Risk Assessment of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin Equivalents in Tissue Samples from Three Species in the Denver Metropolitan Area
Abstract:Polychlorinated dibenzo- p -dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are possible contaminants of concern in areas with a history of organochlorine pesticide production or various other industrial chlo-rination processes. The Rocky Mountain Arsenal (RMA), a Superfund site near Denver, CO, has a history of various industrial processes that may have led to the release of these compounds and subsequent exposure and risk to surrounding biota. PCDDs, and PCDFs, and non- and mono-ortho-substituted PCBs cause a common set of toxic effects that are mediated through the aryl-hydrocarbon receptor (AhR). The total AhR-medi-ated activity of tissue samples collected from the RMA and surrounding reference areas was determined by both instrumental and bioanalytical techniques. Concentrations of dioxin equivalents were measured in carp eggs, great horned owl livers, and American kestrel eggs collected from the RMA and from off-post reference sites. Detected concentrations of dioxin equivalents were used to assess risk to exposed wildlife through the use of Toxicity Reference Values (TRVs) and Hazard Quotients (HQs). Carp and kestrel egg samples had small HQ values, while some great horned owls had relatively large HQ values, indicating exposure to and possible risks from dioxins or dioxin-like chemicals.
Document Type: Research Article
Affiliations: Dept. of Zoology, National Food Safety and Toxicology Center, and Institute for Environmental Toxicology, Michigan State University, East Lansing, MI 48824
Publication date: March 1, 2000