Evaluating Terrestrial Food Chain Impacts Near Sources of Dioxin Release in U.S. EPA Risk Assessments
Prior to the mid 1980s, assessments of health impacts from dioxin-like compounds released into the air only evaluated the inhalation exposure pathway. In the latter 1980s it was demonstrated that consumption of animal food products is the principal source of exposure to dioxin-like compounds. When evaluating the environmental and human health impacts of dioxin-like releases from a given source, the United States Environmental Protection Agency (EPA) currently focuses on the impacts to soils and plants on nearby farms where terrestrial food animals are raised. Exposure is evaluated for consumption of these vegetable/fruit and terrestrial animal farm products by the farming family. Also, dioxins can affect surficial water bodies and fish. However, this paper only evaluates terrestrial farming exposure scenarios in representative EPA dioxin risk assessments. Assessments summarized here were conducted as a part of either national rule-making activities or of site-specific regulatory decision-making processes. The results of the review are arrayed in a table showing similarities and differences in these assessments.