WA5 Wildlife Toxicology: Forensic Approaches
203 Oregon Ballroom
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() Waterfowl Toxicity of Vanadium Compounds Present at an Oil Refinery Fly Ash Pond.
Rattner, B1, Eisenreich, K1, McKernan, M1, Olsen, G1, Link, W1, McGowan, P2, Knowles, K3, 1 USGS-Patuxent Wildlife Research Center, Laurel, MD, USA2 USFWS-Chesapeake Bay Field Office, Annapolis, MD, USA3 State of Delaware Department Natural Resources and Environmental Control, Dover, DE, USA
ABSTRACT- In the winter of 2003, dead Canada geese (Branta canadensis) were collected at a petroleum refinery fly ash pond that received vanadium pentoxide, and presumably contained several forms of vanadium (V). Pond water contained 476 mg V/L. Liver and kidney tissue of these geese had high V concentrations (>50 ug/g dw), whereas levels of As, Cd, Hg, Ni, Pb, and Tl were low. There was no evidence of infectious agents or ChE-inhibiting pesticide exposure in dead geese. Limited knowledge of V toxicity in birds complicates interpretation, and thus two forms of pentavalent V presumed to be present in the receiving pond were studied. In 7-d single oral dose trials with male mallards (Anas platyrhynchos), the estimated LD50 (95% CI) of sodium metavanadate (NaVO3) was 75.6 mg/kg (44.9-126 mg/kg), and the LD50 of vanadium pentoxide (V2O5) was 113 mg/kg (84.2-157 mg/kg). Several birds that succumbed to NaVO3 exhibited tremors and had ventricular hemorrhage, whereas birds receiving higher doses of V2O5 had hemorrhagic enteritis and sloughing of intestinal mucosa. In a study with geese, the estimated LD50 of NaVO3 was 36.8 mg/kg (12.2-72.2 mg/kg); intoxicated birds appeared un-groomed and subdued, and exhibited tremors, diarrhea, cardiac ventricular lesions, and hemorrhagic intestines with mucosal sloughing. Based on LD50 estimates, geese may be more sensitive (P<0.05) to NaVO3 than mallards. In a chronic trial evaluating V uptake and toxicity, mallards were initially provided feed containing 38 ppm NaVO3, and its concentration was increased weekly by a factor of 1.6. Reduced food intake and weight loss were apparent by week 8 (1036 ppm), and tremors were observed in two drakes during week 9 (1657 ppm). The study was terminated on day 68 (2651 ppm) when half of the treated birds lost 25% of their body weight. Necropsies revealed liver lesions in 5 mallards ingesting NaVO3, and mild hemorrhagic enteritis was observed in 7 individuals. Hematocrit, serum AST activity and P were elevated in treated drakes, while serum Na and Cl were slightly reduced compared to controls. Liver and kidney analyses to determine V uptake are pending. Although overt signs of V toxicity and other endpoints are nonspecific, several pathological observations in our study were consistent with necropsy findings in dead geese collected at the fly ash pond.
Key words: fly ash, vanadium, waterfowl, toxicity