Epidemiological methods in regulatory toxicology

Abstract

A major challenge in the field of toxicology is extrapolating the findings from in vitro and in vivo animal experiments to infer a causal effect of exposure on disease in people. Specifically, differences in species, exposure dose, route of administration, duration of follow-up, and co-exposures may lead to substantially different effects of exposures in animals or cells than in humans. Randomized trials or intervention studies in people provide an opportunity for assessing the health effects of exposures, but high costs and safety concerns often limit the types of exposures that can be evaluated with this approach. In the context of regulatory toxicology of potentially hazardous toxicants with little potential for benefit, safety and ethical concerns are paramount, leaving very few toxicants which can be ethically studied with randomized trials or intervention studies. Observational epidemiology provides a means to study the links between potentially harmful exposures and disease in people.