Distribution of mercury in Gypsy Cortinarius caperatus mushrooms from several populations: An efficient accumulator species and estimated intake of element

• Gypsy mushroom efficiently sequesters Hg in fruit bodies.
• Gypsy that emerge at background areas can contain elevated quantity of Hg.
• Gypsy mushroom eaten frequently can provide relatively high dose of Hg.

Mushroom Cortinarius caperatus is one of the several edible wild-grown species that are widely collected by fanciers. For specimens collected from 20 spatially and distantly distributed sites in Poland the median values of Hg contents of caps ranged from 0.81 to 2.4 mg kg−1 dry matter and in stipes they were 2.5-fold lower. C. caperatus efficiently accumulates Hg and the median values of the bioconcentration factor for caps range from 120 to 18 and for stipes from 47 to 7.3. This mushroom even when collected at background (uncontaminated) forested areas could be a source of elevated intake of Hg. The irregular consumption of the caps or whole fruiting bodies is not considered to pose a risk. Frequent eating of C. caperatus during the fruiting season by fanciers should be avoided because of possible health risk from Hg. Available data on Hg contents of C. caperatus from several places in Europe are also summarized.