Lead residue levels in raw milk from different regions of Iran

During February 2004, 97 samples of raw whole milk were collected from milk tankers arriving at 15 dairy plants in different Iranian regions and analyzed by the atomic absorption spectroscopy. The mean recovery of the analytical method at 10, 20 and 40 ng/ml was 85 ± 5%. The mean level of lead content obtained from 97 samples was 7.9 ng/ml, with a range from 1 to 46 ng/ml and a standard deviation of 8.8. Fewer than 10% of samples exceeded 22 ng/ml; 60% of the samples were between 5.7 and 1.1 ng/ml. The daily intakes of lead in milk based on the results have also been estimated. Three sets of the samples, from Isfahan, Tehran and West Azerbaijan seemed to show a higher level of contamination and a need for further studies especially because of the two newly established infant formula milk plants in two of the regions under study.