ABSTRACT
Agency for Toxic Substances and Disease Registries (ATSDR) was set up in 1983 as a result of the legislation entitled the Comprehensive Environmental Response, Compensation and Liability Act, passed in 1980, that also established the Superfund to manage and ameliorate the effects of hazardous waste sites. The causes of some increasingly common chronic diseases in developed countries remain largely unknown. Exposure assessment entails numerous techniques to measure or estimate the contaminant, its source, the environmental media of exposure, avenues of transport through each medium, chemical and physical transformations, routes of entry to the body, intensity and frequency of contact, and its spatial and temporal concentration patterns. The grey literature includes state-generated reports and reports on analyses conducted by researchers involved in litigation, some of which contain critical information. The role of the researcher in evaluating aggregate statistics, in order to detect trends or patterns that are not apparent at a local level, is critical.
