Heavy metals in irrigation water, soil pollution of vineyards and human health risk assessment

Heavy metals (HMs) in irrigation water and soil have always been an environmental research hotspot. Therefore, in this study, 13 irrigation water and 13 soil samples were collected from randomly selected vineyards of Gonabad between June and September 2022 and the contents of HMs in the samples were determined utilizing inductively coupled plasma optical emission spectrometry (ICP-OES). The soil contamination indices and health risks of HMs including Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe were assessed. The concentrations of HMs in all samples of irrigation water were within the permissible limits of FAO/WHO. The mean Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe concentrations in the surface soils of vineyards were 0.14, 6.96, 35.80, 36.95, 496.55, 34.89, 90.23, 55.30 and 11700.00 mg/kg, respectively. In all vineyards, the concentrations of all HMs except Pb (in 30.7% of vineyards) were within the limits of FAO/WHO in soils. Soil contamination indices showed no contamination to moderate contamination of the vineyards. There was no non-carcinogenic risk of HMs as evaluated by Hazard Quotient (HQ) and the Hazardous Index (HI) for adults and children. For children, the carcinogenic risk of Cr and Ni from exposure to soil was unacceptable . In both carcinogenic and non-carcinogenic health effects estimations, children were more vulnerable to HM-related health risks than adults. This research sheds light on the need to evaluate further the quality of farming soils with signs of pollution to guarantee public health.