Characterization of potential endocrine-related health effects at low-doselevels of exposure to PCBs

This article addresses issues related to the characterization of endocrine- related health effects resulting from low-level exposures to polychlorinate d biphenyis (PCBs). it is not intended to be a comprehensive review of the literature but reflects workshop discussions. "The Characterizing the Effec ts of Endocrine Disrupters on Human Health at Environmental Exposure Levels ," workshop provided a forum to discuss the methods and data needed to impr ove risk assessments of endocrine disrupters. This article contains an over view of endocrine-related (estrogen and thyroid system) interactions and ot her low-dose effects of PCBs. The data set on endocrine effects includes re sults obtained from mechanistic methods/ and models (receptor based, metabo lism based, and transport protein based), as well as from in vivo models, i ncluding studies with experimental animals and wildlife species. Other low- dose effects induced by PCBs, such as neurodevelopmental and reproductive e ffects and endocrine-sensitive tumors, have been evaluated with respect to a possible causative linkage with PCB-induced alterations in endocrine syst ems. In addition. studies of low-dose exposure and effects in human populat ions are presented and critically evaluated. A list of conclusions and reco mmendations is included.