366 J. Seo et al.: Radioprotection 2025, 60( 4), 360 – 369
Fig. 4. Concentration factors( CFs) of 137 Cs in the fish species for this study are colored and grouped by body length( S, small; M, medium; L, large). The data for comparison( fishes from seas surrounding Korea in 2015 – 2017, gray bars in right panel) are from Kim et al.( 2019). The dashed line represents the recommended CF value provided by the IAEA. A technical report issued by the IAEA( 2004) indicated that the surface-water fish approximately have a CF of 100, although it is variability based on species-specific characteristics. In addition, the CFs in this study were significantly lower than those observed in freshwater fishes near the Fukushima NPP in 2020 – 2023( 30 to 25,000; Ishii et al., 2020), implying that there was no significant input of artificial radionuclides in the Korean Seas in the present study. We noted that our study had more detailed data on fish CF based on habitat, lifespan, and biological size than the IAEA report, which can assess the factors that cause CF to vary more within the same species. This also suggested that it can provide information on the scale of potential impact in the event of an accident. Future studies based on the large range of fish species observed in the seas surrounding South Korea are necessary to build a comprehensive database of various marine products to enable more accurate comparisons.
The calculated AED of all species by 137 Cs intake ranged from 0.10 10 �6 – 4.81 10 �6 mSv y �1( Fig. 5), which was low or similar to the values observed in marine products( 3.71 – 40.4 10 �6 mSv y �1) in the seas surrounding South Korea( Kim et al., 2019; Lee and Kim, 2021). Kim et al.( 2017) reported that the mean AED of 210 Po, a natural radionuclide in seafood, was 9.4 10 �2 mSv y �1 in South Korea residents. Thus, the calculated AED of all fish species in this study ranged from three to four orders of magnitude lower than that of 210 Po. These values are also significantly lower than the recommended values( ∼1 mSv y �1) from the IAEA and the International Commission on Radiological Protection( ICRP, 2007). These results suggested that 137 Cs activity in marine products is unlikely to pose a significant health risk to humans. However, monitoring of seafood( fish) is only focused on the edible parts( flesh, especially muscle in fish). The necessity of the 137 Cs database in various parts of fish is also suggested to understand the behavior of 137 Cs in fish, and to establish detailed safety recommendations for 137 Cs in marine products. Furthermore, considering that the Korean Peninsula is located next to countries highly dependent on nuclear power, continuous monitoring of various species is necessary to provide background data for the preparation for potential accidents.
5 Conclusions
We investigated the distribution of 137 Cs according to size and body part in fish( collected in 2021 – 2022) migrating around the Korean seas for the first time. In these fish species( armored weaselfish, croaker, flounder, hairtail, catfish, conger, and mackerel), no particular accumulation patterns were observed according to body size. The highest 137 Cs activity was observed in the body parts, with differences between species and sizes. The annual effective doses of 137 Cs related to seafood consumption for these fish in South Korea were estimated to be 0.10 10 to 4.81 10 �6 mSv y �1, which