Following up this post,http://fukushima-diary.com/2011/10/breaking-news-57-5microsvh-in-chiba/
The exact location and the contamination level was revealed by the city government.
According to their report,they took 3 samples:
Sample 1 (Ground soil)
- Cs-134 70,200 Bq/Kg
- Cs-137 85,100 Bq/Kg
- Total 155,300 Bq/Kg
Sample2 (30cm deep in the ground)
- Cs-134 87,000 Bq/Kg
- Cs-137 105,000 Bq/Kg
- Total 192,000 Bq/Kg
Sample3 (30cm deep in the ground)
- Cs-134 124,000 Bq/Kg
- Cs-137 152,000 Bq/Kg
- Total 276,000 Bq/Kg
By Gamma ray spectrometer
They covered the spot with soil (50cm) and waterproof sheet.
They announce there is no problem anymore because the radiation level at 10m distance is the same as the radiation at other places, which is 0.3 microSv/h. This is another problem itself.
Because it contains Cs-134, it is obviously from Fukushima,and also because it’s higher underground ,probably “someone” (or some government) secretly abandoned radioactive waste/soil into the area and covered.
Before 311,you were forbidden to take out 4 Bq/Kg of radioactive material out of a lab.You had to make a written apology.
276,000 Bq/kg deserves 69,000 written apologies.
(Source)