Risk assessment of environmental chemicals.

Risk assessment is an evolving process, based not only upon toxicology but also upon a broad background of knowledge in fields ranging from chemistry to physiology and molecular biology and from environmental transport processes to applied statistics. Risk assessment procedures must be continually updated to reflect advances in these basic sciences. This review addresses several areas of risk assessment that are receiving heightened attention, including neurotoxicity, immunotoxicity, reproductive and developmental toxicity, genotoxicity, carcinogenicity, and toxicokinetics and modeling. Risk assessors must work with the scientific community at large to incorporate advances in the basic sciences into their extrapolations. A concerted attempt to better define the variability and decrease the uncertainty of hazard estimates will result in more efficient protection of the public and the environment against toxic hazards.