Mushrooms concentrate Cesium from the logs that they grow on such that there is 3 times more cesium in the mushrooms than the logs.
Fukushima produced most of the mushroom logs in Japan. Even after 311, they distributed contaminated mushroom logs all around Japan until 8/12/2011 when it was finally banned.
Even after 8/12/2011, they were permitted to sell logs that had lower than 150 Bq/kg. On the logs with 150 Bq/kg, mushrooms grew that contained 450 Bq/ kg of cesium.
12/7/2011, an Aomori mushroom farmer reported that they measured 3,790 Bq/kg from one of their mushroom logs, which is 25 times higher than the “safety” limit.
According to Aomori prefecture, the log was cut out from woods in 1/2011 and stored outside. At the end of April, the farmer bought this log (1~1.5m length, 10~15 cm diameter).
Though the farmer bought 2,000 logs in total he said that he did not use any of them.
Considering the 3:1 (at least) concentrating activity of these mushrooms, they would contain 11,370 Bq/kg of cesium from being grown on these logs yet the Aomori prefecture states that there is no problem.
This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.