Source identification of heavy metals and stable carbon isotope in indoor dust from different functional areas in Hefei, China.

Dust on air conditioning filters can represent the re-suspended particulate matter in indoor air, which may pose potential health risks to humans. However, source identification and influence factors of indoor dust are controversial. The present study investigated the distribution of Cd, Cr, Mn, Ni, Pb, Sb, V, and Zn, as well as stable carbon isotope, in indoor dust from three different functional zones in Hefei to discuss the sources and influence factors of indoor dust. PCA analysis of heavy metals showed that indoor sources (such as cooking and smoking) were the main sources. Negative correlation appeared between family size and heavy metal concentrations. This was because people acted as a sink of pollutants. Concentration analysis of heavy metals revealed that smoking and cooking had weak relevance with heavy metal concentrations. While through the δ13C analysis, cooking had a significant correlation with δ13C of indoor dust, instructing that cooking was a significant source of indoor dust. Besides, smoking also had a certain correlation with δ13C of indoor dust, instructing that smoking was one of the sources of indoor dust.