Evaluation of Lead, Cadmium and Nickel Contamination in Lactuca Sativa Cultivated in Savadkooh Region, Iran

Aims: To investigate the level of heavy metal contamination in the lettuce cultivated in Place: Savadkooh County in Mazandaran, Iran. Methodology: five samples were taken from the lettuce produced in this area and also from the soils in which they were cultivated, and the concentrations of Nickel, Lead, and Cadmium were measured by atomic absorption spectrometry. Descriptive and inferential statistics were used to analyze the measured data. Data analysis was performed by SPSS ver.16 at the 0.05 significance level. Results: The highest lead concentration, 0.07ppm, was observed in the sample No. 5 (Lettuce 5), the highest cadmium concentration, 0.008ppm, was measured in the sample No. 2 (Lettuce 2), and the highest nickel concentration, 0.07ppm, was observed in the samples No. 1 and 4 (Lettuce 1 and Lettuce 4). Conclusion: The results of this study show that while all the lettuces cultivated in the Savadkooh region contain some amounts of nickel, cadmium, and lead, these amounts are much lower than the limits specified in Iran’s national standard, and therefore these products are perfectly safe to consume. Also, the concentration of each heavy metal in the lettuces was found to be directly correlated with the corresponding concentration in the soil in which they were grown, indicating that the heavy metal content of the products increases with the increasing heavy metal content of the soil.