The evolution of chronic hazard evaluation

Abstract The advent of modern epidemiology has been briefly reviewed from the early observational studies to the nested case control technique. While the cohort study has been neglected, many of the significant milestones in epidemiology have been reviewed. The lessons learned from the investigations of nickel, asbestos, benzene, chromates, smoking and many other hazards which were too long ignored must be applied, otherwise the tragedies of the past will recur. To accomplish the preventive goals inherent in occupational medicine, cooperation between industry, government, physicians and scientists is necessary. Toxicological, epidemiological and medical research must continue to improve our understanding of environmental hazards. New chemicals or new uses of old agents should be assumed to be potentially hazardous and worker exposure kept to a minimum until the long risk assessment process indicates otherwise.