Fine particles from village air in northern China in winter: Large contribution of primary organic aerosols from residential solid fuel burning

Rural residential emissions contribute significantly to regional air pollution in China, but our understanding on how residential solid fuel burning influences the village outdoor air quality is limited. In this study, we compared the fine particulate matter (PM2.5) composition and individual particle characteristics from 11 to 18 January 2017 at a village and an urban site in northern China. At the village site, each day was divided into four periods: cooking (07:30–10:00; 16:00–17:00), daytime (10:00–16:00), heating (17:00–24:00), and midnight (00:00–07:30) periods. The highest PM2.5 concentration occurred during the cooking period (236 ± 88 μg m−3), which was characterized by high concentrations of K+ and abundant primary OM-K particles (i.e., organic matter mixed with K-salts) emitted from residential biomass burning. The second highest PM2.5 concentration was found during the heating period (161 ± 97 μg m−3), and the PM2.5 contained abundant spherical primary OM particles (i.e., tarballs) emitted from residential coal burning. The primary emissions from residential solid fuel burning resulted in 75% of the village OM by mass consisting of primary OM and 67% of the village aerosol particles by number internally mixing with primary OM particles. The village PM2.5 composition was different from that of the urban PM2.5, with the former containing more OM (47% vs 32%) and less secondary inorganic ions (30% vs 46%). Individual primary OM-K and tarballs were abundant in the village air. These results suggest a large contribution of village residential emissions in the winter to village air pollution. Our study highlights that the residential health in villages of northern China should be paid more attention because of high PM2.5 concentrations and abundant toxic particles during the cooking and heating periods per day in winter. [Display omitted] •Aerosol particles of the village and urban sites in northern China in winter were analyzed.•Village aerosol contained more primary organic particles than urban aerosol.•The village air quality was heavily influenced by residential emissions.•Village residents were exposed to high PM2.5 concentration in winter.•Abundant tarballs were detected in the village air. Residential emissions contributed abundant primary organic aerosols to village outdoor air.