Enrichment and assessment of the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China.

The present study aims to investigate the influence of human activity on heavy metals in a typical arid urban area of China and assess human health risks posed by heavy metals in PM1 (particles <1.0 μm in diameter) for different people. In this paper, Changji (Xinjiang, China) was selected as the study area, and samples were collected from March 2014 to March 2015. A total 14 elements in PM1 were quantified using ICP-MS. An enrichment factor (EF) was used to assess the influence of human activity on the contamination of these metals. The results indicated that Mn was not enriched; Co, Cu, Cr, Ni, Tl, and V were slightly enriched; Mo, Pb, and Sb were moderately enriched; and Ag, As, and Cd were strongly enriched. To assess the health risks associated with inhaling PM1, the risk assessment code and loss in life expectancy based on the individual metals were calculated. The results showed that the elements Ag, Cu, Mo, Pb, Sb, Tl, and V in PM1 posed low levels of non-carcinogenic risks, but these metals may still pose risks to certain susceptible populations. In addition, the results also showed that As, Co, and Cr posed an appreciable carcinogenic risk, while Cd and Ni posed low levels of carcinogenic risk. The total predicted loss of life expectancy caused by the three metals As, Co, and Ni was 63.67 d for the elderly, 30.95 d for adult males, 26.62 d for adult females, and 48.22 d for children. Therefore, the safety of the elderly and children exposed to PM1 should be given more attention than the safety of adults. The results from this study demonstrate that the health risks posed by heavy metals in PM1 in Changji, Xinjiang, China should be examined.