Cs-134/137 found from swallow nests in 13 prefectures in Japan
Xinhua, May 27, 2015 Adjust font size:
Cesium-134/137 was found from swallow nests collected in 12 prefectures and Tokyo, which include all the prefectures in Kanto, North East, North West coasts and Mid Japan area except Tochigi, local media reported Wednesday.
The research was conducted by Yamashina Institute for Ornithology. Researchers of the institute collected 197 samples from 21 prefectures from Hokkaido to Kyushu and found 150 of them contain Cs-134/137.
"The average reading was 7,502-becquerel per kilogram, while the highest reading was 90,000 Bq/Kg in Fukushima, far higher than the government's 8,000 Bq/Kg limit, above which such materials should be handled by the government as 'specified waste'," according to a report released by the institute.
Researchers believed that swallow nests are made of clay and straw, thus the radioactive substance detected in them show clearly the pollution level of soils nearby.
The samples were collected from 2011 to March 2012 after the Fukushima Daiichi Nuclear disaster. Researchers even measured the radioactive Cs-134/137 from the samples collected in Shizuoka prefecture, almost 500 km far from the nuclear plant, said Tokyo Shimbun. Endi