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PH25 Wildlife Ecotoxicology II
(PH278) Influence of oral 2,4-dinitrotoluene (DNT) exposure on the northern bobwhite (Colinus virginianus).
Johnson, M1, Michie, M1, Suski, J1, 1 U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD, USA
ABSTRACT- Military activities associated with training, munitions manufacturing, and demilitarization has resulted in soil residues of munition compounds and their breakdown products. Two isomers of dinitrotoluene (2,4 and 2,6) are often found in soil associated with those activities at considerable concentrations. Consequently, issues regarding the effects of exposure to birds that visit these habitats require evaluation. To provide toxicity data useful to a risk assessment approach, we used a controlled dosing regime using the Northern Bobwhite (Colinus virginianus). Northern Bobwhites were orally dosed for 60 days following a 14-day range finding study and the determination of a LD50 using the up/down method. The LD50 was determined to be 55 mg/kg using corn oil as a vehicle. Most individuals were moribund or died 60 hrs post exposure. Morbidity and death occurred at similar exposures and times during the 14-d range-finding study at dosing regimens of 35 and 55, but not at 15, 5, and 0.5 mg/kg-d. Morbidity/mortality occurred in the 60-d study during the first week of exposure at exposures of 25 and 15, but not at 5, 1, and 0 mg/kg-d. Each treatment consisted of 12 birds/sex (N=120). Overt signs of toxicity occurred with both sexes at the onset of exposure. Signs included weight loss, diarrhea, and lethargy. Gross observations of sacrificed individuals found food in the gizzard yet body weight and food consumption decreased. No dose related changes in egg production, body weight, or feed consumption were found. These data suggests that 2,4-DNT may affect the movement of food in the gastrointestinal tract at high concentrations.
Key words: energetics, Dinitrotoluene, birds, DNT
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