#7 Years of Fukushima Greenpeace Radiation Survey in Namie and Iitate towns.
Greenpeace radiation surveys of the Fukushima Prefecture area in September 2017 showed that while some of the area has levels close to the government decontamination target (0.23 micro-sieverts per hour) there were many areas which were higher, including above 5 microsieverts per hour.
20 millisieverts per year 