Introduction and overview.

The series of papers contained in this issue of ENVIRONMENTAL HEALTH PERSPECTIVES was presented at a symposium sponsored by the National Institute of Environmental Health Sciences at their facility in Research Triangle Park, North Carolina, on October 27-28, 1981. The objective of the conference was to review the science base for evaluating health effects from human exposure to improperly disposed chemical wastes and to identify areas where new research efforts might be directed. Concerns about the potential for chemical wastes to cause human health effects have come into sharper focus since the Love Canal, New York, problem in late 1978 (1). In 1979, a Subcommittee of the Committee to Coordinate Environmental and Related Programs of the U.S. Department of Health, Education and Welfare reviewed the scientific background for the alleged health effects of residents of the Love Canal area and outlined a strategy for such investigations (2). The review also noted a need for more sensitive tests that might be clinically applicable and the need for expansion of the toxicological information base regarding chemicals that might be present in waste dumps. Once the potential for human exposure to chemicals from a particular dump site becomes recognized, physicians are expected to answer questions about health effects. Another statement of the health questions related to this problem as well as a summary of this Conference and other related activities has recently appeared (3,4). The first question that might be asked is whether or not the chemicals identified at a dump site are toxic to people. The answer here depends on available toxicity data. It was quickly learned from the Love Canal experience that many of the chemicals present in dumps are not "household names," they are not always end products of commercial processes but may in fact be the residuals of such processes or even intermediate or precursor substances. The continuing efforts of the National