Radiation Dose Estimation from the Analysis of Radionuclides in Marine Fish of the Bay of Bengal

Abstract

The concentrations of some natural radionuclides and fallout radionuclides in fifteen species of marine fish samples from the Bay of Bengal were determined using a p-type coaxial high purity Ge detector with 23% relative efficiency. In some body parts of the fish samples contamination by 137Cs radionuclide was observed, 134Cs was below detection level of 0.07 Bq.kg-1. The 137Cs concentrations in fish samples varied from 0.04 ± 0.03 to 1.50 ± 0.33 Bq.kg-1. The potassium concentration was calculated from the observed 40K activity concentration: these values ranged from 0.54 to 2.6 g.kg-1. 226Ra and 228Ra concentrations of 0.10 to 1.66 Bq.kg-1 and 0.39 to 1.35 Bq.kg-1 were found, respectively. The annual effective doses due to ingestion of radionuclides from fish have been estimated to be 0.36 µSv for the natural 226Ra and 228Ra isotopes and only 3.5 nSv (0.0035 µSv) for the fallout radionuclide 137Cs. The contribution of 137Cs amounts to less than 2% of the effective dose caused by the naturally occurring 40K.