Developmental toxicity of lead-contaminated sediment in Canada geese (Branta canadensis)

Sediment ingestion has recently been identified as an important exposure ro ute for toxicants in waterfowl. The effects of lead-contaminated sediment f rom the Coeur d'Alene River Basin (CDARB) in Idaho on posthatching developm ent of Canada geese (Branta canadensis) were examined for 6 wk. Day-old gos lings received either untreated control diet, clean sediment (48%) suppleme nted control diet, or CDARB sediment (3449 mu g/g lead) supplemented diets at 12%, 24%, or 48%. The 12% CDARB diet resulted in a geometric mean blood lead concentration of 0.68 ppm (ww), with over 90% depression of red blood cell ALAD activity and over fourfold elevation of free erythrocyte protopor phyrin concentration. The 24% CDARB diet resulted in blood lead of 1.61 ppm with decreased hematocrit, hemoglobin, and plasma protein in addition to t he effects just described. The 48% CDARB diet resulted in blood lead of 2.5 2 ppm with 22% mortality, decreased growth, and elevated plasma lactate deh ydrogenase-L (LDH-L) activity. In this group the liver lead concentration w as 6.57 ppm (ww), with twofold increases in hepatic lipid peroxidation (thi obarbituric acid-reactive substances, TBARS) and in reduced glutathione con centration; associated effects included elevated glutathione reductase acti vity but lower protein-bound thiols concentration and glucose-6-phosphate d ehydrogenase (G-6-PDH) activity. The kidney lead concentration in this grou p was 14.93 ppm with subacute renal tubular nephrosis in one of the survivi ng goslings. Three other geese in this treatment group exhibited calcified areas of marrow, and one of these displayed severe chronic fibrosing pancre atitis. Lead from CDARB sediment accumulated less readily in gosling blood and tissues than reported in ducklings but at given concentrations was gene rally more toxic to goslings. Many of these effects were similar to those r eported in wild geese and mallards within the Coeur d'Alene River Basin.