Wild mushroom in some parts of Germany are still radioactive to this day exactly because of this. After Chernobyl, clouds with radioactive particles moved west and then started raining over Germany. Certain species of mushroom tend to accumulate the Caesium-137 from that and these mushroom then get eaten by wild animals. To this day if you sell wild animals that were shot in these areas you have to get them tested. They regularly exceed legal contamination levels deemed safe for human consumption.
> In the last years values of up to several thousand becquerel per kilogram were measured in wild game and certain edible mushrooms. In Germany it is not permitted to market food with more than 600 becquerel caesium-137 per kilogram. [1]
[1] https://www.bfs.de/EN/topics/ion/environment/foodstuffs/mush...
Not only Chernobyl, but also mostly nuclear weapon tests during the cold war.
https://pubs.acs.org/doi/full/10.1021/acs.est.3c03565
There have been proposals to remediate contaminated agricultural areas by sporulating and harvesting mushroom species that concentrate radiocesium.
What amazes me is the mushroom mycelium are actually sorting out the radioactive material grain by grain, which would be highly impractical any other way.
http://large.stanford.edu/courses/2016/ph241/stein1/
One of my relatives freaked out the summer after Chernobyl accident happened, when finding some glow-in-the-dark mushrooms in the forest nearby. Upon examination by a pro they turned out to be naturally bioluminescent fungi.