MERCURY IN EDIBLE WILD-GROWN MUSHROOMS FROM HISTORICAL MINING AREA – SLOVAKIA: BIOACCUMULATION AND RISK ASSESSMENT

Abstract

In the present paper, we focused on assessment of the contamination levels of five species (n = 33) of edible wild mushrooms (Macrolepiota procera, Boletus reticulatus, Suillus grevillei, Russula xerampelina and Xerocomellus chrysenteron). We collected samples of above-ground parts of the macroscopic fungi species in historical mining and processing area surrounding Banská Bystrica (Central Slovakia) in 2014. Within 2 m radius of the samples, we also took samples of underlying substrate. On the basis of the substrate, along with the monitored contaminant – mercury, we calculated bioaccumulation factors for individual species and their anatomical parts (cap and stipe). From the obtained results of the mercury content in the edible mushrooms, we then determined provisionally tolerable weekly intake (PTWI). The limit value for mercury (0.350 mg Hg kg-1 for an individual with average weight of 70 kg) is defined by the World Health Organization (WHO). Our results suggest that despite the relatively low level of Hg in the underlying substrate, the species Macrolepiota procera (1.98 mg kg-1 ± 68.2 (0.41 - 3.20 mg kg-1 DW)) is characterized by extremely high bioaccumulation ability, as confirmed by the bioaccumulation factors (BAFc = 15.3; BAFs = 8.02). PTWI value was exceeded by almost 20%. In case of the other studied edible wild mushroom species, we did not record any increased risk of mercury intake by consumers. Generally it can be stated that consumption of wild mushrooms represents a relatively small but significant risk of negative impact on the consumer´s health.