PH25 Wildlife Ecotoxicology II
Exhibit Hall
8:00 AM - Thursday
(PH286) Are lower Roanoke River wood ducks at risk from PCDD / PCDF exposure?
Augspurger, T1, Orazio, C2, Echols, K2, Peterman, P2, Tillitt, D2, 1 U.S. Fish and Wildlife Service, Raleigh, NC, USA2 U.S. Geological Survey, Columbia, MO, USA
ABSTRACT- Polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were measured in eggs of wood ducks (Aix sponsa) nesting downstream of a paper mill with a history of PCDD / PCDF contamination. Using WHO toxicity equivalency factors for birds, 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent (TEQ) concentrations were 2 to 31 pg/g wet weight in eggs (n=40) collected during 2002 and 2003. These concentrations were significantly greater than those from a nearby reference site (< 2 pg/g wet weight). In eggs collected from nests along the lower Roanoke River and tributaries, 2,3,7,8-TCDF accounted for about 70 percent of the TEQs; the percent contribution from 2,3,7,8-TCDF tended to be greater in the most contaminated eggs. Geometric mean wood duck egg TEQ concentrations (7 pg/g wet weight) were about 5-times less than those measured from this site in 1992 and 1993, and they approximate those known to cause developmental anomalies in domestic chicken embryos, a species which is sensitive to PCDDs / PCDFs. To further examine the importance of this exposure, eggs of wood ducks collected from a reference site were injected with 2,3,7,8-TCDD at doses from 0 to 1,500 pg/g wet weight. Statistically significant embryo mortality was not observed at these concentrations. Results from histological (liver, heart, brain, and eye) and biochemical (hepatic concentrations of oxidized and reduced glutathione) evaluations addressing potential sublethal effects are pending.
Key words: birds, dioxin, avian, North Carolina