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Radiation monitoring surveys at beaches
To enable bathers to use beaches safely and with peace of mind with regard to the influence of the nuclear accident on such places, the Hokkaido government measured levels of radioactive substances and air radiation at beaches in various regions (see map of measurement sites) before and after they were opened to the public.
Before being opened to the public
|
Beach name |
Nuclide analysis (sea water) |
Radiation levels in the air (beaches) | |||||
|
Date samples were taken |
Date of measurement |
Iodine -131 |
Cesium -134 |
Cesium -137 |
Date of measurement |
Radiation level | |
|
Ishikari-hama (within the jurisdiction of Ishikari Subprefectural Bureau) |
June 21, 2011 |
June 22, 2011 |
Not detectable |
Not detectable |
Not detectable |
June 21, 2011 |
0.048 μ Gy/h |
|
Otaru Dream Beach (within the jurisdiction of Shiribeshi General Subprefectural Bureau) |
June 21, 2011 |
June 22, 2011 |
Not detectable |
Not detectable |
Not detectable |
June 21, 2011 |
0.046 μ Gy/h |
|
Golden Beach Rumoi (within the jurisdiction of Rumoi Subprefectural Bureau) |
June 24, 2011 |
June 27, 2011 |
Not detectable |
Not detectable |
Not detectable |
June 24, 2011 |
0.036 μ Gy/h |
|
Muroran Itanki-hama (within the jurisdiction of Iburi General Subprefectural Bureau) |
June 24, 2011 |
June 27, 2011 |
Not detectable |
Not detectable |
Not detectable |
June 24, 2011 |
0.022 μ Gy/h |
|
Oyakoiwa Fureai Beach (within the jurisdiction of Hidaka Subprefectural Bureau) |
June 24, 2011 |
June 27, 2011 |
Not detectable |
Not detectable |
Not detectable |
June 24, 2011 |
0.032 μ Gy/h |
|
Yunokawa (within the jurisdiction of the Oshima General Subprefectural Bureau) |
July 6, 2011 |
July 7, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 6, 2011 |
0.020 μ Gy/h |
|
Gennadai Beach Park “Sea Pool” (within the jurisdiction of Hiyama Subprefectural Bureau) |
July 5, 2011 |
July 7, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 5, 2011 |
0.040 μ Gy/h |
|
Wakkanai Sakanoshita (within the jurisdiction Souya General Subprefectural Bureau) |
July 4, 2011 |
July 5, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 6, 2011 |
0.038 μ Gy/h |
|
Tokoro Jounan Beach (with the jurisdiction of Okhotsk General Subprefectural Bureau) |
July 5, 2011 |
July 7, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 5, 2011 |
0.030 μ Gy/h |
After being opened to the public
|
Beach name |
Nuclide analysis (sea water) |
Radiation levels in the air (beaches) | |||||
|
Date samples were taken |
Date of measurement |
Iodine -131 |
Cesium -134 |
Cesium -137 |
Date of measurement |
Radiation level | |
|
Ishikari-hama (within the jurisdiction of Ishikari Subprefectural Bureau) |
July 25, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 27, 2011 |
0.036 μ Gy/h |
|
Otaru Dream Beach (within the jurisdiction of Shiribeshi General Subprefectural Bureau) |
July 28, 2011 |
August 2, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 27, 2011 |
0.038 μ Gy/h |
|
Golden Beach Rumoi (within the jurisdiction of Rumoi Subprefectural Bureau) |
July 26, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 26, 2011 |
0.036 μ Gy/h |
|
Muroran Itanki-hama (within the jurisdiction of Iburi General Subprefectural Bureau) |
July 26, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 26, 2011 |
0.022 μ Gy/h |
|
Oyakoiwa Fureai Beach (within the jurisdiction of Hidaka Subprefectural Bureau) |
July 26, 2011 |
August 2, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 26, 2011 |
0.040 μ Gy/h |
|
Yunokawa (within the jurisdiction of the Oshima General Subprefectural Bureau) |
July 26, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 26, 2011 |
0.020 μ Gy/h |
|
Gennadai Beach Park “Sea Pool” (within the jurisdiction of Hiyama Subprefectural Bureau) |
July 25, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 25, 2011 |
0.040 μ Gy/h |
|
Wakkanai Sakanoshita (within the jurisdiction Souya General Subprefectural Bureau) |
July 25, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 25, 2011 |
0.032 μ Gy/h |
|
Tokoro Jounan Beach (with the jurisdiction of Okhotsk General Subprefectural Bureau) |
July 27, 2011 |
August 1, 2011 |
Not detectable |
Not detectable |
Not detectable |
July 27, 2011 |
0.030 μ Gy/h |
○ “Not detectable” indicates a value lower than the detectable limit.
○ A rough indication of water quality concerning beach radiation, according to guidelines (Ministry of the Environment) related to radioactivity at beaches.
(Provisional values applicable only this summer)
・Radioactive iodine 131: 30 Bq (Becquerel)/ℓ
・Radioactive cesium: 50 Bq (Becquerel)/ℓ （Total sum of radioactive cesium 134 and 137）
○ Extent of air radiation levels measured by each subprefectural bureau in Hokkaido (March 23 to July 28, 2011)
・Shifting within the extent of 0.022 to 0.078 μ Gy/h (microGray per hour), which are normal levels.
