Decontamination is one of the measures for radiation protection*to remove radioactive materials from the inhabitation areas in order to promptly decrease impacts on human health and the environment.
*The national government aims at a long-term goal to reduce additional annual dose to 1 mSv or less by comprehensive measures for radiation risk management including not only decontamination, but also monitoring survey, food safety administration, risk communication, etc.
| Municipality | Evacuation order was lifted on |
|---|---|
| Tamura City | April 1, 2014 |
| Kawauchi Village |
October 1, 2014*1/June 14, 2016*2 *1:Former Areas to which evacuation orders are ready to lift up *2:Former Areas in which residents are not permitted to live |
| Naraha Town | September 5, 2015 |
| Katsurao Village | June 12, 2016 |
| Minamisoma City | July 12, 2016 |
| Iitate Village | March 31, 2017 |
| Kawamata Village | March 31, 2017 |
| Namie Town | March 31, 2017 |
| Tomioka Town | April 1, 2017 |
| Okuma Town | April 10, 2019 |
| Futaba Town | March 4, 2020 |
| Municipality | Completion of decontamination |
|---|---|
| Tamura City | June 2013 |
| Naraha Town | March 2014 |
| Kawauchi Village | March 2014 |
| Okuma Town | March 2014 |
| Katsurao Village | December 2015 |
| Kawamata Town | December 2015 |
| Futaba Town | March 2016 |
| Iitate Village | December 2016 |
| Tomioka Town | January 2017 |
| Minamisoma City | March 2017 |
| Namie Town | March 2017 |
| Municipality | Residential area | Farmland | Forest | Road | Evacuation order was lifted on |
|---|---|---|---|---|---|
| Number of implementated houses | Implemented area ha | Implemented area ha | Implemented area ha | ||
| Minami soma |
4,500 | 1,700ha | 1,300ha | 270ha | July 12, 2016 |
| Namie | 5,600 | 1,400ha | 390ha | 210ha | March 31, 2017 |
| Tomioka | 6,000 | 750ha | 510ha | 170ha | April 1, 2017 |
| Iitate | 2,000 | 2,100ha | 1,500ha | 330ha | March 31, 2017 |
| Futaba | 97 | 100ha | 6.2ha | 8.4ha | March 4, 2020 |
| Kawamata | 360 | 600ha | 510ha | 71ha | March 31, 2017 |
| Katsurao | 460 | 570ha | 660ha | 95ha | June 12, 2016 |
| Okuma | 180 | 170ha | 160ha | 31ha | April 10, 2019 |
| Kawauchi | 160 | 130ha | 200ha | 38ha | Former Preparation Areas for lift of Evacuation Order : October 1, 2014 Former Habitation Restricted Areas: June 14, 2016 |
| Naraha | 2,600 | 830ha | 470ha | 170ha | September 5, 2015 |
| Tamura | 140 | 140ha | 190ha | 29ha | April 1, 2014 |
| Total Number | 22,000 | 8,500ha | 5,800ha | 1,400ha |
Whole area decontamination on the Act on Special Measures was completed on March 19, 2018 except in Difficult-to-Return Zones.
Residential houses / Public facilities / Roads / Farmland & meadows / Forests in living areas: Completed in all categories
Residential houses / Schools & nurseries/ Parks, sports facilities / Roads / Farmland & meadows/ Forests in living areas: Completed in all categories
NOTE: The chart shows the air dose rate average in each category (aggregated data of measuring points).
Residential areas include schools, parks, cemeteries, and large-sized facilities, farmland includes orchard, and forests include slopes, grassland and lawn.
Post-decontamination monitoring was implemented after 6 months to a year after the decontamination work. The latest result of post decontamination monitoring in municipalities were summarized
[Implementation period]
Compared air dose rate of 7months after the accident (as of November 2011) with that of 91months after the accident (as of October 2018), the latter decreased by 74%. It was confirmed that the decrease was faster than natural attenuation as an overall tendency
Distribution map showing transition of the air dose rate within 80km radius
Result of airborne monitoring in and around Fukushima Prefecture ( NSR / as of March 8, 2019)