Sources and atmospheric transformation of PM2.5 at forest site in southern China revealed by δ13C
Description
Suburban forest sites are influenced by both biogenic emissions and anthropogenic pollutants from nearby urban areas. This study investigated PM2.5 sources and atmospheric transformation processes using chemical components and stable carbon isotopes (δ13C) at a suburban forest site in southern China. The average PM2.5 concentration was 62.72 ± 28.90 μg/m3, dominated by secondary inorganic aerosols and organic matter. SOC contributed about 53% of OC during the sampling period. PMF identified six major sources, including biomass burning, vehicle emissions, coal combustion, dust, industrial dust, and waste incineration. PSCF results showed that PM2.5 and OC were affected by both local emissions and regional transport in autumn, but mainly by local sources in winter. δ13C analysis indicated that carbonaceous aerosols were primarily derived from C3 plant biomass and vehicular emissions. High WSOC/OC and SOC/OC ratios suggested significant aerosol aging and secondary organic carbon formation, which strongly influenced δ13C variations in PM2.5.