Advances in dietary exposure research at the United States Environmental Protection Agency-National Exposure Research Laboratory.

The United States Environmental Protection Agency-National Exposure Research Laboratory's (USEPA-NERL) dietary exposure research program investigates the role of diet, including drinking water, as a potential pathway of human exposure to environmental contaminants. A primary program goal is to establish measurement methods for ingestion that are consistent with approaches used by the USEPA to measure inhalation and dermal exposures, and, hence, total exposure. Research has focused on developing and field-testing measurement methods for personal dietary monitoring, known as duplicate-diet methodology, and on the methods to support analyses of environmental contaminants in foods and beverages. Guidance for measuring personal dietary exposure has been developed for the researcher performing measurements in which there is an established or potential route of exposure to environmental contaminants from foods consumed. Useful information for other types of dietary exposure assessment can be found in existing food consumption and food residue databases. Several of the major food databases have been integrated into an exposure model that provides estimates of potential dietary exposure and identifies potentially highly exposed people for guidance in exposure monitoring. Another component of this research program explores priority, diet-related issues to identify and reduce exposures from foods and beverages. The methods of preparing mercury-contaminated fish by Native Americans and children exposed to lead-laden environments are currently under investigation. Other research is designed to improve our understanding of the process of excess food contamination and the reduction of dietary exposure. Additional research needs are summarized. An overview of the USEPA-NERL dietary exposure program is presented and research discussed in this paper is described in the following papers in this issue.