Arsenic in Edible Mushrooms

Abstract

The arsenic content of 225 samples representing 79 species of edible mushrooms were determined by hydride generation atomic absorption spectrophotometry. Average arsenic concentrations in cultivated mushrooms such as the champignon de Paris, shiitake and oyster mushrooms ranged from 0,2-0,5 mg/kg dry weight, which is the same order of magnitude as that measured in most fruits and vegetables. The levels determined in wildgrowing dried mushrooms of commerce (boletus, morels and chanterelles) were equally low. Among the numerous wild mushrooms admitted for sale on Swiss markets there were several species, notably members of the genus Agaricus, having a higher arsenic content that sometimes even exceeded 10 mg/kg. The high concentrations (up to 200 mg/kg on dry weight) reported in literature for Laccaria amethystina, a mushroom of minor culinary importance, were amply confirmed. The significance of these findings is briefly discussed. Moderate consumption of most edible mushrooms will contribute little to the arsenic intake of the average consumer. Even eating L. amethystina may well be harmless, since the arsenic in this species is mostly present as methylated arsinic acids of low toxicity.