Bioaccumulation, inter-organ distribution, and retention of waterborne and dietary 241Am in silver crucian carp

The bioaccumulation of actinide Am-241 from food and water in bodies of freshwater fish (Carassius auratus gibelio, silver crucian carp) has been investigated in laboratory experiments. Homogenized biomass of submerged macrophytes labeled with Am-241 was injected into the fish gullet. Internal organs and tissues of crucian carp could be ranked according to activity concentration of dietary Am-241 after depuration of the digestive tract as follows: liver > gonads > bones > muscles. Accumulation of waterborne Am-241 in internal organs and tissues of crucian carp mainly occurred via the digestive tract. While the concentration of Am-241 in liver of crucian carps decreased during depuration time, its concentration in bones increased indicating slower transfer of Am-241 to skeleton compared to muscles and liver. The retention of dietary Am-241 in the bodies of crucian carp reached 35%-46% of ingested Am-241: 20%-31% was retained in liver, 0.6%-0.8% in skeleton, and 1.4%-2.0% in muscles. The concentration factor of Am-241 from water was 0.4 for the whole body, 0.3 for liver, 0.01 for muscles, and 0.01 for skeleton. Trace amounts of Am-241 were recorded in viscera and muscles of a wild population of silver crucian carp inhabiting a radioactively contaminated part of the Yenisei River.