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 |