Radioactive water detected in 6 prefectures

Radioactive water has been detected at water purification facilities in Tokyo and 5 other prefectures. The level of radioactive iodine-131 at 18 purification plants exceeds Japan's safety limit for infants.

Radioactive iodine-131 does not exist in nature. Experts believe it was carried by the wind from the troubled Fukushima Daiichi nuclear power plant to surrounding areas, and then washed down into rivers by rain.

The governments of Tokyo, Fukushima, Ibaraki, Chiba, Saitama and Tochigi prefectures have detected more than 100 becquerels of iodine per liter of water, above the safety level for infants under 12 months. But the water is safe for adults because it's not above the 300 becquerel safety limit for them.