- 14 μSv/h from the yellow substance on the roof in Kashiwa Chiba (Fukushima Diary, Aug 10, 2012):
Around the end of July, I had the professional cleaners wash the roof of our house.
The roof was covered with something like this yellow moss. It was 0.7 μSv/h on its surface.
I took 20g of it by a kitchen knife. Radiation meter indicated it was red zone, 1.2 μSv/h.
I haven’t measured 1.2μSv/h from merely 20g of sample even around here known to be hotspot.
It was totally washed off after cleaning, radiation level was decreased a little bit, 0.4 μSv/h on the surface, but the yellow substance was still with mud in the rain gutter.
I took 3.6 kg of it with the perfect protective clothing (tyvek, gas mask, goggles, plastic gloves).
I packed the clothing soon after taking off the sample, had shower to clean eyes, ears, nostrils carefully.
This is very dangerous, please don’t do it. I can’t take a responsibility if something happened to you.
The radiation level was 14 μSv/h. I haven’t measured higher than 10 μSv/h before. It makes sense why the radiation level is high on the second floor.
We were living with such a thing on our roof..
When I stepped on the roof, I saw the roofs of other houses, most of them were covered with the same yellow substance. Probably the radiation level is high as well.
As reference, in March. 2011, yellow power remained on the street or rain gutters after rain and they measured quite high level of radiation as well. (cf. 2.16 μSv/h from yellow powder)
It is not known what the yellow powder was.
The connection between the yellow powder and this yellow substance is not known either.