Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from seawater

Most of the activity prior to and after depuration is found to be in the shell, with indications that shell and soft parts accumulate and depurate 131I at a similar rate. The operculum displays the highest specific activity of all fractions with a concentration factor of 750 l kg−1. Concentration factors for whole winkle, shell, soft parts and digestive gland are in the order of 40-60 l kg−1, higher than the IAEA recommended CF value for iodine in molluscs of 10 l kg−1. The 131I CF in winkles is closer to that of the conservative radionuclides 99Tc and 137Cs than the CF of the particle reactive radionuclides 239,240Pu and 241Am.