Contamination and Dietary Intake Risks Assessment of Heavy Metals in Some Species of Wild Edible Mushrooms Grown in Southern Nigeria

In this study, wild edible mushroom collected from Rivers and Imo state Nigeria were evaluated for heavy metals and dietary intake risks assessment. Four species of edible mushrooms were collected each in Imo (Lentinus squarrosulus, Pleurotus ostreatus, Lenziles betulina and Grifola polypilus frondosa) and River state (Lentinus squarrosulus, Pleurotus tuber-regium, Lenziles betulina, Auricularia aurucula) and metals extracted using HNO3 before analysis using flame atomic absorption spectrometry (F-AAS) in Varian AA 240 FS apparatus. Results showed that all metals showed concentrations lower than the permissible limits of World Health Organization (WHO) and Food and Agricultural Organization (FAO) while Pb was not detected in all samples analyzed and Cd in samples collected from Rivers state. However, Cd was only detected (0.003 mg/kg) in one sample (Lenziles betulina) collected from Imo state. Fe exceeded recommended values in Lentinus squarrosulus, Pleurotus ostreatus and Lenziles betulina in Imo State. Bioaccumulation factors for all mushrooms were generally low (< 3). However, the potential tolerable weekly intake and target hazard quotient values for the four mushroom species were usually extremely low except for Fe (2.24) in Lenziles betulina. Consumption of mushrooms from these areas might pose no potential risk in terms of heavy metals except for Fe content in Lenziles betulina from Rivers state. However, in general, it can be concluded that the consumption of the studied mushroom species from all sites does not present any health risk arising from their regular consumption.