Component analysis and source identification of atmospheric aerosols at the neighborhood scale in a coastal industrial city in China.

A multiple-site filter-sampling observation study was conducted in a coastal industrial city (Rizhao, 35°10'59″N, 119°23'57″E) to understand the main components, formation mechanisms, and potential sources of particulate matter. The average (±σ) mass concentration of PM across all the sites was 42 (±27) μg/m, with high variability (6-202 μg/m). Water-soluble inorganic ions (WSIIs) were the major contributors (54%-60%) to PM with mean values for sulfate (13 μg/m), nitrate (6 μg/m), and ammonium (7 μg/m) (SNA). Cl and K were the two components that accounted for large proportions of the water-soluble inorganic ions (WSIIs) in addition to SNA. Organic carbon (OC) and element carbon (EC) accounted for 19% and 9% of the total PM, respectively. The highest concentrations of Cl (1.9 μg/m) and Fe (1.3 μg/m) at the steel mill site imply that the site was heavily impacted by coal combustion and industrial burning. The residential area site presented the highest K concentration (0.86 μg/m), which was attributed to the strong influence of biomass burning. The highest char-EC/soot-EC ratios (2.4-6.1) occurred in winter, indicating that Rizhao was more affected by fuel combustion. The positive matrix factorization model (PMF) showed that secondary aerosols and vehicle emissions dominated the observation period. With increasing pollution in winter, the contributions of combustion sources and secondary aerosol sources increased significantly. Among all the sites, the steel mill site had the highest contribution of primary source emissions (67%), with emissions from combustion sources being particularly prominent.