Cattle hair as a biomarker of lead pollution in the region of the Shiraz oil and petrochemical industries in Iran

This survey aimed to evaluate the level of lead (Pb) pollution in cattle in the vicinity of the Shiraz oil and petrochemical industries using hair samples. Dairy farms located within 10 km of the Shiraz oil and petrochemical industries were identified and divided into four groups. Farms that were located in the radial zones of 0.5-1.5 km, 1.5-5 km, 5-7 km, 7-10.5 km were considered as groups A, B, C and D, respectively. Fifteen cattle from a farm that was located far from the polluting areas comprised the control group (E). Head hair samples were collected from fifteen age-matched cows from each of the five groups in each season round year. Cattle that were located closer to the oil and petrochemical industries had higher hair Pb concentration. In all groups, the hair lead concentrations of cattle that were reared near to the oil industry were significantly higher than of those reared in the region of the petrochemical industry (p<0.05); and showed pollution factors of about two folds when groups in the same distances of oil and petrochemical industries were compared. In this study, there was a declining trend in hair lead concentration from spring to winter from 8.3 to 2.6 ppm and from 4 to 2.2 ppm in cows located near to the oil and petrochemical industry plants, respectively.