Assessment of Heavy Metals Residue in Edible Vegetables Distributed in Shiraz, Iran

Background: Given the importance of vegetables in the food pyramid, their safety is very important from view point of public health. Vegetable contamination by heavy metals can lead to bioaccumulation of these toxic and disease-causing elements in the body of consumers. Therefore, in this study, the concentration of some heavy metals, including lead (Pb), cadmium (Cd), zinc (Zn) and copper (Cu) in edible vegetables distributed in Shiraz, Iran was investigated. Methods: During spring 2014, a total of 184 vegetable samples, including basil, mint, parsley, torre, tarragon, purslane, and lettuce were randomly taken from markets of Shiraz, Iran. After sample preparation, atomic absorption spectroscopy (AAS) was used for determination of heavy metals concentrations. SPSS software version 16.0 with the significance level of 0.01 was used to analyze the data. Results: The mean concentrations of Zn, Cu, Pb, and Cd in vegetables were 59, 51, 0.17 and 0.032 mg/kg, respectively. Mean values of heavy metals concentrations of different vegetable types were significantly (p<0.01) different. Conclusions: The results of sample analysis and their comparison with standard values showed that the average concentration of all of the heavy metals in the studied vegetables was below the standard levels of the world health organization and food and agriculture organization and they had acceptable conditions for human consumption. However, considerable attention should also be paid to the potential health risk of heavy metals via other exposure pathways and other regions of this country.