Mercury in fruiting bodies of dark honey fungus (Armillaria solidipes) and beneath substratum soils collected from spatially distant areas.

BACKGROUND: This paper reports data on bioconcentration potential and baseline mercury concentrations of fruiting bodies of dark honey fungus (Armillaria solidipes) Peck and soil substrate layer (0-10 cm) from 12 spatially distant sites across Poland. Mercury content of caps, stipes and soil samples were determined using validated analytical procedure including cold-vapor atomic absorption spectroscopy after thermal decomposition of the sample matrix and further amalgamation and desorption of mercury from gold wool. RESULTS: Mean mercury concentrations ranged from 20 ± 8 to 300 ± 70 ng g(-1) dry weight (dw) in caps, from 20 ± 6 to 160 ± 40 ng g(-1) dw in stipes, and in underlying soil were from 20 ± 2 to 100 ± 130 ng g(-1) dw. The results showed that stipes mercury concentrations were 1.1- to 1.7-fold lower than those of caps. All caps and the majority of stipes were characterized by bioconcentration factor values > 1, indicating that dark honey fungus can be characterized as a moderate mercury accumulator. CONCLUSION: Occasional or relatively frequent eating of meals including caps of dark honey fungus is considered safe in view of the low total mercury content, and the mercury intake rates are below the current reference dose and provisionally tolerable weekly intake limits for this hazardous metal.

Selected elements in Brown Birch Scaber Stalk Leccinum scabrum.

A survey of 26 metallic elements and metalloids such as Ag, Al, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Rb, Sb, Se, Sr, Tl, V and Zn was carried out using ICP-MS, ICP-OES, HG-AAS and CV-AAS in the caps and stalks of edible mushroom Brown Birch Scaber Stalk collected from two lowland and one mountain sites in Poland. Ag, Al, Cd, Cr, Cs, Cu, Fe, Hg, K, Mg, Mo, Pb, Rb, Se, V and Zn occurred in greater concentration in the caps than stalks of Brown Birch Scaber Stalk, and opposite situation was for Tl and Na. Brown Birch Scaber Stalk collected from the site in Sudety Mountains did contain Al, Ba, Cs, Fe, Ga, Ni, Pb, Sr and V in significantly greater concentration when compared to specimens collected from the lowland sites, and what imply on significance of geological origin and/or soil substrate pollution impacting on mineral composition of this mushroom species. The results provide useful environmental and nutritional baseline level information on mineral composition of Brown Birch Scaber Stalk from unpolluted sites.

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.

Content and bioconcentration factors of mercury by Parasol Mushroom Macrolepiota procera.

The carpophores of Parasol Mushroom and underlying soil substrate collected from several unpolluted and spatially distant sites across Poland were examined to know content and bioconcentration potential of mercury by this species. The total mercury content of the caps of Parasol Mushroom for the particular sites ranged from 1.1 +/- 1.0 to 8.4 +/- 7.4 microg/g dry matter (total range from 0.05 to 22 microg/g dm), while in the stalks were from 0.53 +/- 0.27 to 6.8 +/- 7.1 microg/g dm (total range from 0.078 to 20 microg/g dm). A top soil layer (0-10 cm) showed baseline mercury concentration from 0.022 +/- 0.011 to 0.36 +/- 0.16 microg/g dm (total range from 0.010 to 0.54 microg/g dm). Parasol Mushroom is an effective mercury accumulator in the carpophores and bioconcentration factor (BCF) values of this element in the caps and depending on the sampling site ranged from 16 +/- 6 to 220 +/- 110 (total range from 0.52 to 470), while for the stalks were from 7.6 +/- 2.6 to 130 +/- 96 (total range from 0.52 to 340). It seems reasonable to state that tolerance (maximum allowable concentration) of the total mercury in a single cap of Parasol Mushroom at unpolluted areas should not exceed 25 microg/g dm. A value greater then 25 mu g/g dm will imply an elevated content due to site pollution problems. Nevertheless, knowledge on highly toxic methylmercury content and its fraction in the total mercury content of Parasol Mushroom is lacking.