Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, 2-15 Natushima-cho, Yokosuka, Kanagawa, 2370061, Japan.
Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, 3058577, Japan; Institute of Environmental Radioactivity, Fukushima University, Fukushima, 9601296, Japan.
J Environ Radioact. 2022 Oct;251-252:106949. doi: 10.1016/j.jenvrad.2022.106949. Epub 2022 Jun 21.
We measured dissolved radiocesium (Cs and Cs) in surface seawater collected in the western subarctic area of the North Pacific Ocean, Bering Sea, and Arctic Ocean in 2019 and 2020. The radiocesium released from the accident of the Fukushima Dai-ichi nuclear power plant (FNPP1) in 2011 was still observed in these areas (∼2 Bq m decay-corrected to the date of the accident). In 2019/2020, the FNPP1-derived radiocesium concentrations in the Bering Sea and the Chukchi Sea, which is a marginal sea of the Arctic Ocean connecting the Bering Sea to the Arctic Ocean, were within the range of those observed in 2017/2018. On the other hand, the FNPP1-derived radiocesium was detected in the Arctic Ocean farther north of the Chukchi Sea in 2019/2020 for the first time. This was probably derived from the long-range transport of the FNPP1-derived radiocesium from the North Pacific coastal area of Japan to the Arctic Ocean through the Bering Sea during the past decade. The transport of the FNPP1-derived radiocesium from the Bering Sea to the western subarctic area in 2019/2020 is not clear, which implies the retainment of the FNPP1-derived radiocesium within the Bering Sea.
我们测量了 2019 年和 2020 年在北太平洋西部亚北极区、白令海和北冰洋采集的表层海水中的溶解放射性铯（Cs 和 Cs）。2011 年福岛第一核电站（FNPP1）事故释放的放射性铯仍在这些地区被观测到（~2 Bq m，校正到事故日期的衰减）。在 2019/2020 年，白令海和楚科奇海（北冰洋的一个边缘海，连接白令海和北冰洋）的 FNPP1 衍生放射性铯浓度处于 2017/2018 年观测到的范围内。另一方面，在 2019/2020 年，首次在楚科奇海以北的北冰洋中检测到 FNPP1 衍生放射性铯。这可能是由于过去十年中，来自日本北太平洋沿海地区的 FNPP1 衍生放射性铯通过白令海长距离输运到北冰洋的结果。2019/2020 年 FNPP1 衍生放射性铯从白令海输运到西部亚北极区的情况尚不清楚，这意味着 FNPP1 衍生放射性铯在白令海中被滞留。
