title: Internal radiocesium contamination of adults and children in Fukushima 7 to 20 months after the Fukushima NPP accident as measured by extensive whole-body-counter surveys.
abstract: The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the (137)Cs body burdens of all children (n = 1,383, ages 6-15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data.
authors.affiliation: Department of Physics, The University of Tokyo, Tokyo, Japan. hayano@phys.s.u-tokyo.ac.jp
authors.forename: Ryugo S
authors.initials: RS
authors.lastname: Hayano
authors.forename: Masaharu
authors.initials: M
authors.lastname: Tsubokura
authors.forename: Makoto
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Satou
authors.forename: Katsumi
authors.initials: K
authors.lastname: Sato
authors.forename: Shin
authors.initials: S
authors.lastname: Masaki
authors.forename: Yu
authors.initials: Y
authors.lastname: Sakuma
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002588:Cesium Radioisotopes / Q000032:analysis; D002648:Child; D003625:Data Collection; D004781:Environmental Exposure / Q000032:analysis; D062406:Fukushima Nuclear Accident; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D008875:Middle Aged; D055848:Nuclear Power Plants; D011834:Radiation Monitoring; D013997:Time Factors; D014915:Whole-Body Counting; D055815:Young Adult
chemical_list: D002588:Cesium Radioisotopes