Photo: High street, Tomioka, Fukushima Prefecture, October 2016
9km south of Fukushima Daiichi Nuclear power Plant
Once a busy shopping area, now abandoned and derelict.
There were numerous radiation micro hotspots here, particularly around drains and gutters where radionuclides typically accumulate, transported there by rain, melted snow and street-cleaning. The highest level of radioactivity I found was in some mud in a drain at the edge of a forecourt, measuring 11.8μSv/h (microsieverts per hour) ~ 103 millisieverts per year.
In 2011 the number of people evacuated from 13 of Japan’s 47 prefectures both under government orders and voluntarily peaked at around 165,000.
Approximately 25,000 people  will never be able to return to their homes.
Since 2011 some people have continued to evacuate voluntarily. In some cases this is the result of noticing changes in their health and/or the health of their children, which are consistent with the effects of chronic exposure to low-level internal radiation .
In 2016 86,700 people were still living as evacuees, 47,000 of whom were displaced within Fukushima prefecture.
Out of the 86,700 evacuees, 26,601 are voluntary evacuees.
According to the Yomiuri Shimbun – Japan News , the total number of Fukushima households which evacuated voluntarily, both within and outside Fukushima prefecture was 10,524 (26,601 people).
These households comprise:
5,294 households voluntarily evacuated within Fukushima prefecture: all of these will have their subsidies terminated;
5,230 households voluntarily evacuated to outside Fukushima prefecture:
3,607 of which will continue to receive subsides from the prefectures where they have settled;
1,237 will have their subsidies terminated;
386 don’t yet know wether or not their subsidies will be terminated.
Hence the total no. of households which evacuated voluntarily definitely facing termination of subsidies: 6,531
 Dr Sigeru Mita discusses the effects of chronic exposure to low-level internal contamination in his 2014 letter to fellow doctors: