Health risk assessment consequent to wastewater irrigation in Pakistan

The aim of this study was to investigate the uptake and accumulation of heavy metals including cadmium, chromium, iron, nickel, and lead in 8 food crops irrigated with industrial wastewater and correlate the levels with potential human health risks. The concentrations of these metals in the food crops irrigated with wastewater decreased in the order iron (Fe) ˃ chromium (Cr) ˃ cadmium (Cd) ˃ nickel (Ni) ˃ lead (Pb). In all cases, the metallic contents in the vegetables exceeded the safe limits recommended by FAO/WHO. The highest bioaccumulation factor was recorded for cadmium. Further, the health risk indices of cadmium and lead were greater than 1 in seven food crops. For nickel, health risk was exceeded only for Pisum sativum and Solanum tuberosum. The indices for various food crops were in decreasing order: Cd > Pb > Ni > Cr > Fe. Out of 8 food crops, only Cantiquorum antiquorum showed risk indices lower than 1 for all 5 metals. Data demonstrated that food crops irrigated with wastewater in this study area are highly metal contaminated and may constitute a serious health risk to the local human and animal populations.