The printing, commercial photography and reproduction industries are important worldwide in terms of their economic significance. The printing industry is very diverse in technologies and in size of enterprises. However, regardless of size as measured by production volume, the different printing technologies described in this chapter are the most common. In terms of production volume, there are a limited number of large-scale operations, but many small ones. From the economic perspective, the printing industry is one of the largest industries and generates annual revenues of at least US$500 billion worldwide. Similarly, the commercial photography industry is diverse, with a limited number of large-volume and many small-volume operations. Photofinishing volume is about equally divided between the large and small-volume operations. The commercial photographic market generates annual revenues of approximately US$60 billion worldwide, with photofinishing operations comprising approximately 40% of this total. The reproduction industry, which consists of smaller-volume operations with combined annual revenues of about US$27 billion, generates close to 2 trillion copies annually. In addition, reproduction and duplication services on an even smaller scale are provided onsite at most organizations and companies.

Health, environmental and safety issues in these industries are evolving in response to substitutions with potentially less hazardous materials, new industrial hygiene control strategies, and the advent of new technologies, such as the introduction of digital technologies, electronic imaging and computers. Many historically important health and safety issues (e.g., solvents in the printing industry or formaldehyde as a stabilizer in photoprocessing solutions) will not be issues in the future due to material substitution or other risk management strategies. Nevertheless, new health, environmental and safety issues will arise that will have to be addressed by health and safety professionals. This suggests the continued importance of health and environmental monitoring as part of an effective risk management strategy in the printing, commercial photography and reproduction industries.

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We thank the Edmonton Fire-fighters’ Union for their interest and generous support of the development of this chapter. The “Edmonton Sun” and the “Edmonton Journal” graciously allowed their news photographs to be used in the articles on firefighting. Ms. Beverly Cann of the Manitoba Federation of Labour Occupational Health Centre contributed invaluable advice on the article on paramedical personnel and ambulance attendants.

Fire-brigade personnel may be engaged on a full-time, part-time, paid-on-call or unpaid, volunteer basis—or on a combination of these systems. The type of organization employed will, in most cases, depend on the size of the community, the value of the property to be protected, the types of fire risk and the number of calls typically answered. Cities of any appreciable size require regular fire brigades with full crews on duty equipped with the appropriate apparatus.

Smaller communities, residential districts and rural areas having few fire calls usually depend upon volunteer or paid-on-call fire-fighters for either full staffing of their firefighting apparatus or to assist a skeleton force of full-time regulars.

Although there are a great many efficient, well equipped volunteer fire departments, full-time, paid fire departments are essential in larger communities. A call or volunteer organization does not lend itself as readily to the continuous fire-prevention inspection work that is an essential activity of modern fire departments. Using volunteer and call systems, frequent alarms may call out workers who hold other jobs, causing a loss of time with seldom any direct benefit to employers. Where full-time fire-fighters are not employed, the volunteers must come to a central fire hall before response can be made to a call, causing a delay. Where there are only a few regulars, a supplementary group of well-trained call or volunteer fire-fighters should be provided. There should be a reserve arrangement that make assistance available for the response of neighbouring departments on a mutual-aid basis.

Firefighting is a highly unusual occupation, in that it is perceived of as dirty and dangerous but is indispensable and even prestigious. Fire-fighters enjoy public admiration for the essential work that they do. They are well aware of the hazards. Their work involves intermittent periods of exposure to extreme physical and psychological stress on the job. Fire-fighters are also exposed to serious chemical and physical hazards, to a degree unusual in the modern workforce.

Hazards

Occupational hazards experienced by fire-fighters may be categorized as physical (mostly unsafe conditions, thermal stress and ergonomic stress), chemical and psychological. The level of exposure to hazards that may be experienced by a fire-fighter in a given fire depends on what is burning, the combustion characteristics of the fire, the structure that is on fire, the presence of non-fuel chemicals, the measures taken to control the fire, the presence of victims that require rescue and the position or line of duty held by the fire-fighter while fighting the fire. The hazards and levels of exposure experienced by the first fire-fighter to enter a burning building are also different from those of the fire-fighters who enter later or who clean up after the flames are extinguished. There is usually rotation among the active firefighting jobs in each team or platoon, and a regular transfer of personnel between fire halls. Fire-fighters may also have special rank and duties. Captains accompany and direct the crews but are still actively involved in fighting the fire on site. Fire chiefs are the heads of the fire service and are called out only in the worst fires. Individual fire-fighters may still experience unusual exposures in particular incidents, of course.

Physical hazards

There are many physical dangers in firefighting that can lead to serious physical injury. Walls, ceilings and floors can collapse abruptly, trapping fire-fighters. Flashovers are explosive eruptions of flame in a confined space that occur as a result of the sudden ignition of flammable gas products driven out of burning or hot materials and combined with superheated air. Fire situations that lead to flashovers may engulf the fire-fighter or cut off escape routes. The extent and number of injuries can be minimized by intensive training, job experience, competency and good physical fitness. However, the nature of the job is such that fire-fighters may be placed in dangerous situations by miscalculation, circumstance or during rescues.

Some fire departments have compiled computerized databases on structures, materials and potential hazards likely to be encountered in the district. Quick access to these databases assists the crew in responding to known hazards and anticipating possibly dangerous situations.

Thermal hazards

Heat stress during firefighting may come from hot air, radiant heat, contact with hot surfaces or endogenous heat that is produced by the body during exercise but which cannot be cooled during the fire. Heat stress is compounded in firefighting by the insulating properties of the protective clothing and by physical exertion, which result in heat production within the body. Heat may result in local injury in the form of burns or generalized heat stress, with the risk of dehydration, heat stroke and cardiovascular collapse.

Hot air by itself is not usually a great hazard to the fire-fighter. Dry air does not have much capacity to retain heat. Steam or hot, wet air can cause serious burns because much more heat energy can be stored in water vapour than in dry air. Fortunately, steam burns are not common.

Radiant heat is often intense in a fire situation. Burns may occur from radiant heat alone. Fire-fighters may also show skin changes characteristic of prolonged exposure to heat.

Chemical hazards

Over 50% of fire-related fatalities are the result of exposure to smoke rather than burns. One of the major contributing factors to mortality and morbidity in fires is hypoxia because of oxygen depletion in the affected atmosphere, leading to loss of physical performance, confusion and inability to escape. The constituents of smoke, singly and in combination, are also toxic. Figure 1 shows a fire-fighter using self-contained breathing apparatus (SCBA) rescuing an unprotected fire-fighter who was trapped in a very smoky fire in a tire warehouse. (The fire-fighter being rescued ran out of air, took off his SCBA to breathe as best he could, and was fortunate enough to be rescued before it was too late.)

Figure 1.  Fire-fighter rescuing another fire-fighter who was trapped in the toxic smoke from a fire in a tire warehouse.

All smoke, including that from simple wood fires, is hazardous and potentially lethal with concentrated inhalation. Smoke is a variable combination of compounds. The toxicity of smoke depends primarily on the fuel, the heat of the fire and whether or how much oxygen is available for combustion. Fire-fighters on the scene of a fire are frequently exposed to carbon monoxide, hydrogen cyanide, nitrogen dioxide, sulphur dioxide, hydrogen chloride, aldehydes and organic compounds such as benzene. Different gas combinations present different degrees of hazard. Only carbon monoxide and hydrogen cyanide are commonly produced in lethal concentrations in building fires.

Carbon monoxide is the most common, characteristic and serious acute hazard of firefighting. Carboxyhaemoglobin accumulates rapidly in the blood with duration of exposure, as a result of the affinity of carbon monoxide for haemoglobin. High levels of carboxyhaemoglobin may result, particularly when heavy exertion increases minute ventilation and therefore delivery to the lung during unprotected firefighting. There is no apparent correlation between the intensity of smoke and the amount of carbon monoxide in the air. Fire-fighters should particularly avoid cigarette smoking during the clean-up phase, when burning material is smouldering and therefore burning incompletely, as this adds to the already elevated levels of carbon monoxide in the blood. Hydrogen cyanide is formed from the lower temperature combustion of nitrogen-rich materials, including natural fibres such as wool and silk, as well as common synthetics such as polyurethane and polyacrylonitrile.

Light-molecular-weight hydrocarbons, aldehydes (such as formaldehyde) and organic acids may be formed when hydrocarbon fuels burn at lower temperatures. The oxides of nitrogen are also formed in quantity when temperatures are high, as a consequence of the oxidation of atmospheric nitrogen, and in lower temperature fires where the fuel contains significant nitrogen. When the fuel contains chlorine, hydrogen chloride is formed. Polymeric plastic materials pose particular hazards. These synthetic materials were introduced into building construction and furnishings in the 1950s and thereafter. They combust into particularly hazardous products. Acrolein, formaldehyde and volatile fatty acids are common in smouldering fires of several polymers, including polyethylene and natural cellulose. Cyanide levels increase with temperature when polyurethane or polyacrylonitriles are burned; acrylonitrile, acetonitrile pyridine and benzonitrile occur in quantity above 800 but below 1,000 °C. Polyvinyl chloride has been proposed as a desirable polymer for furnishings because of its self-extinguishing characteristics due to the high chlorine content. Unfortunately, the material produces large quantities of hydrochloric acid and, sometimes, dioxins when fires are prolonged.

Synthetic materials are most dangerous during smouldering conditions, not in conditions of high heat. Concrete retains heat very efficiently and may act as a “sponge” for trapped gases that are then released from the porous material, releasing hydrogen chloride or other toxic fumes long after a fire has been extinguished.

Psychological hazards

A fire-fighter enters a situation that others are fleeing, walking into immediate personal danger greater than in almost any other civilian occupation. There is much that can go wrong in any fire, and the course of a serious fire is often unpredictable. Besides personal security, the fire-fighter must be concerned with the safety of others threatened by the fire. Rescuing victims is an especially stressful activity.

The professional life of a fire-fighter is more than an endless round of anxious waiting punctuated by stressful crises, however. Fire-fighters enjoy the many positive aspects of their work. Few occupations are so respected by the community. Job security is largely assured in urban fire departments once a fire-fighter is hired, and the pay usually compares well with other jobs. Fire-fighters also enjoy a strong sense of team membership and group bonding. These positive aspects of the job offset the stressful aspects and tend to protect the fire-fighter against the emotional consequences of repeated stress.

At the sound of an alarm, a fire-fighter experiences a degree of immediate anxiety because of the inherent unpredictability of the situation he or she is about to encounter. The psychological stress experienced at this moment is as great and perhaps greater than any of the stresses that follow during the course of responding to an alarm. Physiological and biochemical indicators of stress have shown that fire-fighters on duty have sustained psychological stress that reflects subjectively perceived patterns of psychological stress and activity levels at the station.

Health Risks

The acute hazards of firefighting include trauma, thermal injury and smoke inhalation. The chronic health effects that follow recurrent exposure have not been so clear until recently. This uncertainty has led to a patchwork of employment and workers’ compensation board policies. The occupational risks of fire-fighters have received a great deal of attention because of their known exposure to toxic agents. A large body of literature has developed on the mortality experience of fire-fighters. This literature has grown with the addition of several substantial studies in recent years, and a sufficient database is now available to describe certain patterns in the literature.

The critical compensation issue is whether a general presumption of risk can be made for all fire-fighters. This means that one must decide whether all fire-fighters can be assumed to have an elevated risk of a particular disease or injury because of their occupation. To satisfy the usual compensation standard of proof that the occupational cause must be more likely than not responsible for the outcome (giving the benefit of the doubt to the claimant), a general presumption of risk requires a demonstration that the risk associated with occupation must be at least as great as the risk in the general population. This can be demonstrated if the usual measure of risk in epidemiological studies is at least double the expected risk, making allowances for uncertainty in the estimate. Arguments against presumption in the specific, individual case under consideration are called “rebuttal criteria”, because they can be used to question, or rebut, the application of the presumption in an individual case.

There are a number of unusual epidemiological characteristics that influence the interpretation of studies of fire-fighters and their occupational mortality and morbidity. Fire-fighters do not show a strong “healthy worker effect” in most cohort mortality studies. This may suggest an excess mortality from some causes compared to the rest of the healthy, fit workforce. There are two types of healthy worker effect that may conceal excess mortality. One healthy worker effect operates at the time of hire, when new workers are screened for firefighting duty. Because of the strenuous fitness requirements for duty, this effect is very strong and might be expected to have an effect of reducing mortality from cardiovascular disease, especially in the early years following hire, when few deaths would be expected anyway. The second healthy worker effect occurs when workers become unfit following employment due to obvious or subclinical illness and are reassigned to other duties or are lost to follow-up. Their relative high contribution to total risk is lost by undercount. The magnitude of this effect is not known but there is a strong evidence that this effect occurs among fire-fighters. This effect would not be apparent for cancer because, unlike cardiovascular disease, the risk of cancer has little to do with fitness at the time of hire.

Lung Cancer

Lung cancer has been the most difficult cancer site to evaluate in epidemiological studies of fire-fighters. A major issue is whether the large-scale introduction of synthetic polymers into building materials and furnishings after about 1950 increased the risk of cancer among fire-fighters because of exposure to the combustion products. Despite the obvious exposure to carcinogens inhaled in smoke, it has been difficult to document an excess in mortality from lung cancer big enough and consistent enough to be compatible with occupational exposure.

There is evidence that work as a fire-fighter contributes to risk of lung cancer. This is seen mostly among fire-fighters who had the highest exposure and who worked the longest time. The added risk may be superimposed on a greater risk from smoking.

Evidence for an association between firefighting and lung cancer suggests that the association is weak and does not attain the attributable risk required to conclude that a given association is “more likely than not” due to occupation. Certain cases with unusual characteristics may warrant this conclusion, such as cancer in a relatively young non-smoking fire-fighter.

Cancer at Other Sites

Other cancer sites have been shown recently to be more consistently associated with firefighting than lung cancer.

The evidence is strong for an association with genito-urinary cancers, including kidney, ureter and bladder. Except for bladder, these are rather uncommon cancers, and the risk among fire-fighters appears to be high, close to or in excess of a doubled relative risk. One could therefore consider any such cancer to be work-related in a fire-fighter unless there is a convincing reason to suspect otherwise. Among the reasons one might doubt (or rebut) the conclusion in an individual case would be heavy cigarette smoking, prior exposure to occupational carcinogens, schistosomiasis (a parasitic infection—this applies to bladder only), analgesic abuse, cancer chemotherapy and urologic conditions that result in stasis and prolonged residence time of urine in the urinary tract. These are all logical rebuttal criteria.

Cancer of the brain and central nervous system has shown highly variable findings in the extant literature, but this is not surprising since the numbers of cases in all reports are relatively small. It is unlikely that this association will be clarified any time soon. It is therefore reasonable to accept a presumption of risk for fire-fighters on the basis of current evidence.

The increased relative risks for lymphatic and haematopoietic cancers appear to be unusually high. However, the small numbers of these relatively rare cancers make it difficult to evaluate the significance of the association in these studies. Because they are individually rare, epidemiologists group them together in order to make statistical generalizations. The interpretation is even more difficult because grouping these very different cancers together makes little sense medically.

Heart Disease

There is no conclusive evidence for an increased risk of death overall from heart disease. Although a single large study has shown an excess of 11%, and a smaller study confined to ischemic heart disease suggested a significant excess of 52%, most studies cannot conclude that there is a consistently increased population risk. Even if the higher estimates are correct, the relative risk estimates still fall far short of what would be required to make a presumption of risk in the individual case.

There is some evidence, primarily from clinical studies, to suggest a risk of sudden cardiac decompensation and risk of a heart attack with sudden maximal exertion and following exposure to carbon monoxide. This does not seem to translate into an excess risk of fatal heart attacks later in life, but if a fire-fighter did have a heart attack during or within a day after a fire it would be reasonable to call it work-related. Each case must therefore be interpreted with a knowledge of individual characteristics, but the evidence does not suggest a generally elevated risk for all fire-fighters.

Aortic Aneurysm

Few studies have accumulated sufficient deaths among fire-fighters from this cause to achieve statistical significance. Although one study conducted in Toronto in 1993 suggests an association with work as a fire-fighter, it should be considered an unproven hypothesis at present. Should it be ultimately confirmed, the magnitude of risk suggests that it would merit acceptance on a schedule of occupational diseases. Rebuttal criteria would logically include severe atherosclerosis, connective tissue disease and associated vasculitis and a history of thoracic trauma.

Lung Disease

Unusual exposures, such as intense exposure to the fumes of burning plastics, can certainly cause severe lung toxicity and even permanent disability. Ordinary firefighting may be associated with short-term changes similar to asthma, resolving over days. This does not appear to result in an increased lifetime risk of dying from chronic lung disease unless there has been an unusually intense exposure (the risk of dying from the consequences of smoke inhalation) or smoke with unusual characteristics (particularly involving burning polyvinyl chloride (PVC)).

Chronic obstructive pulmonary disease has been extensively studied among fire-fighters. The evidence does not support an association with firefighting, and therefore there can be no presumption. An exception may be in rare cases when a chronic lung disease follows an unusual or severe acute exposure and there is a compatible history of medical complications.

A general presumption of risk is not easily or defensibly justified in situations of weak associations or when diseases are common in the general population. A more productive approach may be to take the claims on a case-by-case basis, examining individual risk factors and overall risk profile. A general presumption of risk is more easily applied to unusual disorders with high relative risks, particularly when they are unique to or characteristic of certain occupations. Table 1 presents a summary of specific recommendations, with criteria that could be used to rebut, or question, presumption in the individual case.

Table 1. Summary of recommendations, with rebuttal criteria and special considerations, for compensation decisions.

A = epidemiological association but not sufficient for presumption of association with firefighting. NA = no consistent epidemiological evidence for association. NE = Not established. P = presumption of association with firefighting; risk exceeds doubling over general population. NP = no presumption; risk does not exceed doubling over general population. + = suggests increased risk due to firefighting. - = suggests increased risk due to exposures unrelated to firefighting. / = no likely contribution to risk.

Injuries

Injuries associated with firefighting are predictable: burns, falls and being struck by falling objects. Mortality from these causes is markedly increased among fire-fighters compared to other workers. Jobs in firefighting have a high risk of burns, especially, include those involving early entry and close-in firefighting, such as holding the nozzle. Burns are also more commonly associated with basement fires, recent injury before the incident and training outside the fire department of present employment. Falls tend to be associated with SCBA use and assignment to truck companies.

Ergonomics

Firefighting is a very strenuous occupation and is often performed under extreme environmental conditions. The demands of firefighting are sporadic and unpredictable, characterized by long periods of waiting between bouts of intense activity.

Fire-fighters maintain their level of exertion at a relatively constant, intense level once active firefighting begins. Any additional burden in the form of an encumbrance by protective equipment or victim rescue, however necessary for protection, reduces performance because fire-fighters are already exerting themselves to the maximum. The use of personal protection equipment has imposed new physiological demands on fire-fighters but has removed others by reducing exposure levels.

A great deal is known about the exertion characteristics of fire-fighters as a result of many careful studies on the ergonomics of firefighting. Fire-fighters adjust their levels of exertion in a characteristic pattern during simulated fire conditions, as reflected by heart rate. Initially, their heart rate increases rapidly to 70 to 80% of maximal within the first minute. As firefighting progresses, they maintain their heart rates at 85 to 100% maximal.

The energy requirements for firefighting are complicated by the severe conditions encountered in many inside fires. The metabolic demands of coping with retained body heat, heat from the fire and fluid loss through sweating add to the demands of physical exertion.

The most demanding activity known is building search and victim rescue by the “lead hand” (first fire-fighter to enter building), resulting in the highest average heart rate of 153 beats/minute and highest rise in rectal temperature of 1.3 °C. Serving as “secondary help” (entering a building at a later time to fight the fire or to conduct additional searches and rescues) is next most demanding, followed by exterior firefighting and serving as crew captain (directing the firefighting, usually at some distance from the fire). Other demanding tasks, in decreasing order of energy costs, are climbing ladders, dragging the fire hose, carrying a travelling ladder and raising a ladder.

During firefighting, core body temperature and heart rate follow a cycle over a period of minutes: they both increase slightly in response to work in preparation for entry, then both increase more as a result of environmental heat exposure and subsequently increase more steeply as a result of high work loads under conditions of heat stress. After 20 to 25 minutes, the usual length of time allowed for interior work by the SCBA used by fire-fighters, the physiological stress remains within limits tolerable by a healthy individual. However, in extended firefighting involving multiple re-entries, there is insufficient time between SCBA air bottle changes to cool off, leading to a cumulative rise in core temperature and an increasing risk of heat stress.

Personal Protection

Fire-fighters exert themselves to maximal levels while fighting fires. Under fire conditions, physical demands are complicated by the metabolic demands of coping with heat and loss of fluids. The combined effect of internally generated heat during work and of external heat from the fire may result in markedly increased body temperatures that climb to unusually high levels in an intense firefighting situation. Half-hour interval breaks to change SCBAs are not enough to arrest this climb in temperature, which can reach dangerous levels in prolonged firefighting. Although essential, personal protection, particularly SCBAs, imposes a considerable additional energy burden on the fire-fighter. The protective clothing also becomes much heavier when it gets wet.

The SCBA is an effective personal protection device that prevents exposure to the products of combustion when used properly. Unfortunately, it is often used only during the “knockdown” phase, when the fire is being actively fought, and not during the “overhaul” phase, when the fire is over but the debris is being examined and embers and smouldering flames are being extinguished.

Fire-fighters tend to judge the level of hazard they face by the intensity of smoke and decide whether to use an SCBA solely on the basis of what they see. This may be very misleading, after the flames are extinguished. While the fire scene may appear to be safe at this stage, it can still be dangerous.

The additional burden or energy cost of using personal protective equipment has been a major area of emphasis in occupational health research on firefighting. This undoubtedly reflects the degree to which firefighting is an extreme case of a matter of general interest, the implications for performance of using personal protection.

Although fire-fighters are obliged to use several forms of personal protection in their work, it is respiratory protection that is most problematic and which has received the most attention. A 20% decrement has been found in work performance imposed by carrying an SCBA, which is a substantial restraint under extreme and dangerous conditions. Investigations have identified several factors of importance in evaluating the physiological demands imposed by respirators in particular, among them the characteristics of the respirator, physiological characteristics of the user and the interactive effects with other personal protection and with environmental conditions.

The fire-fighter’s typical “turnout” gear may weigh 23 kg and imposes a high energy cost. Chemical protective clothing (17 kg), as used for clean-up of spills, is the next most demanding gear to wear, followed by the use of SCBA gear while wearing light clothing, which is only slightly more demanding than wearing light, flame-resistant clothing with a low-resistance mask. The firefighting apparatus has been associated with significantly greater retention of internally generated heat and rise in body temperature.

Fitness

Numerous studies have evaluated the physiological characteristics of fire-fighters, usually in the context of other studies to determine the response to firefighting-related demands.

Studies of the fitness of fire-fighters have shown fairly consistently that most fire-fighters are as or somewhat more fit than the general adult male population. They are not, however, necessarily fit to an athletically trained level. Fitness and health maintenance programmes have been developed for fire-fighters but have not been convincingly evaluated for their effectiveness.

The entrance of female applicants into firefighting has caused a re-evaluation of performance tests and studies comparing the sexes. In studies of trained individuals capable of achieving their potential maximum performance, rather than typical applicants, women demonstrated lower scores on average than men in all performance items, but a subgroup of women performed nearly as well in some tasks. The overall difference in performance was attributed primarily to lower absolute lean body weight, which correlated most strongly and consistently with performance differences. The most difficult tests for women were the stair-climbing exercises.

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In 1993, the worldwide production of electricity was 12.3 trillion kilowatt hours (United Nations 1995). (A kilowatt hour is the amount of electricity needed to light ten 100-watt bulbs for 1 hour.) One can judge the magnitude of this endeavour by considering data from the United States, which alone produced 25% of the total energy. The US electric utility industry, a mix of public and privately owned entities, generated 3.1 trillion kilowatt hours in 1993, using more than 10,000 generating units (US Department of Energy 1995). The portion of this industry that is owned by private investors employs 430,000 people in electric operations and maintenance, with revenues of US$200 billion annually.

Electricity is generated in plants which utilize fossil fuel (petroleum, natural gas or coal) or use nuclear energy or hydropower. In 1990, for example, 75% of France’s electrical power came from nuclear power stations. In 1993, 62% of the electricity generated worldwide came from fossil fuels, 19% from hydropower, and 18% from nuclear power. Other reusable sources of energy such as wind, solar, geothermal or biomass account for only a small proportion of world electric production. From generating stations, electricity is then transmitted over interconnected networks or grids to local distribution systems and on through to the consumer.

The workforce that makes all of this possible tends to be primarily male and to possess a high degree of technical skill and knowledge of “the system”. The tasks that these workers undertake are quite diverse, having elements in common with the construction, manufacturing, materials handling, transportation and communications industries. The next few articles describe some of these operations in detail. The articles on electric maintenance standards and environmental concerns also highlight major US government regulatory initiatives that affect the electric utility industry.

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The amount of waste produced by human society is increasing. Commercial and domestic solid waste is a great practical problem for many local governments. Industrial wastes are usually much smaller in volume but are more likely to contain hazardous materials, such as toxic chemicals, flammable liquids and asbestos. Although the total amount is less, the disposal of hazardous industrial waste has been a greater concern than of domestic waste because of the perceived hazard to health and the risk of environmental contamination.

The generation of hazardous waste has become a major problem worldwide. The root cause of the problem is industrial production and distribution. Land pollution occurs when hazardous wastes contaminate soil and groundwater due to inadequate or irresponsible disposal measures. Abandoned or neglected waste disposal sites are a particularly difficult and expensive problem for society. Sometimes, hazardous waste is disposed of illegally and in an even more dangerous manner because the owner cannot find a cheap way to get rid of it. One of the major unresolved issues in managing hazardous waste is to find methods of disposal that are both safe and inexpensive. Public concern over hazardous waste focuses on the potential health effects of exposure to toxic chemicals, and particularly the risk of cancer.

The Basel Convention passed in 1989 is an international agreement to control the transboundary movement of hazardous waste and to prevent dangerous wastes from being shipped for disposal to countries that do not have the facilities to process them safely. The Basel Convention requires that the generation of hazardous wastes and transboundary movement of the wastes be kept to a minimum. Traffic in hazardous wastes is subject to the informed permission and laws of the receiving country. Transboundary movement of hazardous wastes is subject to good environmental practices and assurance that the receiving country is able to handle them safely. All other traffic in hazardous wastes is considered illegal and therefore criminal in intent, subject to national laws and penalties. This international convention provides an essential framework for controlling the problem at an international level.

Hazardous Properties of Chemicals

Hazardous substances are compounds and mixtures that pose a threat to health and property because of their toxicity, flammability, explosive potential, radiation or other dangerous properties. Public attention tends to focus on carcinogens, industrial wastes, pesticides and radiation hazards. However, innumerable compounds that do not fall into these categories can pose a threat to the public’s safety and health.

Hazardous chemicals may present physical hazards, although this is more common in transportation and industrial incidents. Hydrocarbons may catch fire and even explode. Fires and explosions may generate their own toxic hazards depending on the chemicals that were initially present. Fires involving pesticide storage areas are a particularly dangerous situation, as the pesticides may be converted into even more highly toxic combustion products (such as paraoxons in the case of organophosphates) and substantial amounts of environmentally damaging dioxins and furans may be generated from combustion in the presence of chlorine compounds.

Toxicity, however, is the principal concern of most people with respect to hazardous waste. Chemicals may be toxic to human beings and they may also be damaging to the environment through toxicity to animal and plant species. Those that do not readily degrade in the environment (a characteristic called biopersistence) or that accumulate in the environment (a characteristic called bioaccumulation) are of particular concern.

The number and hazardous nature of toxic substances in common use has changed dramatically. In the last generation, research and development in organic chemistry and chemical engineering have introduced thousands of new compounds into widespread commercial use, including persistent compounds such as the polychlorinated biphenyls (PCBs), more potent pesticides, accelerators and plasticizers with unusual and poorly understood effects. The production of chemicals has risen dramatically. In 1941 production of all synthetic organic compounds in the United States alone, for example, was less than one billion kilograms. Today it is much greater than 80 billion kilograms. Many compounds in common use today underwent little testing and are not well understood.

Toxic chemicals are also much more intrusive in daily life than in the past. Many chemical plants or disposal sites which were once isolated or on the edge of town have become incorporated into urban areas by suburban growth. Communities now lie in closer proximity to the problem than they have in the past. Some communities are built directly over old disposal sites. Although incidents involving hazardous substances take many forms and may be highly individual, the great majority seem to involve a relatively narrow range of hazardous substances, which include: solvents, paints and coatings, metal solutions, polychlorinated biphenyls (PCBs), pesticides, and acids and alkalis. In studies conducted in the United States, the ten most common hazardous substances found in disposal sites requiring government intervention were lead, arsenic, mercury, vinyl chloride, benzene, cadmium, PCBs, chloroform, benzo(a)pyrene and trichloroethylene. However, chromium, tetrachloroethylene, toluene and di-2-ethylhexylphthalate were also prominent among those substances that could be shown to migrate or for which there was an opportunity for human exposure. The origin of these chemical wastes varies greatly and depends on the local situation, but typically elecroplating solutions, discarded chemicals, manufacturing by-products and waste solvents contribute to the waste stream.

Groundwater Contamination

Figure 1 presents a cross-section of a hypothetical hazardous waste site to illustrate problems that may be encountered. (In practice, such a site should never be placed near a body of water or over a gravel bed.) In well-designed hazardous waste disposal (containment) facilities, there is an effectively impermeable seal to prevent hazardous chemicals from migrating out of the site and into the underlying soil. Such a site also has facilities to treat those chemicals that can be neutralized or transformed and to reduce the volume of waste that goes into the site; those chemicals that cannot be so treated are contained in impermeable containers. (Permeability, however, is relative, as described below.)

Figure 1. Cross-section of a hypothetical hazardous waste site

Chemicals may escape by leaking if the container is compromised, leaching if water gets in or spilling during handling or after the site is disturbed. Once they permeate the liner of a site, or if the liner is broken or if there is no liner, they enter the ground and migrate downward due to gravity. This migration is much more rapid through porous soil and is slow through clay and bedrock. Even underground, water flows downhill and will take the path of least resistance, and so the groundwater level will fall slightly in the direction of flow and the flow will be much faster through sand or gravel. If there is a water table under the ground, the chemicals will eventually reach it. Lighter chemicals tend to float on the groundwater and form an upper layer. Heavier chemicals and water-soluble compounds tend to dissolve or be carried along by the groundwater as it flows slowly underground through porous rock or gravel. The region of contamination, called the plume, can be mapped by drilling test wells, or bore holes. The plume slowly expands and moves in the direction of groundwater movement.

Surface water contamination may occur by runoff from the site, if the top layer of soil is contaminated, or by groundwater. When the groundwater feeds into a local body of water, such as a river or lake, the contamination is carried into this body of water. Some chemicals tend to deposit in the bottom sediment and others are carried along by the flow.

Groundwater contamination may take centuries to clear by itself. If shallow wells are used as a water source by local residents, there is a possibility of exposure by ingestion and by skin contact.

Human Health Concerns

People come into contact with toxic substances in many ways. Exposure to a toxic substance may occur at several points in the use cycle of the substance. People work in a plant where the substances arise as waste from an industrial process and do not change clothes or wash before coming home. They may reside near hazardous waste disposal sites which are illegal or poorly designed or managed, with opportunities for exposure as a result of accidents or careless handling or lack of containment of the substance, or lack of fencing to keep children off the site. Exposure may occur in the home as the result of consumer products that are mislabelled, poorly stored and not child-proof.

Three routes of exposure are by far the most important in considering the implications for toxicity of hazardous waste: inhalation, ingestion and absorption through the skin. Once absorbed, and depending on the route of exposure, there are many ways in which people can be affected by toxic chemicals. Obviously, the list of possible toxic effects associated with hazardous waste is very long. However, public concern and scientific studies have tended to concentrate on the risk of cancer and reproductive effects. In general, this has reflected the profile of chemical hazards at these sites.

There have been many studies of residents who live around or near such sites. With a few exceptions, these studies have shown remarkably little in the way of verifiable, clinically significant health problems. The exceptions have tended to be situations where the contamination is exceptionally severe and there has been a clear pathway of exposure of residents immediately adjacent to the site or who drink well water drawing on groundwater contaminated by the site. There are several likely reasons for this surprising absence of documentable health effects. One is that unlike air pollution and surface water pollution, the chemicals in land pollution are not easily available to people. People may live in areas highly contaminated by chemicals, but unless they actually come in contact with the chemicals by one of the routes of exposure mentioned above, no toxicity will result. Another reason may be that the chronic effects of exposure to these toxic chemicals take a long time to develop and are very difficult to study. Yet another reason may be that these chemicals are less potent in causing chronic health effects in humans than is usually supposed.

Notwithstanding the human health effects, the damage of land pollution to ecosystems may be very great. Plant and animal species, soil bacteria (which contribute to agricultural productivity) and other ecosystem constituents may be irreversibly damaged by degrees of pollution that are not associated with any visible human health effect.

Control of the Problem

Because of population distributions, land use restrictions, transportation costs and concern from society over environmental effects, there is intense pressure to find a solution to the problem of economical disposal of hazardous waste. This has led to increased interest in methods such as source reduction, recycling, chemical neutralization and secure hazardous waste disposal (containment) sites. The first two reduce the amount of waste that is produced. Chemical neutralization reduces the toxicity of the waste and may convert it into a more easily handled solid. Whenever possible, it is preferred that this be done at the site of production of the waste to reduce the amount of waste that must be moved. Well-designed hazardous waste disposal facilities, using the best available technologies of chemical processing and containment, are needed for the residual waste.

Secure hazardous waste containment sites are relatively expensive to build. The site needs to be selected carefully to ensure that pollution of surface water and major aquifers (groundwater) will not readily occur. The site must be designed and built with impermeable barriers to prevent contamination of soil and groundwater. These barriers are typically heavy plastic liners and layers of tamped clay fill under the holding areas. In reality, the barrier acts to delay breakthrough and to slow the permeation that eventually does occur to an acceptable rate, one that will not result in accumulation or significant pollution of groundwater. Permeability is a property of the material, described in terms of the resistance of the material to a liquid or gas penetrating it under given conditions of pressure and temperature. Even the least permeable barrier, such as plastic liners or packed clay, will eventually allow the passage of some liquid chemical through the barrier, although it may take years and even centuries, and once breakthrough occurs the flow becomes continuous, although it may occur at a very low rate. This means that groundwater immediately below a hazardous waste disposal site is always at some risk of contamination, even if it is very small. Once groundwater is contaminated, it is very difficult and often impossible to decontaminate.

Many hazardous waste disposal sites are regularly monitored with collection systems and by testing nearby wells to ensure that pollution is not spreading. The more advanced are built with recycling and processing facilities on-site or nearby to further reduce the waste that goes into the disposal site.

Hazardous waste containment sites are not a perfect solution to the problem of land pollution. They require expensive expertise to design, are expensive to build, and may require monitoring, which creates an ongoing cost. They do not guarantee that groundwater contamination will not occur in the future, although they are effective in minimizing this. A major disadvantage is that someone, inevitably, must live near one. Communities where hazardous waste sites are located or proposed to be located usually oppose them strongly and make it difficult for governments to grant approval. This is called the “not in my back yard” (NIMBY) syndrome and is a common response to the siting of facilities considered undesirable. In the case of hazardous waste sites, the NIMBY syndrome tends to be especially strong.

Unfortunately, without hazardous waste containment sites, society may lose control of the situation entirely. When no hazardous waste site is available, or when it is too expensive to use one, hazardous waste is often disposed of illegally. Such practices include pouring liquid waste on the ground in remote areas, dumping the waste into drains that go into local waterways and shipping the waste to jurisdictions that have more lax laws governing the handling of hazardous waste. This may create an even more dangerous situation than a poorly managed disposal site would create.

There are several technologies that can be used to dispose of the remaining waste. High-temperature incineration is one of the cleanest and most effective means of disposing of hazardous waste, but the cost of these facilities is very high. One of the more promising approaches has been to incinerate liquid toxic waste in cement kilns, which operate at the necessary high temperatures and are found throughout the developing as well as the developed world. Injection into deep wells, below the water table, is one option for chemicals that cannot be disposed of in any other way. However, groundwater migration can be tricky and sometimes unusual pressure situations underground or leaks in the well lead to groundwater contamination anyway. Dehalogenation is a chemical technology that strips the chlorine and bromine atoms from halogenated hydrocarbons, such as PCBs, so that they can be easily disposed of by incineration.

A major unresolved issue in municipal solid waste handling is contamination by hazardous waste discarded by accident or intent. This can be minimized by diverting disposal into a separate waste stream. Most municipal solid waste systems divert chemical and other hazardous wastes so that they do not contaminate the solid waste stream. The separate waste stream should, ideally, be diverted to a secure hazardous waste disposal site.

There is a pressing need for facilities to collect and properly dispose of small quantities of hazardous waste, at minimal cost. Individuals who find themselves in possession of a bottle or can of solvents, pesticides or some unknown powder or fluid usually cannot afford the high cost of proper disposal and do not understand the risk. Some system for collecting such hazardous waste from consumers is needed before it is poured on the ground, flushed down the toilet or burned and released into the air. A number of municipalities sponsor “toxic roundup” days, when residents bring small quantities of toxic materials to a central location for safe disposal. Decentralized systems have been introduced in some urban areas, involving home or local pick-up of small quantities of toxic substances to be discarded. In the United States, experience has shown that people are willing to drive up to five miles to dispose of household toxic wastes safely. Consumer education to promote awareness of the potential toxicity of common products is urgently needed. Pesticides in aerosol cans, bleaches, household cleaners and cleaning fluids are potentially dangerous, especially to children.

Abandoned Hazardous Waste Disposal Sites

Abandoned or insecure hazardous waste sites are a common problem worldwide. Hazardous waste sites that need to be cleaned up are great liabilities to society. The ability of countries and local jurisdictions to clean up major hazardous waste sites varies greatly. Ideally, the owner of the site or the person who created the site should pay for its clean-up. In practice, such sites have often changed hands and the past owners have often gone out of business, the current owners may not have the financial resources to clean up, and the clean-up effort tends to be delayed for very long periods by expensive technical studies followed by legal battles. Smaller and less affluent countries have little leverage in negotiating clean-ups with the current site owners or the responsible parties, and no substantial resources to clean up the site.

The traditional approaches to cleaning up hazardous waste sites are very slow and expensive. It requires highly specialized expertise that is often in short supply. A hazardous waste site is first evaluated to determine how serious the land pollution is and whether the groundwater is contaminated. The likelihood of residents coming into contact with hazardous substances is determined and, in some cases, an estimate of the risk to health that this poses is calculated. Acceptable clean-up levels must be decided upon, the extent to which exposure must ultimately be reduced to protect human health and the environment. Most governments make decisions about clean-up levels by applying various applicable environmental laws, air pollution standards, drinking water standards, and based on a hazards assessment of health risks posed by the particular site. Clean-up levels are therefore set to reflect both health and environmental concerns. A decision must be made on how the site is to be remediated, or how best to achieve this reduction in exposure. Remediation is a technical problem of achieving these clean-up levels by engineering and other methods. Some of the techniques that are used include incineration, solidification, chemical treatment, evaporation, repeated flushing of soil, biodegradation, containment, removal of soil off-site and pumping out groundwater. These engineering options are too complex and specific to the circumstances to describe in detail. Solutions must fit the particular situation and the funds available to achieve control. In some cases, remediation is not feasible. A decision then has to be made on what land use will be permitted on the site.

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Industrial pollution is a more complicated problem in developing countries than in developed economies. There are greater structural obstacles to preventing and cleaning up pollution. These obstacles are largely economic, because developing countries do not have the resources to control pollution to the extent that developed countries can. On the other hand, the effects of pollution may be very costly to a developing society, in terms of health, waste, environmental degradation, reduced quality of life and clean-up costs in the future. An extreme example is concern for the future of children exposed to lead in some megacities in countries where leaded gasoline is still used, or in the vicinity of smelters. Some of these children have been found to have blood lead levels high enough to impair intelligence and cognition.

Industry in developing countries usually operates short of capital compared to industry in developed countries, and those investment funds that are available are first put into the equipment and resources necessary for production. Capital that is applied toward control of pollution is considered “unproductive” by economists because such investment does not lead to increased production and financial return. However, the reality is more complicated. Investment in control of pollution may not bring an obvious direct return on investment to the company or industry, but that does not mean that there is no return on investment. In many cases, as in an oil refinery, control of pollution also reduces the amount of wastage and increases the efficiency of the operation so that the company does benefit directly. Where public opinion carries weight and it is to the advantage of a company to maintain good public relations, industry may make an effort to control pollution in its own interest. Unfortunately, the social structure in many developing countries does not favour this because the people most negatively affected by pollution tend to be those who are impoverished and marginalized in society.

Pollution may damage the environment and society as a whole, but these are “externalized dis-economies” that do not substantially hurt the company itself, at least not economically. Instead, the costs of pollution tend to be carried by society as a whole, and the company is spared the costs. This is particularly true in situations where the industry is critical to the local economy or national priorities, and there is a high tolerance for the damage it causes. One solution would be to “internalize” the external dis-economies by incorporating the costs of clean-up or the estimated costs of environmental damage into the operating costs of the company as a tax. This would give the company a financial incentive to control its costs by reducing its pollution. Virtually no government in any developing country is in a position to do this and to enforce the tax, however.

In practice, capital is rarely available to invest in equipment to control pollution unless there is pressure from government regulation. However, governments are rarely motivated to regulate industry unless there are compelling reasons to do so, and pressure from their citizens. In most developed countries, people are reasonably secure in their health and their lives, and expect a higher quality of life, which they associate with a cleaner environment. Because there is more economic security, these citizens are more willing to accept an apparent economic sacrifice in order to achieve a cleaner environment. However, in order to be competitive in world markets, many developing countries are very reluctant to impose regulation on their industries. Instead, they hope that industrial growth today will lead to a society rich enough tomorrow to clean up the pollution. Unfortunately, the cost of clean-up increases as fast as, or faster than, the costs associated with industrial development. At an early stage of industrial development, a developing country would in theory have very low costs associated with the prevention of pollution, but hardly ever do such countries have the capital resources they need to do so. Later, when such a country does have the resources, the costs are often staggeringly high and the damage has already been done.

Industry in developing countries tends to be less efficient than in developed countries. This lack of efficiency is a chronic problem in developing economies, reflecting untrained human resources, the cost of importing equipment and technology, and the inevitable wastage that occurs when some parts of the economy are more developed than others.

This inefficiency is also based in part on the need to rely on outdated technologies which are freely available, do not require an expensive licence or that do not cost as much to use. These technologies are often more polluting than the state-of-the-art technologies available to industry in developed countries. An example is the refrigeration industry, where the use of chlorofluorocarbons (CFCs) as refrigerant chemicals is much cheaper than the alternatives, despite the serious effects of these chemicals in depleting ozone from the upper atmosphere and thereby reducing the earth’s shield from ultraviolet radiation; some countries had been very reluctant to agree to prohibit the use of CFCs because it would then be economically impossible for them to manufacture and purchase refrigerators. Technology transfer is the obvious solution, but companies in developed countries who developed or hold the licence for such technologies are understandably reluctant to share them. They are reluctant because they spent their own resources developing the technology, wish to retain the advantage they have in their own markets by controlling such technology, and may make their money from using or selling the technology only during the limited term of the patent.

Another problem faced by developing countries is lack of expertise in and awareness of the effects of pollution, monitoring methods and the technology of pollution control. There are relatively few experts in the field in developing countries, in part because there are fewer jobs and a smaller market for their services even though the need may actually be greater. Because the market for pollution control equipment and services may be small, this expertise and technology may have to be imported, adding to the costs. General recognition of the problem by managers and supervisors in industry may be lacking or very low. Even when an engineer, manager or supervisor in industry realizes that an operation is polluting, it may be difficult to persuade others in the company, their bosses or the owners that there is a problem that must be solved.

Industry in most developing countries competes at the low end of international markets, meaning that it produces products that are competitive on the basis of price and not quality or special features. Few developing countries specialize in making very fine grades of steel for surgical instruments and sophisticated machinery, for example. They manufacture lesser grades of steel for construction and manufacturing because the market is much larger, the technical expertise required to produce it is less, and they can compete on the basis of price as long as the quality is good enough to be acceptable. Pollution control reduces the price advantage by increasing the apparent costs of production without increasing output or sales. The central problem in developing countries is how to balance this economic reality against the need to protect their citizens, the integrity of their environment, and their future, realizing that after development the costs will be even higher and the damage may be permanent.

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