The total amounts of radioactively contaminated materials in forests in Fukushima, Japan.
There has been leakage of radioactive materials from the Fukushima Daiichi Nuclear Power Plant. A heavily contaminated area (≥ ¹³⁴,¹³⁷Cs 1000 kBq m⁻²) has been identified in the area northwest of the plant. The majority of the land in the contaminated area is forest. Here we report the amounts of biomass, litter (small organic matter on the surface of the soil), coarse woody litter, and soil in the contaminated forest area. The estimated overall volume and weight were 33 Mm³ (branches, leaves, litter, and coarse woody litter are not included) and 21 Tg (dry matter), respectively. Our results suggest that removing litter is an efficient method of decontamination. However, litter is being continuously decomposed, and contaminated leaves will continue to fall on the soil surface for several years; hence, the litter should be removed promptly but continuously before more radioactive elements are transferred into the soil.
Soil Resources Laboratory, Department of Forest Site Environment, Forestry and Forest Products Research Institute, 1 Matsunosato, Tsukuba, Ibaraki 305-8687, Japan. shojih@ffpri.affrc.go.jp
Shoji
S
Hashimoto
Shin
S
Ugawa
Kazuki
K
Nanko
Koji
K
Shichi
D018533:Biomass; D002588:Cesium Radioisotopes / Q000032:analysis*; D003666:Decontamination / Q000379:methods / Q000706:statistics & numerical data; D004190:Disasters; D055866:Earthquakes; D017753:Ecosystem; D005843:Geography; D007457:Iodine Radioisotopes / Q000032:analysis*; D007564:Japan; D055848:Nuclear Power Plants; D018515:Plant Leaves / Q000737:chemistry / Q000528:radiation effects; D011834:Radiation Monitoring / Q000379:methods / Q000706:statistics & numerical data; D018788:Radioactive Hazard Release / Q000706:statistics & numerical data; D012987:Soil / Q000032:analysis*; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013997:Time Factors; D014197:Trees / Q000737:chemistry / Q000254:growth & development / Q000528:radiation effects
D002588:Cesium Radioisotopes; D007457:Iodine Radioisotopes; D012987:Soil; D012990:Soil Pollutants, Radioactive