Our knowledge about the distribution of exposures to toxic chemicals in various communities is limited. Only about 6% of approximately 1,400 toxic chemicals have been identified in surveys. Even for those chemicals that are measured, information is often insufficient to identify smaller populations at high risk. The question is whether information about the distribution of diseases in communities can help identify environmental risks, indicate areas of concern, and thus substitute exposure information. Thyroid disorders represent a large group of diseases that cannot be recorded into registries because of the lack of clear caseness; community-based monitoring of subtle health effects is needed. Thus, to identify potential health risks in communities, epidemiologic studies including effect and human exposure monitoring are necessary, However, to overcome the limitation of nonsystematic case studies, the development of a network of exposed communities concerned about exposures is proposed, A network would provide assessments of exposures and health outcomes, with different communities mutually serving as exposed and control groups. Such a network would foster communication and prevention measures within communities often left out of the dissemination of information about risks identified in studies conducted with residents of these communities.
