Occupational Diseases: a Public Health Problem

The indicators traditionally used to determine occupational health conditions include occupational accidents and diseases. Accidents are an abrupt upset of the agent-host-environment balance, are easily identifiable inasmuch as the casual nexus can be clearly established, and can produce varying degrees of injury, including death. Occupational diseases, on the other hand, involve a slower, more insidious destabilization of the agent-host-environment relationship resulting from the nature or conditions of the job. Because of their medical, social, and legal importance, occupational diseases have been the subject of international regulation since 1925, in conventions and recommendations adopted by governments through the International Labor Organization (ILO). The first international regulatory instrument (Convention Number 18, 1925) recognized only three occupational diseases: lead poisoning, mercury poisoning, and anthrax. The two events which resulted in the inclusion of other diseases in international regulations, included the development of industrial technology which created new health risks for workers and the promotion of a greater social awareness. The most recent revision is the 1980 amendment of Convention Number 121, 1964, which recognizes as occupational diseases those that derive from exposure to dangerous substances or conditions inherent in certain professional or occupational processes and activities.' In addition to the diseases which are directly caused by occupational activities (described in Table 1), there are those that result from the particular conditions under which the job is performed but which are not contemplated in the laws or administrative regulations of most countries. Epidemiological morbidity and mortality studies of many common diseases show an uneven distribution among the various occupations: this very extensive group includes stress, mental illness, infectious, psychosomatic, and respiratory diseases, allergies, and lower back pain syndromes, among others. In order to determine the extent of the problem, a large number of countries of the Region have adopted the practice of conducting industrial hygiene surveys as a first stage in organizing occupational health programs. One of the pioneers of industrial hygiene in the