| Patuxent Science Meeting 2006 Poster Abstract |
| | Phosphorus amendment reduces hematological, hepatic and renal |
| | toxicity of lead-contaminated sediment to mallards |
| | Hoffman DJ, Heinz GH, Audet DJ (FWS) |
| | Ingestion of lead-contaminated sediments has resulted in lead poisoning of waterfowl for |
| | decades in the Coeur d'Alene River Basin in Idaho. This study examined whether the addition of |
| | phosphoric acid to contaminated sediments would reduce the bioavailability and toxicity of lead |
| | to mallards (Anas platyrhynchos). Mallards received diets containing 12% clean sediment |
| | (controls) or 12% sediment from each of three different sites containing up to 6990 ug /g lead |
| | (dw) with or without phosphoric acid amendment for 8 weeks. Amendment resulted in |
| | reductions in tissue lead concentrations of up to 64% for blood, 57% for liver, and 77% for |
| | kidney. Unamended lead-contaminated sediment resulted in the following hematological and |
| | plasma alterations: 90% or greater depression of red blood cell ALAD activity, elevated free |
| | erythrocyte protoporphyrin (FEP) concentration, lower hematocrit and hemoblobin |
| | concentrations (as much as 30%), elevated plasma enzyme activities (ALT, CK and LDH-L) and |
| | creatinine concentration. Hepatic effects included: 1.6 fold elevation of liver GSH concentration, |
| | higher GSH S-transferase and GSSG reductase activities, and lower PBSH concentration. |
| | Renal effects included 2.1 fold elevation of kidney GSH concentration with resulting lower GSSG |
| | to GSH ratios, elevated GGT activity, and 1.7 fold increase in lipid peroxidation (TBARs). |
| | Phosphorus amendment restored hematocrit, hemoblobin and plasma enzyme activities so that |
| | they did not differ from controls and lowered elevated FEP concentrations by up to 80%. |
| | Amendment restored all hepatic variables as well as the renal variables TBARS concentration |
| | and GGT activity so they did not differ from controls. Although amendments of phosphorus |
| | substantially reduced the bioavailability of lead and some of the toxic effects, lead |
| | concentrations in the tissues of mallards fed the amended sediments were still above those |
| | Friday, September 22, 2006 |