Assessment of health risks associated with the consumption of wastewater-irrigated vegetables in urban areas

Several health issues are related to toxic metals among which Pb, Cr, Cd, and Ni are categorized as human carcinogenic. We analyzed the health risks linked with food chain contamination due to vegetables irrigated with wastewater containing metals. Thirty-six samples of each vegetable, water, and soil (at two depths, 0–15 cm, and 15–30 cm) were collected individually from 12 different locations near Paharang drain, Faisalabad, and the contamination level of each metal (Cd, Cr, Mn, Ni, and Pb) was determined through atomic absorption spectroscopy. The results have shown that the highest concentration of Cd (0.23 ± 0.007 mg kg⁻¹), Cr (0.33 ± 0.11 mg kg⁻¹), Ni (0.15 ± 0.07 mg kg⁻¹), and Pb (0.35 ± 0.20 mg kg⁻¹) was found in the sewage water, which is used to irrigate soil and vegetables in the study area of Faisalabad, Pakistan. The concentration of all the considered metals in wastewater-irrigated vegetables exceeded the acceptable limits set by European Union and WHO, while the transfer factor (TF) was low for Cr, while for Mn, Ni, Cd, and Pb, it was more than the acceptable limits, respectively. Human risk index (HRI) was also found to be highest for Coriandrum sativum L. (7.36 mg kg⁻¹) for adults against Pb. The leafy vegetables cultivated by wastewater had potential health risks concerning Pb, Mn, and Cd. The hazard quotient of Pb, Mn, Ni, and Cd was more than 1, which revealed strict health risk from Cd, Ni, Cr, Mn and Pb, which showed severe health risk with the utilization of vegetables contaminated with wastewater containing these heavy metals.