Heavy Metal Concentration of Wheat Cultured in Golestan Province, Iran and Its Health Risk Assessment

Introduction: Exposure of grain products in polluted soil lead to adverse effects on human health. In this study, concentrations of HM (As-Cr-Hg) were analyzed in wheat grain cultured in Gonbad-e-Kavus City, Golestan province, Iran. Furthermore, its potential health risk was evaluated among residents. Materials and Methods: The sampling sites were located in arable lands. After separating the wheat grains and cleaning them, the seeds were collected in plastic bags for analysis by ICP/MS method. Digestion of samples was performed with Multi wave PRO microwave apparatus. Results: The mean concentrations of Arsenic (As), Chromium (Cr), Mercury (Hg), and Nickel in wheat seeds were 0.186 ± 0.08, 0.9 ± 0.07, 0.021 ± 0.019, and 0.5 ± 0.17, respectively. The results showed that concentrations of HM in wheat were as follow: Cr > Ni > As > Hg. The Hazard Quotient (HQ) was significantly different among various HMs. The largest HQ was related to As ranging from 0.33 to 13.3. The lowest HQ was attributed to Cr, which may be related to its high RfD = 1.5 mg kg−1. Conclusion: Different HMs varied largely in terms of their HQ. Regarding the exposed people, As and Hg had the highest contributions to the aggregate risks of HMs, while Cr had the lowest contribution. Although the findings showed low environmental concentrations of the studied elements and implied no danger to human health, it should be considered that many non-cancerous conditions weaken the immune system and prone the human beings to cancerous diseases.