Concentration levels of heavy metals in irrigation water and vegetables grown in peri-urban areas of Sanandaj, Iran

Concentration and daily intake (DI) of heavy metals [lead (Pb), chromium (Cr), cadmium (Cd) and copper (Cu)] were investigated in four common edible vegetables including coriander, dill, radish root and radish leaf grown at peri-urban sites in Sanandaj, Iran. A total of 120 composite samples of vegetables were taken from ten vegetable farms during six months from May to October 2012. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to estimate the levels of heavy metals. The results showed that Pb and Cr concentrations exceeded the safety limits given by Food and Agriculture Organization (FAO) or the World Health Organization (WHO) for human consumption with the exception of copper and cadmium that were lower than the permissible leveling in all of the samples. Furthermore, the results showed that there was a significant variation in the levels of these metals among the examined vegetables (P < 0.001). DI values for Pb, Cu, Cr and Cd could be 0.1, 1.5, 0.94 and 0.004 mg per day, respectively. As respect, DI values for Pb and Cd were also below the international guideline bases. Although Pb level was higher than the permissible standard, it seems that daily intake of these vegetables may not have detrimental health hazards to consumers.