Distribution of mercury in Amanita fulva (Schaeff.) Secr. mushrooms: Accumulation, loss in cooking and dietary intake.

Representative individual specimens and pooled samples of carpophores of edible wild-grown fungus Amanita fulva (Schaeff.) Secr. and forest topsoil layer (0-10 cm) beneath the carpophores were collected from 15 spatially distant places in Poland and examined for total Hg. The median values of Hg in soils for most of the sites were below 0.05 mgkg(-1) dry matter. The ability of fungus A. fulva to bioconcentrate Hg was low (BCF, bioconcentration factor values of 1.2-3.6 for caps and 0.66-1.7 for stipes) at five sites that showed Hg in soils ranging from 0.066 to 0.21 mgkg(-1) dry matter, while much higher bioconcentration (BCF of 11-25 for caps and 7.0-12 for stipes) were observed for less contaminated soils with Hg contents of 0.018-0.054mgkg(-1) dry matter. Differences were also observed in Hg contamination of A. fulva from spatially and distantly distributed sites, and the median values (mgkg(-1) dry matter) ranged from 0.13 to 0.67 for caps and from 0.065 to 0.34 for stipes, while 0.63mgkg(-1) dry matter was observed in a set of whole fruiting bodies. Boiling of fresh A. fulva for 10min reduced the Hg content by 10%. A meal of A. fulva containing 0.065mgkg(-1) of Hg in the fresh mushroom product will not result in exceeding the reference dose set for inorganic Hg and for majority of the sites assessed (>90%) intake was substantially lower than the reference dose or the provisional tolerable weekly intake of inorganic Hg.