Accumulation of heavy metals(loids) in soils and crops at a decentralized metal recycling site: Health risk assessment and pollution management

Abstract

Heavy metals(loids) in scrap metal recycling sites pose serious risks to human and environmental health. In this study, the health risks of multiple heavy metals(loids) (i.e., Cd, Cu, Mn, Ni, Pb, and Zn) via soil and crop exposure at a traditional metal recycling site in Vietnam with approximately 1000 years of operation were evaluated. The soil and the 20 most common crops within four groups (rice, leafy vegetables, nonleafy vegetables, and brassica vegetables) were collected. The pollution index (PI) values of the soil (1.01-4.80) ranged from moderately polluted to heavily polluted. Metal accumulation in crops (mg/kg, fresh weight) was in the order of Mn (9.95) > Zn (8.23) > Cu (1.50) > Ni (0.14) > As = Cd (0.04) > Pb (0.03). The results revealed high noncancer (hazard index (HI) = 7.1) and cancer (incremental lifetime cancer risk (ILCR) = 4.31 x 10(-3)) risks to the exposed community. Rice contributed to 84.1% of the total HI and 82.5% of the total ILCR, indicating a high health risk via rice consumption. To reduce health risks, rice, cabbage, fish mint, lemongrass, lettuce, and marjoram should not be grown in the study area. Pollutant management (e.g., pollutant source reduction, selection of proper crop cultivation, remediation of metal-contaminated soil, and reduction of metal uptake by crops) at scattered metal recycling sites should receive adequate attention to reduce the high noncancer and cancer health risks to inhabitants.