A comprehensive exploration on pollution characteristics and health risks of potentially toxic elements in indoor dust from a large Cu smelting area, Central China.

Large-scale smelting activities release large amounts of potentially toxic elements (PTEs) in fine particles. These particles floating in the air eventually settle on leaves, roads, and even indoors. In smelting areas, indoor environments are generally considered relatively safe. However, these areas are not taken seriously and need to be assessed. This paper systematically studied pollution characteristics, main sources and health risks of ten potentially toxic elements, PTEs (Mn, Ni, Cu, Zn, Hg, Cd, As, Cr, Pb, and Tl), of dust samples from different indoor environments in smelting areas using various methods. Therefore, this study analyzed dust samples from 35 indoor environments. The enrichment factors showed that the indoor dust samples were extremely enriched by Cd and Cu and significantly enriched by Hg, Pb, As, and Zn. The result of the spatial distribution showed that the high-value PTEs were mainly distributed near the Cu smeltery. Three sources were quantitatively assigned for these PTEs, and they were industrial smelting and traffic activities (44.40%), coal-fired activities (18.11%), and natural existence (37.49%). Based on the calculation of health risk, the value of THI for children was 7.57, indicating a significant non-carcinogenic risk. For carcinogenic risk, the values of TCR for children and adults were 2.91×10-2 and 2.97×10-3, respectively, which were much higher than the acceptable risk value 1×10-4. Combining health risk assessment with source discrimination, we found that the industrial discharges and traffic activities were the most main source of non-cancer and cancer risks. Therefore, smelting activities should be more strictly monitored, and traffic emission management should be strengthened.