© Mainichi
A worker uses a high-pressure washer on the roof of a home while carrying out decontamination work in Fukushima in October.
Work to decontaminate homes and yards in a district here is not proceeding as hoped, as radiation levels persist and decontamination workers worried about their health stay away.
The city began decontamination work in the Onami district on Oct. 18. Located in the mountains in the eastern part of the city, it has been heavily affected by the Fukushima nuclear disaster, with radiation in rice over the nation's provisional limit of 500 becquerels per kilogram detected, leading to a ban on rice shipments.
Although monitoring of six homes where decontamination was carried out found an average drop of 70 percent in radiation in front of entrances and on gravel parking spots, there was only a 30 percent drop for roofs and a 25 percent drop for asphalt in the yard. Furthermore, there was only a 22 percent drop for second floor interiors.
The city has suggested that the low effect on the roofs may be due to radiation from the surrounding forests, where decontamination has not been carried out. As for the asphalt, radioactive material tends to stick to it and remain even after being washed, so the city has decided to try removing the top layer of the asphalt.
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