Transition of Radioactive Cesium Deposition in Reproductive Organs of Free-Roaming Cats in Namie Town, Fukushima.


Fujishima Y(1), Kino Y(2), Ono T(2), Goh VST(3), Nakata A(4), Ariyoshi K(5), Kasai K(3), Toyoda T(6), Akama T(7), Tazoe H(8), Yamada M(9), Yoshida MA(10), Miura T(11).
Author information:
(1)Department of Radiation Biology, Tohoku University School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
(2)Department of Chemistry, Tohoku University Graduate School of Science, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
(3)Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.
(4)Department of Pharmacy, Faculty of Pharmaceutical Science, Hokkaido University of Science, Sapporo, 7-Jo 15-4-1 Maeda, Teine, Sapporo, Hokkaido 006-8590, Japan.
(5)Integrated Center for Science and Humanities, Fukushima Medical University, 1 Hikariga-oka, Fukushima 960-1295, Japan.
(6)Toyoda Animal Hospital, 402-7 Kanairo, Nihonmatsu, Fukushima 964-0915, Japan.
(7)Akama Industry Co., Ltd., 259-3 Babauchi, Kakura, Namie, Fukushima 979-1536, Japan.
(8)Department of International Cooperation and Collaborative Research, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki 036-8564, Japan.
(9)Central Laboratory, Marine Ecology Research Institute, 300 Iwawada, Onjuku, Isumi, Chiba 299-5105, Japan.
(10)Institute of Chromosome Life Science, 11-5-409, Fukuokachuo 2-Chome, Fujimino-shi, Saitama 356-0031, Japan.
(11)Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine, Hirosaki University, 66-1 Hon-cho, Hirosaki, Aomori 036-8564, Japan.


We investigated the internal contamination by radioactive cesium associated with the FDNPP accident, in the testes or uterus and ovaries of free-roaming cats (Felis silvestris catus), which were protected by volunteers in the Namie Town, Fukushima. A total of 253 samples (145 testes and 108 uterus and ovaries) obtained from adult cats and 15 fetuses from 3 pregnant female cats were measured. Free-roaming cats in Namie Town had a higher level of radioactive contamination in comparison to the control group in Tokyo, as the 134Cs + 137Cs activity concentration ranged from not detectable to 37,882 Bq kg-1 in adult cats. Furthermore, the radioactivity in the fetuses was almost comparable to those in their mother's uterus and ovaries. The radioactivity was also different between several cats protected in the same location, and there was no significant correlation with ambient dose-rates and activity concentrations in soil. Moreover, radioactive cesium levels in cats decreased with each year. Therefore, it is likely that decontamination work in Namie Town and its surroundings could affect radioactive cesium accumulation, and thus possibly reduce the internal radiation exposure of wildlife living in contaminated areas. It is hence necessary to continue radioactivity monitoring efforts for the residents living in Namie Town.