Occupational and environmental health

Occupational diseases are those for which work or, specifically, exposures in the workplace are necessary causes. The most prevalent occupational diseases in developed countries today are musculoskeletal and psychological disorders (usually stress-related conditions), but generally occupationally related malignancies (e.g. mesothelioma related to asbestos exposure) have the most serious outcomes. The proportion of all cancers attributable to occupational exposures is about 4%, with occupationally related cancers almost exclusively concentrated in manual workers aged 20 or over in sectors such as mining, agriculture, and industry. When presented with a patient whose illness might possibly have been caused or aggravated by work or by other environmental factors, the physician can usefully adopt an approach similar to that used for determining causation in epidemiological studies; the key issues being the temporality, reversibility, exposure-response, strength of association, and specificity of the illness with exposure to the factor in question.