Lead in edible mushrooms: levels and bioaccumulation factors

Lead content was determined in 238 samples of 28 species of edible mushrooms collected from different sites in the province of Lugo (NW Spain) during 2005 and 2006. The hymenophore (H) and the rest of the fruiting body (RFB) were analysed separately. The analyses were carried out by an anodic stripping voltammetric technique using drop mercury as the working electrode. The highest mean lead contents (mg/kg dry weight) of 3.6 and 4.1, 3.0 and 2.2, 2.5 and 2.3, 2.4 and 2.3 were determined in Coprinus comatus, Agaricus campestris, Lepista nuda and Calvatia utriformis in hymenophore and the rest of fruiting bodies, respectively, while the lowest in Agaricus bisporus (0.35 in H and 0.54 in RFB) and Fistulina hepatica (0.41 in H and 0.50 in RFB). All mushroom species were bioexclusors of lead (BCF<1) in relation to the underlying soils. There were not statistically significant differences between lead levels in hymenophore and in the rest of the fruiting bodies. The lead concentrations were compared to literature data and levels set by legislation. It can be concluded that the consumption of these mushrooms can not be considered as a toxicological risk from lead content point of view, and they provide a nutritional requirement to the diet.