Ishikawa Tetsuo, Takahashi Hideto, Yasumura Seiji, Ohtsuru Akira, Sakai Akira, Ohira Tetsuya, Sakata Ritsu, Ozasa Kotaro, Akahane Keiichi, Yonai Shunsuke, Kurihara Osamu, Kamiya Kenji, Abe Masafumi
Radiation Medical Science Center for the Fukushima Health Management Survey, Fukushima Medical University, Hikarigaoka 1, Fukushima City, 960-1295, Japan.
J Radiol Prot. 2017 Sep 25;37(3):584-605. doi: 10.1088/1361-6498/aa6649. Epub 2017 Jun 15.
After the Fukushima Dai-ichi Nuclear Power Plant accident, the Fukushima Health Management Survey (FHMS) was launched. The Basic Survey, a component of FHMS, is a questionnaire used to survey residents across the Fukushima Prefecture about their behaviour in the first 4 months after the accident. The questionnaire findings are used to determine individual external doses by linking behaviour data to a computer programme with daily gamma ray dose rate maps, drawn after the accident. Through 30 June 2015, the response rate was only 27.2% (558 550 population), indicating that the findings might not be generalisable because of poor representativeness of the population. The objective of this study was to clarify if the data from the FHMS Basic Survey were representative of the entire population, by conducting a new survey to compare the external doses between non-respondents and respondents in the previous survey. A total of 5350 subjects were randomly selected from 7 local regions of Fukushima Prefecture. An interview survey was conducted with the non-respondents to the FHMS Basic Survey. A total of 990 responses were obtained from the previous non-responders by interview survey. For the regions Kempoku, Kenchu, Kennan, Aizu, Minami-Aizu, Soso, and Iwaki, differences in mean effective dose (95% confidence interval) in mSv between the non-responders and previous responders were 0.12 (0.01-0.23), -0.09 (-0.21-0.03), -0.06 (-0.18-0.07), 0.05 (-0.04-0.14), 0.01 (-0.01-0.02), 0.09 (0.01-0.17), 0.09 (0.00-0.17), respectively. The differences fall neither within the interval (-∞, -0.25) nor within the interval (0.25, ∞). These findings imply that mean effective doses between the previous and new respondents were not different, with a significantly indifferent region of 0.25 mSv according to equivalence tests. The present study indicates that the dose distribution obtained from about one-quarter of Fukushima residents represents the dose distribution for the entire Fukushima Prefecture.
福岛第一核电站事故后，启动了福岛健康管理调查（FHMS）。FHMS的基础调查是一份问卷，用于调查福岛县居民在事故发生后头4个月的行为。通过将行为数据与事故后绘制的每日伽马射线剂量率地图的计算机程序相关联，问卷结果用于确定个人外部剂量。截至2015年6月30日，回复率仅为27.2%（558550人），这表明由于人群代表性差，调查结果可能无法推广。本研究的目的是通过开展一项新的调查，比较前次调查中未回复者和回复者的外部剂量，以明确FHMS基础调查的数据是否代表整个人口。从福岛县7个地区随机选取了5350名受试者。对FHMS基础调查的未回复者进行了访谈调查。通过访谈调查，从前次未回复者中总共获得了990份回复。对于桧前、川内、南相马、会津、南会津、双叶和磐城地区，未回复者与前次回复者之间的平均有效剂量（95%置信区间）的差异（单位为毫希沃特）分别为0.12（0.01 - 0.23）、-0.09（-0.21 - 0.03）、-0.06（-0.18 - 0.07）、0.05（-0.04 - 0.14）、0.01（-0.01 - 0.02）、0.09（0.01 - 0.17）、0.09（0.00 - 0.17）。这些差异既不在区间（-∞, -0.25）内，也不在区间（0.25, ∞）内。根据等效性检验，这些结果表明前次和新回复者之间的平均有效剂量没有差异，显著差异区域为0.25毫希沃特。本研究表明，约四分之一福岛居民的剂量分布代表了整个福岛县的剂量分布。
