title: Environmental contamination and external radiation dose rates from radionuclides released from the Fukushima Nuclear Power Plant.
abstract: To evaluate the environmental contamination and contributory external exposure after the accident at the Fukushima Nuclear Power Plant (FNPP), the concentrations of artificial radionuclides in soil samples from each area were analysed by gamma spectrometry. Six artificial radionuclides ((131)I, (134)Cs, (137)Cs, (129m)Te, (95)Nb and (136)Cs) were detected in soil samples around FNPP. Calculated external effective doses from artificial radionuclide contamination in soil samples around FNPP were 1.9-2.9 μSv h(-1) (8.7-17.8 mSv y(-1)) in Fukushima city on 22 March 2011. After several months, these calculated external effective doses were 0.25-0.88 μSv h(-1) (2.2-7.6 mSv y(-1)) in Fukushima city on 29 June 2011. The present study revealed that the detected artificial radionuclides around FNPP mainly shifted to long-lived radionuclides such as radioactive caesium ((134)Cs and (137)Cs) even though current levels are decreasing gradually due to the decay of short-lived radionuclides such as (131)I, (129m)Te, (95)Nb and (136)Cs. Thus, radiation exposure potency still exists even though the national efforts are ongoing for reducing the annual exposure dose closer to 1 mSv, the public dose limit. Long-term environmental monitoring around FNPP contributes to radiation safety, with a reduction in unnecessary exposure to the residents.
authors.affiliation: Department of Global Health, Medical, and Welfare, Nagasaki University Graduate School of Biomedical Sciences, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Taira
authors.forename: Naomi
authors.initials: N
authors.lastname: Hayashida
authors.forename: Shunichi
authors.initials: S
authors.lastname: Yamashita
authors.forename: Takashi
authors.initials: T
authors.lastname: Kudo
authors.forename: Naoki
authors.initials: N
authors.lastname: Matsuda
authors.forename: Jumpei
authors.initials: J
authors.lastname: Takahashi
authors.forename: Alexander
authors.initials: A
authors.lastname: Gutevitc
authors.forename: Alexander
authors.initials: A
authors.lastname: Kazlovsky
authors.forename: Noboru
authors.initials: N
authors.lastname: Takamura
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D006801:Humans; D055848:Nuclear Power Plants; D011829:Radiation Dosage; D011834:Radiation Monitoring; D018788:Radioactive Hazard Release; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma
chemical_list: D004785:Environmental Pollutants; D012990:Soil Pollutants, Radioactive