Radioactivity Measurement of Soil and Vegetables Contaminated from Low Level Radioactive Fall Out Arised from Fukushima Daiichi Nuclear Accident
—A Study on Institute for Sustainable Agro-Ecosystem Services, Graduate School of Agricultural and Life Sciences, The University of Tokyo—

Abstract

After the accident of Fukushima nuclear power plant, vegetables were grown at an experimental farm of Nishi-Tokyo City in Tokyo, which was located about 230km away from the power plant. The outer leaves of cabbages and leaves of potatoes were taken after 47 and 40 days, respectively, and the radioactivity of ¹³⁴Cs and ¹³⁷Cs was measured. The total radioactivity of ¹³⁴Cs and ¹³⁷Cs in both plants was less than 9Bq/kg, which was far lower than that of the regulated value, 500Bq/kg, for human to intake. The radioactivity of soil was about 130Bq/kg, less than that of the natural activity of ⁴⁰K, about 290Bq/kg. The difference of the radioactivity image of cabbage outer leaves, washed and without washing, was not observed using an imaging plate.