福島県内仮設住宅居住者にみられる高い心的外傷後ストレス症状 High-level Post-traumatic Stress Symptoms of the Residents in Fukushima Temporary Housing : Bio-psycho-social Impacts by Nuclear Power Plant Disaster
本研究は, 東日本大震災に伴って発生した福島原子力発電所事故の2年後に, 福島県内の仮設住宅において避難生活を送る住民の心的外傷後ストレス症状と, そのストレスに影響を与える身体・心理・社会的要因を明らかにしたものである. 2,425世帯に対して無記名で任意回答のアンケート用紙を配布し, 745名 (回答率30.7%) の回答を得た. 欠損値を除く661名の解析を行ったところ, IES-Rの平均値が34.20±20.56であり, PTSDの可能性に対する高いリスクを示すカットオフ値24/25を超えた者が62.56%であった. PTSDの可能性との関連を多重ロジスティック回帰分析で検討した結果, 「経済的困難」 (OR : 2.34, 95%CI : 1.30～4.24), 「賠償の心配」 (OR : 4.16, 95%CI 1.26～13.76), 「持病の悪化」 (OR : 2.94, 95%CI : 1.63～5.30), 「新疾患の罹患」 (OR : 2.20, 95%CI : 1.21～3.99), 「相談者の不在」 (OR : 1.92, 95%CI : 1.07～3.42) が有意な予測因子として認められた. これまでに世界各地で報告されてきた他の災害と比較しても, 原発事故被災者にきわめて高い外傷後ストレス症状が認められた理由として, 事故に対する補償や賠償といった問題など, 本災害の人為災害としての要素が重要であると考えられた.
<b>Backgrounds</b> : Fukushima nuclear power plant disaster occurred following the Great East Japan Earthquake on March 11, 2011. It bears comparison with the incident in Chernobyl in 1986 in the degree of radiological contamination to the surrounding environment. 164,218 residents were displaced losing their home-land by this serious incident, of which 97,321 were relocated to other regions within the Fukushima prefecture, and 57,135 residents were relocated to other prefectures. The evacuees from Fukushima can be considered the largest number of 'internally displaced persons' or 'domestic refugees' in Japan after the world war two. <b>Objective</b> : This study investigated the scale of post-traumatic stress (PTS) symptoms in the evacuees as of two years after the Fukushima nuclear power plant disaster. It also tried to identify the impact of bio-psycho-social factors related to PTS symptoms. <b>Samples and methods</b> : Questionnaire survey was conducted by Waseda University and Japan Broadcasting Corporation (NHK). 2,425 households living at temporary housings within Fukushima prefecture were asked to answer the Impact of Event Scale-Revised (IES-R) and the self-report questionnaires that we generated in order to evaluate the damage by the disaster in relation to several bio-psycho-social factors in refugee lives. There were 745 replies (the cooperation rate ; 30.7%), of which 661 were analyzed. Besides, multiple logistic regression analysis was performed to examine several bio-psycho-social factors as predictors for probable PTSD. <b>Results</b> : High level PTS symptoms were found. The mean score of IES-R was 34.20±20.56, and 62.56% were over 24/25 cut-off point determined as broadly defined PTSD which means high-risk presence of probable PTSD. The significant differences by chi-square test of high-risk subjects were found among economic difficulty (p=.000), concerns about compensation (p=.000), lost jobs (p=.023), unsatisfying housing (p=.025), unsatisfying environment around temporary housing (p=.000), having chronic disease (p=.003), aggravation of chronic disease (p=.000), affection of new disease (p=.000), lack of necessary information (p=.000), family split-up (p=.031), and lack of acquaintance support (p=.000). By the result of multiple logistic regression analysis, the significant predictors of probable PTSD were economic difficulty (OR : 2.34, 95%CI : 1.30-4.24), concerns about compensation (OR : 4.16, 95%CI 1.26-13.76), aggravation of chronic disease (OR : 2.94, 95%CI : 1.63-5.30), affection of new disease (OR : 2.20, 95%CI : 1.21-3.99), and lack of acquaintance support (OR : 1.92, 95%CI : 1.07-3.42). <b>Conclusion</b> : The findings revealed that there is a high-risk presence of probable PTSD strongly related to a number of bio-psycho-social factors due to the nuclear power plant disaster and its consequent evacuation. Our findings underscore the specific characteristics of the nuclear disaster as man-made disaster. Since the socio-economic problems such as compensation and reparation have not been solved, it is suggested that prolonged uncertainty regarding the insufficient salvation of the evacuees might account for the high-level PTS symptoms.
心身医学 56(7), 723-736, 2016