The need for forest decontamination: for the recovery of Fukushima

After the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS) in 2011, the residential areas within the evacuation order areas around FDNPS were extensively decontaminated, but the need for forest decontamination remains controversial. Almost 70% of Fukushima prefecture is covered by forest, and forestry is one of the key industries there. From the perspective of forestry recovery and environmental preservation, Fukushima residents desire the further decontamination of forests; from the perspective of cost-effectiveness and priorities, however, this has both pros and cons(1). Bearing in mind the need to discuss priorities regarding the decontamination of forest, therefore, a radiation dose evaluation of foresters working in the FDNPS vicinity is important. This paper reports on the measurement of individual radiation doses by occupation in Kawauchi village (Figure 1a), which is located within 30 km from the FDNPS(2, 3), using the personal dosimeter (D-Shuttle^R, Chiyoda Technol Corp, Tokyo, Japan). Our results showed that estimated annual doses of 1.19 mSv/year (median) with a range of 0.71 1.89 among foresters, 0.97 (0.66 1.48) mSv/year for farmers, 0.94 (0.59 1.51) mSv/year for builders, 0.88 (0.54 1.48) mSv/year for officers, 1.01 (0.55 1.75) mSv/year for unemployed individuals and 0.98 (0.54 7.07) mSv/ year for decontamination workers (Figure 1b). Thus, the annual doses of foresters was not significantly higher than farmers, builders, officers and unemployed individuals, whereas those of decontamination workers were significantly higher than for other workers, including foresters, suggesting that in terms of protecting foresters from radiation, forest decontamination is not a high-priority policy in Fukushima. The International Commission on Radiological Protection (ICRP) recommends that for the protection of residents living in radio-contaminated areas during the recovery process, the justification of protection strategies goes far beyond the scope of radiological protection, as there may also be various economic, political, environmental, social and psychological consequences(4). For the recovery of Fukushima, stakeholders, including residents, policy-makers and scientists, should discuss this matter based on a deep understanding of the cultural and sociological background of the residents hometown, as well as of monitoring and providing data on environmental and individual radiation doses. Finally, our results suggest that an appropriate radiation protection policy for decontamination workers should be continuously implemented in Fukushima. (authors)