Distribution of ¹³⁷ Cs in fishes from the seas surrounding Korea: its bioaccumulation and annual effective dose

The distribution of artificial radionuclide 137 Cs in fish from the seas surrounding the Korean Peninsula was investigated to estimate the bioaccumulation and annual effective dose rate according to size. The activity of 137 Cs in the muscles of seven fish species (armored weaselfish, croaker, flounder, hairtail, catfish, conger, and mackerel) was in the range of 50–269 mBq kg −1 , which was similar to that observed in Korean Seas between 2017 and 2021 (<22 to 288 mBq kg −1 ). The results showed no particular enrichment pattern based on the fish body size. The activity of 137 Cs in dissected parts, such as the skin, inner organs, gills, and gonads, was in the range of 29–311 mBq kg −1 , and the parts where 137 Cs was most enriched varied among fish species and growth stages. The annual effective dose rate of 137 Cs provided by the seafood consumption of these fish in South Korea was estimated to be 0.10–4.81 × 10 −6 mSv y −1 , which is insignificant relative to that of natural radionuclides such as 210 Po. Thus, these results indicated that annual dose rate by the 137 Cs dose not have a noticeable impact on marine organisms, however, continuous monitoring with various species of fish is necessary to evaluate possible future nuclear power plant accidents.