Mercury and its bioconcentration factors in King Bolete (Boletus edulis) Bull. Fr.

The total mercury content for a representative number of the carpophores of King Bolete from 13 sites across Poland averaged from 1.1 +/- 1.4 to 7.6 +/- 3.1 microg/g dry matter in the caps (total variation between 0.02 and 14 microg/g dm), and from 0.82 +/- 0.71 to 3.8 +/- 1.8 microg/g dm in stalks (total variation between 0.03 and 6.7 microg/g dm). A top soil layer (0-10 cm) collected from the mushroom sampling sites showed mean mercury content at range from 0.02 +/- 0.01 to 0.05 +/- 0.02 microg/g dm (total variation between 0.01 and 0.08 microg/g dm). King Bolete is effective mercury accumulator in the carpophores and bioconcentration factor (BCF) of this element in the caps ranged from 41 +/- 6 to 130 +/- 39 (total variation between 13 and 170) and in the stalks were from 27 +/- 18 to 72 +/- 22 (total variation between 4.0 and 90). Based on a relatively large set of data on the total mercury concentrations obtained in this survey, and dataset available for King Bolete from various sites in Europe, it seems reasonable to state that the upper food hygienic limit for the total mercury content in this species collected from unpolluted (background) sites should not exceed 20 microg/g dm in a single cap or a carpophore, while on an average, per site or consignment, should not exceed 10 mug/g dm in the caps or the carpophores.