Assessment of toxicological health risk of trace metals in vegetables mostly consumed in Punjab, Pakistan

In the present study, levels of trace metals in two commonly consumed vegetables (Spinacia oleracea and Brassica campestris) were assessed. Both vegetables are cultivated in a semi-arid area which receives effluents from various sources. Leafy parts and tender stems are used for human consumption as well as for farm animals as a source of nourishment. However, the aim of the present study was to appraise the concentrations of trace metals in different tissues of both vegetables at the time of harvesting when they become accessible to the humans. The analysis showed that mean trace metal levels in the stem of S. oleracea showed the highest bioconcentration of Zn (25.43 mg kg−1), while in the stem (28.56 mg kg−1) and roots (22.40 mg kg−1), Fe level was the highest. In case of B. campestris, Fe level was highest (18.45 mg kg−1) in the stems. Copper (Cu) has the highest bioconcentration factor values (BF = 1.030) in the stem of B. campestris, whereas Mn (BF = 0.010) was the least accumulated element in the leaves and roots of B. campestris. Collectively, bioconcentration of trace metals in plant tissues exceeded the standard values set by the World Health Organization (WHO) and the US Environmental Protection Agency. So, the vegetables cultivated in effluent-impacted areas may stance a potential public health risk for end-consumers.