Source apportionment of primary and secondary fine particulate matter in Eskisehir/Türkiye using conventional and dispersion-normalized positive matrix factorization

In this study, the organic and inorganic components of atmospheric fine particulate matter (PM2.5) were monitored daily in Eskisehir City/T & uuml;rkiye, for one year, and the contributions of primary and secondary sources to the PM mass were investigated. A total of 94 components were characterized in PM2.5 samples, including 5 anions, 46 trace elements, Organic and Elemental Carbon (OC & EC), 16 Polycyclic Aromatic Hydrocarbons (PAHs), 26 n-alkanes, levoglucosan, and 8 carboxylic acids to obtain a more holistic mass closure. In addition, the principal sources of PM2.5 were apportioned by the Conventional and Dispersion-Normalized Positive Matrix Factorization (C-PMF and DN-PMF) to assess dispersion/dilution characteristics of local meteorological conditions on source contributions of PM. The main sources of PM were classified into 8 factors. A significant seasonal variation was observed in combustion-related PM2.5 constituents, which increased in the winter, while the contribution of Secondary Organic Carbon (SOC) enhanced during the summer period. In addition, a visual effect of seasonal atmospheric dilution/dispersion conditions on measured pollutant levels was observed as a function of Ventilation Coefficients (VC). The mass percent of SOC in PM2.5 varied between 2.3 % and 13.0 %, and the annual mean contribution was over 7.5 %.