Selenium and toxic metals in human hair of the Dashan Region, China: Concentrations, sources, and antagonism effect.

The Dashan Region was a Se-rich region of China. In this study, 131 residents' human hair samples were collected. The concentrations of Se and toxic metals were analyzed, and the health risk was estimated using the concentration data. Cd and As concentrations were significantly higher than in East China. Se and most toxic metal concentrations increased with age (except for the aged people). Furthermore, gender and smoking habits might have a significant impact on toxic metals and Se levels. Multivariable statistics analysis revealed that Se and toxic metals primarily originate in the environment and are then transferred to the human body via the food chain. Dietary habits had an effect on the Se and As concentrations in hair, according to the results of stable isotope analysis. To assess detoxification ability, the Se/ toxic metal molar ratio was used as an indicator. The results demonstrated that the antagonistic effect of Se and Cd, As, Cr, and Hg (molar ratio > 1) could effectively protect residents in the study area from Cd and As pollution in daily life.