Oil fields are a source of heavy metal pollution, but few studies have evaluated its impact on the intake of these contaminants through milk, an important food especially for children. From February 2015 to 2016, 118 samples of raw cow's milk, 14 of fodder and 8 of water in Southwest Iran were collected from farms close to oil fields or related industries. Lead (Pb) and cadmium (Cd) levels were evaluated by graphite furnace atomic absorption spectrometry. Mean±SE in milk and fodder were 47.0±3.9 and 54.0±6.9μg/kg for Pb, and 4.7±1.0 and 3.5±1.3μg/kg for Cd. No Pb or Cd was detected in water. Most milk samples (82.2%) for Pb were above the permissible limits (20μg/kg). Exposure to Pb and Cd from milk consumption was calculated in two scenarios: mean and maximum exposure for the age range of 2-90years. The intake of an average Iranian adult (25years, 60kg b. w., 0.14kg milk/day) would be 6.6μg Pb and 0.66μg Cd/day (WI of 46.2 and 4.6μg, respectively), well below the risk values proposed by some international organizations, even in the maximum exposure scenario. However, Pb exposure for infants and toddlers may be closer to the risk values, since milk and milk products could be the main contributor to Cd and Pb, and small children consume 2-3 times more food than adults relative to their body weight. The risk of Pb and Cd exposure through milk close to oil fields should be considered and a monitoring plan for these contaminants is strongly recommended.

A B S T R A C TBackground and Objectives: Heavy metals such as cadmium and lead are the most important toxins spreading through various ways like water, soil, and air in nature and easily enter human food chain. It is essential to determine the cumulative and harmful effects of these metals in nutrients, especially in cow milk because it is a unique source of food for all ages and it contains both essential and nonessential trace elements. Materials and Methods:A total of 100 milk samples were directly collected from healthy cows in Zabol located on east of Iran. The samples were tested to determine lead and cadmium residues. The rates of the heavy metals were determined using a Rayleigh atomic absorption spectrum equipped with hollow cathode lamps (HCL) at 283.3 nm for lead (Pb) and at 228.8 nm for cadmium (Cd). By using the photo-catalytic titanium dioxide nanoparticles, these toxic metals were removed. Results:The mean ± SD of the concentration of lead and cadmium in raw milk were 9.175± 2.5 and 4.557 ± 1.081 ppb, respectively. Also, the P-values of Kalmogorov-Smiranov test for lead and cadmium were respectively 0.057 ppb (P>0.05) and 0.435 ppb (P>0.05). TiO 2 nanoparticles were used to eliminate and remove lead and cadmium in milk samples. The results showed that there was a significant difference between lead and cadmium contents before and after adding TiO 2 nanoparticles (P<0.05). Conclusions:According to results of this study, there was a very low amount of toxic metals. So, it seems that it is not necessary to use TiO 2 in milk samples but these days it used frequently as an additive to some samples like milk to remove these pollutants.