Voltammetric determination of Pb, Cd, Zn, Cu and Se in milk and dairy products collected from Iran: An emphasis on permissible limits and risk assessment of exposure to heavy metals

This study was carried out to determine the concentrations of some heavy metals in dairy products, collected from five industrial regions in Iran (n = 250 samples) during winter and summer in 2013. The samples were analyzed using the differential pulse anodic and cathodic stripping voltammetry technique. The obtained ranges of mean Pb, Cd, Cu, Zn and Se were as follow: in raw milk 14.0, 1.11, 427, 571, 2.19 μg kg−1, in pasteurized milk 9.59, 1.0, 378, 447, 1.78 μg kg−1, in cheese 14.5, 1.25, 428, 586, 1.68 μg kg−1, in yoghurt 7.54, 0.99, 399, 431, 1.23 μg kg−1 and in doogh 7.2, 0.84, 320, 369, 0.99 μg kg−1, respectively. In nearly all cases the concentrations of the metals were below the international permissible limits and do not pose a health concern for the consumption of milk and dairy products in Iran.