Biomonitoring of Heavy Metal Accumulation in Hair and Serum of Buffaloes from Coal Mining Zones of Chakwal, Pakistan.

Abstract

Although there is little information on metal buildup in buffaloes from the coal mining region of Chakwal, Pakistan, heavy metal exposure in animals grazing close to coal mining sites is a significant environmental problem. Specifically, comparative evaluation of serum and hair as biomonitoring matrices and the impact of location and age on metal load have not gotten much attention. Nine heavy metals (Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn) were assessed in the hair and serum samples of forty five buffaloes from Choa Saidan Shah, Dulmial, and Minhala. Wet acid digestion was used to prepare the samples, and atomic absorption spectrophotometry was used for analysis. The Wilcoxon signed rank test was used to compare hair and serum concentrations while Kruskal-Wallis tests and Bonferroni-adjusted pairwise Mann-Whitney U tests were used to evaluate spatial and age related differences. Metal associations and possible exposure patterns were investigated using principal component analysis (PCA) and Spearman's rank correlation. The range of mean values was 105.61 ± 5.54 for Zn in hair and 1.28 ± 0.05 for Pb in serum. In general, hair had greater amounts than serum, especially for Fe (102.11 ± 6.74 vs. 8.37 ± 0.48), Mn (39.34 ± 2.19 vs. 4.86 ± 0.07), Pb (11.85 ± 1.20 vs. 1.28 ± 0.05), and Zn (105.61 ± 5.54 vs. 9.54). While Cd, Co, Cu, Fe, Ni, and Zn varied significantly with age, Cd and Co showed large regional differences. Two alternative metal association patterns were found using PCA which may indicate different exposure pathways. Overall, the results suggest buffalo hair as a helpful noninvasive matrix for evaluating longer term heavy metal exposure in mining affected areas and offer baseline biomonitoring data.