Detection and activity of iodine-131 in brown algae collected in the Japanese coastal areas |
| |
Authors: | Takami Morita Kentaro Niwa Hiromi Kasai Kou Nishiutch Waichiro Godo Yoshihiro Hayashi Tomokazu Nishigaki Hisamichi Aratake Hiroshi Hashimoto Sigeyoshi Otosaka |
| |
Affiliation: | a Fisheries Research Agency, 15F Queen's Tower B, Minato Mirai Nishi-ku, Yokohama, Kanagawa 220-6115, Japan b Ushimado Marine Laboratory, Okayama University, 130-17, Kashino 130-17, Ushimado, Setouchi, Okayama 701-43, Japan c Kochi Prefectural Fisheries Experimental Station, Uranoutchhaigata 1153-23, Susaki, Kouch, 785-0167 Japan d Kyoto Prefectural Agriculture, Forestry and Fisheries Technology Research Center, Odashukuno, Miyazu, Kyoto, 626-0052 Japan e Miyazaki Prefectural Fisheries Experimental Station, Aoshima 6-16-3, Miyazaki, Miyazaki 889-2162 Japan f Ibaragi Prefectural Fisheries Experimental Station, Mitsuzuka3551-8, Hiraiso, Hitachnaka, Ibaragi, 311-1203 Japan g Fukui Prefectural Fisheries Experimental Station, Urasoko 23-1, Tsuruga, Fukui, 914-0843 Japan h Japan Atomic Energy Agency, Shirakata Shirane 2-4, Tokai, Ibaraki, 319-1195 Japan i Research Reactor Institute, Kyoto University, Kumatori-cho, Osaka, 590-0494 Japan |
| |
Abstract: | Iodine-131 (physical half-life: 8.04 days) was detected in brown algae collected off the Japanese coast. Brown algae have been extensively used as bioindicators for radioiodine because of their ability to accumulate radionuclides in high concentration factors. The maximum measured specific activity of 131I in brown algae was 0.37 ± 0.010 Bq/kg-wet. Cesium-137 was also detected in all brown algal samples used in this study. There was no correlation between specific activities of 131I and 137Cs in these seaweeds. The specific activity of 137Cs ranged from 0.0034 ± 0.00075 to 0.090 ± 0.014 Bq/kg-wet. Low specific activity and minimal variability of 137Cs in brown algae indicated that past nuclear weapon tests were the source of 137Cs. Although nuclear power stations and nuclear fuel reprocessing plants are known to be pollution sources of 131I, there was no relationship between the sites where 131I was detected and the locations of nuclear power facilities. Most of the sites where 131I was detected were near big cities with large populations. Iodine-131 is frequently used in diagnostic and therapeutic nuclear medicine. On the basis of the results, we suggest that the likely pollution source of 131I, detected in brown seaweeds, is not nuclear power facilities, but nuclear medicine procedures. |
| |
Keywords: | Brown alga Marine alga 131I 137Cs Nuclear medicine procedures Nuclear power facility |
本文献已被 ScienceDirect 等数据库收录! |
|