Day-old mallard (Anas platyryhnchos) ducklings received either a clean sediment (24%) supplemented control diet, Coeur d'Alene River Basin, Idaho (CDARB) sediment (3449 ug/g lead) supplemented diets at 12% or 24%, or a positive control diet (24% clean sediment with equivalent lead acetate to the 24% CDARB diet) for 6 weeks. The 12% CDARB diet resulted in a geometric mean concentration of 396 ppb (WW) brain lead with decreased brain protein and ATP concentrations but increased oxidized glutathione (GSSG) relative to the control diet. The 24% CDARB diet resulted in a concentration of 485 ppb brain lead with lower brain weight and ATP concentration than controls but higher concentrations of reduced glutathione (GSH) and calcium. Lead acetate accumulated twice as well as CDARB derived lead and resulted in histopathological lesions of the brain. With a combination of a suboptimal diet and 24% CDARB, brain lead concentration was higher (594 ppb) than with 24% CDARB in the standard diet, histopathological lesions became apparent and GSH was higher than suboptimal diet controls.