Determination of lead and cadmium contamination levels in industrial milk powders produced in Tehran

Contamination of dairy products with heavy metals, lead (Pb) and Cadmium (Cd) in particular, induces their toxic effects on humans. Therefore, this study aimed to determine the contamination levels of Pb and Cd levels in milk powders produced in Tehran area. In this study, a total of 25 samples of milk powder was obtained from four different dairy establishments. The samples were digested and extracted prior to analysis. Pb and Cd concentrations was determined using atomic absorption method with graphite furnace. The results were showed a mean value 57.36 ppb (18.99 to112.90 ppb) for Pb and 14.11 ppb (5.73 to 39.43 ppb) for Cd. According to Codex Alimentarius, approved levels for Pb and Cd in milk are 1000 and 100 ppb, respectively. Based on results, Pb level was less than standard limit in all samples, whereas Cd concentration in 68% of the samples was estimated higher than the standard limit. Since the percentage of Cd-contaminated samples was high, there is a necessity for frequent monitoring of the contamination levels in dairy products as well as to discover the potential contamination sources.