Investigation of long-term caesium-137 radioactivity in fungal species of the Czech Republic.

The accumulation of radionuclides in edible wild fungi represents a potential pathway of human exposure to ionising radiation. This study quantified the specific activity concentration of 137Cs in 25 mushroom species collected from seven forest sites throughout the Czech Republic in 2023. Interspecific and spatial differences were observed. The highest activity concentrations were measured in Imleria badia, reaching up to 7,842 Bq/kg of dry mass, which is 63% below the European Union (EU) safety threshold, followed by other mycorrhizal Boletales such as Boletus edulis, Tylopilus felleus and Suillus grevillei. In contrast, Tapinella atrotomentosa, a saprotrophic member of the Boletales order with a gilled hymenophore, displayed markedly lower accumulation, indicating that both nutritional strategy and hymenophore morphology may modulate radiocaesium uptake independently of taxonomy. Two-way ANOVA and Tukey's post-hoc tests confirmed significant influence of species and locality on radiocaesium activity concentration, whereas trophic type alone was not significant. None of the analysed samples exceeded the 1,250 Bq/kg fresh mass limit set by Council Regulation Euratom 2016/52, although two I. badia samples surpassed the 600 Bq/kg fresh mass import limit of Commission Regulation (EU) 2020/1158. The estimated effective dose for an adult consumer was substantially below the annual 1 mSv dose limit, suggesting minimal radiological risk associated with wild mushroom consumption in the Czech Republic.