title: Radiation dose rates now and in the future for residents neighboring restricted areas of the Fukushima Daiichi Nuclear Power Plant.
abstract: Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August-September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.
authors.affiliation: Department of Health and Environmental Sciences and Department of Preventive Medicine, Kyoto University Graduate School of Medicine, Kyoto 6068501, Japan.
authors.forename: Kouji H
authors.initials: KH
authors.lastname: Harada
authors.forename: Tamon
authors.initials: T
authors.lastname: Niisoe
authors.forename: Mie
authors.initials: M
authors.lastname: Imanaka
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Takahashi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Amako
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Fujii
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kanameishi
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohse
authors.forename: Yasumichi
authors.initials: Y
authors.lastname: Nakai
authors.forename: Tamami
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Yuuichi
authors.initials: Y
authors.lastname: Saito
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Keiko
authors.initials: K
authors.lastname: Ueyama
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hisaki
authors.forename: Eiji
authors.initials: E
authors.lastname: Ohara
authors.forename: Tokiko
authors.initials: T
authors.lastname: Inoue
authors.forename: Kanako
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Matsuoka
authors.forename: Hitomi
authors.initials: H
authors.lastname: Ohata
authors.forename: Kazue
authors.initials: K
authors.lastname: Toshima
authors.forename: Ayumi
authors.initials: A
authors.lastname: Okada
authors.forename: Hitomi
authors.initials: H
authors.lastname: Sato
authors.forename: Toyomi
authors.initials: T
authors.lastname: Kuwamori
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tani
authors.forename: Reiko
authors.initials: R
authors.lastname: Suzuki
authors.forename: Mai
authors.initials: M
authors.lastname: Kashikura
authors.forename: Michiko
authors.initials: M
authors.lastname: Nezu
authors.forename: Yoko
authors.initials: Y
authors.lastname: Miyachi
authors.forename: Fusako
authors.initials: F
authors.lastname: Arai
authors.forename: Masanori
authors.initials: M
authors.lastname: Kuwamori
authors.forename: Sumiko
authors.initials: S
authors.lastname: Harada
authors.forename: Akira
authors.initials: A
authors.lastname: Ohmori
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Akio
authors.initials: A
authors.lastname: Koizumi
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D005544:Forecasting; D062406:Fukushima Nuclear Accident; D005843:Geography; D006801:Humans; D007564:Japan / Q000453:epidemiology; D009369:Neoplasms / Q000453:epidemiology*; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000706:statistics & numerical data*; D012307:Risk Factors
chemical_list: D002588:Cesium Radioisotopes
keywords: Fukushima nuclear disaster; Strontium-90; exposure assessment; food duplicate; forest contamination