Accumulation of certain long-lived radionuclides by littoral algae and bottom animals

The 90Sr, 137Cs, sup(239,240)Pu and 241Am contents in the seaweed Fucus vesiculosus ranged from 15 to 26, from 5.6 to 11, from 0.10 to 0.30 and from 0.011 to 0.070 Bq kg-1 dry weight, respectively. The mean concentration factor on dry weight basis was 840 for 90Sr, 670 for 137Cs, 39,000 for sup(239,240)Pu and 19,000 for 241Am. In the mussel Macoma baltica samples of the activity concentrations of 90Sr, 137Cs, sup(239,240)Pu and 241Am varied from 9.5 to 18, from <0.2 to 1.9, from 0.016 to 0.097 and from 0.007 to 0.029 Bq kg-1 fresh weight, respectively. The mean CF value on fresh weight basis was 650 for 90Sr, 48 for 137Cs, 5800 for sup(239,240)Pu and 2000 for 241Am. In the intact mussel Mytilus edulis samples of the 90Sr contents varied from 5.1 to 6.1, sup(239,240)Pu contents from 0.0034 to 0.012 and 241Am contents from 0.0026 to 0.0056 Bq kg-1 fresh weight. 137Cs concentrations were usually below detection limit, 0.13 Bq kg-1 fresh weight. The mean contents of 90Sr, 137Cs and sup(239,240)Pu in shells were 22, <0.13 and 0.033 Bq kg-1 fresh weight, respectively. The mean CF values on fresh weight basis for 90Sr, 137Cs, sup(239,240)Pu and 241Am for the intact mussel were 240, <9.1, 1300 and 4300, respectively