Health risk assessment of heavy metals via dietary intake of wheat in Golestan Province, Iran

Concentration of five heavy metals including lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in wheat collected from silages of Golestan Province, Iran, was determined using atomic absorption spectroscopy. Dry ashing method was applied for precise determination of the five heavy metal contents. The concentrations of heavy metals were recorded as the following: Pb (0.013-0.14), Cd (0.008-0.031) by graphite furnace method and Cu (0.48-6.2), Fe (58.50-406.9), and Zn (3.41-32.75) by flame method, all in mg.kg(-1). The mean concentration of all the aforementioned heavy metals was (0.057 +/- 0.003), (0.016 +/- 0.005), (2.7 +/- 0.17), (111.2 +/- 21), and (5.7 +/- 0.22) mg.kg(-1), respectively. The level of heavy metals decreased in the order of Fe> Zn> Cu> Pb > Cd. Highest amount was related to Fe and the lowest amount to Cd. Concentrations of heavy metals in all the wheat samples were below the permissible limits set by the Food and Agriculture Organization/World Health Organization and Iranian National Standard Organization and did not pose any threat to the health of consumers.