Lead in Wild Edible Mushroom Species in Leicester, England

The aim was two-fold: to characterise the risks of lead (Pb) in Agaricus bitorquis collected in the city of Leicester (England), and to evaluate its presence in urban topsoils. Pb was monitored by ICP-MS in twenty-two homogenised mushroom samples (caps and stipes) mineralised with HNO3/H2O2 [LoD = 0.872 mg/kg dry weight (dw)]. Moreover, 450 topsoil samples were collected from 18 urban parks across Leicester; Pb was also measured by ICP-MS after appropriate digestion (LoD = 0.698 mg/kg). Levels were significantly higher in the mushroom caps (p-value = 3 × 10−5); median and ranges are provided in mg/kg dw: 2.461 (1.806–6.664) vs. 1.579 (0.988–4.223). Concentrations were much higher than those reported in sixteen A. bisporus (median < 1.0 mg/kg DW) specifically cultivated in high-traffic areas in the inner city of Berlin, suggesting some contamination by Pb. All caps monitored exceeded the established maximum concentration limit for Pb in cultivated mushrooms in the European Union (3 mg/kg dw), in line with the high accumulative metal capability described in the literature for Agaricus spp. Although non-carcinogenic risks characterised for Pb were negligible in the monitored mushrooms, a high consumption of wild green edibles in Leicester’s city should be limited as there are multiple additional sources of Pb and other metals, and they should be substituted by cultivated edibles where possible.