Heavy metals bioaccumulation in wild edible mushrooms of an Indo Burma biodiversity hotspot: Suitability assessment for safe consumption and food safety/security implications

Fungi can bio-accumulate heavy metals (HMs) from the contaminated soil which makes them a valuable tool and potential bio-agent for environmental remediation and agro-ecosystem restoration. However, it is essential to analyse the potential risks associated with the consumption of the HMs contaminated wild edible mushrooms to maintain the food safety/-security. To this end, HMs content was assessed in three wild edible mushrooms species collected from different regions of Aizawl Mizoram, North East India, which is underlying in an Indo Burma biodiversity hotspot. The analysis of HMs was carried out using atomic absorption spectrometry (AAS) to determine the contents of copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), nickel (Ni), lead (Pb) and cadmium (Cd) in mushrooms’ biomass on dry weight basis. The overall heavy metal content in the studied mushrooms was also found to follow the order: Cd (0.003–0.018 mg/kg) < Pb (0.034–0.182 mg/kg) < Ni (0.033–0.058 mg/kg) < Mn (3.3445–6.109 mg/kg) < Cu (7.085–12.285 mg/kg) < Zn (19.089–31.878 mg/kg) < Fe (30.589–49.203 mg/kg). Results revealed that all the HMs in these mushrooms were within safe limits for human consumption, thereby imposing negligible human health risks. However, long-term consumption of mushrooms with elevated Ni levels should be approached with caution. Nevertheless, sustained long-term HMs monitoring and estimation of human health risk assessment indices are warranted in biodiversity hotspots to mitigate the human health risks. Last, the extrapolation of present study is necessary in urbanized and industrial landscapes with intense HMs contamination.