Cs137 contamination in Finnish mushrooms measured with a Radiacode 103
So I came across some chantarelle mushrooms and decided to measure with my Radiacode 103.
I dried 400 g down to about 40 g and put them in a 3D-printed marinelli jar for measurement.
Sure enough, they are clearly contaminated with about 70 Bq of Cs-137, almost certainly from the Chernobyl disaster.
Will I eat them? No, I will keep them for measurement, but at 170 Bq/kg (fresh weight) they're well below the limit of 600 Bq/kg so eating them would be fine.
Are they special in any way? Not really, just ordinary mushrooms. Again, these are by no means super contaminated, but as a science nerd it's cool that the contamination is measurable with a consumer device.
The specific activity of Cs137 is about 3.2 TBq/g, so 70 Bq equates to about 20 picograms of Cs137.
The committed effective dose coefficient for Cs137 is 1.3 x 10^(-8) Sv/Bq, so eating these mushrooms would cause a radiation dose of about
1.3 x 10^(-8) Sv/Bq * 70 Bq = 0.91 μSv (microsievert)
My results are well in line with those of the recent Mushrooms 2025 campaign by the Finnish Nuclear Safety Authority (Säiteliyturvakeskus, STUK).
