Radiocesium transfer into freshwater planktonic Chlamydomonas spp. microalgae in a pond near the Fukushima Dai-ichi Nuclear Power Plant

We investigated the transfer of radiocesium and its behavior in living cells and cellular debris in a Chlamydomonas spp. bloom in a pond located approximately 5 km from the Fukushima Dai-ichi Nuclear Power Plant. A microalgal bloom in the pond was the dominant factor in determining the radiocesium concentration (Bq/L) of the > 0.45 μm pond water fraction. The water-to-algae transfer factor [(137Cs concentration Bq/kg>0.45 μm fraction) × (137Cs concentration Bq/L  0.45 μm) and water in rivers in Fukushima [(137Cs concentration Bq/kg>0.45 μm fraction) × (137Cs concentration Bq/L<0.45 μm water)−1].