The Multinational Monitor

SEPTEMBER 1984 - VOLUME 5 - NUMBER 9


E X P O R T   O F   H A Z A R D S

Occupational Health and the Economic Development of Latin America

by David Michaels, Clara Barrera, and Manuel G. Gachara

Occupational health has not yet been widely recognized as an important public health issue in Latin America. It is only in recent years that Latin American governments have started to allocate significant resources to investigating and taking actions to control hazardous working conditions. Similarly, international organizations have just begun to view occupational health as an important area for their activities. Because Latin American interest and involvement in occupational health is likely to increase in coming decades, this is an opportune time for the international public health community to assist Latin American governments, academic institutions, employers and unions in protecting the health and safety of their workers.

Much of Latin America's industrial growth has occurred in industries in which workers are exposed to significant health hazards. Many Latin American countries, most notably Mexico, Colombia, Venezuela, Peru, Brazil, and Argentina, have developed their own "heavy" industrial concentrations. Workers in these nations produce steel, automobiles, tires, chemicals and other durable goods, the production of which is often associated with increased risk for a wide range of occupational diseases.

Since 1972, world pesticide consumption has on average increased five percent per year. Some regions in Latin America have experienced an even sharper increase. Pesticide sales in Colombia, for example, rose by over 60% in the period 1975-77 alone. While pesticides have a wide range of toxicities, many of the most hazardous are widely used throughout the Least Developed Countries (LDCs). As recently as 1976, approximately one-third of U.S. pesticide exports were of products prohibited for use in the U.S. because of their extreme toxicity.

Much of the rural population of Latin America receives little or no training in the safe handling of these dangerous substances. Among Central American workers employed in cotton growing and exposed to numerous toxic pesticides, one study found three-quarters were not sufficiently literate to read pesticide usage instructions or warnings. Although protective clothing and washing facilities are two of the most basic mechanisms for preventing pesticide intoxication, almost none of the workers in this study had access to protective clothing. Virtually all lived within 100 meters of the cotton fields, many in temporary housing with no walls for protection from pesticides sprayed from airplanes. Seventy-five percent of their houses had no running water and 60 percent-had no toilets. Workers often washed in irrigation channels containing pesticide residues, resulting in increased exposures.

Although there are few studies on the topic, it is apparent that the incidence of pesticide poisoning among Latin American agricultural workers is alarmingly high. During the years 1971-1976, 17,183 cases of pesticide intoxication were reported in El Salvador and Guatemala alone. Similarly, 847 pesticide poisonings, or 1.4 per 100 persons working in the agricultural sector, were reported in Mexico's Laguna region in 1974. It is likely that these are underestimates of the actual incidence of pesticide poisoning, since access to health services in the rural areas in these countries is at best limited.

To, date there have been no comprehensive attempts to measure the impact of workplace exposures on Latin American morbidity and mortality rates. The epidemiologic literature concerning the effects of occupational exposures in Latin America (and in LDCs in general) consists primarily of cross-sectional studies that do not measure the relative risk of disease or death, but only the prevalence of a particular disease or health effect in a segment of the exposed population at one point in time.

These studies do, however, provide important information for understanding worker health in Latin America. The most striking characteristic of these studies is the alarmingly high prevalence of work-related disease detected in the exposed populations.

Colombia: VCM, Lead, Coal, and Noise

A few examples from Colombia illustrate the point. In 1982, a team of investigators from the Colombian Institute of Social Security detected a 5 percent prevalence of radiologically confirmed acro osteolysis (a dissolution of bone) cases among workers in a vinyl chloride monomer (VCM) production plant in Bogota. VCM, which is polymerized into the widely used polyvinyl chloride, is a strong carcinogen. Numerous studies have documented associations between VCM exposure and liver, lung, and brain cancer, as well as osteolysis, a degenerative bone disease, generally affecting the hands. As a result of these studies, as well as animal studies on VCM carcinogenicity. the permissible exposure standard in the U.S. and most industrialized countries was lowered from 500 parts per million (ppm) to one ppm in 1974. The 5% prevalence of acro-osteolysis in the Bogota-area VCM plant is 10 times greater than the prevalence reported in U.S. and Italian plants in the period before the U.S. standard was lowered. At the time of the study, the factory had been in operation only 14 years, less than the induction period for VCMassociated cancer. It is likely that in the near future occupational cancers will begin to appear among workers and ex-workers at this plant.

A 1976 study found that 71% of workers in two Medellin, Colombia battery factories had blood lead-levels of more than 50 micrograms per 100 grams, with one individual having a blood lead-level of 180. At one of the plants, 13 of the 14 employees had lead-levels exceeding the 50 microgram levels. U.S. law requires immediate medical removal of a worker from lead exposure when her or his blood lead level reaches 50 micrograms per 100 grams. Over 70% of the workers in the study showed symptoms consistent with lead exposure, including colic, nausea, and muscle pain.

Finally, the Colombian Ministry of Health has conducted cross-sectional studies of occupational disease in several industries. Their researchers reported a pulmonary disease prevalence rate of 28% in currently employed textile workers and a pulmonary fibrosis prevalence of 15% in active coal miners. These studies found that 70% of Colombian workers exposed to high noise levels suffered from hearing loss and that 34% of the agricultural fumigators examined had depressed cholinesterase levels, a sign of excessive exposure to organophosphate pesticides.

Reports from other Latin American countries hint at problems that mirror those reported from Colombia. In 1981, physicians affiliated with the Sandinista government conducted an investigation into neurological disease in mercuryexposed workers employed in a Nicaraguan chloralkali plant. The investigators determined that 56 (37%) of the 152 exposed workers exhibited symptoms of mercurialism (chronic poisoning from misuse of mercury). The scale of the outbreak that the new government inherited is striking since it had been decades since the last report of an occupational mercury poisoning outbreak of this severity in the U.S. or other developed countries.

Lack of Adequate Control of Occupational and Environmental Exposures

In Brazil, a government-sponsored investigation of occupational disease in 94 electroplating plants in Sao Paolo found 86.6% of the chromium-exposed electroplater popula-tin (303 workers) had chromium-induced lesions, many of which developed after less than one year of exposure. Over one-third of the study population also had ulcers of the nasal septum and approximately one-quarter showed septum perforations.

The current social, economic and environmental conditions of Latin America lead to workers facing greater risk for occupational disease and death than their counterparts in developed countries. The most obvious and important factor is the lack of adequate control of occupational and environmental exposures. It is unfortunately no exaggeration to state that engineering controls of toxic exposures are almost unknown in smaller Latin American factories and are grossly inadequate in many larger ones. Few health standards are applied to limit workplace exposures. In most of the region's countries, the standard setting process is either just beginning or has not yet begun. Where standards regulating work practices or toxic exposure do exist, they are often not enforced, either for political reasons or because of lack of trained inspectors.

The Brazilian electroplating study illustrates this situation. Official state investigators working in Sao Paulo, one of the largest and densest industrial concentrations in the world, found that almost 60% of the unionized electroplating firms had industrial hygiene conditions that were characterized as poor. Working conditions were undoubtedly worse in nonunionized factories, which are generally financially stable. It is therefore not surprising that exposure to chromic acid exceeds the Brazilian government's legal exposure standard. The personal protective equipment supplied to workers was of very limited value. The author of the study, Dr. Edgard Raoul Gomes, Director of Occupational Hygiene and Safety for the Secretariat of Labor and Administration of the State of Sao Paolo, reported:

"We had the opportunity of observing the use of gloves by many workers and yet their hands were wet with acid solution, as they were using short gloves instead of gloves with the required tong cuffs to protect the forearms. We also noted that work was often done with punctured gloves which, instead of protecting, were aggravating the exposure. Frequent burning of gloves with subsequent perforation and lack of protection during work were exposing the workers to risks. .. We actually came across a case of ulceration on the underside of a foot-a rare occurrence-due to working without boots and the wearing of Japanese-type sandals."

Technical Barriers to Alleviating Workplace Hazards

The training of health and safety technicians who can serve as government inspectors, and the training of relevant personnel in the private and academic sectors, is grossly inadequate in much of the developing world. This problem is particularly acute in the area of industrial hygiene. Most Colombian subsidiaries of major transnational chemical and electronic manufacturers have no trained industrial hygienists on their staffs. Comparable factories operated by their parent companies in industrialized nations would employ one or more full-time hygienists to monitor and control hazardous exposures. The manager of a large European owned telecommunications equipment manufacturing facility in Bogota reported to us that although numerous toxic substances were used at the plant, his company had not taken a single environmental measurement during the more than 10 years since the factory was built.

In addition, there is no certification or quality assurance program for occupational health professionals in Latin America. The physicians, hygienists, and other professionals who do claim to be experts in occupational health often do not have the level of expertise required to identify or control work-related injuries and illness.

Much of the practical knowledge of employers and workers in the area of occupational disease prevention is based in traditional, nonscientific beliefs. Most large and medium size employers in Peru and Colombia, for example, regularly provide their workers with milk, under the mistaken belief that milk affords protection from virtually all work-related illnesses. Similarly, urban pesticide applicators in Caribbean countries avoid citrus juices, believing that drinking them will bring about the toxic effects of the chemicals to which they are exposed.

Adequate personal protective equipment is also a rarity in developing nations. In a recent sample of Colombian industries, we found that in lead battery factories and foundries, cloth scarves are used with far greater frequency than respirators or disposable dust masks.

Effects on Children

Children and young people make up a large and apparently growing percentage of the workforce in many developing countries. In 1975, there were 3.3 million children under 15 years old in the Latin American workforce. In recent years, researchers have begun to document the increased susceptibility of children and adolescents to the health effects of toxic substances, particularly those that affect the growth and development of the reproductive system. Prominent among these substances are pesticides, to which many of the children employed in agricultural work are exposed.

In addition, children and adolescent workers are at greater risk for work-related injuries than are their elders. A large proportion of this increased risk can be attributed to their lack of training and experience. It is logical to surmise that the injury toll among the millions of young workers in LDCs is high.

What to Do?

An important question that must be asked is whether the leadership of Latin American governments understands the social costs stemming from the existence and unregulated growth of workplace health and safety hazards. These costs include social security and health services expenditures and lost productive time caused by occupational and environmental injuries, morbidity, and mortality. Furthermore, given the importance of economic development in Latin America, are national governments prepared to intervene in multinational and national enterprises in order to eliminate these hazards?

A number of short-term approaches can be taken by these governments to alleviate the problem.

Training and Education - Increased worker (and employer) education is of paramount importance. Great Britain and Sweden have programs in which worker safety and health repre sentatives are selected in every workplace. These workers attend training courses in the fundamentals of safety and health and have the responsibility to help control hazards in their workplaces. In Sweden, worker health and safety representatives have the right to halt production if they believe a serious hazard exists and the employer is unable to or refuses to eliminate it.

Controlling Toxic Exposure - A uniform, international set of permissible exposure level standards should be developed perhaps by the World Health Organization or the International Labor Organization. Few developing countries have the resources to undertake the toxicologic and epidemiologic studies that serve as the necessary basis for exposure standards. Furthermore, local standard setting processes are easily influenced by powerful economic interests. Internationally accepted standards are less likely to be compromised by local economic interests and more likely to be based on solid scientific data.

Until these standards are developed, multinational corporations should be required to limit workplace exposure to the levels permissble in the parent countries in which these companies are based, or to the lowest permissible in any country in which they operate. A complementary interim measure would be to require multinational corporations who plan to introduce or market potentially toxic substances in an LDC to provide the government with a list of all restrictions on the production´┐Ż sale, or use of the substance imposed in other nations throughout the world. This mechanism, which might be considered a societal informed consent, should be applied to pesticides, pharmaceuticals and consumer products, as well as to industrial chemicals and processes.

Research - More research on the effects of occupational exposures in LDC populations is badly needed. Of particular interest are the effects of toxic exposures on children and adolescents, and on individuals with inadequate nutritional intake or impaired physiologic function.

The economic development of the region is of vital importance for all those concerned with the health of Latin America. It is tragic that, as this development occurs, it is accompanied by a tremendous toll of occupational injury, morbidity, and mortality. There is reason, however, for optimism. Recent years have seen a rapid growth in occupational safety and health related activities in Latin America, particularly on the parts of certain national governments and trade unions. In Colombia, for example, the Institute of Social Security (ISS) has initiated a national program of occupational safety and health education and technical assistance, funded by the allocation of 5%of all occupational injury and illness insurance payments made by employers.

Increased resources are being allocated to occupational health services in Brazil, as well. Brazil provides significant support for the International Labor Organization's Latin American Center for Occupational Safety, Hygiene, and Medicine (CLASET), which recently began operations in Sao Paulo. CLASET, along with the Center for Human Ecology and Health of the Pan America Health Organization, headquartered in Toluca, Mexico, are the primary international organizations that provide technical consultation and support to Latin American government efforts in occupational health.

While these developments are likely to contribute to improvement of workers' conditions, they affect only a small portion of the Latin American workforce. There is little likelihood that the hazards most Latin American workers face daily will lessen in the near future, unless major economic and societal changes occur. Economic development must continue, but not at enormous human cost. Strong international regulation is needed to minimize the burden of injury, illness and death currently borne by Latin American workers.


David Michaels is director of the Program in Occupational Health, Department of Medicine, Albert Einstein College of Medicine, in The Bronx, New York. Clara Barrera is an occupational health specialist at the Occupational Health Section, Ministry of Health, in Bogota, Columbia. Manuel G. Gacharna is director of Epidemiology, Ministry of Health, in Bogota, Columbia.


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