RISK ASSESSMENT

Risk assessment, when applied to living systems, is the process of det ermining the types and likelihoods of adverse effects that may result from exposure to chemical, biological, or physical hazards. Risk asses sment is used as a tool to help set regulations and guidelines to prev ent or minimize adverse health effects of long-term exposures to low l evels of toxicants. It is also applied to evaluating the safety of pha rmaceuticals, to protecting workers exposed intermittently to hazardou s materials in the workplace, and to evaluating the potential future c onsequences of past or current exposures. Most toxicological informati on used in human health risk assessment comes from in vivo experiments in animals and focuses on the pathological response occurring as a re sult of exposure to the toxicant. Dose and response data must then be extrapolated between individuals and species and from high to low dose s, all of which increase the degree of uncertainty in risk estimates. This presentation provides a general overview of risk assessment, expl oring its strengths, weaknesses, and ongoing evolution. The distinctio n between real and perceived risks is also discussed and is shown to b e driven by the extent to which mechanistic information is available a nd how it is integrated into the risk assessment process. Finally, the presentation explores ways in which pathologists and risk assessors c an work more closely to enhance risk assessment's ability to be a defe nsible tool for evaluating health concerns associated with chronic low -level exposures to toxicants in our environment.