The United States Environmental Protection Agency (EPA) is conducting a reassessment of the health and environmental effects of dioxins and dioxin-like compounds. This reassessment began in 1991 and is being coordinated by EPA's Office of Research and Development. First drafts of the health and exposure documents were released in August of 1992. The second drafts of these documents were released in September of 1994. In September of 1994, the EPA announced a program known as the Dioxin Exposure Initiative (DEI). It was created with the intended purpose of providing source, exposure, and environmental trend information to address the critical data needs identified during the reassessment program as well as providing information to the Agency in its emerging dioxin strategy. A key result of the exposure portion was that 90% of the human exposure to dioxins occurs via food ingestion, primarily through animal food products of high fat content including meats, dairy products, and fish. The exposure portion also .concluded that there is a need for further data on quantifiable levels of specific dioxin congeners in the general food supply. This project, National Dioxin Air Monitoring Network (NDAMN) Project is intended to concurrently serve four purposes: 1) provide data useful for calibrating long -range transport models used to estimate air concentrations of these compounds; 2) provide air monitoring capability for the occurrences and levels of dioxin-like compounds in primary areas where animal feeds used to feed livestock are grown; 3) proVide for the air monitoring of dioxin-like compounds in different regions of the United States; and 4) provide results that can be used for the calculation of depositional flux.