- 著者
- Hideo Sugiyama Hiroshi Terada Kimio Isomura Ikuyo Iijima Jun Kobayashi Kiyoshi Kitamura
- 出版者
- 日本毒性学会
- 雑誌
- The Journal of Toxicological Sciences (ISSN:03881350)
- 巻号頁・発行日
- vol.34, no.4, pp.417-425, 2009-08-01 (Released:2009-08-01)
- 参考文献数
- 24
- 被引用文献数
- 9 15
The isotope 210Po was suspected of being involved in the death of a former Russian intelligence agent in 2006 in the UK. Although human exposure to this natural radionuclide in foods is estimated to be high, few studies are available. UNSCEAR Report 2000 does not contain data on 210Po concentrations of foodstuffs in Japan. We analyzed samples of the everyday Japanese diet cooked with foodstuffs purchased at supermarkets in 7 major domestic cities in 2007-2008. 210Po was quantified by alpha spectrometry and natural radionuclides such as 40K by gamma spectrometry. The daily intake and committed effective dose of 210Po, 40K, and other natural radionuclides for Japanese adults were calculated. Daily intake was 0.34-1.84 (mean ± σ : 0.66 ± 0.53) and 68.5-94.2 (81.5 ± 8.5) Bq/d and the committed effective dose was 0.15-0.81 (0.29 ± 0.24) and 0.16-0.21 (0.18 ± 0.02) mSv for 210Po and 40K, respectively, comprising a high percentage of the total exposure. The total of the mean committed effective dose for the two nuclides (0.47 mSv) was higher than the annual effective dose from ingestion of foods reported by UNSCEAR 2000 (0.29 mSv). The mean committed effective dose of 40K in the 7 major Japanese cities was comparable to the global average (0.17 mSv). The dietary exposure of Japanese adults can be characterized by a higher 210Po contribution than in other countries. Of the total daily dietary 210Po exposure (13 food categories excluding water) for adults in Yokohama, about 70% was from fish/shellfish and 20% from vegetables/mushrooms/seaweeds, reflecting preferences of Japanese to eat a considerable amount of fish/shellfish containing high 210Po concentrations.
- 著者
- Gen SUZUKI Ichiro YAMAGUCHI Hiromitsu OGATA Hideo SUGIYAMA Hidenori YONEHARA Fumiyoshi KASAGI Saeko FUJIWARA Yoshimi TATSUKAWA Ippei MORI Shinzo KIMURA
- 出版者
- Journal of Radiation Research Editorial Committee
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.51, no.6, pp.683-689, 2010 (Released:2010-11-23)
- 参考文献数
- 23
- 被引用文献数
- 28
In two previous nation-wide surveys in the late 1980s and early 1990s, Japanese indoor radon concentrations increased in homes built after the mid 1970s. In order to ascertain whether this trend continued, a nation-wide survey was conducted from 2007 to 2010. In total 3,900 houses were allocated to 47 prefectures by the Neyman allocation method and 3,461 radon measurements were performed (88.7% success). The fraction of reinforced concrete / concrete block buildings was 32.4%, similar to the value from national statistics. Arithmetic mean (standard deviation, SD) and geometric mean (geometric SD) of radon concentration after adjusting for seasonal fluctuation were 14.3 (14.7) and 10.8 (2.1) Bq/m3. The corresponding population-weighted values were 13.7 (12.3) and 10.4 (2.0) Bq/m3, respectively. It was estimated that only 0.1% of dwellings exceed 100 Bq/m3, a new WHO reference level for indoor radon. Radon concentrations were highest in houses constructed in the mid 1980s and decreased thereafter. In conclusion, arithmetic mean indoor radon in the present survey was slightly lower than in previous surveys and significant reductions in indoor radon concentrations in both wooden and concrete houses can be attributed to alterations in Japanese housing styles in recent decades.