Lead bioaccumulation and translocation in herbaceous plants grown in urban and peri-urban soil and the potential human health risk

Lead (Pb) contamination risks to crops grown in urban and peri-urban soils is a great concern that should be better evaluated to define the Pb maximum levels in soils for safe cultivation and to identify suitable strategies to remediate Pb polluted urban soils. The objective of this work was to evaluate the potential risk for human health from the ingestion of the edible portions of barley, castor bean, common bean, Indian mustard, sorghum, spinach, and tomato grown in an unpolluted soil (initial Pb content 32.6 mg kg−1) spiked with 0, 300, 650, 1000 mg Pb kg−1, respectively. The potential possibility of using these plants to phyto-remediate the soil of Pb was also assessed. Pot trials were conducted for two years (2008 and 2009). Results highlighted that all the investigated species were able to attain growth to maturity in high Pb spiked soil, although Pb influenced dry matter accumulation. Even in soils with low Pb concentrations, Pb accumulated the edible parts. Noteworthy, even in untreated control soils, all tested species revealed a Pb concentration in the edible parts that was higher than the safe limit set by FAO/WHO. None of the investigated species were considered Pb hyperaccumulators, but all were shown to be potentially suitable for phyto-stabilization.