Concentration Ratios of Radiocesium from soil to wild boar observed in Fukushima Prefecture

After the Fukushima Daiichi Nuclear Power Plant accident, soil surfaces were contaminated with radiocesium. Although the non-uniform contamination was found in Fukushima Prefecture, the radiocesium concentration in wild boar meat can be estimated if the concentration ratios from soil to the animal are obtained. In this study, therefore, reported radiocesium concentration data from food monitoring and soil samples collected in the prefecture were used to estimate the concentration ratios. The ratio was defined as the wild boar meat concentration (Bq/kg-fresh mass) divided by the area concentration (Bq/m2), thus the area base concentration ratio, that is, CRagg was calculated. The wild boar meat data sampled between 551 to 734 days after March 11, 2011 were used, and soil concentrations were selected in the areas corresponding to the areas where meat sample had been obtained. The geometric mean value of the data was used for CRagg calculation. In all, 189 CRagg data were calculated, and the geometric mean value was 8.8×10-3 (range: 3.3×10-4 to 8.4×10-1). Radiocesium concentration in wild boar meat could be roughly estimated using the summarized data