Radioactive contamination of the soil-plant cover at certain locations of Primorsky Krai, Sakhalin Island and Kamchatka Peninsula: Assessment of the Fukushima fallout

Abstract

The contamination densities of soil-plant cover at certain locations within the Primorsky Krai, Sakhalin Island and Kamchatka Peninsula attributable to ⁹⁰Sr, ¹³⁷Cs and ^239,240Pu were 500-1390 Bq m^-2, 980-2300 Bq m^-2 and 37-74 Bq m^-2, respectively. These values do not exceed average global background levels, typical for mid-latitudes of the Northern Hemisphere. The spatial distribution of radionuclides depends on the climatic conditions of the region. A positive dependence of the ⁹⁰Sr and ¹³⁷Cs contamination densities, as well as additional ¹³⁷Cs from NPP "Fukushima" in the soil, was determined based on the sum of annual atmospheric precipitation within the study areas. No trends in the spatial distribution of Pu isotopes were observed. The ¹³⁷Cs contribution from the "Fukushima" NPP constitutes 11-300 Bq m^-2 in the Primorsky Krai, Sakhalin Island and at the Kamchatka peninsula, i.e., 1-22% of the total amount of radionuclides in the soil. The contribution of this radionuclide to the contamination of moss-lichen vegetation ranged from 7 to 42%.

Keywords: Accident at the “Fukushima” NPP; Global fallout; Kamchatka Peninsula; Primorsky Krai; Radionuclides; Sakhalin Island.