Worker exposure studies.

The first federal pesticide law was enacted in 1910 and was replaced by a more expansive Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) in 1947. In 1972 the Federal Environmental Pesticide Control Act amended the FIFRA from primarily a consumer protection law to a risk/benefit regulation with primary emphases on human and environmental health. "Modern" pesticides were beginning to be developed during World War II. Early attempts to assess human exposure to pesticides seemed to coincide with the development of the organophosphate pesticides in the early to mid 1950s. A continually expanding base of toxicological knowledge has forced increased efforts to refine exposure assessments. Early "patch" dosimeters have evolved to numerous and more refined methods of dosimetry. In addition to studying worker exposure, modern students of pesticide application must also deal with a myriad of situations ranging from field or site reentry to bystander and/or residential exposures. Efforts to standardize pesticide exposure assessments resulted in the 1987 issuance of U.S. EPA Pesticide Assessment Guidelines--Subdivision U--Applicator Exposure Monitoring. In October, 1989 (40 CFR Part 160), the Agency directed that studies initiated on or after that date and submitted in support of pesticide regulation must be conducted under the standards of Good Laboratory Practices. All of these and related factors culminate in the continued development and refinement of methodologies for pesticide exposure assessment.