ABSTRACT
Birds accumulate cadmium in their tissues, primarily through their diets. This chapter considers the following major topics: uptake and elimination, metallothionein induction, tissue distribution and accumulation, toxic effects and relationships between tissue concentrations and toxic effects. In vitro studies on embryonic chick femurs indicated that cadmium increases resorption of calcium and phosphorus, inhibits bone matrix formation and decreases bone mineral content. While the relationships between cadmium exposure, bone decalcification and survivorship were correlative and the possible unifying effect of age on the patterns of the observed relationships was not considered, the chapter remains the only example of a free-living population of birds possibly experiencing toxic effects from exposure to cadmium. Cadmium levels in birds vary according to diet, ecosystem use, age, and physiological status. They are higher in seabirds, especially pelagic species, than in most terrestrial birds, freshwater birds, and shorebirds.
