Occupational cancer epidemiology in the coming decades

Occupational studies have identified many of the established chemical carci nogens. Studies in the next millennium will be needed to identify the hazar dous agents in occupations known to have high cancer rates, to assess human risks from animal carcinogens that have not been well evaluated epidemiolo gically, to provide information on women and minorities, to evaluate intera ctions with genetic factors and other risk factors, to contribute to our un derstanding of risks from the spread of chemicals from the workplace to the general environment, and to identify mechanisms of cancer. The traditional retrospective cohort design will be insufficient to meet these needs. Popu lation-based case-control, nested case-control, prospective cohorts, and cr oss-sectional designs will assume more important roles because of the need to collect information on nonoccupational risk factors and biological tissu es. Improvement in the assessment of quantitative exposures is needed for t he efficient evaluation of interactions between occupational exposures, gen etic factors, and nonoccupational exposures.