Difference in Cs-137 concentration of brown rice between the years of 2011 and 2012 in Fukushima Prefecture

The objective of this study was to understand the effect of decrease in available radiocesium independently of the potassium and zeolite application effect on the uptake of radiocesium by rice. Brown rice produced in seven paddy fields located at four different sites of Fukushima Prefecture were sampled in 2011 and 2012. Any decontamination treatment was not conducted in these fields during the 2-year period. The Cs-137 concentrations in brown rice was 30 % lower in 2012 (1.3–160 Bq kg−1) compared to those in 2011 (2.8–290 Bq kg−1) with neither decontamination nor additional application of potassium and/or zeolite.