MERCURY ACCUMULATION IN WILD MUSHROOMS AT ABANDONED Hg-DEPOSIT MALACHOV (SLOVAKIA)

The aim of the presented article was to determine the Hg content in the fruiting bodies of 13 generally consumed mushroom species (Boletus reticulatus, Clitocybe nebularis, Lactarius deliciosus, Macrolepiota procera, Russula spp., Suillus grevillei, Tricholoma spp.) growing at the area of abandoned mercury deposit Malachov. The Hg concentrations were analyzed by thermal decomposition-gold amalgamation atomic absorption spectroscopy, using AMA-254 Advanced Mercury Analyzer. The Hg concentrations in soil varied widely (ranging from 0.01 to 2.44mg·kg-1), furthermore, they were particularly depended on the mushroom species. The fruiting bodies of Russula ochroleuca contained the highest concentrations of Hg (up to 16.69mg·kg-1). The lowest concentrations were detected in Russula aeruginea (from 0.04 to 0.06 in stipe stems and from 0.05 to 0.06mg·kg-1 in pileus) and in Russula vesca (0.05 in stipe stems; 0.09mg·kg-1 in pileus). Mercury is preferentially accumulated in the mushroom pileus (ranging from 0.05 in Russula vesca to 16.69mg·kg-1 in Russula ochroleuca). The bioconcentration factor was calculated for the rate of the Hg content in soil substrate vs. its concentration in the mushroom pileus (ranging from 0.03 to 29.22). The results indicate that some investigated mushroom species can be referred as Hg excluders (e.g. Russula vesca) whereas some other species as accumulators (e.g. Russula ochroleuca or Tricholoma portentosum). The obtained results were compared with the Government Decrees of Slovak Republic, showing that the substantial part of the studied mushroom species exceed the legal tolerance limit (0.25 mg kg-1) suggested for Hg in plant food and therefore they can be considered as inappropriate for human consumption.