Monzen Satoru, Hosoda Masahiro, Osanai Minoru, Tokonami Shinji
Department of Radiological Life Sciences, Division of Medical Life Sciences, Graduate School of Health Sciences, Hirosaki University, Hirosaki, Aomori, Japan.
Research Institute for Radiation Emergency Medicine, Hirosaki University, Hirosaki, Aomori, Japan.
PLoS One. 2014 Jul 7;9(7):e101650. doi: 10.1371/journal.pone.0101650. eCollection 2014.
Numerous radionuclides were released from the Fukushima Daiichi Nuclear Power Station (F1-NPS) in Japan following the magnitude 9.0 earthquake and tsunami on March 11, 2011. Local residents have been eager to calculate their individual radiation exposure. Thus, absorbed dose rates in the indoor and outdoor air at evacuation sites in the Fukushima Prefecture were measured using a gamma-ray measuring devices, and individual radiation exposure was calculated by assessing the radiation dose reduction efficiency (defined as the ratio of absorbed dose rate in the indoor air to the absorbed dose rate in the outdoor air) of wood, aluminum, and reinforced concrete buildings. Between March 2011 and July 2011, dose reduction efficiencies of wood, aluminum, and reinforced concrete buildings were 0.55 ± 0.04, 0.15 ± 0.02, and 0.19 ± 0.04, respectively. The reduction efficiency of wood structures was 1.4 times higher than that reported by the International Atomic Energy Agency. The efficiency of reinforced concrete was similar to previously reported values, whereas that of aluminum structures has not been previously reported. Dose reduction efficiency increased in proportion to the distance from F1-NPS at 8 of the 18 evacuation sites. Time variations did not reflect dose reduction efficiencies at evacuation sites although absorbed dose rates in the outdoor air decreased. These data suggest that dose reduction efficiency depends on structure types, levels of contamination, and evacuee behaviors at evacuation sites.
2011年3月11日发生9.0级地震及海啸后，日本福岛第一核电站（F1-NPS）释放出大量放射性核素。当地居民一直渴望计算自己的个人辐射暴露量。因此，使用伽马射线测量设备对福岛县避难场所室内外空气中的吸收剂量率进行了测量，并通过评估木材、铝和钢筋混凝土建筑物的辐射剂量降低效率（定义为室内空气中吸收剂量率与室外空气中吸收剂量率之比）来计算个人辐射暴露量。在2011年3月至2011年7月期间，木材、铝和钢筋混凝土建筑物的剂量降低效率分别为0.55±0.04、0.15±0.02和0.19±0.04。木结构的降低效率比国际原子能机构报告的高出1.4倍。钢筋混凝土的效率与先前报告的值相似，而铝结构的效率此前尚未有报告。在18个避难场所中的8个，剂量降低效率与距F1-NPS的距离成正比增加。尽管室外空气中的吸收剂量率有所下降，但时间变化并未反映避难场所的剂量降低效率。这些数据表明，剂量降低效率取决于结构类型、污染水平以及避难场所内撤离人员的行为。
