INTUITIVE TOXICOLOGY - EXPERT AND LAY JUDGMENTS OF CHEMICAL RISKS

Human beings have always been intuitive toxicologists, relying on thei r senses of sight, taste, and smell to detect harmful or unsafe food, water, and air. As we have come to recognize that our senses are not a dequate to assess the dangers inherent in exposure to a chemical subst ance, we have created the sciences of toxicology and risk assessment t o perform this function. Yet despite this great effort to overcome the limitations of intuitive toxicology, it has become evident that even our best scientific methods still depend heavily on extrapolations and judgments in order to infer human health risks from animal data. Many observers have acknowledged the inherent subjectivity in the assessme nt of chemical risks and have indicated a need to examine the subjecti ve or intuitive elements of expert and lay risk judgments. Such an exa mination was begun by surveying members of the Society of Toxicology a nd the lay public about basic toxicological concepts, assumptions, and interpretations. The results demonstrated large differences between t oxicologists and laypeople, as well as differences among toxicologists working in industry, academia, and government. In addition, toxicolog ists were found to be sharply divided in their opinions about the abil ity to predict a chemical's effect on human health on the basis of ani mal studies. These results place the problems of risk communication in a new light. Although the survey identifies misconceptions that exper ts should clarify for the public, it also suggests that controversies over chemical risks may be fueled as much by limitations of the scienc e of risk assessment and disagreements among experts as by public misc onceptions.