Mercury in human hair and blood samples from people living in Wanshan mercury mine area, Guizhou, China: An XAS study

Human hair and blood samples from persons living in the town of Wanshan, a mercury mine area in Guizhou Province of China, were collected and the quantitative speciation and structural information of Hg and S in hair samples and of Hg in erythrocyte and serum samples were studied using X-ray absorption spectroscopy. Least-squares fitting of the X-ray absorption near-edge spectra found that inorganic mercury is the major mercury species in hair samples (91.74%), while inorganic and methyl mercury are both about 50% of total mercury in RBC and serum samples, which is in agreement with the data obtained by acidic extraction, fractionation of Hg2+ and CH3Hg+ and quantification by ICP-MS. Curve-fitting analysis revealed that the Hg–S bond length and coordination number in hair were 0.248 ± 0.002 nm and 3.10, respectively, while the S–Hg bond length and coordination number in hair were 0.236 ± 0.002 nm and 4.05. The Hg–S bond length and coordination number in RBC were 0.251 ± 0.003 nm and 4.09, respectively, while they were 0.228 ± 0.002 nm and 4.08 in serum, respectively. The techniques for speciation, structural and binding information described in this study will find the potential application in similar studies of other elements.