Radioactive cesium from the crippled Fukushima No. 1 nuclear power plant continued to flow into Tokyo Bay for five years after the disaster unfolded in March 2011, according to a researcher.
Hideo Yamazaki, a former professor of environmental analysis at Kinki University, led the study on hazardous materials that spewed from the nuclear plant after it was hit by the Great East Japan Earthquake and tsunami on March 11, 2011.
[…]
In July 2016, the study team detected a maximum 104,000 becquerels of cesium per square meter from mud collected in the same area of the bay, Yamazaki said.
He said cesium released in the early stages of the Fukushima disaster remained on the ground upstream of the river, such as in Chiba Prefecture. The radioactive substances were eventually washed into the river and carried to Tokyo Bay, where they accumulated in the mud, he said.
On a per kilogram basis, the maximum level of radioactivity of cesium detected in mud that was dried in the July 2016 study was 350 becquerels.
The government says soil with 8,000 becquerels or lower of radioactive cesium per kilogram can be used in road construction and other purposes.
Read more at Study: Cesium from Fukushima flowed to Tokyo Bay for 5 years
