Heavy metals (Pb, Cd, Cu, Zn, Ni, Co) in leafy vegetables collected from production sites: their potential health risk to the general population in Shiraz, Iran

Heavy metal contamination of vegetables is a great public health concern. One hundred samples of spinach, dill, cilantro, and cress from the production sites of Shiraz, Iran, and its outskirts were, therefore, examined for lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), nickel (Ni), and cobalt (Co) content. The potential health risks of these metals to local residents via the consumption of leafy vegetables were also estimated. The mean concentrations of Pb, Cd, Cu, Zn, Ni, and Co were 3.21, 0.28, 4.55, 40.44, 3.11, and 1.86mg/kg dry weight, respectively. The Pb level exceeded the permissible limit of 0.3mg/kg in 44.7% of vegetable samples. The other elements were, however, within FAO/WHO standards. The estimated daily intake (EDI) of Pb, Cd, Cu, Zn, Ni, and Co from leafy vegetables was 0.10, 0.01, 0.14, 1.26, 0.10, and 0.06g/kg body weight/day, respectively. At the mean and 97.5 percentile levels, all health risk index (HRI) values were less than the safe limit (<1). Thus, within the area this study was focused on, leafy vegetables did not make a major contribution to the dietary intake of the elements which could be mainly attributed to the low vegetable consumption by the study population (20g/day). Nevertheless, the lead content of the vegetables should be viewed with some concern. Regular monitoring of heavy metal contamination of foodstuff is recommended to control the sources of contaminants in the food chain.