New Study of Fukushima Area Indicates Overestimated Radiation Levels

A new, one of a kind study that tested the radiation levels of individual citizens in Date, Japan show radiation levels near the Fukushima Diiachi area were overestimated. Date is located just 30 miles from the Fukushima Daiichi complex.

The study began in 2011 when the mayor of the Date, Japan dispensed a dosimeter to citizens to measure their individual exposure. After a year researchers collected the readings from up to 52,00 of the town's residents.

ANS member and certified health physicist at the School of Nuclear Science and Engineering at Oregon State University Kathryn Higley said, “The work [these] researchers are doing is extremely important … [because] it is logistically challenging to sample and monitor every potentially exposed person.” 

Earlier radiation tests were airborne radiation surveys conducted by the national government. They used sensors attached to helicopters to measure radioactive cesium on the ground, and researchers used scaling laws to convert that data to expected doses at ground level.

In comparing the the thousands of data points from the Date dosimeters with the ground-level estimates from the helicopter data, it was determined that actual radiation doses were roughly 15% of what the helicopters were measuring, four times less radiation than what the Japanese government was previously assuming.

The full report can be found in the Journal of Radiological Protection.