title: Vertical distribution of radiation dose rates in the water of a brackish lake in Aomori Prefecture, Japan.
abstract: Seasonal radiation dose rates were measured with glass dosemeters housed in watertight cases at various depths in the water of Lake Obuchi, a brackish lake in Aomori Prefecture, Japan, during fiscal years 2011-2013 to assess the background external radiation dose to aquatic biota in the lake. The mean radiation dose in the surface water of the lake was found to be 27 nGy h(-1), which is almost the same as the absorption dose rate due to cosmic ray reported in the literature. Radiation dose rates decreased exponentially with water depth down to a depth of 1 m above the bottom sediment. In the water near the sediment, the dose rate increased with depth owing to the emission of γ-rays from natural radionuclides in the sediment.
authors.affiliation: Department of Radioecology, Institute for Environmental Sciences, 1-7 Rokkasho, Aomori 039-3212, Japan ohtsuka@ies.or.jp.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ohtsuka
authors.affiliation: Department of Radioecology, Institute for Environmental Sciences, 1-7 Rokkasho, Aomori 039-3212, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Iyogi
authors.affiliation: Department of Radioecology, Institute for Environmental Sciences, 1-7 Rokkasho, Aomori 039-3212, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Ueda
authors.affiliation: Department of Radioecology, Institute for Environmental Sciences, 1-7 Rokkasho, Aomori 039-3212, Japan.
authors.forename: Shun'ichi
authors.initials: S
authors.lastname: Hisamatsu
mesh_terms: D007564:Japan; D060106:Lakes / Q000737:chemistry*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis; D011834:Radiation Monitoring / Q000379:methods*; D000068357:Saline Waters / Q000737:chemistry*; D012621:Seasons; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D014875:Water Pollutants, Radioactive