In this lecture, students will learn that one critical side of toxicologic pursuits is epidemiology or the undertaking by epidemiologists. As defined in Lecture 1 (Slide 15), epidemiology is the study of factors that modify or influence the distribution of diseases in a (human) population. In many ways, toxicology is a discipline also striving to achieve ultimately much the same goals. The main difference between the two sciences is the study tools and subjects that they employ. Toxicologists tend to rely on controlled experiments, in vitro assays, and laboratory animals to pursue their professional interests. Epidemiologists on the other hand involve themselves more in associating human exposures to outcomes. In addition, the two professions are often different in their focus on the same health problems.

Through three historical toxicologic events, students will learn the importance of epidemiology to toxicologic pursuits. They will appreciate that without this side of the input, many toxicologists cannot pursue too far with their professional or academic interests.

Students will learn too that the impact of epidemiology on toxicologic events is not only dynamic, case-dependent, but usually also tremendous. They will find that in some instances, epidemiologic information is needed to assess the adverse effect(s) of a host of pollutants each with their acute toxic effects already well studied. Yet in other cases, the same type of evidence can be used to confirm the mechanism of toxicity in question.