Radioactive and Conventional Pollutants Accumulated by Edible Mushrooms (Boletus sp.) Are Useful Indicators of Species Origin

Concentrations of artificial radionuclides and trace elements in Boletus samples collected in different areas of the world were detected, respectively, by gamma spectrometry and neutron activation analysis. The particular commercial value of Boletus edulis, B. aestivalis, and B. pinophilus from the Taro Valley (Parma, Italy) has often stimulated local factories to trade edible Boletus imported from several areas of the world as the real Taro Valley mushroom. Starting from this evidence, the calculation of the Chernobyl radioactive contamination in the mushrooms coupled with the presence of particular stable elements and their concentration factors has been demonstrated to be a potential useful tool for identifying the real origin of the samples. In fact, major differences in the radiocesium activity levels and trace element presence were observed even in mushrooms collected in nearby valleys. The radiometric data are supported by the statistical analysis. In particular, both the principal component analysis and the concentration distribution along a regression line support the idea of two different clusters: one referred to the “king boletus” of the Taro Valley and another one to the other conspecific samples from different ecosystems.