jarvik
- 22
- 0
jensjakob said:163.000 becquerels in soil northwest of Fukushima NPP:
http://www3.nhk.or.jp/daily/english/23_28.html
That is quite bad.?
Looking at the story it gives 163 000 becquerels/kg soil, which from the article I think they took from the top 5cm of the soil profile. The story also gives that 100 becquerels/kg is the upper limit of normal. Normal would be normal left over from 1960s global bomb test fallout I presume, (this would check out with my own experience of surface sediment typcally ranging from 1-200 becquerels 137 Cs/kg sediment).
Other naturally occurring radioisotopes 40K, 238U, 232Th and associated daughter products combined would probably add up to a 1000-10000 becquerels/kg soil I think (this can be considerably higher in some soils/regions) But even in the context of the total surface sediment activity it would appear the added 137Cs activity (I'm assuming it's recent reactor sourced fallout) is raising total soil activity by about 10-100 times..wow.
Makes me wonder about the 90Sr, 134Cs, 131I and other fission products in the soil too
Soil certainly isn't the only source of radiation to us humans but when I think about the other fallout nuclei that likely are also be present in large amounts in this soil such as 90Sr I'd be concerned. I don't know enough about human exposure issues to judge whether it crosses the line from meh to an increased longterm health risk for local residents though.
Anyone have a better take?
Last edited by a moderator: