Banner 10


64. Agriculture and Natural Resources Based Industries

Chapter Editor: Melvin L. Myers

Table of Contents

Tables and Figures

General Profile
Melvin L. Myers

     Case Study: Family Farms
     Ted Scharf, David E. Baker and Joyce Salg

Farming  Systems

Melvin L. Myers and I.T. Cabrera

Migrant and Seasonal Farmworkers
Marc B. Schenker

Urban Agriculture
Melvin L. Myers

Greenhouse and Nursery Operations
Mark M. Methner and John A. Miles

Samuel H. Henao

Farmworker Education about Pesticides: A Case Study
Merri Weinger

Planting and Growing Operations
Yuri Kundiev and V.I. Chernyuk

Harvesting Operations
William E. Field

Storing and Transportation Operations
Thomas L. Bean

Manual Operations in Farming
Pranab Kumar Nag

Dennis Murphy

     Case Study: Agricultural Machinery
     L. W. Knapp, Jr.

Food  and Fibre Crops

Malinee Wongphanich

Agricultural Grains and Oilseeds
Charles Schwab

Sugar Cane Cultivation and Processing
R.A. Munoz, E.A. Suchman, J.M. Baztarrica and Carol J. Lehtola

Potato Harvesting
Steven Johnson

Vegetables and Melons
B.H. Xu and Toshio Matsushita   

Tree,  Bramble and Vine Crops

Berries and Grapes
William E. Steinke

Orchard Crops
Melvin L. Myers

Tropical Tree and Palm Crops
Melvin L. Myers

Bark and Sap Production
Melvin L. Myers

Bamboo and Cane
Melvin L. Myers and Y.C. Ko

Specialty  Crops

Tobacco Cultivation
Gerald F. Peedin

Ginseng, Mint and Other Herbs
Larry J. Chapman

L.J.L.D. Van Griensven

Aquatic Plants
Melvin L. Myers and J.W.G. Lund

Beverage Crops

Coffee Cultivation
Jorge da Rocha Gomes and Bernardo Bedrikow

Tea Cultivation
L.V.R. Fernando

Thomas Karsky and William B. Symons

Health  and Environmental Issues

Health Problems and Disease Patterns in Agriculture
Melvin L. Myers

     Case Study: Agromedicine
     Stanley H. Schuman and Jere A. Brittain

Environmental and Public Health Issues in Agriculture
Melvin L. Myers


Click a link below to view table in article context.

1. Sources of nutrients
2. Ten steps for a plantation work risk survey
3. Farming systems in urban areas
4. Safety advice for lawn & garden equipment
5. Categorization of farm activities
6. Common tractor hazards & how they occur
7. Common machinery hazards & where they occur
8. Safety precautions
9. Tropical & subtropical trees, fruits & palms
10. Palm products
11. Bark & sap products & uses
12. Respiratory hazards
13. Dermatological hazards
14. Toxic & neoplastic hazards
15. Injury hazards
16. Lost time injuries, United States, 1993
17. Mechanical & thermal stress hazards
18. Behavioural hazards
19. Comparison of two agromedicine programmes
20. Genetically engineered crops
21. Illicit drug cultivation, 1987, 1991 & 1995


Point to a thumbnail to see figure caption, click to see the figure in the article context.

AGR010F2AGR010F3AGR030F2AGR030F3AGR280F1AGR280F2AGR290F3AGR290F1AGR290F4AGR290F2AGR070F1AGR070F4AGR070F6AGR100F1AGR100F2AGR100F3AGR100F4AGR100F5AGR100F6AGR100F7AGR100F8AGR100F9AG100F10AGR110F1AGR070F5AGR130F8AGR200F1AGR180F3AGR180F2AGR180F5AGR180F4AGR180F6AGR180F7AGR180F8AGR180F9AGR370T1   AGR380F2AGR380F1AGR410F1

Click to return to top of page

Thursday, 10 March 2011 14:02

General Profile


Twelve millennia ago, humankind moved into the Neolithic era and discovered that food, feed and fibre could be produced from the cultivation of plants. This discovery has led to the food and fibre supply that feeds and clothes more than 5 billion people today.

This general profile of the agricultural industry includes its evolution and structure, economic importance of different crop commodities and characteristics of the industry and workforce. Agricultural workforce systems involve three types of major activities:

  1. manual operations
  2. mechanization
  3. draught power, provided specifically by those engaged in livestock rearing, which is discussed in the chapter Livestock rearing.


    The agriculture system is shown as four major processes. These processes represent sequential phases in crop production. The agricultural system produces food, feed and fibre as well as consequences for occupational health and, more generally, public health and the environment.

    Major commodities, such as wheat or sugar, are outputs from agriculture that are used as food, animal feed or fibre. They are represented in this chapter by a series of articles that address processes, occupational hazards and preventive actions specific to each commodity sector. Animal feed and forage are discussed in the chapter Livestock rearing.

    Evolution and Structure of the Industry

    The Neolithic revolution—the change from hunting and gathering to farming—started in three different places in the world. One was west and southwest of the Caspian Sea, another was in Central America and a third was in Thailand near the Burmese border. Agriculture started in about 9750 BC at the latter location, where seeds of peas, beans, cucumbers and water chestnuts have been found. This was 2,000 years before true agriculture was discovered in the other two regions. The essence of the Neolithic revolution and, thus, agriculture is the harvesting of plant seeds, their reintroduction into the soil and cultivation for another harvest.

    In the lower Caspian area, wheat was the early crop of choice. As farmers migrated, taking wheat seed with them, the weeds in other regions were discovered to also be edible. These included rye and oats. In Central America, where maize and beans were the staples, the tomato weed was found to bear nutritious food.

    Agriculture brought with it several problems:

    • Weeds and other pests (insects in the fields and mice and rats in the granaries) became a problem.
    • Early agriculture concerned itself with taking all that it could from the soil, and it would take 50 years to naturally replenish the soil.
    • In some places, the stripping of growth from the soil would turn the land to desert. To provide water to crops, farmers discovered irrigation about 7,000 years ago.


    Solutions to these problems have led to new industries. Ways to control weeds, insects and rodents evolved into the pesticide industry, and the need to replenish the soil has resulted in the fertilizer industry. The need to provide water for irrigation has spawned systems of reservoirs and networks of pipes, canals and ditches.

    Agriculture in the developing nations consists principally of family-owned plots. Many of these plots have been handed down from generation to generation. Peasants make up half of the world’s rural poor, but they produce four-fifths of the developing countries’ food supply. In contrast, farms are increasing in size in the developed countries, turning agriculture into large-scale commercial operations, where production is integrated with processing, marketing and distribution in an agribusiness system (Loftas 1995).

    Agriculture has provided subsistence for farmers and their families for centuries, and it has recently changed into a system of production agriculture. A series of “revolutions” has contributed to an increase in agricultural production. The first of these was the mechanization of agriculture, whereby machines in the fields substituted for manual labour. The second was the chemical revolution that, after the Second World War, contributed to the control of pests in agriculture, but with environmental consequences. A third was the green revolution, which contributed to North American and Asian productivity growth through genetic advances in the new varieties of crops.

    Economic Importance

    The human population has grown from 2.5 billion in 1950 to 5.6 billion in 1994, and the United Nations estimates that it will continue to grow to 7.9 billion by 2025. The continued rise in the human population will increase the demand for food energy and nutrients, both because of the increase in numbers of people and the global drive to combat malnutrition (Brown, Lenssen and Kane 1995). A list of nutrients derived from food is shown in table 1.

    Table 1. Sources of nutrients


    Plant sources

    Animal sources

    Carbohydrates (sugars and starch)

    Fruits, cereals, root vegetables, pulses

    Honey, milk

    Dietary fats

    Oilseeds, nuts, and legumes

    Meat, poultry, butter, ghee, fish


    Pulses, nuts, and cereals

    Meat, fish, dairy products


    Carotenes: carrots, mangoes, papaya
    Vitamin C: fruits and vegetables
    Vitamin B complex: cereals, legumes

    Vitamin A: liver, eggs, milk
    Vitamin B complex: meat, poultry, dairy products


    Calcium: peas, beans
    Iron: dark green leafy vegetables and nuts

    Calcium: milk, meat, cheese
    Iron: meat, fish, shellfish

    Source: Loftas 1995.

    Agriculture today can be understood as an enterprise to provide subsistence for those doing the work, staples for the community in which the food is grown and income from the sale of commodities to an external market. A staple food is one that supplies a major part of energy and nutrient needs and constitutes a dominant part of the diet. Excluding animal products, most people live off of one or two of the following staples: rice, wheat, maize (corn), millet, sorghum, and roots and tubers (potatoes, cassava, yams and taro). Although there are 50,000 edible plant species in the world, only 15 provide 90% of the world’s food energy intake.

    Cereals constitute the principal commodity category that the world depends upon for its staples. Cereals include wheat and rice, the principal food staples, and coarse grains, which are used for animal feed. Three—rice, maize and wheat—are staples to more than 4.0 billion people. Rice feeds about half of the world’s population (Loftas 1995).

    Another basic food crop is the starchy foods: cassava, sweet potatoes, potatoes, yams, taro and plantains. More than 1 billion people in developing nations use roots and tubers as staples. Cassava is grown as a staple in developing countries for 500 million people. For some of these commodities, much of the production and consumption remains at the subsistence level.

    An additional basic food crop is the pulses, which comprise a number of dry beans—peas, chickpeas and lentils; all are legumes. They are important for their starch and protein.

    Other legumes are used as oil crops; they include soybeans and groundnuts. Additional oil crops, used to make vegetable oil, include coconuts, sesame, cotton seed, oil palm and olive. In addition, some maize and rice bran are used to make vegetable oil. Oil crops also have uses other than for food, such as in manufacturing paints and detergents (Alexandratos 1995).

    Small landholders grow many of the same crops as plantation operations do. Plantation crops, typically thought of as tropical export commodities, include natural rubber, palm oil, cane sugar, tropical beverages (coffee, cocoa, tea), cotton, tobacco and bananas. They may include crops that are also grown for both local consumption and export, such as coffee and sugar cane (ILO 1994).

    Urban agriculture is labour intensive, occurs on small plots and is present in developed as well as developing countries. In the United States, more than one-third of the dollar value of agricultural crops is produced in urban areas and agriculture may employ as much as 10% of the urban population. In contrast, up to 80% of the population in smaller Siberian and Asian cities may be employed in agricultural production and processing. An urban farmer’s produce may also be used for barter, such as paying a landlord (UNDP 1996).

    Characteristics of the Industry and Workforce

    The 1994 world population totalled 5,623,500,000, and 2,735,021,000 (49%) of this population was engaged in agriculture, as shown in figure 1 . The largest component of this workforce is in the developing nations and transitional economies. Less than 100 million are in the developed nations, where mechanization has added to their productivity.

    Figure 1. Millions of people engaged in agriculture by world region (1994)


    Farming employs men and women, young and old. Their roles vary; for example, women in sub-Saharan Africa produce and market 90% of locally grown food. Women are also given the task of growing the subsistence diet for their families (Loftas 1995).










    Children become farm labourers around the world at an early age (figure 2 ), working typically 45 hours per week during harvesting operations. Child labour has been a part of plantation agriculture throughout its history, and a prevalent use of contract labour based upon compensation for tasks completed aggravates the problem of child labour. Whole families work to increase the task completion in order to sustain or increase their income.

    Figure 2. Young boy working in agriculture in India


    Data on plantation employment generally show that the highest incidence of poverty is among agricultural wage labourers working in commercial agriculture. Plantations are located in tropical and subtropical regions of the world, and living and working conditions there may aggravate health problems that accompany the poverty (ILO 1994).

    Agriculture in urban areas is another important component of the industry. An estimated 200 million farmers work part-time—equivalent to 150 million full-time workers—in urban agriculture to produce food and other agricultural products for the market. When subsistence agriculture in urban areas is included, the total reaches 800 million (UNDP 1996).

    Total agricultural employment by major world region is shown in figure 1. In both the United States and Canada, a small proportion of the population is employed in agriculture, and farms are becoming fewer as operations consolidate. In Western Europe, agriculture has been characterized by smallholdings, a relic of equal division of the previous holding among the children. However, with the migration from agriculture, holdings in Europe have been increasing in size. Eastern Europe’s agriculture carries a history of socialized farming. The average farm size in the former USSR was more than 10,000 hectares, while in other Eastern European countries it was about one-third that size. This is changing as these countries move toward market economies. Many Asian countries have been modernizing their agricultural operations, with some countries achieving rice surpluses. More than 2 billion people remain engaged in agriculture in this region, and much of the increased production is attributed to high- production species of crops such as rice. Latin America is a diverse region where agriculture plays an important economic role. It has vast resources for agricultural use, which has been increasing, but at the expense of tropical forests. In both the Middle East and Africa, per capita food production has seen a decline. In the Middle East, the principal limiting factor on agriculture is the availability of water. In Africa, traditional farming depends upon small, 3- to 5-hectare plots, which are operated by women while the men are employed elsewhere, some in other countries to earn cash. Some countries are developing larger farming operations.



    Thursday, 10 March 2011 14:12


    Adapted from 3rd edition, “Encyclopaedia of Occupational Health and Safety”.

    The term plantation is widely used to describe large-scale units where industrial methods are applied to certain agricultural enterprises. These enterprises are found primarily in the tropical regions of Asia, Africa and Central and South America, but they are also found in certain subtropical areas where the climate and soil are suitable for the growth of tropical fruits and vegetation.

    Plantation agriculture includes short-rotation crops, such as pineapple and sugar cane, as well as tree crops, such as bananas and rubber. In addition, the following tropical and subtropical crops are usually considered as plantation crops: tea, coffee, cocoa, coconuts, mango, sisal and palm nuts. However, large-scale cultivation of certain other crops, such as rice, tobacco, cotton, maize, citrus fruits, castor beans, peanuts, jute, hemp and bamboo, is also referred to as plantation cultivation. Plantation crops have several characteristics:

    • They are either tropical or subtropical products for which an export market exists.
    • Most require prompt initial processing.
    • The crop passes through few local marketing or processing centres before reaching the consumer.
    • They typically require a significant investment of fixed capital, such as processing facilities.
    • They generate some activity for most of the year, and thus offer continuous employment.
    • Monocropping is typical, which allows for specialization of technology and management.


    While the cultivation of the various plantation crops requires widely different geographic, geological and climatic conditions, practically all of them thrive best in areas where climatic and environmental conditions are arduous. In addition, the extensive nature of plantation undertakings, and in most cases their isolation, has given rise to new settlements that differ considerably from indigenous settlements (NRC 1993).

    Plantation Work

    The main activity on a plantation is the cultivation of one of two kinds of crops. This involves the following kinds of work: soil preparation, planting, cultivation, weeding, crop treatment, harvesting, transportation and storage of produce. These operations entail the use of a variety of tools, machines and agricultural chemicals. Where virgin land is to be cultivated, it may be necessary to clear forest land by felling trees, uprooting stumps and burning off undergrowth, followed by ditch and irrigation channel digging. In addition to the basic cultivation work, other activities may also be carried out on a plantation: raising livestock, processing crops and maintaining and repairing buildings, plants, machinery, implements, roads and railway tracks. It may be necessary to generate electricity, dig wells, maintain irrigation trenches, operate engineering or woodworking shops and transport products to the market.

    Child labour is employed on plantations around the world. Children work with their parents as part of a team for task-based compensation, or they are employed directly for special plantation jobs. They typically experience long and arduous working hours, little safety and health protection and inadequate diet, rest and education. Rather than direct employment, many children are recruited as labour through contractors, which is common for occasional and seasonal tasks. Employing labour through contracted intermediaries is a long-standing practice on plantations. The plantation management thus does not have an employer- employee relationship with the plantation workers. Rather, they contract with the intermediary to supply the labour. Generally, conditions of work for contract labour are inferior to those of directly employed workers.

    Many plantation workers are paid based upon the tasks performed rather than the hours worked. For example, these tasks may include lines of sugar cane cut and loaded, number of rubber trees tapped, rows weeded, bushels of sisal cut, kilograms of tea plucked or hectares of fertilizer applied. Conditions such as climate and terrain may affect the time to complete these tasks, and whole families may work from dawn to dusk without taking a break. The majority of countries where plantation commodities are grown report that plantation employees work more than 40 hours per week. Moreover, most plantation workers move to their work location on foot, and since plantations are large, much time and effort are expended on travel to and from the job. This travel can take hours each way (ILO 1994).

    Hazards and Their Prevention

    Work on plantations involves numerous hazards relating to the work environment, the tools and equipment used and the very nature of the work. One of the first steps toward improving safety and health on plantations is to appoint a safety officer and form a joint safety and health committee. Safety officers should assure that buildings and equipment are kept safe and that work is performed safely. Safety committees bring management and labour together in a common undertaking and enable the workers to participate directly in improving safety. Safety committee functions include developing work rules for safety, participating in injury and disease investigations and identifying locations that place workers and their families in danger.

    Medical services and first aid materials with adequate instruction should be provided. Medical doctors should be trained in the recognition of occupational diseases related to plantation work including pesticide poisoning and heat stress. A risk survey should be implemented on the plantation. The purpose of the survey is to comprehend risk circumstances so that preventive action can be taken. The safety and health committee can be engaged in the survey along with experts including the safety officer, the medical supervisor and inspectors. Table 1  shows the steps involved in a survey. The survey should result in action including the control of potential hazards as well as hazards that have resulted in an injury or disease (Partanen 1996). A description of some potential hazards and their control follow.


    Table 1. Ten steps for a plantation work risk survey


    1. Define the problem and its priority.
    2. Find existing data.
    3. Justify the need for more data.
    4. Define survey objectives, design, population, time and methods.
    5. Define tasks and costs, and their timing.
    6. Prepare protocol.
    7. Collect data.
    8. Analyse data and assess risks.
    9. Publish results.
    10. Follow up.

    Source: Partanen 1996.


    Fatigue and climate-related hazards

    The long hours and demanding work make fatigue a major concern. Fatigued workers may be unable to make safe judgements; this may lead to incidents that can result in injuries or other inadvertent exposures. Rest periods and shorter workdays can reduce fatigue.

    Physical stress is increased by heat and relative humidity. Frequent water consumption and rest breaks help to avoid problems with heat stress.

    Tool and equipment-related injuries

    Poorly designed tools will often result in poor work posture, and poorly sharpened tools will require greater physical effort to complete tasks. Working in a bent or stooping position and lifting heavy loads imposes strain on the back. Working with arms above the shoulder can cause upper-extremity musculoskeletal disorders (figure 1). Proper tools should be selected to eliminate poor posture, and they should be well maintained. Heavy lifting can be reduced by lessening the weight of the load or engaging more workers to lift the load.

    Figure 1. Banana cutters at work on "La Julia" plantation in Ecuador


    Injuries can result from improper uses of hand tools such as machetes, scythes, axes and other sharp-edged or pointed tools, or portable power tools such as chain-saws; poor positioning and disrepair of ladders; or unsuitable replacements for broken ropes and chains. Workers should be trained in the proper use and maintenance of equipment and tools. Appropriate replacements should be provided for broken or damaged tools and equipment.

    Unguarded machinery can entangle clothing or hair and can crush workers and result in serious injury or death. All machines should have safety built in, and the possibility of dangerous contact with moving parts should be eliminated. A lockout/tagout programme should be in effect for all maintenance and repair.

    Machinery and equipment are also sources of excessive noise, resulting in hearing loss among plantation workers. Hearing protection should be used with machinery with high levels of noise. Low noise levels should be a factor in selecting equipment.


    Vehicle-related injuries

    Plantation roadways and paths may be narrow, thus presenting the hazard of head-on crashes between vehicles or overturns off the side of the road. Safe boarding of transport vehicles including trucks, tractor- or animal-drawn trailers and railways should be ensured. Where two-way roads are used, wider passages should be provided at suitable intervals to allow vehicles to pass. Adequate railing should be provided on bridges and along precipices and ravines.

    Tractors and other vehicles pose two principal dangers to workers. One is tractor overturns, which commonly result in the fatal crushing of the operator. Employers should ensure that rollover protective structures are mounted on tractors. Seat-belts should also be worn during tractor operation. The other major problem is vehicle run-overs; workers should remain clear of vehicle travel paths, and extra riders should not be allowed on tractors unless safe seating is available.


    Electricity is used on plantations in shops and for processing crops and lighting buildings and grounds. Improper use of electric installations or equipment can expose workers to severe shocks, burns or electrocutions. The danger is more acute in damp places or when working with wet hands or clothing. Wherever water is present, or for electrical outlets outdoors, ground fault interrupter circuits should be installed. Wherever thunderstorms are frequent or severe, lightning protection should be provided for all plantation buildings, and workers should be trained in ways to minimize their danger of being struck and to locate safe refuges.


    Electricity as well as open flames or smouldering cigarettes can provide the ignition source for fuel or organic dust explosions. Fuels—kerosene, gasoline or diesel fuel—can cause fires or explosions if mishandled or improperly stored. Greasy and combustible waste poses a risk of fire in shops. Fuels should be kept clear of any ignition source. Flameproof electrical devices and appliances should be used wherever flammables or explosives are present. Fuses or electrical breaker devices should also be used in electrical circuits.


    The use of toxic agrochemicals is a major concern, particularly during the intensive use of pesticides, including herbicides, fungicides and insecticides. Exposures can take place during agricultural production, packaging, storage, transport, retailing, application (often by hand or aerial spraying), recycling or disposal. Risk of exposure to pesticides can be aggravated by illiteracy, poor or faulty labelling, leaking containers, poor or no protective gear, dangerous reformulations, ignorance of the hazard, disregard of rules and a lack of supervision or technical training. Workers applying pesticides should be trained in pesticide use and should wear appropriate clothing and respiratory protection, a particularly difficult behaviour to enforce in tropical areas where protective equipment can add to the heat stress of the wearer (figure 2 ). Alternatives to pesticide use should be a priority, or less toxic pesticides should be used.

    Figure 2. Protective clothing worn when applying pesticides


    Animal-inflicted injuries and illnesses

    On some plantations, draught animals are used for dragging or carrying loads. These animals include horses, donkeys, mules and oxen. These types of animals have injured workers by kicking or biting. They also potentially expose workers to zoonotic diseases including anthrax, brucellosis, rabies, Q-fever or tularaemia. Animals should be well trained, and those that exhibit dangerous behaviour should not be used for work. Bridles, harnesses, saddles and so on should be used and maintained in good condition and be properly adjusted. Diseased animals should be identified and treated or disposed of.

    Poisonous snakes may be present on the ground or some species may fall from trees onto workers. Snakebite kits should be provided to workers and emergency procedures should be in place for obtaining medical assistance and the appropriate anti-venom drugs should be available. Special hats made of hard materials that are capable of deflecting snakes should be provided and worn in locations where snakes drop on their victims from trees.

    Infectious diseases

    Infectious diseases can be transmitted to plantation workers by rats that infest buildings, or by drinking water or food. Unsanitary water leads to dysentery, a common problem among plantation workers. Sanitary and washing facilities should be installed and maintained in accordance with national legislation, and safe drinking water consistent with national requirements should be provided to workers and their families.

    Confined spaces

    Confined spaces, such as silos, can pose problems of toxic gases or oxygen deficiency. Good ventilation of confined spaces should be assured prior to entry, or appropriate respiratory protective equipment should be worn.



    Thursday, 10 March 2011 15:52

    Coffee Cultivation

    It is thought that the word coffee derives from Kaffa, a village in Ethiopia where the plant is thought to have its origin. Some, however, consider that the word stems from qahwa, meaning wine in Arabic. Coffee cultivation spread the world over, starting in Arabia (one species is called Coffea arabica, and a variety is Moka, named after an Arab village), passing through many countries, such as Ceylon, Java, India, the Philippines, Hawaii and Viet Nam, among others, some of which are important producers to this day. In America, coffee was introduced from plants previously adapted to the climate in Amsterdam and Paris, planted in Martinique, Surinam and French Guyana, from where it was brought to Brazil, the largest producing country in the world.

    World production may be estimated from figure 1. The 1995–96 crop generated wealth estimated at approximately US$27 million, indicating the economic significance of this product worldwide.

    Figure 1. World coffee production for 1995 - 96


    The trend towards a global economy, growing competition and the search for technologies with higher productivity also have effects upon coffee cultivation. Mechanization is being disseminated and updated. Moreover, new methods of cultivation are introduced, among them high-density cultivation, in which the distance between plants is being reduced. This modern method increases the number of coffee trees from 3,000 or 4,000 to 100,000 plants per hectare, with an increase in productivity of around 50% over the traditional method. This procedure is important for workers’ health, since lower risks are involved and less herbicide is applied, especially after the third year. On the other hand, there is an increase in the frequency of tree cutting and higher demand for control of fungus disease in the plants.

    Coffee is highly sensitive to fluctuations in international commerce; many countries tend to replace coffee with other crops in which financial return is more predictable. In Brazil, for instance, coffee represented 68% of the total volume of exports in 1920; in the 1990s it is only 4%. Coffee is being replaced by                                                                                                                         soy bean, citric fruits, corn, latex and especially sugar cane.

    It is extremely difficult to obtain a reliable estimate of the total labour force involved in coffee cultivation because the number of employed workers is quite variable. During harvest, a large number of seasonal workers are hired, to be dismissed soon after the crop is over. Moreover, in small properties, very often workers are not legally registered, and therefore are not shown in official reports. In Brazil in 1993, for a production of 28.5 million coffee bags, the number of workers was estimated at 1.1 million in direct and 4 to 5 million in indirect jobs. If the same parameters are applied to world production for the same year, coffee workers around the world could be estimated at approximately 3.6 million.

    It is equally difficult to know the average figure of workers per rural property. In general, small or medium-sized properties are predominant. The sex and age distribution of the working population is equally unknown, even though female population among workers is increasing and children are known to be employed in coffee plantations. Figures for unionized workers vary according to the labour policies in each country, but they are known to be generally scarce.


    Coffee cultivation and treatment involve the following steps: tree abatement; soil preparation; planting (small plants are usually grown in nurseries in the same or in external properties); treatment (soil correction, fertilizing, pest control and terrain cleaning manually or with herbicides); fruit picking (ripe fruit is usually red and therefore called a berry—see figure 2; sieving to get rid of impurities; transportation; washing to remove pulp and membranes; sun drying, revolving grains with a rake, or mechanical drying through hot air blasting; hand separation of grains; storing in silos; and bagging.

    Figure 2. High-density coffee cultivation showing berries


    Potential Risks

    Risk factors that may affect workers’ health in coffee cultivation are the same as for agricultural workers in general.

    From tree abatement and terrain preparation to the final storage of coffee bags, each step may involve several risk factors for workers’ health and safety. Injury risks are present mainly in mechanized processes, tree abatement, terrain preparation, mechanical picking, transportation of coffee and workers as well, fruit treatment (including the risk of boiler explosion) and use of hand tools (very often improvised or without maintenance).

    Potential risks of occupational diseases due to physical conditions are related to heat exposure in drying operations, solar radiation, machine noise, ergonomic problems from hand tools, vibration from machinery and tractors, and cold and humidity from outdoor exposure.

    The main chemical agents present as potential risks for workers’ health are pesticides and herbicides. Those most often used are gliphosate as an herbicide, copper salts as fungicides and organophosphorus compounds for other pests commonly found on coffee trees. The number of pesticide applications varies according to tree age, soil composition, climatic conditions, vegetation species or variety, cultivation system (e.g., high or low density) and other factors. Spraying is usually done individually with backpack equipment, or from tractors. Large amounts are usually required, and it is said that “without spraying no crop is available”.

    Chemical fertilizers may also present a health risk. Often used are compounds derived from boron, zinc, nitrogen, sodium, potassium, calcium, magnesium and sulphur. The release of particles from fertilizer handling should be kept under control.

    Biological agents may represent important risks for workers’ health. They may include, for instance, bites or stings from snakes, spiders, bees, mosquitoes and acarids, some of them important as disease vectors. In certain areas, endemic diseases may be serious risks for coffee workers.

    Ergonomic, psychosocial and organizational factors are discussed below.

    Health Effects

    Examples of injuries related to work are cuts from hand tools, sprains and fractures from machines and injuries from tractors. Fatal injuries, even if unusual, have occurred as a result of overturning of tractors or inadequate vehicles used in transportation of workers. When artificial drying is employed, heat sources may cause burns and explosions.

    Occupational diseases may result from exposure to solar ultraviolet radiation; cutaneous conditions may range from a simple erythema to skin cancer. Hearing loss among machine operators, pulmonary allergic conditions, poisoning from herbicides and pesticides, callosities, lung diseases, bone and circulatory conditions due to vibration, and muscular and skeletal trouble due to poor ergonomic positions or excessive weight (one coffee bag can weigh 60 kg) are other occupational conditions that may occur among coffee cultivation workers. Although primarily a problem among workers processing coffee beans, green bean handlers have complained of respiratory and eye problems. Coffee bean dust has been associated with occupational dust diseases.

    Tropical diseases such as malaria, yellow fever, filariasis, trypanossomiasis, leishmaniasis and onchocercosis are prevalent in certain cultivating areas. Tetanus is still prevalent in many rural areas.

    More complex health problems related to psychosocial and organizational factors may also affect coffee workers. Since large numbers of workers are required during harvest, and very few during the rest of the year, seasonal contracts are usually practised, often resulting in difficult health problems.

    In many cases, workers leave their families and remain during the harvest season in precarious lodgings under inadequate sanitary conditions. If the planting area is close to town, the farmer will contract only one man in the family. However, to increase the profit, the worker himself may bring his whole family to help, including women and children. In some areas, the number of children at work is so high that schools will be closed during the whole harvest season.

    In this type of seasonal activity, workers will turn from one type of cultivation to another, according to each harvest period. Since men leave their families, women are called “widows with living husbands”. Very often, a man will raise another family, away from his original town.

    Proper compliance with labour legislation and social security is usually restricted to large plantations, and labour inspection in rural areas is generally ineffective. Health care is usually very limited. Duration of work is extended to many hours daily; weekends and normal vacations are seldom respected.

    These psychosocial and organizational factors result in marked deterioration in workers’ health, manifested through early ageing, low life expectancy, increase in prevalence and longer duration of diseases, malnutrition (eating the food taken to the field in cans without heating it has led to workers being given a nickname—boias frias in Portuguese), anaemia and hypovitaminoses leading to loss of disposition to work, mental trouble and other manifestations.


    Preventive measures concerning coffee are the same that apply to rural work in general. Collective protection includes machine guarding, care in application of pesticides and herbicides, mechanizing operations that require undue effort and energy consumption, and adequate transportation of workers. In high-density plantations, regular cutting will not allow the trees to grow, which will eliminate the use of dangerous and uncomfortable ladders for hand picking. When drying requires the use of boilers, careful periodic preventive maintenance is of utmost importance. Biological pest control and proper selection of species resistant to plagues are important preventive measures concerning pesticides, avoiding workers’ disease and environmental protection as well.

    Implementation of the use of recommended PPE is difficult because such equipment is usually not adapted to climatic conditions or to the biotype of workers. Moreover, there is usually no educational orientation to facilitate the use, and the selection of equipment is not always correct. Equipment in general use is restricted to boots, hats and clothing to protect from the weather, even though hand, lung, eye and ear protection may be required.

    Prevention to control psychosocial and organizational factors may bring up many difficulties. Workers’ awareness should be raised through educational activities, especially in unions and other workers’ organizations, increasing perceptions about workers’ rights to better living and working conditions; moreover, employers should develop their perceptions concerning their social responsibilities towards the labour force. The State should exercise an effective and constant orientation and enforcement wherever legal action is required. Some countries have developed rules and regulations specifically applicable to rural workers. In Brazil, for example, Rural Regulatory Standards establish general directives concerning safety in rural activities, the organization of occupational health services and safety committees in plantations, use of personal protective equipment and handling of chemicals (pesticides, fertilizers and soil-correcting products).

    Health control through occupational medicine should cover the evaluation of health effects due to exposure to pesticides, ultraviolet radiation, excessive noise and many other hazards. It may, in many circumstances, be more necessary to control worm diseases, anaemia, hypertension, behavioural problems, eye defects and similar problems, due to their high prevalence in rural areas. Health education should be stressed, as well as tetanus immunization, including for pregnant workers to prevent neonatal tetanus. In some regions, immunization against yellow fever is necessary. Chemoprophylaxis is recommended in areas where malaria is endemic, together with the use of repellents and a preventive orientation against mosquitoes, until sanitation is adequate to control or suppress vectors of the aetiological agent. Serum against snake poison should be available.

    Acknowledgement: The authors are obliged to the cooperation received from Professor Nelson Batista Martin, from the Institute of Rural Economy, State Secretary of Agriculture, Sao Paulo; Andre Nasser and Ricardo Luiz Zucas, from the Brazilian Rural Society; and Monica Levy Costa, from the School Health Center, School of Public Health, Sao Paulo University.



    Thursday, 10 March 2011 14:20

    Migrant and Seasonal Farmworkers

    Migrant and seasonal farmworkers represent a large, global population with the double hazard of occupational health hazards of farming superimposed on a foundation of poverty and migrancy, with its associated health and safety problems. In the United States, for example, there are as many as 5 million migrant and seasonal farmworkers, although precise numbers are not known. As the total farm population has decreased in the United States, the proportion of hired farmworkers has increased. Globally, workers migrate in every region of the world for work, with movement generally from poorer to wealthier countries. In general, migrants are given more hazardous and difficult jobs and have increased rates of illness and injury. Poverty and lack of adequate legal protection exacerbate the risks of occupational and non-occupational disease.

    Studies of hazardous exposures and health problems in this population have been limited because of the general paucity of occupational health studies in agriculture and the specific difficulties in studying farmworkers, due to their migratory residence patterns, language and cultural barriers, and limited economic and political resources.

    Migrant and seasonal agricultural workers in the United States are predominantly young, Hispanic males, although farmworkers also include whites, blacks, Southeast Asians and other ethnic groups. Almost two-thirds are foreign born; most have low levels of education and do not speak or read English. Poverty is a hallmark of agricultural workers, with over half having family incomes below the poverty level. Substandard working conditions prevail, salaries are low and there are few benefits. For example, less than one-fourth have health insurance. Seasonal and migrant agricultural workers in the United States work about half the year on the farm. Most work is in labour-intensive crops such as harvesting of fruits, nuts or vegetables.

    The general health status of agricultural workers directly derives from their working conditions and low income. Deficiencies exist in nutrition, housing, sanitation, education and access to medical care. Crowded living conditions and inadequate nutrition may also contribute to the increased risks of acute, infectious illnesses. Farmworkers see a physician less often than non-farmworking populations, and their visits are overwhelmingly for treatment of acute illnesses and injuries. Preventive care is deficient in farmworker populations, and surveys of farmworker communities find a high prevalence of individuals with medical problems requiring attention. Preventive services such as vision and dental care are seriously deficient, and other preventive services such as immunizations are below the population averages. Anaemia is common, probably reflecting poor nutritional status.

    The poverty and other barriers for migrant and seasonal farmworkers generally result in substandard living and working conditions. Many workers still lack access to basic sanitary facilities at the worksite. Living conditions vary from adequate government-maintained housing to substandard shacks and camps used while work exists in a particular area. Poor sanitation and crowding may be particular problems, increasing the risks of infectious diseases in the population. These problems are exacerbated among workers who migrate to follow agricultural work, reducing community resources and interactions at each living site.

    Various studies have shown a greater burden of infectious diseases on morbidity and mortality in this population. Parasitic diseases are significantly increased among migrant workers. Increased deaths have been found for tuberculosis, as well as many other chronic diseases such as those of the cardiovascular, respiratory and urinary tracts. The greatest increase in mortality rates is for traumatic injuries, similar to the increase seen for this cause among farmers.

    The health status of children of farmworkers is of particular concern. In addition to the stresses of poverty, poor nutrition and poor living conditions, the relative deficiency of preventive health services has a particularly serious impact on children. They also are exposed to the hazards of farming at a young age, both by living in the farming environment and by doing agricultural work. Children under 5 years of age are most at risk of unintentional injury from agricultural hazards such as machinery and farm animals. Above 10 years of age, many children begin working, particularly at times of acute labour need such as during harvesting. Working children may not have the necessary physical strength and coordination for farm labour, nor do they have adequate judgement for many situations. Exposure to agrochemicals is a particular problem, since children may not be aware of recent field application or be able to read warnings on chemical containers.

    Farmworkers are at increased risk of pesticide illness during work in the fields. Exposures most commonly occur from direct contact with the spray of application equipment, from prolonged contact with recently sprayed foliage or from drift of pesticide applied by aircraft or other spray equipment. Re-entry intervals exist in some countries to prevent foliar contact while the pesticide on foliage is still toxic, but many places have no re-entry intervals, or they may not be obeyed to hasten the harvest. Mass poisonings from pesticide exposure continue to occur among agricultural workers.

    The greatest workplace hazard to farmworkers is from sprains, strains and traumatic injuries. The risk of these outcomes is increased by the repetitive nature of much labour-intensive agricultural work, which often involves workers bending or stooping to reach crops. Some harvesting tasks may require the worker to carry heavy bags full of the harvested commodity, often while balancing on a ladder. There is substantial risk of traumatic injuries and musculoskeletal strains in this situation.

    In the United States, one of the most serious causes of fatal injuries to farmworkers is motor vehicle accidents. These often occur when farmworkers are driving or being driven to or from the fields very early or late in the day on unsafe rural roads. Collisions may also occur with slow-moving farm equipment.

    Dust and chemical exposures result in an increased risk of respiratory symptoms and disease in farmworkers. The specific hazard will vary with the local conditions and commodities. For example, in dry-climate farming, inorganic dust exposure may result in chronic bronchitis and dust-borne diseases of the lung.

    Skin disease is the most common work-related health problem among agricultural workers. There are numerous causes of skin disease in this population, including trauma from using hand equipment such as clippers, irritants and allergens in agrochemicals, allergenic plant and animal materials (including poison ivy and poison oak), nettles and other irritant plants, skin infections caused or exacerbated by heat or prolonged water contact, and sun exposure (which can cause skin cancer).

    Many other chronic diseases may be more common among migrant and seasonal farmworkers, but data on actual risks are limited. These include cancer; adverse reproductive outcomes, including miscarriage, infertility and birth defects; and chronic neurologic disorders. All of these outcomes have been observed in other farming populations, or those with high-level exposure to various agricultural toxins, but little is known about actual risk in farmworkers.



    Thursday, 10 March 2011 14:09

    Case Study: Family Farms

    The family farm is an enterprise and a homestead on which both children and the elderly are likely to be present. In some parts of the world, farm families live in villages surrounded by their farm land. The family farm combines family relationships and child raising with the production of food and other raw materials. Family farms range from small, subsistence or part-time operations worked with draught animals and hand tools to very large, family-held corporations with numerous full-time employees. Types of family farms are distinguished by national, regional, cultural, historical, economic, religious and several other factors. The size and type of operations determine the demand for labour from family members and the need for hired full- or part-time workers. A typical farm operation may combine the tasks of livestock handling, manure disposal, grain storage, heavy equipment operation, pesticide application, machinery maintenance, construction and many other jobs.

    The Organization for Economic Cooperation and Development (OECD 1994) reports several trends in agriculture, including:

    1. the increasing economic dominance of large, highly mechanized producers
    2. the increase in off-farm employment as the principal source of income for small farms
    3. the controlling role of national and international agricultural policies and trade agreements.


      The concentration of farm operations and the reduction in the number of family farms has been recognized for decades. These economic forces affect the work processes, workload and safety and health of the family farm. Several key changes are occurring in family farming as a direct result of these economic forces, including expanding workloads, increasing reliance on hired labor, use of new techniques, unsupervised adolescents and struggling to maintain economic viability.

      Children nearing adolescence contribute to family farm productivity. Small and medium-size family farms are likely to rely on this labor, especially when adult family members work off the farm. The result may be unsupervised work by farm children.


      The family farm is a hazardous work environment. It is one of few hazardous workplaces where multiple generations of family members may live, work and play. A farm can be the source of many and differing life-threatening hazards. The most important indicator for safety and health is workload per worker—both physical labor and decision-making or mental workload. Many serious injuries happen to experienced farmers, working with familiar equipment in familiar fields, while doing tasks that they have been performing for years and even decades.

      Hazardous agricultural materials including pesticides, fertilizers, flammable liquids, solvents and other cleaners are responsible for acute and chronic illnesses in farm workers and family members. Tractors, augers and other mechanized equipment have permitted a dramatic increase in the land and livestock that can be worked by a single farmer, but mechanization has contributed to severe injuries in agriculture. Machinery entanglement or tractor rollover, livestock, operating equipment on public roads, falling or being struck by falling objects, material handling, confined spaces and exposures to toxins, dust, moulds, gases, chemicals, vibration and noise are among the principal risks for illness and injury on farms. Climate and topography (e.g., weather, water, slopes, sinkholes and other obstacles) also contribute to the hazards.

      Overall, agricultural occupations produce some of the highest rates of death and injury of all types of jobs. Unfortunately, farm children are at great risk along with their parents. As farm families attempt to remain profitable as they expand, family members may take on too high a workload and place themselves at greatly increased risk of fatigue, stress and injury. It is under these conditions that farm children are most likely to try to help out, often working unsupervised. In addition, unrelenting stressors associated with farming may lead to depression, family breakup and suicide. For example, principal owner-operators on single-family farms appear to be at particularly high risk for suicide when compared to other rural residents (Gunderson 1995). Further, the costs of illnesses and injuries are most often borne by the family member(s), and by the family enterprise—both as direct medical costs and in the reduction of labour necessary to maintain the operation.


      Classic agricultural safety and health programmes emphasize improved engineering design, education and good practices. Special attention on these farms needs to be placed on age-appropriate tasks for children and older adults. Young children should neither be allowed near operating farm equipment nor ever ride on tractors and other farm equipment. They should also be excluded from farmstead buildings that present hazards including electricity, confined spaces, chemical storage areas and operating equipment (National Committee for Childhood Agricultural Injury Prevention 1996). Warning labels should be maintained on equipment and chemicals so adults are informed of hazards and can thus better protect their families. The availability of experienced part-time or full-time workers reduces the burden on the family during periods of high workloads. The abilities of older adults should be a factor in the tasks that they perform.

      Self-reliant farmers, determined to complete tasks regardless of the risks, may ignore safe work practices if they perceive them to interfere with farm productivity. Improving safety and health on family farms requires engaging the active participation of farmers and farm workers; improving attitudes, behavioral intentions and work practices; recognizing farm economics and productivity as powerful determinants in shaping the structure and organization of the enterprise; and including agricultural specialists, equipment dealers, insurance agents, bankers, local media, youth and other community members in generating and sustaining a broad climate of farm and community safety.



      Thursday, 10 March 2011 14:23

      Urban Agriculture

      Agriculture conducted in urban areas is a major contributor to food, fuel and fibre production in the world, and it exists largely for the daily needs of consumers within cities and towns. Urban agriculture uses and reuses natural resources and urban wastes to produce crops and livestock. Table 1 summarizes the variety of farming systems in urban areas. Urban agriculture is a source of income for an estimated 100 million people, and a source of food for 500 million. It is oriented to urban markets rather than national or global markets, and it consists of many small-scale farms and some large-scale agribusinesses. Urban farmers range from a household garden in 20 m2 or less, to a small-scale farmer making a living on 200 m2, to a large-scale operator who may rent 10 hectares in an industrial zone (UNDP 1996).

      Table 1. Farming systems in urban areas

      Farming systems


      Location or technique


      Fish and seafood, frogs, vegetables, seaweed and fodder

      Ponds, streams, cages, estuaries, sewage, lagoons, wetlands


      Vegetables, fruit, herbs, beverages, compost

      Homesites, parks, rights-of-way, containers, rooftops, hydroponics, wetlands, greenhouses, shallow bed techniques, layered horticulture


      Flowers, insecticides, house plants

      Ornamental horticulture, rooftops, containers, greenhouses, rights-of-way


      Milk, eggs, meat, manure, hides, and fur

      Zero-grazing, rights-of-way, hillsides, cooperatives, pens, open spaces


      Fuel, fruits and nuts, compost, building material

      Street trees, homesites, steep slopes, vineyards, green belts, wetlands, orchards, forest parks, hedgerows


      Mushrooms, compost

      Sheds, cellers


      Compost, worms for animal and fish feed

      Sheds, trays



      Homesites, trays


      Honey, pollination, wax

      Beehives, rights-of-way

      Landscape gardening, arboriculture

      Grounds design and upkeep, ornamentation, lawns, gardens

      Yards, parks, play fields, commercial frontage, road sides, lawn and garden equipment

      Beverage crops cultivation

      Grapes (wine), hibiscus, palm tea, coffee, sugar cane, qat (tea substitute), matte (herbed tea), banana (beer)

      Steep slopes, beverage processing

      Sources: UNDP 1996; Rowntree 1987.

      Landscaping, an offshoot of architecture, has emerged as another urban agriculture endeavour. Landscape gardening is the tending of plants for their ornamental appearance in public parks and gardens, private yards and gardens, and industrial and commercial building plantings. Landscape gardening includes lawn care, planting annuals (bedding plants), and planting and caring for perennials, shrubs and trees. Related to landscape gardening is grounds keeping, in which playing fields, golf courses, municipal parks and so on are tended (Franck and Brownstone 1987).

      Process Overview

      Urban agriculture is seen as a method for establishing ecological sustainability for towns and cities in the future. Urban agriculture usually engages shorter-cycle, higher-value market crops and uses multi-cropping and integrated farming techniques located where space and water are scarce. It uses both vertical and horizontal space to its best advantage. The principal feature of urban farming is the reuse of waste. The processes are typical of agriculture with similar inputs and steps, but the design is to use both human and animal wastes as fertilizer and water sources for growing vegetation. In this near idealized model, external inputs still exist, however, such as pesticides (UNDP 1996).

      In the special case of landscaping, appearance is the product. The care of lawns and ornamental trees, shrubs and flowers are the focus of the landscape operation. In general, the landscaper purchases planting stock from a nursery or a turf farm, plants the stock and cares for it routinely and frequently. It typically is labour and chemical intensive, and the use of hand and power tools and lawn and garden equipment is also common. Grass mowing is a routine chore in landscaping.

      Hazards and Their Control

      Urban agriculture is typically small scale, close to housing, exposed to urban pollutants, engaged in the reuse of waste and exposed to potential theft of products and related violence. The hazards related to various types of agriculture, pesticides and composting discussed elsewhere in this volume are similar (UNDP 1996).

      In the developed countries, suburban farms and landscaping enterprises make use of lawn and garden equipment. This equipment includes small tractors (tractor attachments such as mowers, front-end loaders and blades) and utility haulers (similar to all-terrain vehicles). Other tractor attachments include tillers, carts, snow blowers and trimmers. These tractors all have engines, use fuel, have moving parts, carry an operator and are often used with towed or mounted equipment. They are substantially smaller than the typical agricultural tractor, but they can be overturned and cause serious injury. The fuel used on these tractors poses a fire hazard (Deere & Co. 1994).

      Many of the tractor attachments have their own peculiar hazards. Children riding with adults have fallen from the tractor and been crushed under the wheels or chopped by mower blades. Mowers pose two types of hazards: one is potential contact with rotating blades and the other is being struck by objects thrown from the blades. Both front-end loaders and blades are operated hydraulically, and if left unattended and elevated, pose a hazard of falling onto anyone who gets a body part under the attachment. Utility haulers are inexpensive when compared to the cost of a small truck. They can turn over on steep terrain, especially when turning. They are dangerous when used on public roads because of the possibility of collision. (See table 2 for several safety tips for operating some types of lawn and garden equipment.)

      Table 2. Safety advice for using mechanical lawn and garden equipment

      Tractors (smaller than regular farm equipment)

      Prevent rollovers:

      • Do not drive where the tractor can tip or slip; avoid steep slopes; watch for rocks, holes
        and similar hazards.
      • Travel up and down slopes or hillsides; avoid travelling across steep slopes.
      • Slow down and use care in turning to prevent tipping or losing steering and braking control.
      • Stay within the tractor load limits; use ballast for stability; refer to the operator’s manual.


      Never allow extra riders.

      Maintain safety interlocks; they ensure that powered equipment is disengaged
      when the operator is not seated or when starting the tractor.

      Rotary lawn mowers (tractor mounted or walk-behind type)

      Maintain safety interlocks.

      Use proper blades and guards.

      Keep all safety blades and guards in place and in good condition.

      Wear substantial closed-toe shoes to prevent slipping and protect against injury.

      Do not allow anyone to put their hands or feet near the mower deck or discharge chute
      while the machine is running; stop the mower if children are nearby.

      When leaving the machine, shut it down.

      To prevent thrown object injuries:

      • Clear the area to be mowed.
      • Keep the mower deck guards, discharge chute, or bag in place.
      • Stop the mower whenever someone comes near.


      When working on mower (on push or walk-behind type mowers), disconnect the spark plug
      to prevent engine starting.

      Avoid fires by not spilling fuel on hot surfaces nor handling fuel near sparks or flames;
      avoid the accumulation of fuel, oil and trash around hot surfaces.

      Front-end loaders (attached to lawn and garden tractors)

      Avoid overloading.

      Back down ramps and steep inclines with the loader bucket lowered.

      Watch the driving route rather than watching the bucket.

      Operate the hydraulic loader controls only from the tractor seat.

      Use the loader only for materials that it was designed to handle.

      Lower the bucket to the ground when leaving the machine.

      Utility haulers (similar to all-terrain vehicles but designed for off-the-road work)

      Avoid rollovers:

      • Practise driving on smooth terrain before driving on rough terrain.
      • Do not speed; slow down before turning (especially on slopes).
      • Reduce speed on slopes and rough terrain.
      • Watch for holes, rocks and other hidden hazards.


      Never allow extra riders.

      Avoid tipping over by distributing the cargo box load so it is not too high or too far to rear.

      Avoid an upset when raising the cargo box by staying clear of the edge of loading docks
      or embankments.

      When towing loads, place weight in the cargo box to assure traction.

      Avoid driving on public roads.

      Children should not operate these machines.

      A helmet is recommended head protection.

      Source: Adapted from Deere & Co. 1994.




      Thursday, 10 March 2011 14:26

      Greenhouse and Nursery Operations

      The nursery industry raises plants for the replanting market (see figure 1). Hardy plants are grown outside, and the less hardy plants are propagated and raised inside, typically in greenhouses, to protect them from cold temperatures or too much solar radiation or wind. Many plants grown inside during harsh growing conditions are grown outside in favourable weather conditions. Typical nursery crops are trees and shrubs, and the typical greenhouse crops include flowers, vegetables and herbs. The nursery industry grows plants for the replanting market, but greenhouses are also used for growing crops for seasonal markets, such as tomatoes during the freezing months of winter.

      Figure 1. Setting coffee plants in a nursery in Cote d’Ivoire


      The plant nursery industry constitutes a large and growing sector of agriculture. In California, where there are more than 3,000 commercial nursery operations, nursery crops are a high value-per-acre commodity, ranking fifth in state farm income. As with much of western US agriculture, the employee population is dominated by workers from Mexico or other Central American countries. The majority of these workers are not migrant, but are settled in local communities with their families (Mines and Martin 1986). Most speak Spanish only or as a primary language and have little or no formal education. Wages are low for most jobs, and there is a labour surplus. Similar situations exist throughout the world.

      Nursery work is considered a comparatively good job by most agricultural workers because it is year-round, comparatively well-paid and frequently includes workers’ compensation insurance and employee health benefits. Few workers belong to labour organizations in this industry, and most workers are employed directly by the enterprise rather than by farm labour contractors.

      Greenhouses provide a controlled environment for plants and are used for a variety of purposes, which include growing rare and exotic plants, protecting producing plants (such as flowers, tomatoes and peppers) from winter weather and starting seedlings. The controlled environment within a greenhouse is advantageous to those who wish to grow crops year-round, regardless of seasonal conditions outdoors. Greenhouse operations have expanded in temperate climates. For example, in the Ukraine, the total area of greenhouses has grown from 3,070 hectares (ha) in 1985 to 3,200 ha in 1990 to an estimated 3,400 ha in 1995 (Viten, Krashyyuh and Ilyna 1994).

      The gable (equal sloping roof) greenhouse is typical. It provides good exposure to winter sunlight, drainage and wind protection. The framing materials for greenhouses include wood, aluminium or a combination of steel pipe and wood. Side walls or siding can be made from a variety of materials including plywood, aluminium, wood or vinyl. In the Ukraine, 60% of the greenhouses have masonry block walls. Covers include glass or plastic, and in some parts of the world, the glass-covered house is called a glasshouse. The plastic can be either rigid or a flexible film. Rigid plastics used as covers include fibreglass, acrylic and polycarbonate. Flexible plastic covers include polyethylene, polyvinyl chloride and polyester. Polycarbonate, which withstands breakage from thrown objects, and the flexible plastics require frequent replacement. Covers can vary from clear to opaque, and they serve three purposes. One is to let sunlight in for the plants. Another is for heating within an enclosure. The last is protecting the plants from environmental stress, including snow, rain, hail, high winds, birds, small animals and insects.

      The greenhouse operation requires the control of temperature, humidity and ventilation, using artificial heat sources, exhaust and inlet fans, shading (such as with movable slats or netting), cooling equipment (such as wet-pad or evaporative cooling), humidification and climate-control equipment (Jones 1978).

      Nursery and greenhouse workers are exposed to a variety of hazards, including skin irritants, dust, noise, heat stress, musculoskeletal disorders (sprains and strains), pesticides and injuries related to vehicles, machines, slips and falls and electricity. The hazards discussed below are limited to ergonomic hazards in nursery work and pesticide hazards in greenhouse work. Many of these hazards are common for the two operations.

      Nursery Operations

      Typical operations at a large wholesale nursery specializing in container-grown outdoor bedding and ornamental plants consist of four stages:

        1. Propagation stage. New plants are started in a specialized medium using one of four standard methods: cuttings from mature plants, tissue culture, seeds and grafting.
        2. Replanting stage. As plants grow they are replanted into individual plastic containers called “cans” (typically 2 or 3 times during the early growth cycle). A powered conveyor carries the new, larger cans past a hopper where they are filled with soil. As the cans continue down the conveyor, plants are manually transplanted into them, and finally they are manually transferred onto a trailer for transport to the field.
        3. Growing stage or field operations. Plants are held in outdoor groups until fully mature. During this period, tasks include watering, pruning, fertilizing and weeding, tying-staking-shaping and spacing as plants grow.
        4. Shipping. Mature plants are removed to the shipping area, labelled, organized by order load, and loaded into trucks. This operation can also include truck unloading at retail sites.


              Ergonomic hazards

              Nursery work, as with other agricultural commodities, has a pattern of high rates of sprain and strain injuries. AgSafe data (1992) suggest that 38.9% of all reported injuries in horticultural specialties (including nurseries) were sprains and strains, slightly above the proportion for agriculture as a whole. Overexertion as a cause of injury for this area was cited for 30.2% of reported injuries, also above the proportion for the industry as a whole.

              The most common risk factors for the development of work-related musculoskeletal problems have been identified as occurring in the following job tasks:

              During propagation, the worker stands or sits at a work table, empties a basket of plant cuttings, and uses hand shears to cut them into smaller pieces. The shears are held in the dominant hand; plant material is grasped with the other hand. After each piece of plant material is cut, the shears must be disinfected by dipping them in a solution in a small container in the work bench.

              When cutting, one hand is engaged in very repetitive gripping, with an average of 50 to 60 cuts per minute. Mild to moderate wrist flexion and ulnar deviation occur throughout the cutting cycle. The other hand is used to hold the cuttings, orient them for cutting, and discard the remains in a bin. Moderate wrist extension and ulnar deviation occur throughout this cycle also.

              Workers in this specialized job are highly skilled and work virtually full-time year-round without rotation into other jobs. Workers report pain and numbness in the hand, wrist and arm. After a period of years on this job, they demonstrate an elevated incidence of carpal tunnel syndrome.

              In transporting plants from a conveyor belt to a trailer, the worker grasps 3 or 4 3.8-litre containers in each hand and places them on a trailer located either to one side of or behind him or her. This job cycle is repeated 13 to 20 times per minute. Risk factors include highly repetitive gripping, high pinch forces and awkward postures, including trunk, lumbar and shoulder flexion.

              In transporting plants from a trailer to a planting bed, the worker grasps 3 or 4 3.8-l containers in each hand, carries them up to 17 m, and places them on the ground along a predetermined row. This job cycle is repeated 3 to 5 times per minute. Handling cans is a nearly full-time, year-round job for many workers. It is associated with pain in the fingers and hands, upper extremities and lower back. Because field workers tend to be younger, the predicted high rate of chronic back injury is not documented at this time.

              The pruner works with various shears to snip unwanted or dead parts off the tops and sides of plants. The worker is usually standing or bent over to reach plants. The dominant hand holds the shears and is engaged in very repetitive gripping, with an average of 40 to 50 cuts per minute. The fingers of the same hand are also used to pinch off small twigs or other plant parts. The nondominant hand grasps the can for a rapid pick and place, and also holds the cuttings in a static grip with a moderate wrist flexion and ulnar deviation present throughout the cutting cycle. Because pruning is a part-time task for most field workers, some relief and recovery are achieved due to task variation. However, it is associated with pain in the fingers and hand, wrist, upper extremities and lower back.

              To allow plants adequate room to grow and expand, spacing must be done periodically. This entails grasping and lifting 3 to 4 plants in each hand, carrying them a short distance, and placing them on the ground in rows. This cycle is repeated 3 to 5 times per minute. Like pruning, spacing is a part-time task for most field workers, allowing opportunity for relief and recovery. It is also associated with pain in fingers and hands, wrists, upper extremities and lower back.

              Most nursery jobs are human-energy intensive, and this, coupled with the repetitive nature of many tasks, leads to substantial risk of repetitive-motion injuries. Tools to assist the workers by improving body posture and reducing the energy requirements of particular tasks have just begun to be developed.

              Greenhouse Operations

              Typical operations in a greenhouse vary depending on whether the purpose is to grow rare and exotic plants, production plants or seedlings. The growing of rare or exotic plants is a year-round enterprise. Production plants are typically grown within the greenhouse to protect them from the weather; thus, greenhouses can be used seasonally. The growth of seedlings is similar to nursery operations, but the market is plants for spring replanting after the last freeze. The tasks involved in greenhouse growing include putting the soil into small containers, planting the seed in each of the containers, watering and fertilizing the plants, trimming or thinning the plants as needed (see figure 2), applying fumigants or pesticides and transporting the plants or product from the greenhouse. Soil filling and planting has become a mechanized operation in the production greenhouse. The composition of the potting soil may be a mix of peat, perlite and vermiculite. Trimming may be mechanized, depending upon the crop. Watering may be directly with a hose or through an automated sprinkler or piping system. Nutrients are added to the water to fertilize the plants. Application of pesticides by hand sprayer is typical. Soil sterilization is done either by steam or chemicals, including dibromochloropropane (DBCP). The transport of plants or product is typically a manual exercise.

              Figure 2. Clipping (mowing) tobacco transplants in a greenhouse in North Carolina


              Pesticides Used in Greenhouses

              Diseases and insects that attack plants can result in major problems for greenhouse operators. Often, preventing such damage is easier than trying to eradicate the pests afterward. Some common pests that inflict the most damage on greenhouse crops are insects, fungi, viruses, bacteria and nematodes. To combat these undesirable organisms, special chemicals (pesticides) are applied to the plants to kill the pests.

              There are many ways of applying pesticides so that they are effective. The most common application methods are: liquid sprays, mists, dusts, fogs, smokes, aerosol canisters and granules. Pesticide sprays involve the use of a water/pesticide mixture contained in a tank that has a hose with a spray nozzle attached to it. Under pressure, the mixture is directed onto the plants as liquid droplets. Mists are generated by a technique similar to the spray technique, but the resulting droplets are smaller. Pesticide dusts are often released into the air and allowed to settle onto the plant surface. Foggers use heating devices to generate very small droplets directed at the plants. Pesticide smokes are generated by igniting a sparkler and placing it in a canister that contains the chemical.

              Aerosol canisters are pressurized metal containers that release the pesticide to the air when a valve is opened. Finally, granular pesticides are placed on top of the soil and then watered. The watering dissolves the granules and transports the chemical to the roots of the plant, where it can either kill organisms in the soil or be absorbed by the plant and kill organisms that feed on it.

              With each different method of application of a pesticide comes the hazard of being exposed to the chemical. The two most common routes of exposure are through the skin (dermal) and through the lungs (respiratory). Another, but less common, route of exposure is by ingesting food or drinks contaminated with pesticides. Greenhouse workers who handle the chemicals or the treated plants may be poisoned if proper safety precautions are not followed.

              Ways to avoid poisoning include proper use of greenhouse ventilation systems, using and maintaining the appropriate PPE (suits, gloves, respirators, boots—see figure 3), observing recommended re-entry times and following the pesticide label instructions. Some additional safety precautions are: storage of all pesticides inside a locked, well-ventilated area; posting signs in areas where plants have been treated; and comprehensive pesticide training that includes proper application and handling techniques. Finally, all pesticide applicators should be trained in appropriate disposal techniques for old pesticides and empty pesticide containers.

              Figure 3. Worker in full protective gear applies pesticides in a greenhouse.




              Thursday, 10 March 2011 14:37


              Since the early 1990s, in many countries and across several continents, floriculture as an economic activity has been expanding rapidly. Its growing importance in export markets has resulted in an integrated development of several aspects of this field of activity, including production, technology, scientific research, transportation and conservation.


              The production of cut flowers has two essential components:

              1. the process of production, which involves all activities directly related to the generation and the development of the product up to the moment of packing
              2. the various activities that aid in the production and promote the marketing and distribution of cut flowers.


              The production process itself can be divided into three basic parts: germination, cultivation and post-harvest procedures.

              Germination is carried out by planting parent plants from which cuttings are obtained for cultivation.

              The cuttings of different flowers are planted on beds of a rooting medium. The beds are made from steam-treated dross and treated with chemical products to disinfect the growing medium and to facilitate root development.

              Cultivation is done in greenhouses which house the beds of rooting medium where the flowers are planted and grown as discussed in the article “Greenhouse and nursery operations” in this chapter and as shown in figure 1. Cultivation includes preparing the soil, planting the cuttings (figure 2) and harvesting the flowers.

              Figure 1. Tending flowers in a greenhouse


              Figure 2. Planting cuttings in a greenhouse


              Planting includes the cycle that begins with placing the cuttings in the rooting medium and ends with the flowering plant. It includes the following activities: planting, normal irrigation, drip irrigation with fertilizer, cultivation and weeding of the soil, pinching the tip of the plants to force branching and obtain more flowers, preparing the props that hold the plants upright, and the growth, branching and flowering of the plant.

              Production concludes with the gathering of the flowers and their separation by classification.

              At the post-harvest stage—in addition to selection and classification—the flowers are covered with plastic hoods, a sanitary treatment is applied, and they are packed for shipment.

              Secondary activities include monitoring the health of the plants to detect pests and to diagnose plant illnesses early, obtaining raw materials from the warehouse, and maintaining the furnaces.

              Health Risk Factors

              The most important risk factors in each of the different areas of work are:

              • chemical substances
              • extreme temperatures—heat
              • non-ionizing radiation
              • infectious disease
              • ergonomic factors
              • mechanical factors
              • psychosocial factors.


              Chemical substances

              Intoxication and chronic illness due to pesticides

              The levels of morbidity/mortality found in workers due to exposure to pesticides are not the consequence of a simple relation between the chemical agent and the person who has suffered exposure to it, but also reflect the interplay of many other factors. Among these are the length of exposure, individual susceptibility, the nutritional state of the person exposed, educational and cultural variables and the socioeconomic conditions under which the workers live.

              In addition to the active ingredients of pesticides, the substances that convey the active ingredients and the additives should also be taken into consideration, because sometimes those substances can have adverse effects that are more harmful than those of the active ingredients.

              The toxicity of pesticides made with organophosphates is due to their effect on the central nervous system, because they inhibit the activity of the enzyme acetylcholinesterase. The effects are cumulative, and delayed effects have also been noted on the central and the peripheral nervous systems. According to studies carried out in several countries, the prevalence of inhibition of this enzyme among workers who handle these pesticides fluctuates between 3 and 18%.

              The long-term effects are pathological processes that develop after a latency period and are due to repeated exposures. Among the long-term effects known to be due to pesticide exposure are skin lesions, nerve damage and mutagenic effects.

              Respiratory problems

              Decorative plants can irritate the respiratory system and cause coughing and sneezing. In addition, plant scents or odours may exacerbate symptoms of asthma or allergic rhinitis, although they have not been shown to cause allergies. Pollen from the chrysanthemum and the sunflower can cause asthma. Dust from dried plants sometimes causes allergies.


              The cases of occupational dermatitis found in floriculture are about 90% primarily due to contact dermatitis. Of these, about 60% are caused by primary irritants and 40% are due to allergic reactions. The acute form is characterized by reddening (erythema), swelling (oedema), pimples (papules), vesicles or blisters. It is especially localized on the hands, wrists and forearms. The chronic form can have deep fissures, lichenification (thickening and hardening) of the skin, and severe xerosis (dryness). It can be incapacitating and even irreversible.

              Floriculture is one of those activities where contact with primary irritants or allergenic substances is high, and for that reason it is important to promote and use preventive measures, such as gloves.

              Extreme temperatures—heat

              When work must be carried out in a hot environment, as in the case of hothouses, the thermal load on the worker is the sum of the heat of the work environment plus the energy expended on the task itself.

              Physical effects of excessive exposure to heat include heat rash, cramps and muscle spasms, exhaustion and fainting spells. Heat rash, in addition to being uncomfortable, lowers the worker’s tolerance to heat. If perspiration is abundant and liquids and electrolytes are not replenished adequately, cramps and muscle spasms can set in. Heat exhaustion occurs when vasomotor control and cardiac output are insufficient to compensate for the additional demands placed on these systems by the heat stress. Fainting spells represent a very serious clinical situation that can lead to confusion, delirium and coma.

              Precautions include frequent rest breaks in cool areas, availability of beverages to drink, rotating of tasks requiring heavy exertion and wearing of light-coloured clothing.

              Non-ionizing radiation

              The most important kinds of non-ionizing radiation that floriculture workers are exposed to are ultraviolet (UV) radiation, visible light and infrared radiation. The most serious effects of UV radiation are solar erythema, actinic dermatitis, irritative conjunctivitis and photokeratitis.

              Radiation from the visible spectrum of light may cause retinal and macular degeneration. One symptom of exposure to infrared radiation is superficial burn of the cornea, and prolonged exposure can lead to the premature appearance of cataracts.

              Precautions include keeping the skin covered, wearing tinted glasses, and medical surveillance.

              Ergonomic factors

              Workers who maintain a static body posture for long periods of time (see figure 3) can suffer from resulting static muscle contractions and from alterations of the peripheral, vascular and nervous systems. Repetitive movements are more common in tasks that require manual dexterity. For example, clipping shears can require a lot of force and involve repetitive motion. The most frequently observed effects are musculoskeletal impairments, including tendinitis of the elbow and wrist, carpal tunnel syndrome and impairment of movement at the shoulder.

              Figure 3. Bending over for extended periods is a common cause of ergonomic problems


              Job rotation and the proper ergonomic design of equipment such as clipping shears are needed precautions. Redesigning the workplace to require less bending is another solution.

              Infectious diseases

              Floriculture may expose workers to a variety of biological agents. Early signs of an infection are rarely specific, although they are generally well-defined enough to lead to a suspicion of illness. The signs, symptomatology and precautions depend on the agent, which includes tetanus, rabies, hepatitis and so on. Preventive measures include a source of potable water, good sanitary facilities, first aid and medical care for cuts and abrasions.

              Other factors

              The most common health and safety hazards associated with mechanical factors are cuts, abrasions and single and multiple traumas, which most frequently injure the hands and face. Such injuries must be attended to immediately. Workers should have up-to-date tetanus shots and adequate first-aid facilities must be available.

              The psychosocial environment can also endanger worker health. The results of exposure to these factors can have the following consequences: physiological changes (indigestion, constipation, palpitations, difficulty breathing, hyperventilation, insomnia and anxiety); psychological disturbances (tension and depression); and behavioural disturbances (absenteeism, instability, dissatisfaction).



              At the San Antonio farm, several workers became poisoned when applying the pesticide Lannate. An investigation of the case revealed that the workers had been using backpack sprayers for application without wearing any protective clothing, gloves or boots. Their employer had never provided the necessary equipment, and soap and showers were also unavailable. Following the poisonings, the employer was directed to take the appropriate corrective actions.

              When the Ministry of Health made a follow-up inspection, they discovered that many farmers were still not using any protective clothing or equipment. When they were asked why, some said that the equipment was too hot and uncomfortable. Others explained that they had been working this way for years and never had any problems. Several commented that they didn’t need the equipment because they drank a large glass of milk after applying pesticides.

              This experience, which took place in Nicaragua, is common to many parts of the world and illustrates the challenge to effective farmworker training. Training must be accompanied by provision of a safe work environment and legislative enforcement, but must also consider the barriers to implementing safe work practices and incorporate them in training programmes. These barriers, such as unsafe work environments, absence of protective equipment and attitudes and beliefs which are not health-promoting, should be directly discussed in training sessions, and strategies to address them should be developed.

              This article describes an action-oriented training approach applied in two multidisciplinary pesticide projects that were designed to address the problem of farmworker pesticide poisoning. They were implemented in Nicaragua by CARE, Nicaragua and the American Friends Service Committee (1985 to 1989) and in the Central American region by the International Labour Organization (ILO, 1993 to present). In addition to a strong educational approach, the Nicaraguan project developed improved methods to mix and load pesticides, a medical monitoring plan to screen workers for overexposure to pesticides and a system to collect data for epidemiological investigation (Weinger and Lyons 1992). Within its multifaceted project, the ILO emphasized legislative improvements, training and building a regional network of pesticide educators.

              Key elements of both projects were the implementation of a training needs assessment in order to tailor teaching content to the target audience, the use of a variety of participatory teaching approaches (Weinger and Wallerstein 1990) and the production of a teacher’s guide and educational materials to facilitate the learning process. Training topics included the health effects of pesticides, symptoms of pesticide poisoning, rights, resources and a problem-solving component which analysed the obstacles to working safely and how to resolve them.

              Although there were many similarities between the two projects, the Nicaraguan project emphasized worker education while the regional project focused on teacher training. This article provides selected guidelines for both worker and teacher training.

              Worker Education

              Needs assessment

              The first step in developing the training programme was the needs assessment or “listening phase”, which identified problems and obstacles to effective change, recognized factors which were conducive to change, defined values and beliefs held by the farmworkers and identified specific hazardous exposures and experiences which needed to be incorporated into the training. Walkthrough inspections were used by the Nicaraguan project team to observe work practices and sources of worker exposure to pesticides. Photographs were taken of the work environment and work practices for documentation, analysis and discussion during the training. The team also listened for emotional issues which might be barriers to action: worker frustration with inadequate personal protection, lack of soap and water or lack of safe alternatives to currently used pesticides.

              Training methods and objectives

              The next step in the training process was to identify the content areas to be covered utilizing information gained from listening to workers and then to select appropriate training methods based on the learning objectives. The training had four objectives: providing information; identifying and changing attitudes/emotions; promoting healthy behaviours; and developing action/problem-solving skills. What follows are examples of methods grouped under the objective which they best achieve. The following methods were incorporated into a 2-day training session (Wallerstein and Weinger 1992).

              Methods for information objectives

              Flipchart. In Nicaragua, the project staff needed visual educational tools which were easily portable and independent of electricity for use during field training or with medical screening on the farms. The flipchart included 18 drawings based on real-life situations, which were designed for use as discussion starters. Each picture had specific objectives and key questions that were outlined in an accompanying guide for instructors.

              The flipchart could be used both to provide information and to promote problem analysis leading to action planning. For example, a drawing was used to provide information on the routes of entry by asking “How do pesticides enter the body?” To generate analysis of the problem of pesticide poisoning, the instructor would ask participants: “What’s happening here? Is this scene familiar? Why does this occur? What can (he) you do about it?” The introduction of two or more people into a drawing (of two people entering a recently sprayed field) encourages discussion of suspected motivations and feelings. “Why is she reading the sign? Why did he go right in?” With effective visual images, the same picture may trigger a variety of discussions, depending upon the group.

              Slides. Slides which portray familiar images or problems were used in the same way as the flipchart. Using photos taken during the needs assessment phase, a slide show was created following the path of pesticide use from selection and purchase to disposal and clean-up at the end of the workday.

              Methods for attitude-emotion objectives

              Attitudes and emotions may effectively block learning and influence how health and safety practices are implemented back on the job.

              Scripted role-play. A scripted role-play was often used to explore attitudes and trigger discussion of the problems of exposure to pesticides. The following script was given to three workers, who read their roles to the entire group.

              Jose: What’s the matter?

              Rafael: I’m about ready to give up. Two workers were poisoned today, just one week after that big training session. Nothing ever changes around here.

              Jose: What did you expect? The managers didn’t even attend the training.

              Sara: But at least they scheduled a training for the workers. That’s more than the other farms are doing.

              Jose: Setting up a training is one thing, but what about follow-up? Are the managers providing showers and adequate protective equipment?

              Sara: Have you ever thought that the workers might have something to do with these poisonings? How do you know they’re working safely?

              Rafael: I don’t know. All I know is that two guys are in the hospital today and I have to go back to work.

              The role-play was developed to explore the complex problem of pesticide health and safety and the multiple elements involved in resolving it, including training. In the discussion which followed, the facilitator asked the group if they shared any of the attitudes expressed by the farmworkers in the role-play, explored obstacles to resolving the problems portrayed and solicited strategies for overcoming them.

              Worksheet questionnaire. In addition to serving as an excellent discussion starter and providing factual information, a questionnaire can also be a vehicle for eliciting attitudes. Sample questions for a farmworker group in Nicaragua were:

              1. Drinking milk before work is effective in preventing pesticide poisoning.

                Agree            Disagree

                2. All pesticides have the same effect on your health.

                  Agree            Disagree


                  A discussion of attitudes was encouraged by inviting participants with conflicting viewpoints to present and justify their opinions. Rather than affirming the “correct” answer, the instructor acknowledged useful elements in the variety of attitudes that were expressed.

                  Methods for behavioural skill objectives

                  Behavioural skills are the desired competencies that workers will acquire as a result of training. The most effective way to achieve objectives for behavioural skill development is to provide participants with opportunities to practise in the class, to see an activity and perform it.

                  Personal protective equipment demonstration. A display of protective equipment and clothing was laid out on a table in front of the class, including an array of appropriate and inappropriate options. The trainer asked a volunteer from the audience to get dressed for work applying pesticides. The farmworker chose clothing from the display and put it on; the audience was asked to comment. A discussion followed concerning appropriate protective clothing and alternatives to uncomfortable clothing.

                  Hands-on practice. Both trainers and farmworkers in Nicaragua learned to interpret pesticide labels by reading them in small groups during the class. In this activity, the class was divided into groups and given the task of reading different labels as a group. For low-literacy groups, volunteer participants were recruited to read the label aloud and lead their group through a worksheet questionnaire on the label, which emphasized visual cues to determine level of toxicity. Back in the large group, volunteer spokespeople introduced their pesticide to the group with instructions for potential users.

                  Methods for action/problem-solving objectives

                  A primary goal of the training session is to provide farmworkers with the information and skills to make changes back on the job.

                  Discussion starters. A discussion starter can be used to pose problems or potential obstacles to change, for analysis by the group. A discussion starter can take a variety of forms: a role-play, a picture in a flipchart or slide, a case study. To lead a dialogue on the discussion starter, there is a 5-step questioning process which invites participants to identify the problem, project themselves into the situation being presented, share their personal reactions, analyse the causes of the problem and suggest action strategies (Weinger and Wallerstein 1990).

                  Case studies. Cases were drawn from real and familiar situations that occurred in Nicaragua that were identified in the planning process. They most commonly illustrated problems such as employer noncompliance, worker noncompliance with safety precautions within their control and the dilemma of a worker with symptoms that may be related to pesticide exposure. A sample case study was used to introduce this article.

                  Participants read the case in small groups and responded to a series of questions such as: What are some of the causes of pesticide poisoning in this incident? Who’s benefiting? Who’s being harmed? What steps would you take to prevent a similar problem in the future?

                  Action planning. Prior to the conclusion of the training session, participants worked independently or in groups to develop a plan of action to increase workplace health and safety when pesticides are used. Using a worksheet, participants identified at least one step they could take to promote safe working conditions and practices.

                  Evaluation and Teacher Training

                  Determining the extent to which the sessions met their objectives is a crucial part of training projects. Evaluation tools included a written post-workshop questionnaire and follow-up visits to farms as well as surveys and interviews with participants 6 months following the training session.

                  Training teachers who would utilize the approach outlined above to provide information and training to farmworkers was an essential component of the ILO-sponsored Central American programmes. The objectives of the teacher training programme were to increase the knowledge on pesticide health and safety and the teaching skill of trainers; to increase the number and quality of training sessions directed toward farmworkers, employers, extension workers and agronomists in project countries; and to initiate a network of educators in pesticide health and safety in the region.

                  Training topics in the 1-week session included: an overview of the health effects of pesticides, safe work practices and equipment; the principles of adult education; steps in planning an educational programme and how to implement them; demonstration of selected teaching methods; overview of presentation skills; practice teaching by participants using participatory methods, with critique; and development of action plans for future teaching about pesticides and alternatives to their use. A 2-week session allows time to conduct a field visit and training needs assessment during the workshop, to develop educational materials in the classroom and to conduct worker training sessions in the field.

                  A trainer’s guide and sample curricula were provided during the workshop to facilitate practice teaching both in the classroom and following the workshop. The educators’ network offers another source of support and a vehicle for sharing innovative teaching approaches and materials.


                  The success of this teaching approach with workers in the cotton fields of Nicaragua, trade unionists in Panama and trainers from the Ministry of Health in Costa Rica, among others, demonstrates its adaptability to a variety of work settings and target groups. Its goals are not only to increase knowledge and skills, but also to provide the tools for problem-solving in the field after the teaching sessions have ended. One must be clear, however, that education alone cannot resolve the problems of pesticide use and abuse. A multidisciplinary approach which includes farmworker organizing, legislative enforcement strategies, engineering controls, medical monitoring and investigation into alternatives to pesticides is essential to effect comprehensive changes in pesticide practices.



                  Thursday, 10 March 2011 14:44

                  Planting and Growing Operations

                  Modern agriculture is based on highly efficient equipment, especially high-speed, powerful tractors and agricultural machines. Tractors with mounted and trailed implements allow the mechanization of many agricultural operations.

                  Use of tractors allows farmers to accomplish the main tillage and care of plants in the optimum time without major manual labour. Permanent enlargement of farms, extension of land under cultivation and intensification of crop rotation promotes more efficient agriculture as well. Widespread use of high-speed assemblies is hampered by two factors: existing agricultural methods based mainly on machines and implements with passive tools; and difficulties in ensuring safe working conditions for the high-speed tractor assembly operator.

                  Mechanization can accomplish approximately 70% of planting and growing operations. It is used at all stages of crop cultivation and harvesting as well. Nevertheless, each stage of planting and growing has its own requisite set of machines, tools and environmental conditions, and this variability of the production and environmental factors has an influence upon the tractor driver.

                  Cultivation of the Land

                  Cultivation of the land (ploughing, harrowing, scuffing, disk harrowing, entire cultivation, rolling-down) is important and the most labour-intensive preliminary stage of crop production. These operations involve 30% of planting and growing operations.

                  As a rule, loosening of the soil results in the formation of dust. The nature of the dust in the air is variable, and depends on meteorological conditions, season, kind of work, type of soil and so on. Dust concentration in tractor cabs can vary from a few mg/m3 to hundreds of mg/m3, depending essentially on the cab enclosure. Approximately 60 to 65% of cases exceed the permissible total dust concentration level; permissible levels of respirable (less than or equal to 5 microns) dust are exceeded 60 to 80% of the time (see figure 1). Silica content in the dust varies from 0.5 to 20% (Kundiev 1983).

                  Figure 1. Tractor driver exposures to dust during land cultivation


                  Cultivation consists of power-consuming operations, especially during ploughing, and it demands a considerable mobilization of the power resources of machines, generating considerable levels of noise where tractor drivers sit. These noise levels amount to 86 to 90 dBA and higher, creating a considerable risk of hearing disorders for these workers.

                  As a rule, whole-body vibration levels where the tractor driver is seated can be very high, exceeding levels established by the International Organization for Standardization (ISO 1985) for fatigue-decreased proficiency boundary and frequently for exposure limit.

                  Ground preparation is conducted mainly in early spring and autumn, so the microclimate of cabs in temperate zones for machines without air conditioners is not a health problem except on occasional hot days.

                  Sowing and Growing

                  Ensuring that sowing attachments or ploughing implements move in a straight line and that tractors follow marker tracks or the middle of the row are characteristic features of the sowing and care of crops.

                  In general, these activities require the driver to work in uncomfortable positions and involve considerable nervous and emotional tension due to restricted working-zone visibility, resulting in rapid development of operator fatigue.

                  The layout of sowing machines and their preparation for use, as well as the necessity of manual auxiliary work, especially materials handling, may involve considerable physical loads.

                  A wide geographical distribution of grain varieties results in a diversity of meteorological conditions when sowing. Winter crop sowing for different climate zones can be performed, for example, when the outdoor temperature ranges from 3–10 °C to 30–35 °C. Spring crop sowings are performed when the outdoor temperature ranges from 0 °C to 15–20 °C. The temperatures in tractor cabs without air conditioners can be very high in regions where climate is mild and hot.

                  Microclimate conditions in tractor cabs are favourable as a rule during tilled crops sowing (sugar beet, maize, sunflower) in temperate zones. Cultivation of crops is performed when the outdoor temperature is high and solar radiation is intense. The air temperature in cabs without microclimate control can rise to 40 °C and more. Tractor drivers can work under uncomfortable conditions about 40 to 70% of the total time involved in the care of crops.

                  Working operations for tilled crops cultivation involve considerable moving of earth, causing formation of dust. Maximum ground dust concentrations in the breathing zone air do not exceed 10 to 20 mg/m3. The dust is 90% inorganic, containing a large amount of free silica. Noise and vibration levels where the driver sits are a little lower than those existing during cultivation.

                  During sowing and cultivation, workers can be exposed to manures, chemical fertilizers and pesticides. When safety regulations for handling these materials are not followed, and if machines are not working properly, the breathing zone concentration of hazardous materials can exceed permissible values.


                  As a rule, harvesting lasts from 25 to 40 days. Dust, microclimate conditions and noise can be hazards during harvesting.

                  Breathing zone dust concentrations depend chiefly on outside concentration and the airtightness of the harvesting machine’s cab. Older machines without cabs leave drivers exposed to the dust. Dust formation is most intensive during the harvesting of dry corn, when the dust concentration at non-enclosed combines’ cabs can be as much as 60 to 90 mg/m3. Dust consists mainly of plant scraps, pollen and mushroom spores, mostly in large, nonrespirable particles (larger than 10 microns). Free silica content is less than 5.5%.

                  Formation of dust during sugar beet harvesting is lower. Maximum dust concentration at the cab does not exceed 30 mg/m3.

                  Harvesting of grain is generally performed in the hottest season. Temperature in the cab can rise to 36 to 40 °C. The flux level of direct solar radiation is 500 W/m2 and more when ordinary glass is used for cab windows. Tinted glass lowers the temperature of air in the cab by 1 to 1.6 °C. A mechanical forced ventilation system with a flow rate of 350 m3/h can create a temperature difference between inside and outside air of 5 to 7 °C. If the combine is equipped with adjustable louvers, this difference drops to 4 to 6 °C.

                  Tilled crops are harvested in the autumn months. As a rule conditions of the microclimate in cabs in this time are not a great health problem.

                  Experience in developed countries points to the fact that agriculture at small farms can be profitable with the use of small-scale mechanization (minitractors—motorized units with a capacity of up to 18 horsepower, with different kinds of auxiliary equipment).

                  Use of such equipment gives rise to a number of specific health problems. These problems include: intensification of workload in certain seasons, the use of child labour and the labour of elderly persons, absence of the means of protection against intensive noise, whole-body and local vibration, harmful meteorological conditions, dust, pesticides, and exhaust gases. The effort necessary to move the control levers of motorized units can amount to 60 to 80 N (newtons).

                  Some kinds of work are performed with the help of draught animals or done manually due to insufficient equipment or because of the impossibility of using machinery for some reason. Manual labour demands as a rule considerable physical effort. Power requirements during ploughing, horse-drawn sowing and manual mowing can amount to 5,000 to 6,000 cal/day and more.

                  Injuries are common during manual work, especially among inexperienced workers, and cases of plant burns, insect and reptile stings and dermatitis from the sap of some plants are frequent.


                  One of the main trends in tractor construction is the improvement of working conditions of tractor operators. Side by side with perfection of the design of protective cabs is the search for ways of coordinating technical parameters of various tractor units with the functional abilities of operators. The aim of this research consists of ensuring the effectiveness of control and driving functions as well as necessary ergonomic parameters of the workplace environment.

                  Effectiveness of control and driving of tractor assemblies is ensured by good visibility of the working zone, by optimizing assemblies and control panel design and by proper ergonomic design of tractor seats.

                  Common ways of increasing visibility are increasing the viewing area of the cab using panoramic glass, improved layout of auxiliary equipment (e.g., fuel tank), rationalization of seat location, use of rear view mirrors and so on.

                  Optimization of construction control elements is connected with the construction of the control mechanism’s drive. Along with hydraulic and electric drives, a new improvement is suspended control pedals. This allows improved access and increased driving comfort. Functional coding (by means of form, colour and/or symbolic signs) plays an important part in recognition of the control elements.

                  Rational layout of instrumentation (which comprises 15 to 20 units in modern tractors) requires taking into account further increases in indicators due to remote control of technological process conditions, automation of the driving and operating of the technological equipment.

                  The operator’s seat is designed to guarantee a comfortable position and effective driving of the machine and tractor assembly. Design of modern tractor seats takes into account anthropometric data of the human body. Seats have adjustable back and arms and can be adjusted according to the operator’s size, in both horizontal and vertical dimensions (figure 2).

                  Figure 2. Angle parameters of optimal work posture of a tractor driver


                  Precautions against harmful working conditions for tractor drivers include means of protection against noise and vibration, microclimate normalization and airtight sealing of cabs.

                  Besides special engineering of the engine to reduce noise at its source, considerable effect is achieved by mounting the engine on vibration isolators, isolating the cab from the tractor body with the help of shock absorbers and a number of measures designed for absorption of noise in the cab. Flaky, sound-absorbing lagging with a decorative surface is applied for this purpose to cab wall panels, and rugs made of rubber and porolon are laid on the cab floor. Hard perforated panelling with an air gap of 30 to 50 mm is applied to the ceiling. These measures have reduced noise levels in cabs to 80–83 dBA.

                  The main means of damping low-frequency vibration in the cab is use of an effective seat suspension. Nevertheless, the effect of whole-body vibration damping achieved this way does not exceed 20 to 30%.

                  Agricultural ground levelling gives considerable opportunities for decreasing vibration.

                  Improvement of the microclimate conditions in tractor cabs is reached with the help of both standard equipment (e.g., fans with filter elements, thermo-insulating tinted glass, sun-proof cap peaks, adjustable louvers) and special devices (e.g., air conditioners). Modern tractor heating systems are designed as an autonomous assembly attached to the engine’s cooling system and using warmed water to heat the air. Combined air conditioners and air heaters are also available.

                  Complex solutions of the problem of noise, vibration and heat isolation and sealing of cabs can be reached with the help of sealed cab capsules designed with suspended control pedals and wire rope systems of drives.

                  Ease of access to tractor engines and assemblies for their maintenance and repairs, as well as obtaining timely information about technical condition of certain units of the assembly, are important indices of the level of tractor operator working conditions. Eliminating the cab bonnet, forward inclination of the cab, detachable panels of the engine’s bonnet and so on are available in certain types of tractors.

                  In the future, tractor cabs are likely to be equipped with automatic control units, with television screens for observation of implements that are out of the operator’s field of vision and with units for conditioning of microclimate. Cabs will be mounted on outside rotary rods so they can be moved to a required position.

                  Rational organization of work and rest is of great importance for the prevention of fatigue and diseases of agricultural workers. In the hot season, daily routine ought to provide for working mainly in the morning and evening hours, reserving the hottest time for rest. During exhausting work (moving, hoeing), short regular breaks are necessary. Special attention has to be devoted to the rational, balanced nourishment of workers with due regard for the energy requirements of the tasks. Drinking regularly during the heat is of great importance. As a rule, workers drink traditional beverages (tea, coffee, fruit juices, infusions, broths and so on) in addition to water. Availability of sufficient amounts of wholesome liquids of high quality is very important.

                  Availability of comfortable overalls and personal protection equipment (PPE) (respirators, hearing protectors), especially during contact with dust and chemicals, is very important as well.

                  Medical control of the agricultural workers’ health has to be oriented to prevention of common occupational diseases, such as infectious diseases, chemical exposures, injuries, ergonomic problems and so forth. Teaching safe working methods, information about matters of hygiene and sanitation are of great importance.



                  Page 1 of 3

                  " DISCLAIMER: The ILO does not take responsibility for content presented on this web portal that is presented in any language other than English, which is the language used for the initial production and peer-review of original content. Certain statistics have not been updated since the production of the 4th edition of the Encyclopaedia (1998)."