Collation of Strontium Concentration Ratios from Water to Aquatic Biota Species in Freshwater and Marine Environments and Factors Affecting the Ratios.

Affiliation

Tagami K(1), Fukaya Y(2), Hirayama M(2), Uchida S(1)(2).
Author information:
(1)National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan.
(2)Safety and Environment Analysis Unit, Japan NUS Co., Ltd., Nishi-Shinjuku Prime Square 5F, 7-5-25 Nishi-Shinjuku, Shinjuku-Ku, Tokyo 160-0023, Japan.

Abstract

The fate of strontium-90 (90Sr) from water to aquatic biota is of concern since the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident because of continuous small 90Sr releases to the seawater from the FDNPP site. The Japanese diet includes many edible marine and freshwater species, and the environmental parameter, that is, the concentration ratio (CR) from water to biota, is useful to estimate the potential 90Sr intake, especially from frequently consumed seafoods. However, widely used CR data for radiation dose assessment only have provided values for biota types such as fish, crustaceans, macroalgae, and so forth, and thus, it is difficult to identify specific data for each species. In this study, therefore, we collated CR data of Sr for aquatic biota by surveying available open data sources from the 1950s to 2019, not only for edible parts but also for whole and inedible parts. In total, we obtained 3800 CR data: 3013 data for marine biota, 28 data for brackish water biota, and 759 data for freshwater biota. The results showed that species-specific CRs may decrease the uncertainties compared to those published in IAEA documents; however, different diets and living areas by species may lead to different uncertainties for different species.