Measurement results of radiation and radioactivity levels in Tokyo
The Tokyo Metropolitan Institute of Public Health monitors environmental radiation doses throughout the year.
In response to the accident at TEPCO's Fukushima Daiichi Nuclear Power Plant in March 2011, we have posted the latest measurement results of radiation doses in the air and radioactive material levels in tap water and fallout (dust and rain) on this website, in order to relieve health concerns among Tokyo residents.
Radiation doses in the air (latest)
Measurement at monitoring posts
0:01-1:00 Sun., 22 Dec (average value)
-
0.0375
0.0329
0.0304
0.0397
0.0349
0.0286
0.0343
Radiation dose per hour (microgray=µGy)
* 1 gray (Gy) of radiation dose in the air can be converted to 1 sievert (Sv).* Three significant digits are indicated.
The dose of radiation in Tokyo is comparable with that in major cities in the world.
Radiological Monitoring data in the Major Cities
| City | Dose of Radiation (uSv/h) |
Date of measurement |
|---|---|---|
| New York | 0.046 | 18 Jan.,2019 |
| Paris | 0.043 | 15 Oct.,2017 |
| London | 0.108 | 24 Jan.,2018 |
| Beijing | 0.072 | 24 Sep.,2019 |
Monitoring posts in Shinjuku, Ota, Adachi, Hachioji and Chofu have been established at the request of the Ministry of Education, Culture, Sports, Science and Technology.
Monitoring posts in Edogawa and Kodaira have been established by the Tokyo Metropolitan Government’s Bureau of Social Welfare and Public Health, and the one in Koto by the Industrial Technology Research Institute.
Only the monitoring post in Shinjuku has been collecting data since before the Great East Japan Earthquake.
Examination results of radioactive materials in tap water (latest)
Unit: Bq/kg
| Sampling date/time | lodine | Radioactive cesium | |
|---|---|---|---|
| 131 | 134 | 137 | |
| 19 Dec.,2024 | ND(not detectable) | ND(not detectable) | ND(not detectable) |
| 18 Dec.,2024 | ND(not detectable) | ND(not detectable) | ND(not detectable) |
| 17 Dec.,2024 | ND(not detectable) | ND(not detectable) | ND(not detectable) |
Examination results of radioactive materials in fallout (latest)
Unit: Bq/kg
| Sampling date | lodine | Radioactive cesium | |
|---|---|---|---|
| 131 | 134 | 137 | |
| 9:30, Thu., 19 Dec. - 9:30 the following day | ND(not detectable) | ND(not detectable) | ND(not detectable) |
| 9:30, Wed., 18 Dec. - 9:30 the following day | ND(not detectable) | ND(not detectable) | ND(not detectable) |
| 9:30, Tue., 17 Dec. - 9:30 the following day | ND(not detectable) | ND(not detectable) | ND(not detectable) |
Measurement at 1 meter above the ground (latest)
Measurement results of radiation doses in the air at 100 locations in Tokyo (Jun. 2011)
- June 24, 2011
- We zoned the entire Tokyo area and in principle measured radiation doses in the air at one location in each zone.
Examination results of radioactive materials in soil
Measurement results of radiation doses in the air in the mountains in Tokyo (Oct. 2011)
Examination results of radioactive materials in foodstuffs and beef distributed in Tokyo
- Examination results of radioactive materials in foodstuffs distributed in Tokyo (Updated every week)
- Examination results of radioactive materials in beef supplied by the Shibaura Meat Treatment Center
Examination results of radioactive materials in agricultural and livestock products/fishery products, etc.
Radioactive Material Examination Results for Ocean Swimming Areas
- Radioactive material measurement results in seawater
- Measurement results of radiation doses in the air at beach
Examination results of radioactive materials in raw tap water, Etc.
- Examination results of radioactive materials in raw tap water, Etc. (2022 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2021 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2020 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2019 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2018 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2017 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2016 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2015 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2014 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2013 Fiscal year)
- Examination results of radioactive materials in raw tap water, Etc. (2012 Fiscal year)
Links to pages showing radiation measurement results
Tokyo Metropolitan Government
- Measurement of nuclear fission products of dust particles in the air in Tokyo (Bureau of Industrial and Labor Affairs)
- The effect on purified water by radioactivity (Bureau of Waterworks)
- Measurement of radiation and radioactivity in Tokyo Port(Bureau of Port and Harbor)
- Measurement results of radiation on sewage works(Bureau of Sewerage)
Japan
Links to related information
- Information on the Great East Japan Earthquake (Ministry of Health, Labour and Welfare)
- The Great East Japan Earthquake (Ministry of Agriculture, Forestry and Fisheries)
- Health and safety | Great East Japan Earthquake (The Prime Minister’s Office website)
- Message on human rights related to radiation exposure (Bureau of General Affairs, Tokyo Metropolitan Government) (Japanese)
- The National Institute of Radiological Sciences