DOI: https://doi.org/10.21203/rs.3.rs-681169/v1
Human exposure to metals on road dust might have potential health risks through touching, ingesting, and inhaling. There were limited studies to link seasonal emission sources to health risks from metals on road dust. In this study, metals on road dust from different functional areas were seasonally monitored. The pollutant sources in study city varied slightly with the seasons, but the major pollutant source in the particular study site were significantly affected by the seasons. By combining the source apportionment model (PMF), line sources model and health risk models (HI: Hazard index and ILCR: Incremental Lifetime Carcinogenic risk), industrial and construction activity was identified as the crucial source of both the pollutants on road dust (29% - 47%), and the HI for adults (27% - 45%) and children (41% - 50%) in different seasons. The traffic non-exhaust emission dominated in the carcinogenic risks for children in spring (45%) and summer (36%). Factors such as seasons, particle size, metal bioavailability, human exposure time, and exposure area were all taken into consideration to avoid overestimating or underestimating health risks. The carcinogenic risks for children (1.6 E-06) and adults (2.8 E-06) exposed to Cr both exceed the minimum threshold (10-6). Measured metals mainly posed hazard to human health through ingestion route. Pb and Mn, Fe and Mn were the main harmful elements that induced non-carcinogenic risks for adults and children, respectively. Effectively identifying the source-specific health risks in different seasons will help in the formulation of adaptive strategies to diminish the potential risks.