Cadmium and lead accumulation in important food crops due to wastewater irrigation: Pollution index and health risks assessment.

The contamination of farm soils with heavy metals (HMs) has raised significant concerns due to the increased bioavailability and accumulation of HMs in agricultural food crops. To address this issue, a survey experiment was conducted in the suburbs of Multan and Faisalabad to investigate the spatial distribution, bioaccumulation, translocation, and health risks of cadmium (Cd) and lead (Pb) in agricultural crops. The results show a considerable concentration of Cd and Pb in soils irrigated with wastewater, even though these levels were below the permissible limits in water and soil matrices. The pollution index for Cd was mostly greater than 1 at the selected sites, indicating its accumulation in soil over time due to wastewater irrigation. Conversely, the pollution index for Pb was below 1 at all sites. Among the plants, accumulated the highest concentration of Cd and Pb. The translocation factor from soil to root was highest for (7.037 for Cd) and (6.383 for Pb). The target hazard quotient (THQ) value of Cd exceeded the non-carcinogenic limit for most vegetables. The highest value was found in (5.256) and the lowest in (0.040). In contrast, the THQ level of Pb was below the non-carcinogenic limit for most vegetables, except for (1.479), (1.367), and (1.326). The study highlights that poses the highest health risk for humans, while poses the highest risk for animals due to Cd and Pb contamination. These results underscore the urgent need for effective measures to mitigate the health risks associated with HM contamination in crops and soils.