Health risk assessment and multivariate apportionment of trace metals in wild leafy vegetables from Lesser Himalayas, Pakistan

Fresh wild leafy vegetables and related soil samples were collected from Lesser Himalayas, Pakistan to evaluate the trace metal levels and related health risk to the consumers. The samples were prepared by acid digestion, followed by quantification of selected trace metals (Fe, Zn, Cu, Mn, Cr, Cd and Pb) on atomic absorption spectrophotometer. Generally, in the vegetables highest concentrations were detected for Fe, followed by Zn, Mn and Pb. Among the vegetables, highest concentrations of Zn, Cu and Cr were found in Solanum nigrum, while Stellaria media showed the elevated levels of Fe and Cd. Nevertheless, maximum concentrations of Mn and Pb were found in Convolvulus arvensis and Amaranthus viridis, respectively. In the case of soil, highest levels were observed for Fe, followed by Mn, Zn, Pb, Cr and Cu. Translocation of trace metals from soil to the vegetables exhibited highest values for Cd, followed by Zn. Multivariate principal component analysis showed significant anthropogenic contributions of the Pb, Cr, Zn, Cd and Fe in the vegetables. Health risk assessment was evaluated in terms of health risk index, target hazard quotient and hazard index which showed that the intake of some trace metals through vegetables was higher than the recommended values, consequently consumption of the vegetables may be associated with non-carcinogenic health risks. Nonetheless, elevated levels of Cr and Pb were also found to be associated with lifetime carcinogenic risk to the consumers.

► Elevated levels of Fe, Zn, Mn and Pb were found in the vegetables.
► The accumulation factors of Cd and Zn were higher than other trace metals.
► PCA showed anthropogenic contribution of Pb, Cr, Zn, Cd and Fe in the vegetables.
► Non-carcinogenic health risk was associated with Cr, Pb, Cd and Fe.
► Lifetime carcinogenic risk was found to be associated with Cr and Pb.