title: Global fallout Pu recorded in lacustrine sediments in Lake Hongfeng, SW China.
abstract: Studies on the distribution and isotope compositions of fallout Pu are important for source characterization of possible future non-fallout Pu contamination in aquatic environments, and useful for dating of recent sediments to understand the pollution history of environmental contaminants. We present the historical record of atmospheric Pu fallout reconstructed from a sediment core from Lake Hongfeng, China. The Pu activity profile was in agreement with the 137Cs profile. Inventories were 50.7 Bq m(-2) for 239+240Pu and 1586 Bq m(-2) for 137Cs. The average 240Pu/239Pu atom ratio was 0.185+/-0.009, indicating that Pu originated from global stratospheric fallout rather than from direct tropospheric or close-in fallout from the Chinese nuclear testing conducted in the 1970s. Our data suggested that Lake Hongfeng would be an ideal setting for monitoring atmospheric fallout and environmental changes in this region.
authors.affiliation: Nakaminato Laboratory for Marine Radioecology, Environmental Radiation Effects Research Group, National Institute of Radiological Sciences, 3609 Isozaki-cho, Hitachinaka, Ibaraki 311-1202, Japan. jzheng@nirs.go.jp
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.forename: Fengchang
authors.initials: F
authors.lastname: Wu
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yamada
authors.forename: Haiqing
authors.initials: H
authors.lastname: Liao
authors.forename: Congqiang
authors.initials: C
authors.lastname: Liu
authors.forename: Guojiang
authors.initials: G
authors.lastname: Wan
mesh_terms: D002586:Cesium / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry*; D011005:Plutonium / Q000032:analysis*; D011834:Radiation Monitoring / Q000379:methods; D011847:Radioactive Fallout / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D011847:Radioactive Fallout; D012990:Soil Pollutants, Radioactive; D002586:Cesium; D011005:Plutonium