Anthropogenic and Natural Radioactivity in Pond Water, Soil and Biota at the Ecology Field in Saitama Prefecture

Abstract

Activity concentrations in pond water, soil and biota samples, collected at the ecology field in Saitama prefecture during the period of 2011 to 2013, were measured by γ-ray spectrometry. In all samples collected at the ecology field, Fukushima Dai-ichi Nuclear Power Plant derived ¹³⁴Cs and ¹³⁷Cs, and natural ⁴⁰K were detected. The concentrations of ¹³⁴Cs and ¹³⁷Cs varied widely in each sample. Moreover, ^110mAg was detected in crayfish, and the concentrations of ^110mAg were in the range of 0.11～1.0 Bq/kg・wet. Concentration ratios of ¹³⁷Cs in soil and biota (Bq/kg) to that in pond water (Bq/kg) were about 5～5400. It was so suggested that ¹³⁷Cs tended to be accumulated in these samples at the ecology field.