury. They suffer from pay inequity and are much more likely than men to be burdened with homemaking responsibilities and the care of children and elderly dependants.

In industrialized countries women have a longer life expectancy than men; this applies to every age group. At age 45, a Japanese woman may expect to live on average another 37.5 years, and a 45-year-old Scottish woman another 32.8 years, with women from most of the other countries of the developed world falling between these limits. These facts lead to an assumption that women are, therefore, healthy. There is a lack of awareness that these “extra” years are frequently marred by chronic illness and disability much of which is preventable. Many women know far too little about the health risks they face and, therefore, about the measures they can take to control those risks and protect themselves against serious disease and injury. For example, many women are rightfully concerned about breast cancer but ignore the fact that heart disease is by far the major cause of death in women and that, owing primarily to the increase in their cigarette smoking—which is also a major risk factor for coronary artery disease—the incidence of lung cancer among women is increasing.

In the United States, a 1993 national survey (Harris et al. 1993), involving interviews of more than 2,500 adult women and 1,000 adult men, confirmed that women suffer from serious health problems and that many do not receive the care they need. Between three and four out of ten women, the survey found, are at risk for undetected treatable disease because they are not receiving appropriate clinical preventive services, largely because they lack health care insurance or because their doctors never suggested that appropriate tests were available and should be sought. Furthermore, a substantial number of the American women surveyed were not happy with their personal physicians: four out of ten (twice the proportion of men) said their physicians “spoke down” to them and 17% (compared to 10% of men) had been told that their symptoms were “all in the head”.

While overall rates of mental illness are roughly the same for men and women, the patterns are different: women suffer more from depression and anxiety disorders while drug and alcohol abuse and antisocial personality disorders are more common among men (Glied and Kofman 1995). Men are more likely to seek and receive care from mental health specialists while women are more often treated by primary care physicians, many of whom lack the interest if not the expertise to treat mental health problems. Women, especially older women, receive a disproportionate share of the prescriptions for psychotropic drugs, so that concern has arisen that these drugs are possibly being overutilized. All too often, difficulties stemming from inordinate levels of stress or from problems that are preventable and treatable are explained away by health professionals, family members, supervisors and co-workers, and even by women themselves, as being reflective of the “time of the month” or “change of life”, and, therefore, go untreated.

These circumstances are compounded by the assumption that women—young and old alike—know all there is to know about their bodies and how they function. This is far from the truth. There exists widespread ignorance and uncritically accepted misinformation. Many women feel ashamed to reveal their lack of knowledge and are being needlessly worried by symptoms that are in fact either “normal” or simply explained.

As women constitute some 50% of the workforce in a large section of the employment arena, and considerably more in some service industries, the consequences of their preventable and correctable health problems levy a significant and avoidable toll on their well-being and productivity and on the organization as well. That toll may be considerably reduced by a worksite health promotion program designed for women.

Worksite Health Promotion for Women

A good deal of health information is provided by newspapers and magazines and on television but much of that is incomplete, sensationalized or geared to the promotion of particular products or services. Too often, in reporting on current medical and scientific advances, the media raise more questions than they answer and even cause needless anxiety. Health care professionals in hospitals, clinics and private offices often fail to make sure that their patients are properly educated about the problems they present, to say nothing of taking the time to inform them about important health issues unrelated to their symptoms.

A properly designed and administered worksite health promotion program should provide accurate and complete information, opportunities to ask questions either in group or individual sessions, clinical preventive services, access to a variety of health promotion activities and counseling about adjustments that may prevent or minimize distress and disability. The worksite offers an ideal venue for the sharing of health experiences and information, particularly when they are relevant to circumstances encountered on the job. One can also take advantage of the peer pressure that is present in the workplace to provide workers with additional motivation for participating and persisting in health promoting activities and in maintaining a healthful lifestyle.

There is a variety of approaches to programming for women. Ernst and Young, the large accounting firm, offered its London employees a series of Health Seminars for Women conducted by an outside consultant. They were attended by all grades of staff and were well received. The women who attended were secure in the format of the presentations. As an outsider, the consultant posed no threat to their employment status, and together they cleared up many areas of confusion about women’s health.

Marks and Spencer, a major retailer in the United Kingdom, conducts a program through its in-house medical department using outside resources to provide services to employees in their many regional worksites. They offer screening examinations and individual advice to all their staff, together with an extensive range of health literature and videotapes, many of which are produced in-house.

Many companies use independent health advisers outside the company. An example in the United Kingdom is the service provided by the BUPA (British United Provident Association) Medical Centers, who see many thousands of women through their network of 35 integrated but geographically scattered units, supplemented by their mobile units. Most of these women are referred through their employers’ health promotion programs; the remainder come independently.

BUPA was probably the first, at least in the United Kingdom, to establish a women’s health centre dedicated to preventive services exclusively for women. Hospital-based and free-standing women’s health centers are becoming more common and are proving attractive to women who have not been well served by the prevailing health care system. In addition to providing prenatal and obstetrical care, they tend to offer broad-ranging primary care, with most placing particular emphasis on preventive services.

The National Survey of Women’s Health Centers, conducted in 1994 by researchers from the Johns Hopkins School of Hygiene and Public Health with support from the Commonwealth Foundation (Weisman 1995), estimated that there are 3,600 women’s health centers in the United States, of which 71% are reproductive health centers providing primarily routine outpatient gynaecological examinations, Pap tests and family planning services. They also provide pregnancy tests, abortion counseling (82%) and abortions (50%), screening and treatment for sexually transmitted diseases, breast examinations and blood pressure checks.

Twelve per cent are primary care centers (these include women’s college health services) which provide basic well-woman and preventive care including periodic physical examinations, routine gynaecological examinations and Pap tests, diagnosis and treatment of menstrual problems, menopausal counseling and hormone replacement therapy, and mental health services, including drug and alcohol abuse counseling and treatment.

Breast centers constitute 6% of the total (see below), while the remainder are centers providing various combinations of services. Many of these centers have demonstrated interest in contracting to provide services to female employees of nearby organizations as part of their worksite health promotion programs.

Regardless of the venue, the success of worksite health promotion programming for women hinges not only on the reliability of the information and services offered but, more important, on the manner in which they are presented. The programs must be sensitized to women’s attitudes and aspirations as well as to their concerns and, while being supportive, they should be free of the condescension with which these problems are so often addressed.

The remainder of this article will focus on three categories of problems regarded as particularly important health concerns for women—menstrual disorders, cervical and breast cancer and osteoporosis. However, in addressing other health categories, the worksite health promotion program should ensure that any other problems of particular relevance for women will not be overlooked.

Menstrual Disorders

For the great majority of women, menstruation is a “natural” process that presents few difficulties. The menstrual cycle may be disturbed by a variety of conditions which may cause discomfort or concern for the employee. These may lead her to take sick absence on a regular basis, often reporting a “cold” or “sore throat” rather than a menstrual problem, especially if the absence certificate is to be submitted to a male manager. However, the absence pattern is obvious and referral to a qualified health professional may resolve the problem rapidly. Menstrual problems that may affect the workplace include amenorrhoea, menorrhagia, dysmenorrhoea, the premenstrual syndrome (PMS) and menopause.

Amenorrhoea

While amenorrhoea may create concern, it does not ordinarily affect work performance. The most common cause of amenorrhoea in younger women is pregnancy and in older women it is menopause or a hysterectomy. However, it may also be attributable to the following circumstances:

  • Poor nutrition or underweight. The reason for poor nutrition may be socioeconomic in that little food is available or affordable, but it may also be the result of self-starvation related to eating disorders such as anorexia nervosa or bulimia.
  • Excessive exercise. In many developed countries. women train excessively in physical fitness or sports programmes. Even though their food intake may be adequate, they may have amenorrhoea.
  • Medical conditions. Problems arising from hypothyroidism or other endocrine disorders, tuberculosis, anaemia from any cause and certain serious, life-threatening diseases can all cause amenorrhoea.
  • Contraceptive measures. Medications containing progesterone only will commonly lead to amenorrhoea. It should be noted that sterilization without цphorectomy does not cause a woman’s periods to stop.

 

Menorrhagia

In the absence of any objective measure of menstrual flow, it is commonly accepted that any flow of menses which is heavy enough to interfere with a woman’s normal day-to-day activities, or which leads to anemia, is excessive. When the flow is heavy enough to overwhelm the normal circulating anti-clotting factor, the woman with “heavy periods” may complain of passing clots. Inability to control the blood flow by any normal sanitary protection can lead to considerable embarrassment in the workplace and may lead to a pattern of regular, monthly one- or two-day absences.

Menorrhagia may be caused by uterine fibroids or polyps. It can also be caused by an intrauterine contraceptive device (IUD) and, rarely, it may be the first indication of a severe anemia or other serious blood disorder such as leukaemia.

Dysmenorrhoea

Although the vast majority of menstruating women experience some discomfort at the time of menstruation, only a few have pain sufficient to interfere with normal activity and, thus, require referral for medical attention. Again, this problem may be suggested by a pattern of regular monthly absences. Such difficulties associated with menstruation may for certain practical purposes be classified thus:

  1. Primary dysmenorrhoea. Young women with no evidence of disease may suffer pain on the day before or on the first day of their period that is serious enough to induce them to take time off from work. Although no cause has been found, it is known to be associated with ovulation and, hence, can be prevented by the oral contraceptive pill or by other medication which prevents ovulation.
  2. Secondary dysmenorrhoea. The onset of painful periods in a woman in her middle thirties or later suggests pelvic pathology and should be fully investigated by a gynaecologist.

 

It should be noted that some over-the-counter or prescribed analgesics taken for dysmenorrhoea may cause drowsiness and can present a problem for women working in jobs that require alertness to occupational hazards.

Premenstrual syndrome

Premenstrual syndrome (PMS), a combination of physical and psychological symptoms experienced by a relatively small percentage of women during the seven or ten days prior to menstruation, has developed its own mythology. It has falsely been credited as the cause of women’s so-called emotionalism and “flightiness”. According to some men, all women suffer from it, while ardent feminists claim that no women have it. In the workplace, it has improperly been cited as a rationale for keeping women out of positions requiring decision making and the exercise of judgment, and it has served as a convenient excuse for denying women promotion to managerial and executive levels. It has been blamed for women’s problems with interpersonal relations and, indeed, in England it has provided the grounds for pleas of temporary insanity that enabled two separate female defendants to escape charges of murder.

The physical symptoms of PMS may include abdominal distention, breast tenderness, constipation, sleeplessness, weight gain due to increased appetite or to sodium and fluid retention, fine-movement clumsiness and inaccuracy in judgment. The emotional symptoms include excessive crying, temper tantrums, depression, difficulty in making decisions, an inability to cope in general and a lack of confidence. They always occur in the premenstrual days, and are always relieved by the onset of the period. Women taking the combined oral contraceptive pill and those who have had oophorectomies rarely get PMS.

The diagnosis of PMS is based on the history of its temporal relationship to menstrual periods; in the absence of definitive causes, there are no diagnostic tests. Its treatment, the intensity of which is determined by the intensity of the symptoms and their effect on normal activities, is empirical. Most cases respond to simple self-help measures which include abolishing caffeine from the diet (tea, coffee, chocolate and most cola soft drinks all contain significant amounts of caffeine), frequent small feedings to minimize any tendency to hypoglycemia, restricting sodium intake to minimize fluid retention and weight gain, and regular moderate exercise. When these fail to control the symptoms, physicians may prescribe mild diuretics (for two to three days only) that control sodium and fluid retention and/or oral hormones that modify ovulation and the menstrual cycle. In general, PMS is treatable and should not represent a significant problem to women in the workplace.

Menopause

Menopause reflecting ovarian failure may occur in women in their thirties or may be postponed to well beyond the age of 50; by the age of 48, about half of all women will have experienced it. The actual time of the menopause is influenced by general health, nutrition and familial factors.

The symptoms of the menopause are diminished frequency of periods usually coupled with scanty menstrual flow, hot flushes with or without night sweats, and a diminution in vaginal secretions, which may cause pain during sexual intercourse. Other symptoms frequently attributed to the menopause include depression, anxiety, tearfulness, lack of confidence, headaches, changes in skin texture, loss of sexual interest, urinary difficulties and sleeplessness. Interestingly, a controlled study involving a symptom questionnaire administered to both men and women showed that a significant portion of these complaints were shared by men of the same age (Bungay, Vessey and McPherson 1980).

The menopause, coming as it does at about the age of 50, may coincide with what has been called the “mid-life transition” or the “mid-life crisis”, terms coined to denote collectively the experiences which seem to be shared by both men and women in their middle years (if anything, they appear to be more common among men). These include loss of purpose, dissatisfaction with one’s job and with life in general, depression, waning interest in sexual activity and a tendency to diminished social contacts. It may be precipitated by the loss of spouse or partner through separation or death or, as regards one’s job, by failure to win an expected promotion or by separation, whether by termination or voluntary retirement. In contrast to menopause, there is no known hormonal basis for the mid-life transition.

Particularly in women, this period may be associated with the “empty nest syndrome,” the sense of purposelessness that may be felt when, their children having left the home, their whole perceived raison d’être seems to have been lost. In such cases, the job and the social contacts in the workplace often provide a stabilizing, therapeutic influence.

Like many of the other “female problems,” menopause has developed its own mythology. Preparatory education debunking these myths supplemented by sensitive supportive counseling will go far to preventing significant dislocations. Continuing to work and maintaining her satisfactory performance on the job may be of crucial value in sustaining a woman’s well-being at this time.

It is at this point that the advisability of hormone replacement therapy (HRT) needs to be considered. Currently the subject of some controversy, HRT was originally prescribed to control menopausal symptoms if they became excessively severe. While usually effective, the hormones commonly used often precipitated vaginal bleeding and, more important, they were suspected of being carcinogenic. As a result, they were prescribed only for limited periods of time, just long enough to control the troublesome menopausal symptoms.

HRT has no effect on the symptoms of the mid-life transition. However, if a woman’s flushes are controlled and she can get a good night’s sleep because her night sweats are prevented, or if she can respond to lovemaking more enthusiastically because it is no longer painful, then some of her other problems may be resolved.

Today, the value of long-term HRT is increasingly being recognized in maintaining the integrity of bone in women with osteoporosis (see below) and in reducing the risk of coronary heart disease, now the highest-ranking cause of death among women in industrialized countries. Newer hormones, combinations and sequences of administration may eliminate the occurrence of planned vaginal bleeding and there appears to be little or no risk of carcinogenesis, even among women with a history of cancer. However, because many physicians are strongly biased for or against HRT, women need to be educated about its benefits and disadvantages so that they can participate confidently in the decision about whether to use it or not.

Recently, calling to mind the millions of women “baby boomers” (children born after the Second World War) who will be reaching the age of menopause within the next decade, the American College of Obstetricians and Gynecologists (ACOG) warned that staggering increases in osteoporosis and heart disease could result unless women are better educated about menopause and the interventions designed to prevent disease and disability and to prolong and enhance their lives after menopause (Voelker 1995). ACOG president William C. Andrews, MD, has proposed a three-pronged program that includes a massive campaign to educate physicians about the menopause, a “perimenopausal visit” to a physician by all women over the age of 45 for a personal risk assessment and in-depth counseling, and involvement of the news media in educating women and their families about the symptoms of menopause and the benefits and risks of treatments like HRT before women reach menopause. The worksite health promotion program can make a major contribution to such an educational effort.

Screening for Cervical and Breast Disease

With regard to women’s needs, a health promotion program should either provide or, at least, recommend periodic screening for cervical and breast cancer.

Cervical disease

Regular screening for precancerous cervical changes by means of the Pap test is a well-established practice. In many organizations, it is made available in the workplace or in a mobile unit brought to it, eliminating the need for female employees to spend time traveling to a facility in the community or visiting their personal physicians. The services of a physician are not required in the administration of this procedure: satisfactory smears may be taken by a well-trained nurse or technician. More important is the quality of the reading of the smears and the integrity of the procedures for record-keeping and reporting of the results.

Breast cancer

Although breast screening by mammography is widely practiced in almost all developed countries, it has been established on a national basis only within the United Kingdom. Currently, over a million women in the United Kingdom are screened, with each woman aged 50 to 64 having a mammogram every three years. All the examinations, including any further diagnostic studies needed to clarify abnormalities in the initial films, are free of charge to the participants. The response to the offer of this three-year cycle of mammography has been over 70%. Reports for the 1993-1994 period (Patnick 1995) show a rate of 5.5% for referral to further assessment; 5.5 women per 1,000 women screened were discovered to have breast cancer. The positive predictive value for surgical biopsy was 70% in this program, compared to some 10% in programs reported elsewhere in the world.

The critical issues in mammography are the quality of the procedure, with particular emphasis on minimizing radiation exposure, and the accuracy of the interpretation of the films. In the United States, the Food and Drug Administration (FDA) has promulgated a set of quality regulations proposed by the American College of Radiology that, commencing October 1, 1994, must be observed by the more than 10,000 medical units taking or interpreting mammograms around the country (Charafin 1994). In accordance with the national Mammography Standards Act (enacted in 1992), all mammography facilities in the United States (except those operated by the Department of Veterans Affairs, which is developing its own standards) had to be certified by the FDA as of this date. These regulations are summarized in figure 1.

Figure 1. Mammography quality standards in the United States.

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A recent phenomenon in the United States is the increase in the number of breast or breast health centers, 76% of which have appeared since 1985 (Weisman 1995). They are predominantly hospital-affiliated (82%); the others are primarily profit-making enterprises owned by physician groups. About a fifth maintain mobile units. They provide outpatient screening and diagnostic services including physical breast examinations, screening and diagnostic mammography, breast ultrasound, fine-needle biopsy and instruction in breast self-examination. Slightly more than one-third also offer treatment for breast cancer. While primarily focused on attracting self-referrals and referrals by community physicians, many of these centers are making an effort to contract with employer- or labor union-sponsored health promotion programs to provide breast screening services to their female participants.

Introducing such screening programs into the workplace can generate considerable anxiety among some women, particularly those with personal or family histories of cancer and those found to have “abnormal” (or inconclusive) results. The possibility of such non-negative results should be carefully explained in presenting the program, along with the assurance that arrangements are in place for the additional examinations needed to explain and to act upon them. Supervisors should be educated to sanction absences by these women when the necessary follow-up procedures cannot be expeditiously arranged outside of working hours.

Osteoporosis

Osteoporosis is a metabolic bone disorder, much more prevalent in women than in men, that is characterized by a gradual decline in bone mass leading to susceptibility to fractures which may result from seemingly innocuous movements and accidents. It represents an important public health problem in most developed countries.

The most common sites for fractures are the vertebrae, the distal portion of the radius and the upper portion of the femur. All fractures at these sites in older individuals should cause one to suspect osteoporosis as a contributing cause.

While such fractures usually occur later in life, after the individual has left the workforce, osteoporosis is a desirable target for worksite health promotion programs for a number of reasons: (1) the fractures may involve retirees and add significantly to their medical care costs, for which the employer may be responsible; (2) the fractures may involve the elderly parents or in-laws of current employees, creating a dependant-care burden that can compromise their attendance and work performance; and (3) the workplace presents an opportunity to educate younger people about the eventual danger of osteoporosis and to urge them to initiate the lifestyle changes that can slow its progress.

There are two types of primary osteoporosis:

  • Post-menopausal, which is related to loss of oestrogens and, hence, is more prevalent in women than in men (ratio = 6:1). It is commonly found in the 50-to-70 age group and is associated with vertebral fractures and Colles fractures (of the wrist).
  • Involutional, which occurs mainly in those over the age of 70 and is only twice as common among women than in men. It is thought to be due to age-related changes in vitamin D synthesis and is associated chiefly with vertebral and femoral fractures.

 

Both types may be present simultaneously in women. In addition, in a small percentage of cases, osteoporosis has been attributed to a variety of secondary causes including: hyperparathyroidism; the use of corticosteroids, L-thyroxine, aluminum-containing antacids and other drugs; prolonged bed rest; diabetes mellitus; the use of alcohol and tobacco; and rheumatoid arthritis.

Osteoporosis may be present for years and even decades before fractures result. It can be detected by well-standardized x-ray measurements of bone density, calibrated for age and sex, and supplemented by laboratory evaluation of calcium and phosphorus metabolism. Unusual radiolucency of bone in conventional x rays may be suggestive, but such osteopenia usually cannot be reliably detected until more than 30% of the bone is lost.

It is generally agreed that screening asymptomatic individuals for osteoporosis should not be employed as a routine procedure, especially in worksite health promotion programs. It is costly, not very reliable except in the most well-staffed facilities, involves exposure to radiation and, most important, does not identify those women with osteoporosis who are most likely to have fractures.

Accordingly, although everyone is subject to some degree of bone loss, the prevention program for osteoporosis is focused on those individuals who are at higher risk for its more rapid progression and who are therefore more susceptible to fractures. A special problem is that although the earlier in life the preventive measures are started, the more effective they are, it is nonetheless difficult to motivate younger people to adopt lifestyle changes in the hope of avoiding a health problem that may develop at what many of them consider to be a very remote age of life. A saving grace is that many of the recommended changes are also useful in the prevention of other problems as well as in promoting general health and well-being.

Some risk factors for osteoporosis cannot be changed. They include:

  • Race. On average, Whites and Orientals have lower bone density than Blacks matched age for age and are therefore at greater risk.
  • Sex. Women have less dense bones than men when matched for age and race and therefore are at greater risk.
  • Age. All people lose bone mass with age. The stronger the bones are in youth, the less likely is it that the loss will reach potentially dangerous levels in old age.
  • Family history. There is some evidence of a genetic component in the attainment of peak bone mass and the rate of subsequent bone loss; thus, a family history of suggestive fractures in family members may represent an important risk factor.

 

The fact that these risk factors cannot be altered makes it important to give attention to those that can be modified. Among the measures that may be taken to delay the onset of osteoporosis or to diminish its severity, the following may be mentioned:

  • Diet. If adequate amounts of calcium and vitamin D are not present in the diet, supplementation is recommended. This is particularly important for people with lactose intolerance who tend to avoid milk and milk products, the major sources of dietary calcium, and is most effective if maintained from childhood until the thirties as peak bone density is being achieved. Calcium carbonate, the most commonly used form of calcium supplementation, frequently causes side effects such as constipation, rebound hyperacidity, abdominal bloating and other gastrointestinal symptoms. Accordingly, many people substitute preparations of calcium citrate which, despite a significantly lower content of elemental calcium, is better absorbed and has fewer side-effects. The amounts of vitamin D present in the usual multivitamin preparation suffice for slowing the bone loss of osteoporosis. Women should be cautioned against excessive doses, which may lead to hypervitaminosis D, a syndrome that includes acute renal failure and increased resorption of bone.
  • Exercise. Regular moderate weight-bearing exercise-for example, 45 to 60 minutes of walking at least three times a week-is advisable.
  • Smoking. Women who smoke have their menopause on average two years earlier than non-smokers. Without hormone replacement, the earlier menopause will accelerate post-menopausal bone loss. This is another important reason to counter the current trend to increased cigarette smoking among women.
  • Hormone replacement therapy. If oestrogen replacement is undertaken, it should be started early in the progress of the menopausal changes since the rate of bone loss is greatest during the first few years after menopause. Because bone loss is resumed after the discontinuation of oestrogen therapy, it should be maintained indefinitely.

 

Once osteoporosis is diagnosed, treatment is aimed at circumventing further bone loss by following all of the above recommendations. Some recommend using calcitonin, which has been shown to increase total body calcium. However, it must be given parenterally; it is expensive; and there is yet no evidence that it retards or reverses the loss of calcium in the bone or reduces the occurrence of fractures. Biphosphonates are gaining ground as anti-resorptive agents.

It must be remembered that osteoporosis sets the stage for fractures but it does not cause them. Fractures are caused by falls or sudden injudicious movements. While the prevention of falls should be an integral part of every worksite safety program, it is particularly important for individuals who may have osteoporosis. Thus, the health promotion program should include education about safeguarding the environment in both the workplace and in the home (e.g., eliminating or taping down trailing electrical wires, painting the edges of steps or irregularities in the floor, tacking down slippery rugs and promptly drying up any wet spots) as well as sensitizing individuals to such hazards as insecure footwear and seats that are difficult to get out of because they are too low or too soft.

Women’s Health and Their Work

Women are in the paid workforce to stay. In fact, they are the mainstay of many industries. They should be treated as equal to men in every respect; only some aspects of their health experience are different. The health promotion program should inform women about these differences and empower them to seek the kind and quality of health care they need and deserve. Organizations and those who manage them should be educated to understand that most women do not suffer from the problems described in this article, and that, for the small proportion of women who do, prevention or control is possible. Except in rare instances, no more frequent than among men with similar health problems, these problems do not constitute barriers to good attendance and effective work performance.

Many women managers get to their high positions not only because their work is excellent, but because they experience none of the problems of female health that have been outlined above. This can make some of them intolerant and unsupportive of other women who do have such difficulties. One major area of resistance to women’s status in the workplace, it appears, can be women themselves.

A worksite health promotion program that embodies a focus on women’s health issues and problems and addresses them with appropriate sensitivity and integrity can have an important positive impact for good, not only for the women in the workforce, but also for their families, the community and, most important, the organization.

 

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Tuesday, 25 January 2011 14:45

Cancer Prevention and Control

Within the next decade, it is predicted, cancer will become the leading cause of death in many developed countries. This reflects not so much an increase in the incidence of cancer but rather a decrease in mortality due to cardiovascular disease, currently topping the mortality tables. Equally with its high mortality rate, we are disturbed by the specter of cancer as a “dread” disease: one associated with a more or less rapid course of disability and a high degree of suffering. This somewhat fearsome picture is being made easier to contemplate by our growing knowledge of how to reduce risk, by techniques permitting early detection and by new and powerful achievements in the field of therapy. However, the latter may be associated with physical, emotional and economic costs for both the patients and those concerned about them. According to the US National Cancer Institute (NCI), a significant reduction in cancer morbidity and mortality rates is possible if current recommendations relating to use of tobacco, dietary changes, environmental controls, screening and state-of-the-art treatment are effectively applied.

To the employer, cancer presents significant problems entirely apart from the responsibility for possible occupational cancer. Workers with cancer may have impaired productivity and recurrent absenteeism due both to the cancer itself and the side effects of its treatment. Valuable employees will be lost through prolonged periods of disability and premature death, leading to the considerable cost of recruiting and training replacements.

There is a cost to the employer even when it is a spouse or other dependant rather than the healthy employee who develops the cancer. The caregiving burden may lead to distraction, fatigue and absenteeism which tax that employee’s productivity, and the often considerable medical expenses increase the cost of employer-sponsored health insurance. It is entirely appropriate, therefore, that cancer prevention should be a major focus of worksite wellness programs.

Primary Prevention

Primary prevention involves avoidance of smoking and modifying other host factors that may influence the development of cancer, and identifying potential carcinogens in the work environment and eliminating or at least limiting workers’ exposure to them.

Controlling exposures

Potential as well as proven carcinogens are identified through basic scientific research and by epidemiological studies of exposed populations. The latter involves industrial hygiene measurements of the frequency, magnitude and duration of the exposures, coupled with comprehensive medical surveillance of the exposed workers, including analysis of causes of disability and death. Controlling exposures involves the elimination of these potential carcinogens from the workplace or, when that is not possible, minimizing exposure to them. It also involves the proper labeling of such hazardous materials and continuing education of workers with respect to their handling, containment and disposal.

Smoking and cancer risk

Approximately one-third of all cancer deaths and 87% of all lung cancers in the US are attributable to smoking. Tobacco use is also the principal cause of cancers of the larynx, oral cavity and oesophagus and it contributes to the development of cancers of the bladder, pancreas, kidney, and uterine cervix. There is a clear dose-response relationship between lung cancer risk and daily cigarette consumption: those who smoke more than 25 cigarettes a day have a risk that is about 20 times greater than that of non-smokers.

Experts believe that the involuntary intake of the tobacco smoke emitted by smokers (“environmental tobacco smoke”) is a significant risk factor for lung cancer in non-smokers. In January 1993, the US Environmental Protection Agency (EPA) classified environmental tobacco smoke as a known human carcinogen which, it estimated, is responsible for approximately 3,000 lung cancer deaths annually among US non-smokers.

The 1990 US Surgeon General’s report on the health benefits of smoking cessation provides clear evidence that quitting smoking at any age is beneficial to one’s health. For example, five years after quitting, former smokers experience a diminished risk for lung cancer; their risk, however, remains higher than that of non-smokers for as long as 25 years.

The elimination of tobacco exposure by employer-sponsored/ labor union-sponsored smoking cessation programs and worksite policies enforcing a smoke-free working environment represent a major element in most worksite wellness programs.

Modifying host factors

Cancer is an aberration of normal cell division and growth in which certain cells divide at abnormal rates and grow abnormally, sometimes migrating to other parts of the body, affecting the form and function of involved organs, and ultimately causing death of the organism. Recent, continuing biomedical advances are providing increasing knowledge of the carcinogenesis process and are beginning to identify the genetic, humoral, hormonal, dietary and other factors that may accelerate or inhibit it—thus leading to research on interventions that have the potential to identify the early, precancerous process and so to help restore the normal cellular growth patterns.

Genetic factors

Epidemiologists continue to accumulate evidence of familial variations in the frequency of particular types of cancer. These data have been bolstered by molecular biologists who have already identified genes that appear to control steps in cellular division and growth. When these “tumor suppressor” genes are damaged by naturally-occurring mutations or the effects of an environmental carcinogen, the process may go out of control and a cancer is initiated.

Heritable genes have been found in patients with cancer and members of their immediate families. One gene has been associated with a high risk of colon cancer and endometrial or ovarian cancer in women; another with a high risk of breast and ovarian cancer; and a third with a form of malignant melanoma. These discoveries led to a debate about the ethical and sociological issues surrounding DNA testing to identify individuals carrying these genes with the implication that they then might be excluded from jobs involving possible exposure to potential or actual carcinogens. After studying this question, the National Advisory Council for Human Genome Research (1994), raising issues to do with the reliability of the testing, the present effectiveness of potential therapeutic interventions, and the likelihood of genetic discrimination against those found to be at high risk, concluded that “it is premature to offer DNA testing or screening for cancer predisposition outside a carefully monitored research environment”.

Humoral factors

The value of the prostate specific antigen (PSA) test as a routine screening test for prostatic cancer in older men has not been scientifically demonstrated in a clinical trial. However, in some instances, it is being offered to male workers, sometimes as a token of gender equity to balance the offering of mammography and cervical Pap smears to female workers. Clinics providing routine periodic examinations are offering the PSA test as a supplement to and, sometimes, even as a replacement for the traditional digital rectal examination as well as the recently introduced rectal ultrasound examination. Although its use appears to be valid in men with prostatic abnormalities or symptoms, a recent multinational review concludes that measurement of PSA should not be a routine procedure in screening healthy male populations (Adami, Baron and Rothman 1994).

Hormonal factors

Research has implicated hormones in the genesis of some cancers and they have been used in the treatment of others. Hormones, however, do not appear to be an appropriate item to emphasize in workplace health promotion programs. A possible exception would be warnings of their potential carcinogenic hazard in certain cases when recommending hormones for the treatment of menopausal symptoms and the prevention of osteoporosis.

Dietary factors

Researchers have estimated that approximately 35% of all cancer mortality in the US may be related to diet. In 1988, the US Surgeon General’s Report on Nutrition and Health indicated that cancers of the lung, colon-rectum, breast, prostate, stomach, ovary and bladder may be associated with diet. Research indicates that certain dietary factors—fat, fiber, and micronutrients such as beta-carotene, vitamin A, vitamin C, vitamin E and selenium—may influence cancer risk. Epidemiological and experimental evidence indicates that modulation of these factors in the diet can reduce the occurrence of some types of cancer.

Dietary fat

Associations between excess intake of dietary fat and the risk of various cancers, particularly cancers of the breast, colon and prostate, have been demonstrated in both epidemiological and laboratory studies. International correlational studies have shown a strong association between the incidence of cancers at these sites and total dietary fat intake, even after adjusting for total caloric intake.

In addition to the amount of fat, the type of fat consumed may be an important risk factor in cancer development. Different fatty acids may have various site-specific tumor-promoting or tumor-inhibiting properties. Intake of total fat and saturated fat has been strongly and positively associated with colon, prostate, and post-menopausal breast cancers; intake of polyunsaturated vegetable oil has been positively associated with post-menopausal breast and prostate cancers, but not with colon cancer. Conversely, consumption of highly polyunsaturated omega-3 fatty acids found in certain fish oils may not affect or may even decrease the risk of breast and colon cancers.

Dietary fiber

Epidemiological evidence suggests that the risk of certain cancers, particularly colon and breast cancers, may be lowered by increased intake of dietary fiber and other dietary constituents associated with high intakes of vegetables, fruits, and whole grains.

Micronutrients

Epidemiological studies generally show an inverse relationship between cancer incidence and intake of foods high in several nutrients having antioxidant properties, such as beta-carotene, vitamin C (ascorbic acid), and vitamin E (alpha-tocopherol). A number of studies have shown that low intakes of fruits and vegetables are associated with increased risk of lung cancer. Deficiencies of selenium and zinc have also been implicated in increased cancer risk.

In a number of studies in which the use of antioxidant supplements was shown to reduce the expected number of serious heart attacks and strokes, the data on cancer were less clear. However, results from the Alpha-Tocopherol, Beta-Carotene (ATBC) Lung Cancer Prevention clinical trial, conducted by the NCI in collaboration with the National Public Health Institute of Finland, indicated that vitamin E and beta-carotene supplements did not prevent lung cancer. Vitamin E supplementation also resulted in 34% fewer prostate cancers and 16% fewer colorectal cancers, but those subjects taking beta-carotene had 16% more lung cancers, which was statistically significant, and had slightly more cases of other cancers than those taking vitamin E or the placebo. There was no evidence that the combination of vitamin E and beta-carotene was better or worse than either supplement alone. The researchers have not yet determined why those taking beta-carotene in the study were observed to have more lung cancers. These results suggest the possibility that a different compound or compounds in foods which have high levels of beta-carotene or vitamin E may be responsible for the protective effect observed in epidemiological studies. The researchers also speculated that the length of time of supplementation may have been too short to inhibit the development of cancers in long-term smokers. Further analyses of the ATBC study, as well as results from other trials in progress, will help resolve some of the questions that have arisen in this trial, particularly the question of whether large doses of beta-carotene may be harmful to smokers.

Alcohol

Excessive use of alcoholic beverages has been associated with cancer of the rectum, pancreas, breast and liver. There is also strong evidence supporting a synergistic association of alcohol consumption and tobacco use with increased risk of cancer of the mouth, pharynx, oesophagus and larynx.

Dietary recommendations

Based on the compelling evidence that diet is related to cancer risk, the NCI has developed dietary guidelines that include the following recommendations:

  • Reduce fat intake to 30% or less of calories.
  • Increase fibre intake to 20 to 30 grams per day, with an upper limit of 35 grams.
  • Include a variety of vegetables and fruits in the daily diet.
  • Avoid obesity.
  • Consume alcoholic beverages in moderation, if at all.
  • Minimize consumption of salt-cured (packed in salt), salt-pickled (soaked in brine), or smoked foods (associated with increased incidence of stomach and oesophageal cancer).

 

These guidelines are intended to be incorporated into a general dietary regimen that can be recommended for the entire population.

Infectious diseases

There is increasing knowledge of the association of certain infectious agents with several types of cancer: for example, the hepatitis B virus with liver cancer, the human papillomavirus with cervical cancer, and the Epstein-Barr virus with Burkitt’s lymphoma. (The frequency of cancer among patients with AIDS is attributable to the patient’s immunodeficiency and is not a direct carcinogenic effect of the HIV agent.) A vaccine for hepatitis B is now available that, when given to children, ultimately will reduce their risk for liver cancer.

Worksite Cancer Prevention

To explore the potential of the workplace as an arena for the promotion of a broad set of cancer prevention and control behaviors, the NCI is sponsoring the Working Well Project. This project is designed to determine whether worksite-based interventions to reduce tobacco use, achieve cancer preventive dietary modifications, increase screening prevalence and reduce occupational exposure can be developed and implemented in a cost-effective way. It was initiated in September 1989 at the following four research centers in the United States.

  • M.D. Anderson Cancer Center, Houston, Texas
  • University of Florida, Gainesville, Florida
  • Dana Farber Cancer Institute, Boston, Massachusetts
  • Miriam Hospital/Brown University, Providence, Rhode Island

 

The project involves approximately 21,000 employees at 114 different worksites around the United States. Most of the selected worksites are involved predominantly in manufacturing; other types of worksites in the project included fire stations and newspaper printers. Tobacco reduction and dietary modification were areas of intervention included in all of the worksites; however, each site maximized or minimized particular intervention programs or included additional options to meet the climatic and socioeconomic conditions of the geographic area. The centers in Florida and Texas, for example, included and emphasized skin cancer screening and the use of sun screens because of increased exposure to the sun in those geographic regions. The centers in Boston and Texas offered programs that emphasized the relationship between cancer and tobacco use. The Florida centre enhanced the diet modification intervention with supplies of fresh citrus fruits, readily available from the state’s farming and fruit industry. Management-employee consumer boards also were established at the worksites of the Florida centre to work with the food service to ensure that the cafeterias offered fresh vegetable and fruit selections. Several of the worksites participating in the project offered small prizes—gift certificates or cafeteria lunches—for continued participation in the project or for achievement of a desired goal, such as smoking cessation. Reduction of exposure to occupational hazards was of special interest at those worksites where diesel exhaust, solvent use or radiation equipment were prevalent. The worksite-based programs included:

  • group activities to generate interest, such as taste testing of various foods
  • directed group activities, such as quit-smoking contests
  • medical/scientific-based demonstrations, such as  testing, to verify the effect of smoking on the respiratory system
  • seminars on business practices and policy development aimed at significantly reducing or eliminating occupational exposure to potentially or actually dangerous or toxic materials
  • computer-based self-help and self-assessment programmes on cancer risk and prevention
  • manuals and self-help classes to help reduce or eliminate tobacco use, achieve dietary modifications, and increase cancer screening.

 

Cancer education

Worksite health education programs should include information about signs and symptoms that are suggestive of early cancer—for example, lumps, bleeding from the rectum and other orifices, skin lesions that do not appear to heal—coupled with advice to seek evaluation by a physician promptly. These programs might also offer instruction, preferably with supervised practice, in self-examination of the breast.

Cancer screening

Screening for precancerous lesions or early cancer is carried out with a view to their earliest possible detection and removal. Educating individuals about the early signs and symptoms of cancer so that they may seek the attention of a physician is an important part of screening.

A search for early cancer should be included in every routine or periodic medical examination. In addition, mass screenings for particular types of cancer may be carried out in the workplace or in a community facility near the worksite. Any acceptable and justifiable screening of an asymptomatic population for cancer should meet the following criteria:

  • The disease in question should represent a substantial burden at the public health level and should have a prevalent, asymptomatic, nonmetastatic phase.
  • The asymptomatic, nonmetastatic phase should be recognizable.
  • The screening procedure should have reasonable specificity, sensitivity and predictive values; it should be of low risk and low cost, and be acceptable to both the screener and the person being screened.
  • Early detection followed by appropriate treatment should offer a substantially greater potential for cure than exists in cases in which discovery was delayed.
  • Treatment of lesions detected by screening should offer improved outcomes as measured in cause-specific morbidity and mortality.

 

The following additional criteria are particularly relevant in the workplace:

  • Employees (and their dependants, when involved in the programme) should be informed of the purpose, nature and potential results of the screening, and a formal “informed consent” should be obtained.
  • The screening programme should be conducted with due consideration for the comfort, dignity and privacy of the individuals consenting to be screened and should involve minimal interference with working arrangements and production schedules.
  • Screening results should be conveyed promptly and privately, with copies forwarded to personal physicians designated by the workers. Counselling by trained health professionals should be available to those seeking clarification of the screening report.
  • The individuals screened should be informed of the possibility of false negatives and warned to seek medical evaluation of any signs or symptoms developing soon after the screening exercise.
  • A prearranged referral network should be in place to which those with positive results who are not able or do not wish to consult their personal physicians may be referred.
  • The costs of the necessary confirmatory examinations and the costs of treatment should be covered by health insurance or otherwise be affordable.
  • A prearranged follow-up system should be in place to be sure that positive reports have been promptly confirmed and proper interventions arranged.

 

A further final criterion is of fundamental importance: the screening exercise should be conducted by properly skilled and accredited health professionals using state-of-the-art equipment and interpretation and analysis of the results should be of the highest possible quality and accuracy.

In 1989 the US Preventive Services Task Force, a panel of 20 experts from medicine and other related fields drawing upon hundreds of “advisors” and others from the United States, Canada and the United Kingdom, assessed the effectiveness of some 169 preventive interventions. Its recommendations with respect to screening for cancer are summarized in table 1. Reflecting the Task Force’s somewhat conservative attitude and rigorously applied criteria, these recommendations may differ from those advanced by other groups.

Table 1. Screening for neoplastic diseases.

Types of cancer

Recommendations of the US Preventive Services Task Force*

Breast

All women over age 40 should receive an annual clinical breast examination. Mammography every one to two years is recommended for all women beginning at age 50 and continuing until age 75 unless pathology has been detected. It may be prudent to begin mammography at an earlier age for women at high risk for breast cancer. Although the teaching of breast self-examination is not specifically recommended at this time, there is insufficient evidence to recommend any change in current breast self- examination practices (i.e., those who are now teaching it should continue the practice).

Colorectal

There is insufficient evidence to recommend for or against fecal occult blood testing or sigmoidoscopy as effective screening tests for colorectal cancer in asymptomatic individuals. There are also insufficient grounds for discontinuing this form of screening where it is currently practiced or for withholding it from persons who request it. It may be clinically prudent to offer screening to persons aged 50 or older with known risk factors for colorectal cancer.

Cervical

Regular Papanicolaou (Pap) testing is recommended for all women who are or have been sexually active. Pap smears should begin with the onset of sexual activity and should be repeated every one to three years at the physician’s discretion. They may be discontinued at age 65 if previous smears have been consistently normal.

Prostate

There is insufficient evidence to recommend for or against routine digital rectal examination as an effective screening test for prostate cancer in asymptomatic men. Transrectal ultrasound and serum tumor markers are not recommended for routine screening in asymptomatic men.

Lung

Screening asymptomatic persons for lung cancer by performing routine chest radiography or sputum cytology is not recommended.

Skin

Routine screening for skin cancer is recommended for persons at high risk. Clinicians should advise all patients with increased outdoor exposure to use sunscreen preparations and other measures to protect from ultraviolet rays. Currently there is no evidence for or against advising patients to perform skin self-examination.

Testicular

Periodic screening for testicular cancer by testicular examination is recommended for men with a history of cryptorchidism, orchiopexy, or testicular atrophy. There is no evidence of clinical benefit or harm to recommend for or against routine screening of other men for testicular cancer. Currently there is insufficient evidence for or against counseling patients to perform periodic self-examination of the testicles.

Ovarian

Screening of asymptomatic women for ovarian cancer is not recommended. It is prudent to examine the adnexa when performing gynecologic examinations for other reasons.

Pancreatic

Routine screening for pancreatic cancer in asymptomatic persons is not recommended.

Oral

Routine screening of asymptomatic persons for oral cancer by primary care clinicians is not recommended. All patients should be counseled to receive regular dental examinations,  to discontinue the use of all forms of tobacco,  and to limit consumption of alcohol.

Source: Preventive Services Task Force 1989.

Screening for breast cancer

There is a general consensus among experts that screening with mammography combined with clinical breast examination every one to two years will save lives among women aged 50 to 69, reducing breast cancer deaths in this age group by up to 30%. Experts have not reached agreement, however, on the value of breast cancer screening with mammography for asymptomatic women aged 40 to 49. The NCI recommends that women in this age group should be screened every one to two years and that women at increased risk for breast cancer should seek medical advice about whether to begin screening before age 40.

The female population in most organizations may be too small to warrant the installation of mammography equipment onsite. Accordingly, most programs sponsored by employers or labor unions (or both) rely on contracts with providers who bring mobile units to the workplace or on providers in the community to whom participating female employees are referred either during working hours or on their own time. In making such arrangements, it is essential to be sure that the equipment meets standards for x-ray exposure and safety such as those promulgated by the American College of Radiology, and that the quality of the films and their interpretation is satisfactory. Further, it is imperative that a referral resource be prearranged for those women who will require a small needle aspiration or other confirmatory diagnostic procedures.

Screening for cervical cancer

Scientific evidence strongly suggests that regular screening with Pap tests will significantly decrease mortality from cervical cancer among women who are sexually active or who have reached the age of 18. Survival appears to be directly related to the stage of the disease at diagnosis. Early detection, using cervical cytology, is currently the only practical means of detecting cervical cancer in localized or premalignant stages. The risk of developing invasive cervical cancer is three to ten times greater in women who have never been screened than in those who have had Pap tests every two or three years.

Of particular relevance to the cost of workplace screening programs is the fact that cervical cytology smears can be obtained quite efficiently by properly trained nurses and do not require the involvement of a physician. Perhaps of even greater importance is the quality of the laboratory to which they are sent for interpretation.

Screening for colorectal cancer

It is generally agreed that early detection of precancerous colorectal polyps and cancers by periodic tests for fecal blood, as well as digital rectal and sigmoidoscopic examinations, and their timely removal, will reduce mortality from colorectal cancer among individuals aged 50 and over. The examination has been made less uncomfortable and more reliable with the replacement of the rigid sigmoidoscope by the longer, flexible fibreoptic instrument. There remains, however, some disagreement as to which tests should be relied upon and how often they should be applied.

Pros and cons of screening

There is general agreement about the value of cancer screening in individuals at risk because of family history, prior occurrence of cancer, or known exposure to potential carcinogens. But there appear to be justifiable concerns about the mass screening of healthy populations.

Advocates of mass screening for the detection of cancer are guided by the premise that early detection will be followed by improvements in morbidity and mortality. This has been demonstrated in some instances, but is not always the case. For example, although it is possible to detect lung cancer earlier by use of chest x rays and sputum cytology, this has not led to any improvement in treatment outcomes. Similarly, concern has been expressed that increasing the lead time for treatment of early prostatic cancers may not only be without benefit but may, in fact, be counterproductive in view of the longer period of well-being enjoyed by patients whose treatment is delayed.

In planning mass screening programs, consideration must also be given to the impact on the well-being and pocketbooks of patients with false positives. For example, in several series of cases, 3 to 8% of women with positive breast screenings had unnecessary biopsies for benign tumors; and in one experience with the fecal blood test for colorectal cancer, nearly one-third of those screened were referred for diagnostic colonoscopy, and most of them showed negative results.

It is clear that additional research is needed. To assess the efficacy of screening, the NCI has launched a major study, the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trials (PLCO) to evaluate early detection techniques for these four cancer sites. Enrolment for the PLCO began in November 1993, and will involve 148,000 men and women, aged 60 to 74 years, randomized to either the intervention or the control group. In the intervention group, men will be screened for lung, colorectal and prostatic cancer while women will be screened for lung, colorectal and ovarian cancer; those assigned to the control group will receive their usual medical care. For lung cancer, the value of an annual single-view chest x ray will be studied; for colorectal cancer, annual fibreoptic sigmoidoscopy will be performed; for prostate cancer, digital rectal examination and a blood test for PSA will be done; and for ovarian cancer, yearly physical and transvaginal ultrasound examinations will be supplemented by an annual blood test for the tumor marker known as CA-125. At the end of 16 years and the expenditure of US$ 87.8 million, it is hoped that solid data will be obtained about how screening may be used to obtain early diagnoses that may extend lives and reduce mortality.

Treatment and Continuing Care

Treatment and continuing care comprise efforts to enhance the quality of life for those in whom a cancer has taken hold and for those involved with them. Occupational health services and employee assistance programs sponsored by employers and unions can provide useful counsel and support to workers being treated for cancer or who have a dependant receiving treatment. This support can include explanations of what is going on and what to expect, information that is sometimes not provided by oncologists and surgeons; guidance in referrals for second opinions; and consultations and assistance with regard to access to centers of highly specialized care. Leaves of absence and modified work arrangements may make it possible for workers to remain productive while in treatment and to return to work earlier when a remission is achieved. In some workplaces, peer support groups have been formed to provide an exchange of experiences and mutual support for workers facing similar problems.

Conclusion

Programs for the prevention and detection of cancer can make a meaningful contribution to the well-being of the workers involved and their dependants and yield a significant return to the employers and labor unions that sponsor them. As with other preventive interventions, it is necessary that these programs be properly designed and carefully implemented and, since their benefits will accrue over many years, they should be continued on a steady basis.

 

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In 1990, the US Government demonstrated strong support for workplace health promotion programs with the publication of Healthy People 2000, setting forth the National Health Promotion and Disease Prevention Objectives for the Year 2000 (US Public Health Service 1991). One of these objectives calls for an increase in the percentage of worksites offering health promotion activities for their employees by the year 2000, “preferably as part of a comprehensive employee health promotion program” (Objective 8.6). Two objectives specifically include efforts to prohibit or severely restrict smoking at work by increasing the percentage of worksites with a formal smoking policy (Objective 3.11) and by enacting comprehensive state laws on clean indoor air (Objective 3.12).

In response to these objectives and employee interest, Merrill Lynch and Company, Inc. (hereafter called Merrill Lynch) launched the Wellness and You program for employees at headquarters locations in New York City and in the state of New Jersey. Merrill Lynch is a US-based, global financial management and advisory company, with a leadership position in businesses serving individuals as well as corporate and institutional clients. Merrill Lynch’s 42,000 employees in more than 30 countries provide services including securities underwriting, trading and brokering; investment banking; trading of foreign exchange, commodities and derivatives; banking and lending; and insurance sales and underwriting services. The employee population is diverse in terms of ethnicity, nationality, educational achievement and salary level. Nearly half of the employee population is headquartered in the New York City metropolitan area (includes part of New Jersey) and in two service centers in Florida and Colorado.

Merrill Lynch’s Wellness and You Program

The Wellness and You program is based in the Health Care Services Department and is managed by a doctorate-level health educator who reports to the medical director. The core wellness staff consists of the manager and a full-time assistant, and is supplemented by staff physicians, nurses and employee assistance counselors as well as outside consultants as needed.

In 1993, its initial year, over 9,000 employees representing approximately 25% of the workforce participated in a variety of Wellness and You activities, including the following:

  • self-help and written information programmes, including the distribution of pamphlets on a diversity of health topics and a Merrill Lynch personal health guide designed to encourage employees to get the tests, immunizations, and guidance they need to stay healthy
  • educational seminars and workshops on topics of broad interest such as smoking cessation, stress management, AIDS, and Lyme disease
  • comprehensive screening programmes to identify employees at risk for cardiovascular disease, skin cancer, and breast cancer. These programmes were provided by outside contractors on company premises either in health services clinics or mobile van units
  • ongoing programmes, including aerobic exercise in the company cafeteria and personal weight management classes in company conference rooms
  • clinical care, including influenza immunizations, dermatology services, periodic health examinations and nutritional counselling in the employee health services clinics.

 

In 1994, the program expanded to include an onsite gynecology screening program comprising of Pap smears and pelvic and breast examinations; and a worldwide emergency medical assistance program to help American employees locate an English-speaking doctor anywhere in the world. In 1995, wellness programs will be extended to service offices in Florida and Colorado and will reach approximately half of the entire workforce. Most services are offered to employees free of charge or at nominal cost.

Smoking Control Programs at Merrill Lynch

Anti-smoking programs have gained a prominent place in the workplace wellness arena in recent years. In 1964, the US Surgeon General identified smoking as the single cause of the greater part of preventable disease and premature death (US Department of Health, Education, and Welfare 1964). Since then, research has demonstrated that the health risk from inhaling tobacco smoke is not limited to the smoker, but includes those who inhale second-hand smoke (US Department of Health and Human Services 1991). Consequently, many employers are taking steps to limit or curtail smoking by employees out of concern for employee health as well as their own “bottom lines”. At Merrill Lynch, Wellness and You includes three types of smoking cessation effort: (1) the distribution of written material, (2) smoking cessation programs, and (3) restrictive smoking policies.

Written materials

The wellness program maintains a wide selection of quality educational materials to provide information, assistance and encouragement to employees to improve their health. Self-help materials such as pamphlets and audiotapes designed to educate employees about the harmful effects of smoking and about the benefits of quitting are available in the health care clinic waiting rooms and through interoffice mail by request.

Written materials also are distributed at health fairs. Often these health fairs are sponsored in conjunction with national health initiatives so as to capitalize on existing media attention. For example, on the third Thursday of each November, the American Cancer Society sponsors the Great American Smokeout. This national campaign, designed to encourage smokers to give up cigarettes for 24 hours, is well publicized throughout the United States by television, radio and newspapers. The idea is that if smokers can prove to themselves that they can quit for the day, they might quit for good. In 1993’s Smokeout, 20.5% of smokers in the United States (9.4 million) stopped smoking or reduced the number of cigarettes they smoked for the day; 8 million of them reported continuing not to smoke or reducing their smoking one to ten days later.

Each year, members of Merrill Lynch’s medical department set up quit-smoking booths on the day of the Great American Smokeout at home office locations. Booths are stationed in high-traffic locations (lobbies and cafeterias) and provide literature, “survival kits” (containing chewing gum, cinnamon sticks, and self-help materials), and quit-smoking pledge cards to encourage smokers to quit smoking at least for the day.

Smoking cessation programs

Since no single smoking cessation program works for everyone, employees at Merrill Lynch are offered a variety of options. These include self-help written materials (“quit kits”), group programs, audiotapes, individual counseling and physician intervention. Interventions range from education and classic behavior modification to hypnosis, nicotine replacement therapy (e.g., “the patch” and nicotine chewing gum), or a combination. Most of these services are available to employees free of charge and some programs, such as group interventions, have been subsidized by the firm’s benefits department.

Non-smoking policies

In addition to smoking cessation efforts aimed at individuals, smoking restrictions are becoming increasingly common in the workplace. Many jurisdictions in the United States, including the states of New York and New Jersey, have enacted strict workplace smoking laws that, for the most part, limit smoking to private offices. Smoking in common work areas and conference rooms is permitted, but only if each and every person present agrees to allow it. The statutes typically mandate that non-smokers’ preferences receive priority even to the point of banning smoking entirely. Figure 1 summarizes the city and state regulations applicable in New York City.

Figure 1. Summary of city and state restrictions on smoking in New York.

HPP260F1

In many offices, Merrill Lynch has implemented smoking policies which extend beyond the legal requirements. Most headquarters cafeterias in New York City and in New Jersey have gone smoke-free. In addition, total smoking bans have been implemented in some office buildings in New Jersey and Florida, and in certain work areas in New York City.

There seems to be little debate about the adverse health effects of tobacco exposure. However, other issues should be considered in developing a corporate smoking policy. Figure 2 outlines many of the reasons why a company may or may not elect to restrict smoking beyond the legal requirements.

Figure 2. Reasons for and against restricting smoking in the workplace.

HPP260F2

Evaluation of Smoking Cessation Programs and Policies

Given the relative youth of the Wellness and You program, no formal evaluation has yet been conducted to determine the effect of these efforts on employee morale or smoking habits. However, some studies suggest that worksite smoking restrictions are favored by a majority of employees (Stave and Jackson 1991), result in decreased cigarette consumption (Brigham et al. 1994; Baile et al. 1991; Woodruff et al. 1993), and effectively increase smoking cessation rates (Sorensen et al. 1991).

 

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Tuesday, 25 January 2011 14:28

Smoking Control in the Workplace

Introduction

Awareness of the adverse effects associated with cigarette smoking has increased since the 1960s when the first US Surgeon General’s report on this topic was released. Since that time, attitudes towards cigarette smoking have steadily grown towards the negative, with warning labels being required on cigarette packages and advertisements, bans on television advertising of cigarettes in some countries, the institution of non-smoking areas in some public places and the complete prohibition of smoking in others. Well-founded public health messages describing the dangers of tobacco products are increasingly widespread despite the tobacco industry’s attempts to deny that a problem exists. Many millions of dollars are spent each year by people trying to “kick the habit”. Books, tapes, group therapy, nicotine gum and skin patches, and even pocket computers have all been used with varying degrees of success in aiding those with nicotine addiction. Validation of the carcinogenic effects of passive, “second-hand” smoking has added impetus to the growing efforts to control the use of tobacco.

With this background, it is natural that smoking in the workplace should become a growing concern for employers and employees. On the most basic level, smoking represents a fire hazard. From a productivity standpoint, smoking represents either a distraction or an annoyance, depending on whether the employee is a smoker or a non-smoker. Smoking is a significant cause of morbidity in the workforce. It represents a drain in productivity in the form of the loss of work days due to illness, as well as a financial drain on an organization’s resources in terms of health-related costs. Furthermore, smoking has either an additive or multiplicative interaction with environmental hazards found in certain workplaces increasing significantly the risk of many occupational diseases (figure 1).

Figure 1. Examples of interactions between occupation and cigarette smoking causing disease.

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This article will concern itself with the rationale for smoking control in the workplace and suggest a practical attitude and approach to managing it, recognizing that mere exhortation is not enough. At the same time, the terrible, addictive nature of nicotine and the human difficulties associated with quitting will not be underestimated. One hopes that it represents a more realistic approach to this complicated problem than some of those taken in the past.

Smoking in the Workplace

Organizations are increasingly associating unhealthy habits such as smoking with higher operating costs, and employers are taking measures to reduce the excess costs associated with employees who smoke. People who smoke one or more packs of cigarettes a day account for 18% higher medical claim costs than non-smokers, according to a study of the impact of various lifestyle risks compiled by the Ceridian Corporation, a technology services company based in Minneapolis, Minnesota. Heavy smokers spend 25% more days as inpatients in hospitals and are 29% more likely than non-smokers to have annual health care claims costs that exceed US$5,000, the study shows (Lesmes 1993).

The impact of smoking on the health of the population and the health care system is unparalleled (US Department of Health and Human Services 1989). According to the World Health Association (1992), tobacco kills at least 3 million people each year worldwide: in countries where smoking has been a long-established behavior, it is responsible for about 90% of all lung cancer deaths; 30% of all cancers; over 80% of cases of chronic bronchitis and emphysema; and some 20 to 25% of coronary heart disease and stroke deaths. Numerous other adverse health conditions, including respiratory diseases, peptic ulcers and pregnancy complications, are also attributable to smoking. Smoking remains the leading cause of avoidable death in many countries, so pervasive that it is responsible for about one sixth of deaths from all causes in the United States, for example (Davis 1987).

The combined effect of smoking and occupational hazards has been demonstrated by the significant differences in morbidity of smokers and non-smokers in many occupations. The interaction of the two types of hazards increases the risk of many diseases, particularly the chronic obstructive pulmonary diseases, lung cancer, cardiovascular diseases, as well as disabilities (figure 1).

Well-recognized complications resulting from exposure to tobacco-related hazards are outlined in great detail throughout the technical literature. Recent attention has focused on the following:

  • Female risks. Changes in oestrogen metabolism, menstrual disorders, early menopause, delayed conception or infertility, cancer of the cervix.
  • Maternal and pregnancy risks. Spontaneous abortion, ectopic pregnancy, placental irregularities, placenta praevia, abruptio placentae, vaginal bleeding, foetal mortality, preterm birth, retardation of foetal development, low birth weight, congenital anomalies and chronic hypoxia.
  • Childhood complications. Increased neonatal mortality, sudden infant death syndrome (SIDS), impaired physical and intellectual development.

 

Environmental Tobacco Smoke (ETS)

Tobacco smoking is not only dangerous to the smoker but to non-smokers as well. ETS (“passive smoking” and “second-hand smoke”) is a unique risk for people, such as office workers, working in a closed environment. In developed countries, the World Health Organization (1992) points out, tobacco smoke is the most common pollutant of indoor air and is usually present at higher concentrations than other air pollutants. Besides the acute effects of eye and throat irritation, ETS increases the risk of lung cancer and possibly of cardiovascular disease. It is particularly troublesome to individuals with pre-existing health conditions, such as asthma, bronchitis, cardiovascular disease, allergies and upper respiratory infections, and also is a vexatious challenge to those who have recently given up smoking and are struggling to maintain their abstinence.

The US National Institute for Occupational Safety and Health, NIOSH, concluded that (1991):

  • ETS is a potential carcinogen.
  • Exposure to ETS should be reduced to the lowest possible concentration.
  • Employers should minimize occupational exposure to ETS by using all available control measures.
  • Worker exposure to ETS is most efficiently and completely controlled by simply eliminating tobacco smoke from the workplace.
  • Employers should prohibit smoking at the workplace and provide sufficient disincentives for those who do not comply.

 

Except where legislation has mandated the smoke-free workplace, the protection of non-smoking employees from the health risks associated with exposure to ETS remains a formidable challenge for many public and private sector employees. Smokers, with encouragement from the tobacco industry, have maintained that continuation of smoking is inherently an individual right, despite the fact that eliminating tobacco smoke from the workplace has required innovations in ventilation engineering and expense by the employer. Legal precedents have established a clear duty for employers to provide workplaces free from hazards such as ETS and courts of law in some countries have found employers liable for the adverse health effects of ETS exposure on the job.

Surveys of public knowledge and attitudes about the risks of ETS and the desirability of workplace smoking restrictions show widespread concern about this sort of exposure and increasingly strong support for significant restrictions among both non-smokers and smokers (American Lung Association 1992). Governments have adopted an increasing number of ordinances and regulations limiting smoking in public and private workplaces (Corporate Health Policies Group 1993).

Impact of Smoking on Employers’ Costs

Historically, employers’ efforts to reduce smoking in the workplace have been driven by issues of cost and productivity losses related to smoking behavior. A number of studies have compared employers’ costs associated with smoking and non-smoking employees. For example, in one study of employees in a large-scale group health insurance plan, tobacco users had higher average outpatient medical care costs ($122 versus $75), higher average insured medical costs ($1,145 versus $762), more hospital admissions per 1,000 employees (174 versus 76), more hospital days per 1,000 employees (800 versus 381), and longer average lengths of hospital stay (6.47 versus 5.03 days) (Penner and Penner 1990).

Another study, undertaken over a period of three and one-half years by the Dow Chemical Company and covering 1,400 employees (Fishbeck 1979), showed that smokers were absent 5.5 days more per year than non-smokers, costing Dow over $650,000 annually in excess wages alone. This figure did not include extra health care costs. In addition, smokers had 17.4 disability days per year compared with 9.7 days for non-smokers. Smokers also had twice the frequency of circulatory disease problems, three times more pneumonia, 41% more bronchitis and emphysema, and 76% more respiratory diseases of all types. For every two non-smokers who died during the study period, seven smokers died.

A study by the United States Steel Corporation found that employees who smoke have more work-loss days than those who have never smoked. It also showed that in every age group, as the number of cigarettes smoked per day by confirmed smokers increased, so did the number of absences due to illness. Additionally, male smokers of more than two packs per day had nearly twice as much absence as their non-smoking counterparts. In a study on how much individual behavioral risk factors contribute to the total disability and health care costs of a large, multi-location industrial company, smokers had 32% greater absenteeism and $960 excess average annual illness costs per employee (Bertera 1991).

The annual report of the Kansas State Employees Health Care Commission found that smokers incurred 33% more hospital admissions than non-smokers (106.5 versus 71.06 hospital admissions per 1,000 persons). The total average claim payment per employee was $282.62 more for smokers than for non-smokers.

Results like these have prompted some US employers to add a “surcharge” to their smoking employees’ share of group health insurance premiums to cover the higher claims payments associated with this population. The Resinoid Engineering Corporation stopped hiring smokers in its Ohio plant because their health care claims were $6,000 higher per employee per year for smokers than for non-smokers; a similar move by a Chicago, Illinois company was barred because the state law prohibits discriminatory hiring on the basis of lifestyle.

Other employers, using the “carrot” rather than the “stick” approach, have offered inducements such as monetary or other types of awards to employees who successfully quit smoking. A popular approach is to refund the tuition required for participating in a smoking cessation program to those who complete the course or, more strictly, to those who remain abstinent for a defined period following the completion of the course.

In addition to increased health care costs and costs associated with lost productivity due to sickness among smokers, there are other increased costs associated with smoking, namely those arising from lost productivity during smoking breaks, higher fire and life insurance costs, and higher general cleaning costs related to smoking. For example, Air Canada identified savings of about US$700,000 per year by not having to clean ashtrays and being able to extend the frequency of deep cleaning of its planes from six to nine months after implementing its tobacco-free policy (WHO 1992). A study by Kristein (1983) designed to take into account all of the increased costs due to smoking estimated the total to be $1,300 per smoker per year (adjusted to 1993 dollars). He also discussed other areas of excess cost, including, in particular, the costs of higher levels of maintenance for computers and other sensitive equipment, and for installing and maintaining ventilation systems. Furthermore, he added that other costs result from the “inefficiency and errors based on the established literature as to the effects of higher carbon monoxide levels in smokers, eye irritation, measured lower attentiveness, cognitive and exercise capacity function”.

Smoking Policies and Regulations

In the 1980s, laws and voluntary policies to restrict smoking at the workplace increased in number and strength. Some pertain only to government worksites which, together with places of work where children are present, have often taken the lead. Others affect both government and private worksites. They are characterized by banning smoking altogether (“smoke-free” worksites); restricting smoking in common areas such as cafeterias and meeting rooms; allowing smoking only in special smoking areas; and requiring accommodation of the interests of smokers and non-smokers, with primacy given to the wishes of the latter.

Some programs regulate smoking in worksites where certain hazardous materials are present. For example, in 1976 Norway issued rules prohibiting the assignment of persons who smoke to areas where they may be exposed to asbestos. In 1988, Spain prohibited smoking in any place where the combination of smoking and occupational hazards results in greater risk to the health of workers. Spain also prohibits smoking in any worksite where pregnant women work. Other countries that have taken legislative measures to restrict smoking in the workplace include Costa Rica, Cuba, Denmark, Iceland and Israel (WHO 1992).

Increasingly, legislation restricting smoking at the worksite is part of a broader regulation covering public places. New Zealand, Norway and Sweden have enacted such legislation while Belgium, the Netherlands and Ireland have passed laws prohibiting smoking in most public places. The 1991 French law prohibits smoking in all places designed for collective use, notably schools and public transportation (WHO 1992).

In the United States and Canada, although federal agencies have adopted smoking control policies, legislation has been limited to states and provinces and to municipalities. By 1989, 45 US states had enacted laws restricting smoking in public places, while 19 states and the District of Columbia had adopted ordinances restricting smoking in private workplaces (Bureau of National Affairs 1989). The state of California has a bill pending that would totally ban smoking in all indoor employment areas and would also obligate an employer to take reasonable steps to prevent visitors from smoking (Maskin, Connelly and Noonan 1993). For some time, the Occupational Safety and Health Administration (OSHA) in the US Department of Labor has been considering the regulation of ETS in the workplace both as an independent toxicant and as a component of indoor air (Corporate Health Policies Group 1993).

Another incentive for employers to reduce smoking in the workplace comes from cases of disability stemming from exposure to ETS that have won worker’s compensation awards. In 1982, a federal appellate court found an employee eligible for disability retirement because she had been forced to work in a smoke-filled environment (Parodi vs. Veterans Administration 1982). Similarly, employees have been awarded worker’s compensation payments because of adverse reactions to tobacco smoke on the job. Indeed, William Reilly, the former administrator of the US Environmental Protection Agency (EPA) has expressed the hope that the threat of employer liability raised by the recent release of the EPA’s designation of EST as a significant health hazard would obviate the necessity of additional federal government regulations (Noah 1993).

Another factor favoring the establishment of policies curbing workplace smoking is the change in public attitudes reflecting (1) recognition of the mounting scientific evidence of the risks of cigarette smoke to smokers and non-smokers alike, (2) a decline in the prevalence of smoking, (3) a decline in the social acceptability of smoking and (4) a heightened awareness of the rights of non-smokers. The American Lung Association (1992) reported consistent increases in the overall percentage of adults who favor workplace smoking restrictions, from 81% in 1983 to 94% in 1992, while in the same period, those favoring a total ban increased from 17% to 30% and those favoring no restrictions fell from 15% to 5%.

Labor unions are also increasingly supportive of non-smoking policies (Corporate Health Policies Group 1993).

Recent US surveys have shown a marked trend towards not only increased adoption of smoking restrictions but also their increasing stringency (Bureau of National Affairs 1986, 1991). The percentage of companies with such policies rose from 36% in 1986 to 85% in 1991 while, in the same period, there was a sixteen-fold increase in the percentage with total bans or “smoke-free” policies (Bureau of National Affairs 1991; Coalition on Smoking and Health 1992).

Smoking Cessation Programs

Worksites are becoming increasingly common settings for health education and promotion efforts. Of several cited studies (Coalition on Smoking and Health 1992), one survey indicates that 35.6% of companies offer some kind of smoking cessation assistance. Another study shows that non-smoking policies may also provide environmental support to individuals attempting to quit smoking. Thus, a non-smoking policy may also be considered an important element in a smoking cessation program.

Smoking cessation methods are divided into two categories:

  • Unassisted methods, which include going “cold turkey” (i.e., just stopping without recourse to any special techniques); gradually reducing the number of cigarettes smoked per day; using low-tar or low-nicotine cigarettes; quitting with friends, relatives or acquaintances; using special cigarette filters or holders; using other nonprescription products; or substituting another tobacco product for cigarettes (snuff, chewing tobacco, pipes or cigars).
  • Assisted methods, which include attending a programme or a course with or without a fee; consulting a mental health professional; hypnosis; acupuncture; and using nicotine gum or nicotine skin patches.

 

The efficacy of these various methods is the subject of much controversy largely due to the difficulties and costs associated with long-term follow-up and the obvious self-interest of the vendors of programs and products. Another serious limitation relates to the ability to verify the smoking status of program participants (Elixhauser 1990). Saliva tests measuring cotinine, a metabolite of nicotine, are an effective objective indicator of whether an individual has recently been smoking, but they are moderately complicated and expensive and, thus. not widely used. Accordingly, one is forced to depend on the questionable reliability of the individual’s self-reports of success in either quitting or cutting down on the amount smoked. These problems make it extremely difficult to compare various methods to one another or even to make proper use of a control group.

Despite these encumbrances, two general conclusions can be drawn. First, those individuals most successful in permanently quitting do so largely on their own, often after numerous attempts to do so. Secondly, barring the individual “cold turkey” approach, multiple interventions in combination appear to enhance the effectiveness of efforts to quit, especially when accompanied by support in maintaining abstinence and reinforcement of the quit-smoking message (Bureau of National Affairs 1991). The importance of the latter is confirmed by a study (Sorenson, Lando and Pechacek 1993) which found that the highest overall cessation rate was achieved by smokers who worked among a high proportion of non-smokers and who were frequently asked not to smoke. Still, the six-month quitting rate was only 12%, compared to a rate of 9% among the control group. Obviously, cessation programs in general must not be expected to produce dramatic positive results but, instead, must be viewed as requiring a persistent, patient effort towards the goal of quitting smoking.

Some workplace smoking cessation programs have been overly simple or naive in their approach, while others have lacked long-term determination and commitment. Companies have tried everything from simply restricting smoking to specified areas of the worksite or autocratically making a sudden announcement banning all smoking, to providing expensive and intensive (but often short-lived) programs offered by outside consultants. The problem and the challenge is to successfully accomplish the transition to a smoke-free workplace without sacrificing worker morale or productivity.

The following section will present an approach that incorporates our present knowledge of the difficulties individuals face in quitting and the employer attitude necessary to best achieve the goal of non-smoking in the workplace.

An Alternative Approach to Achievinga Smoke-free Workplace

Past experience has shown that simply offering smoking cessation programs to volunteers does not advance the goal of a smoke-free workplace because the majority of smokers will not participate in them. At any given time, only about 20% of smokers are ready to quit and only a minority of this group will sign up for a cessation program. For the other 80% of smokers who don’t want to quit or who don’t believe they can quit when the enterprise goes smoke-free, instituting a ban on smoking in the workplace will just tend to cause them to move their smoking during working hours “out the door” to a designated smoking area or somewhere outside the building. This “80% problem”—the problem that 80% of the smokers are not going to be helped or even consider participating in the program if only smoking cessation programs are offered—has numerous consequent negative effects on employee relations, productivity, operating costs and health-related costs.

An alternative, and successful, approach has been developed by Addiction Management Systems, an organization based in Toronto, Canada. This approach is based on the knowledge that change and the modification of behavior is a process which can be planned and managed using organizational and behavioral techniques. It involves dealing with control of smoking in the workplace in the same way as any other major policy or procedural change for the company, with informed decisions made by management after input from representative employee groups. A controlled change is made by supporting those managers responsible for overseeing the change and making all smokers positive participants in the change by providing them with the “tools” to accommodate to the new non-smoking environment without requiring them to quit smoking. The focus is on communications and team-building by involving and educating all of those affected by the policy change.

The actual process of the transition to a smoke-free workplace begins with the announcement of the policy change and the start of a transition period of several months’ duration before the policy goes into effect. In behavioral terms, the upcoming policy change to becoming smoke-free acts as a “stimulus to change” and creates a new environment in which it is in the interest of all smokers to seek a means of successfully adapting to the new environment.

The announcement of this policy change is followed by a communication program aimed at all employees, but focused on two important groups: the supervisors who must implement and oversee the new non-smoking policy, and the smokers who need to learn to adapt to the new environment. An important part of the communication program is making smokers aware that, while they will not be required to quit smoking unless they so choose, they must nonetheless adhere to the new policy forbidding smoking in the workplace during the workday. All employees receive the communications about the policy and upcoming changes.

During the transition period, supervisors are provided with communications materials and a training program to enable them to understand the policy change and to anticipate questions, problems or other concerns which may come up during or after the change. As the group most directly affected when the policy goes into effect, smokers are consulted about their specific needs and also receive their own training program. The special focus of the latter is to acquaint them with a voluntary self-help “smoking control” program that contains a number of options and choices which allow the smokers to understand the program and to learn to modify their smoking behavior in order to refrain from smoking during the workday as required once the new policy goes into effect. This allows each smoker to personalize his or her own program, with “success” defined by the individual, whether it be quitting altogether or just learning how not to smoke during the workday. Accordingly, resentment is neutralized and the change to the smoke-free workplace becomes a positive motivating factor for the smoker.

The end result of this approach is that when the effective date of the policy arrives, the transition to a smoke-free workplace becomes a “non-event”—it simply happens, and it is successful. The reason this occurs is that the groundwork has been laid, the communications have been carried out, and all of those persons involved understand what needs to happen and have the means to make a successful transition.

What is important from an organizational standpoint is that the change is one which tends to be self-maintaining, with only minimal ongoing input from management. Also important is the effect that once successful in learning to “manage” their smoking problem, the smokers in the “80% group” tend to build on their success and to progress towards quitting completely. Finally, in addition to the beneficial effect on the well-being and morale of employees who are positively involved in the transition to a smoke-free environment, the organization accrues over time benefits in terms of higher productivity and reduced costs related to health care.

Evaluation of Effectiveness

In evaluating the effectiveness of the program, there are two separate criteria that must be considered. The first is whether the workplace truly becomes a smoke-free environment. Success with respect to this goal is relatively easy to measure: it is based on regular supervisors’ reports on violations of the policy within their work areas; monitoring complaints from other employees; and the results of unannounced spot checks of the workplace to reveal the presence or absence of cigarette butts, ashes and smoke-laden air.

The second measure of success, and more difficult to determine, is the number of employees who actually quit smoking and maintain their smoke-free status. While perhaps the most practical position to take is to be concerned only with worksite smoking, such a limited success will bring about fewer long-term benefits, especially with respect to decreasing illness and health care costs. While periodic mandatory saliva tests for cotinine to identify those who continue to smoke would be the best and most objective method for evaluating long-term program success, this is not only complicated and expensive but also is fraught with numerous legal and ethical questions regarding employee privacy. A compromise is the use of annual or semi-annual anonymous questionnaires that ask how individuals’ smoking habits have changed and how long abstinence from smoking has been maintained and that, at the same time, probe changes in employees’ attitudes toward the policy and the program. Such questionnaires have the added advantage of being a means of reinforcing the non-smoking message and of keeping the door open for those still smoking to reconsider dropping the habit.

A final long-term outcome evaluation involves monitoring employee absenteeism, illnesses and health care costs. Any changes would at first be subtle, but over a number of years they should be cumulatively significant. Death benefits paid prior to normal retirement age could be another long-term reflection of the success of the program. Of course, it is important to adjust such data for such factors as changes in the work force, employee characteristics such as age and sex, and other factors affecting the organization. Analysis of these data is manifestly subject to the rules of statistics and would probably be valid only in organizations with a large and stable workforce and adequate data collection, storage and analysis capabilities.

Smoking Control Worldwide

There is a growing worldwide unwillingness to continue to bear the burdens of cigarette smoking and nicotine addiction in terms of their effects on human well-being and productivity, on health and health care costs, and on the economic health of work organizations and nations. This is exemplified by the expanding participation in World No-Tobacco Day that has been spearheaded by the World Health Organization in May of each year since 1987 (WHO 1992).

The aim of this event is not only to ask people to stop smoking for one day but also to trigger interest in controlling smoking among public and private organizations and to promote pressure for the passage of laws, by-laws or regulations advancing the cause of tobacco-free societies. It is also hoped that the relevant agencies will be stimulated to initiate research on specific themes, publish information or initiate action. To this end, each World No-Tobacco Day is assigned a specific theme (table 1); of particular interest to readers of this article is the 1992 Day which addressed “Tobacco-free workplaces: safer and healthier”.


Table 1. Themes of "World No-Tobacco Days"

1992    Tobacco Free Workplaces: safer and healthier

1993    Health Services: our window to a tobacco-free world

1994    The Media and Tobacco: getting the health message across

1995    The Economics of Tobacco: tobacco costs more than you think

1996    Sports and the Arts

1997    United Nations and Specialized Agencies against Tobacco


A problem beginning to be recognized is the increase in cigarette smoking in developing countries where, prompted by the marketing blandishments of the tobacco industry, populations are being encouraged to view smoking as a hallmark of social advancement and sophistication.

Conclusion

The adverse effects of cigarette smoking on individuals and societies are increasingly being recognized and understood (except by the tobacco industry). Nevertheless, smoking continues to enjoy social acceptability and widespread use. A special problem is that many young people become addicted to nicotine years before they are old enough to work.

The workplace is an exceptionally useful arena for combating this health hazard. Workplace policies and programs can have a strong positive influence over the behavior of employees who smoke, abetted by peer pressure from non-smoking coworkers. The wise organization will not only appreciate that control of workplace smoking is something that serves its own self-interest in terms of legal liabilities, absenteeism, production and health-related costs, but will also recognize that it can be a matter of life and death for its employees.

 

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Contents

Preface
Part I. The Body
Part II. Health Care
Part III. Management & Policy
Part IV. Tools and Approaches
Part V. Psychosocial and Organizational Factors
Part VI. General Hazards
Part VII. The Environment
Part VIII. Accidents and Safety Management
Part IX. Chemicals
Part X. Industries Based on Biological Resources
Part XI. Industries Based on Natural Resources
Part XII. Chemical Industries
Part XIII. Manufacturing Industries
Part XIV. Textile and Apparel Industries
Part XV. Transport Industries
Part XVI. Construction
Part XVII. Services and Trade
Part XVIII. Guides