Content of Cadmium, Lead, and Oxalic Acid in Wild Edible Mushrooms Harvested in Places with Different Pollution Levels

Our study was aimed at determining contents of cadmium, lead, and oxalic acid in select wild edible mushrooms harvested from areas potentially more (Ostrowiec Św (P1). and Ożarów (P2)) or less the protection zone of Magurski National Park (M – mountain) exposed to pollution. The experimental material were fruiting bodies of four species of edible mushrooms: boletus (Boletus edulis), bay bolete (Xerocomus badius), red-capped scaber stalk (Leccinum aurantiacum), and slippery Jack (Suillus luteus) collected in late August/early September of 2009. The results of contents of cadmium in the examined mushrooms indicate that the permissible (3 mg·kg d.m.) level was exceeded in fruiting bodies of boletus originating from the polluted (P1, P2) areas and mountain area (M), where its concentration was the highest. Caps and stalks of boletus originating from the protection zone of Magurski National Park were found to contain, respectively, 5.22 mg Cd·kg d.m. and 1.86 mg Cd·kg d.m., on average, (with the value of 3.54 mg Cd·kg d.m. that may be assumed for the whole fruiting body). Taking into a small contribution of mushrooms in a human diet, it does not pose a risk to human health. The concentration of lead in the analyzed mushrooms did not exceed 1.0 mg·kg d.m. The mean content of soluble oxalates in the analyzed species of mushrooms ranged from 35.5 to 104.1 mg·100 g d.m. (per whole fruiting body). Irrespective of the origin, the lowest content of oxalates was reported in fruiting bodies of slippery Jack (35.5-59.1 mg·100 g d.m). Caps of all investigated mushroom species were characterized by ca. 1.6 to 3.1 times higher content of oxalates than the stalks.