Comparison of physicochemical properties between fine (PM2.5) and coarse airborne particles at cold season in Korea

Although it has been well-known that atmospheric aerosols affect negatively the local air quality, human health, and climate changes, the chemical and physical properties of atmospheric aerosols are not fully understood yet. This study experimentally measured the physiochemical characteristics of fine and coarse aerosol particles at the suburban area to evaluate relative contribution to environmental pollution in consecutive seasons of autumn and winter, 2014–2015, using XRD, SEM–EDX, XNI, ICP-MS, and TOF-SIMS. For these experimental works, the fine and coarse aerosols were collected by the high volume air sampler for 7days each season. The fine particles contain approximately 10μgm−3 of carbonaceous aerosols consisting of 90% organic and 10% elemental carbon. The spherical-shape carbonaceous particles were observed for the coarse samples as well. Interestingly, the coarse particles in winter showed the increased frequency of carbon-rich particles with high contents of heavy metals. These results suggest that, for the cold season, the coarse particles could contribute relatively more to the conveyance of toxic contaminants compared to the fine particles in the study area. However, the fine particles showed acidic properties so that their deposition to surface may cause facilitate the increase of mobility for toxic heavy metals in soil and groundwater environments. The fine and coarse particulate matters, therefore, should be monitored separately with temporal variation to evaluate the impact of atmospheric aerosols to environmental pollution and human health. [Display omitted] •We characterized physicochemical properties of ambient aerosols at cold seasons.•Surface chemistry and morphologies between fine and coarse particles were compared.•Water solution soaked by PM2.5 particles showed acidic condition.•Spherical carbonaceous particles were frequently observed for coarse sample.•Coarse particles contribute to conveyance of toxic contaminants into environments.