Concentration and exposure assessments of cadmium and lead in pumpkin, sunflower, watermelon, and jabooni seeds collected in Iran

Introduction â�� Heavy metals such as lead (Pb) and cadmium (Cd) are known to have high human toxicity. Their presence at various rates in oilseeds has gained more importance during the last few years in the absence of regulation in seeds. The consumption of seeds has been recently reported to increase in Iran, especially among adolescents and young people, so that heavy metal contamination in these seeds could become a great problem of public health. Materials and methods â�� This study investigated the Cd and Pb levels present in 168 seed samples (pumpkin, sunflower, watermelon and jabooni seeds) collected over the country, using graphite furnace atomic absorption spectrometry after microwave digestion. The data were used to estimate the weekly intake of Cd and Pb in Iranian consumers. Results and discussion â�� The highest concentrations of Pb and Cd were found in pumpkin shells and sunflower kernels, respectively. The concentrations of Pb and Cd detected in the seed samples averaged 77±28 I¼g kg-1 and 264±177 I¼g kg-1, respectively. The Pb content in 39 seed samples was exceeding the limit of 100 I¼g kg-1 established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The seeds with the highest Pb contamination were pumpkin seeds (67), followed by sunflower (30), watermelon (25), and jabooni seeds (15). None of the watermelon and jabooni seed samples were contaminated with Cd. The highest concentration (731 I¼g kg-1) and the highest number of samples (35) contaminated with Cd were recorded in the sunflower seeds. The differences in mean value of Pb and Cd among the seeds collected in various Iranian cities were not found statistically significant. Similarly, the mean intake of Pb and Cd estimated from the seed samples was much lower than the tolerable weekly intake (25.0 and 2.5 µg kg-1 week-1 for Pb and Cd, respectively) estimated by the JECFA. Conclusion â�� Although the mean dietary exposure of cadmium and lead was much lower than the reference doses, the high incidence of Pb and Cd in widely consumed oilseeds in Iran, and the toxic effects of Pb and Cd, indicate the necessity for regular surveillance to reduce intake of heavy metals by Iranian population. © ISHS 2018.