福島第一原子力発電所事故に係る避難区域等における除染実証業務; 個人線量調査事業編(受託研究)

Decontamination pilot projects for the environmental remediation of evacuation areas contaminated with radioactive materials discharged from the Fukushima Daiichi Nuclear Power Plant accident; Survey on individual doses to the inhabitants living in the areas contaminated by the accident (Contract research)

高原 省五  ; 飯島 正史; 串田 輝雄; 白鳥 芳武

Takahara, Shogo; Iijima, Masashi; Kushida, Teruo; Shiratori, Yoshitake

生活習慣の違いが住民の被ばくに及ぼす影響を明らかにするために、福島第一原子力発電所事故の影響を受けた地域において生活行動時間を調査するとともに、外部被ばくによる個人線量の測定を行った。また、個人線量の評価モデルを作成し、放射線量率の測定結果と生活行動時間の調査結果をもとに個人線量を評価して、実測値との比較より評価の妥当性を検証した。住民の生活行動時間には、職業によって屋外での滞在時間に明らかな差がみられ、屋外作業者の個人線量と屋内作業者の個人線量には有意な違いが観察された。事故の影響を受けた地域で生活を続ける住民の線量をより正確に評価するためには、職業などによる生活行動時間の違いを反映して評価を実施すべきである。

In the areas contaminated by the Fukushima Daiichi Nuclear Power Plant accident, to clarify the influences of the lifestyle habits to radiation exposures for inhabitants, we performed surveys on their behavioral patterns and measurements of their individual doses due to external exposures. In addition, an assessment model was developed and the assessments of the doses were performed based on the results of the surveys and the measurements of ambient dose equivalent rates. The assessed individual doses were compared with those measured in order to confirm the validity of the model. Clear differences were found in time spent outdoors of the inhabitants of various occupations. Significant differences in individual doses were also observed between those of indoor workers and outdoor workers. In order to assess more precisely the doses of inhabitants who continue to live in the affected areas, assessments should be performed taking into account the population-specific behavioral patterns.