Radiocesium concentration in flying insects collected from a radioactive contaminated area after the Fukushima Dai-ichi Nuclear Power Plant accident

Tanaka, Sota; Kakinuma, Hotaru*; Adachi, Taro*; Takahashi, Tomoyuki*; Takahashi, Sentaro*

The concentration of Cs in flying insects was investigated after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. The insects were collected at about 11 km north west of the FDNPP at two different sites in the forest and riverside. The median concentration of Cs in flying insects in the forest was significantly higher than riverside. However, high concentration of Cs in detritus fly (Diptera: Calliphoridae) was observed at both sites. The concentration of fly at the forest and riverside were 1610 Bq/kg fw and 1810 Bq/kg fw, respectively. The result shows that the concentration of radiocesium in detritus fly were still high 8 years after the accident. This suggests that detritus food chain is a dominant transfer pathway of radiocesium to higher trophic level species such as spiders.