The concentrations and bioconcentration factors of copper and zinc in edible mushrooms

Copper and zinc contents have been determined in up to 28 species of edible mushrooms from different sites in the province of Lugo (NW Spain). Two hundred thirty-eight collected samples were analyzed by an anodic stripping voltammetric technique using a drop mercury as the working electrode. The results showed that the element concentrations were species-dependent, and the highest metal levels corresponded to the following species: Calvatia utriformis (235.5 mg Cu/kg), Macrolepiota procera (217.8 mg Cu/kg), and Agaricus macrosporus (217.7 mg Cu/kg) and Calvatia utrifomis (265.8 mg Zn/kg), Lactarius delicious (231.0 mg Zn/kg), and Agaricus macrosporus (221.3 mg Zn/kg) for Cu and Zn, respectively. All mushroom species bioaccumulated copper and zinc. Nevertheless, some individual samples of the species, such as Hydnum repandum, Cantharellus cibarius, and Coprinus comatus, were bioexclusors (BCF < 1). The hymenophore in mushrooms showed higher mean metal levels than the rest of the fruit bodies, with statistically significant differences. The copper and zinc concentrations were compared to literature data and levels set by legislation. It can be concluded that the consumption of these mushrooms cannot be considered a toxicological risk, and they provide an important nutritional requirement to the diet.