ACCUMULATION IN AND EFFECTS OF LEAD AND CADMIUM ON WATERFOWL AND PASSERINES IN NORTHERN IDAHO

Waterfowl and passerines in northern Idaho in 1987 had high levels of lend in their blood and tissues that originated primarily from mining and smelting activities. Four Canada geese (Branta canadensis) and one common goldeneye (Bucephala clangula) found dead contained 8 to 38 mu g/g (wet mass) of lead in their livers. These levels exceed the lower lethal limit of 5 mu g/g in experimental birds. Two of the Canada gee se (one each from the contaminated and reference areas) died with inge sted lead shotgun pellets (shot) in their gizzards, whereas the other three birds from the contaminated area contained no ingested shot and evidently died from ingesting environmental lend in sediment or biota. Lead burdens in most American robins (Turdus migratorius) and mallard s (Anas platyrhynchos) were high, whereas those in tree swallows (Tach ycineta bicolor) were slightly elevated. Lead accumulated to potential ly hazardous levels in blood and tissues of some nestling robins (maxi ma of 0.87 mu g/g in blood and 5.6 mu g/g in fiver) and mallards (maxi ma of 10.2 mu g/g in blood and 2.8 mu g/g in liver). In mallards, lead levels and associated physiological characteristics of blood were sig nificantly different in juveniles (HY) versus adults (AHY). Activity o f delta-aminole-vulinic acid dehydratase (ALAD) was about 87 to 95% lo wer than values for control birds in experimental studies. Activity of ALAD was significantly inversely cor related with blood lead levels. Cadmium was detected in kidneys of most birds, but even the maximum co ncentration of 7.5 mu g/g in an AHY mallard was below known harmful le vels.