Characteristics of airborne PM1.0 and associated chemical constituents at a roadside area in Korea

Abstract

Despite the severity of health impacts caused by particulate matter with an aerodynamic diameter ≤ 1.0 μm (PM1.0), corresponding data have been poorly documented compared to that of particulate matter with an aerodynamic diameter ≤ 2.5 μm (PM2.5) or ≤ 10 μm (PM10). In this study, the characteristics of PM1.0 and its chemical species (black carbon [BC], SO42-, NO3-, NH4+, and 16 metals) were investigated in the roadside area of Daejeon. The mean PM1.0 concentration was 19.9 ± 5.50 μg m-3 (range of 6.86–34.7 μg m-3) near a road with high traffic density during a 3-month period in the fall/winter of 2019. The mean concentrations (± SD and range) of BC, NO3-, and SO42- in PM1.0 were 4.89 ± 4.21 (1.26–8.23), 4.21 ± 1.39 (1.76–9.78), and 4.30 ± 1.10 (1.16–7.03) μg m-3, respectively. Strong relationships between PM1.0 and major species such as BC, SO42-, NO3-, and NH4+ were observed with correlation coefficients of 0.52–0.96. After evaluating the factors affecting PM1.0 concentrations using a positive matrix factorization model, six source types were revealed: secondary aerosol (54.1%), vehicle exhaust (21.2%), re-suspended soil-road dust (9.6%), fossil fuel combustion (9.1%), biomass burning (3.3%), and industrial activities (2.6%).