Accumulation and distribution of cadmium in willow ptarmigan

The accumulation and distribution of cadmium (Cd) were studied in willow ptarmigan from a mountainous area in Central Norway. The highest concentrations were found in the kidneys. The liver also accumulated substantial amounts, but heart and breast muscles had low concentrations. There was a significant correlation between the Cd content and age in all tissues. The liver and kidneys showed a rapid increase in Cd content during the ptarmigan's first autumn and winter, but the accumulation seemed to level off when the bird passed its first year of life. Furthermore, a positive correlation was found among all four tissues, the strongest being between liver and kidneys, and the weakest between heart muscle and breast muscle. The ratio of cadmium in liver to cadmium in kidney was less than 1, which indicates a chronic low-level exposure situation. This ratio varied among seasons, being significantly higher in winter/spring than in summer/autumn. In general, the Cd content in the kidneys was approximately 7-10 times that of the liver. Breast muscle had a very low Cd content when the concentration of cadmium in the kidney was less than 75-80 mg kg(-1) of Cd, but the content increased markedly when the kidney contained more Cd than this.