engleski

Accumulation of heavy metals in edible saprotrophic and ectomycorrhizal mushrooms

Heavy metals cause serious problems in the environment, and they can be accumulated in organisms, especially in the higher fungi. The increasing concentrations of heavy metals in mushrooms also increase the importance of fungi as potential biological indicators of environmental pollution. However, extremely high concentrations of toxic heavy metals in mushrooms can have negative effects on human health. Therefore, the aim of this study was to determine the concentrations of heavy metals Ni, Cr, Pb, Cd and Hg in certain edible species of saprotrophic and ectomycorrhizal fungi and the substrate collected in Gorski kotar. In this study we used 87 samples from 10 species of wild edible mushrooms from seven different genera, five of them saprotrophic species (Agaricus campestris (L) Fries, Armilariella mellea (Vahl. ex Fr.) Karst., Clitocybe inversa (Scop. ex Fr.) Pat., Clitocybe nebularis Batsch. ex Fr., Macrolepiota procera (Scop. ex Fr.) Sing., ) and five species of ectomycorrhizal fungi (Lactarius deterimus Groger, Boletus edulis Bull. ex Fries, Boletus aestivalis Paulet ex Fries, Tricholoma portentosum (Fr.) Quelet, Tricholoma terreum (Schff. ex Fr.) Kummer). The analyses of heavy metals in mushrooms and soil substrate were carried out by inductively coupled plasma - optical emission spectrometry (ICP-OES). The highest concentrations of Ni (1.84 mg kg-1), Cr (1.32 mg kg-1), and Pb (1.38 mg kg-1) were determined in Macrolepiota procera. The highest concentration of Cd (1.47 mg kg-1) was determined in Agaricus campestris, and the highest concentration of Hg (1.59 mg kg-1) was determined in Boletus edulis. The concentration of Ni, Cr, Pb and Cd significantly differed (p<0.001) between examined saprophytic and ectomycorrhizal mushrooms, while the Hg content was not significantly different with respect to the nutrients absorbed by mushrooms. In terms of the anatomical part of the fruiting body (cap-stipe), a considerably greater concentration of the analysed elements was found in the cap for analysed mushroom species According to calculated bioconcentration factors, all the examined species were found to be bioexclusors of Ni, Cr and Pb, and bioaccumulators of Cd and Hg. According to the regulations on maximum levels of certain contaminants in foodstuffs (Official Gazette 154/2008 ) and determined concentrations analysed heavy metals, it can be concluded that the consumption of the tested mushrooms cannot be considered to provide a toxicological risk from Ni, Cr, Pb, Cd and Hg content for humans. However, to evaluate the possible danger of heavy metals on human health, their level should be analyzed more often in wild edible mushrooms.

food safety, fungi, ICP-OES, toxicological risk

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