Evaluation of the radioactive contamination in fungi genus Boletus in the region of Europe and Yunnan Province in China

Numerous species of wild-grown mushrooms are among the most vulnerable organisms for contamination with radiocesium released from a radioactive fallout. A comparison was made on radiocesium as well as the natural gamma ray-emitting radionuclide (K) activity concentrations in the fruiting bodies of several valued edible Boletus mushrooms collected from the region of Europe and Yunnan Province in China. Data available for the first time for Boletus edulis collected in Yunnan, China, showed a very weak contamination with Cs. Radiocesium concentration activity of B. edulis samples that were collected between 2011 and 2014 in Yunnan ranged from 5.2 ± 1.7 to 10 ± 1 Bq kg dry matter for caps and from 4.7 ± 1.3 to 5.5 ± 1.0 Bq kg dry matter for stipes. The mushrooms Boletus badius, B. edulis, Boletus impolitus, Boletus luridus, Boletus pinophilus, and Boletus reticulatus collected from the European locations between 1995 and 2010 showed two to four orders of magnitude greater radioactivity from Cs compared to B. edulis from Yunnan. The nuclide K in B. badius was equally distributed between the caps and stipes, while for B. edulis, B. impolitus, B. luridus, B. pinophilus, and B. reticulatus, the caps were richer, and for each mushroom, activity concentration seemed to be more or less species-specific.