Mercury Contamination in Domestic Ducks in Geita, Northwest Tanzania

Total mercury concentrations (THg) were determined in domestic ducks (Anas platyrhncha) tissues in Mgusu Village, Geita District NW Tanzania. Elevated mercury levels were found in all tissue samples and showed a trend of increasing mercury concentration with weight/age of the poultry. Highest total mercury (THg) levels (mg/kg) in domestic ducks were found in liver (ducklings: 30.5; juvenile: 254.1; mature ducks: 590.2), followed by gizzards (ducklings: 45.9; juvenile: 230.3; mature: 254.6), lungs (ducklings: 12.2; juvenile: 29.1; mature: 46.9) and feathers (ducklings: 0.1; juvenile: 62.1; mature: 198.3). Corresponding THg statistical values (mg/kg) for the tissues increased with age and weight. Highest THg values were found in liver and gizzard suggesting prevalent mercury accumulation in body through ingestion. Low values of THg in lungs were correlated with inhalation of atmospheric Hg, while in feathers they were correlated to THg exposure during bathe in amalgamation pond waters.