Metals of King Bolete (Boletus edulis) Bull.: Fr. collected at the same site over two years

The caps of King Bolete collected from the same site over two years had similar content of Cu, Fe, K, Mg, Mn, Na and Zn but different of Al, Ba, Ca, Cd, Hg and Sr (p < 0.05; U Mann-Whitney test). In the case of stipes, statistically significant difference was noted only for Hg (p < 0.05). These findings imply that under a real environmental condition and stable geochemical composition of the surface horizon of soil substrate, the biological factors related probably to mycelium and to year-to-year fluctuating weather conditions, can cause variation in some metallic elements content of wild grown mushrooms. Fluctuation in minerals content of mushrooms collected from the same region over time have to be considered as one of parameters impacting their nutritional status as wild food. This imply also, that a more intensive research is needed to confirm, if elevated content of certain metals in mushrooms from the background (unpolluted) areas of different geochemical bedrock composition is in fact a feature related to geochemistry of parent soil bedrock and/or to natural seasonal variability - that can take place over a period of several years of mycelium life.