Source Apportionment of Inorganic and Organic PM in the Ambient Air around a Cement Plant: Assessment of Complementary Tools

In this study, we analyzed the sources of ambient PM inorganic and organic components near a cement plant using fossil fuels as well as alternative fuels, such as sewage sludge and biomass. Source apportionment methodologies, i.e., principal component analysis (PCA) and multivariate curve resolution by alternating least squares (MCR-ALS), and carbon isotope analysis (δ13C) were used to determine the potential sources and their contributions. Four sources of PM10 main tracer compounds constituents were identified: marine and secondary inorganic aerosol, cement plant/industrial, traffic and crustal. The contributions of those sources varied significantly depending on the period of the year. However, the inorganic tracer PM species in the area were mainly released by combustion sources, namely traffic and the activity of the cement plant, especially in winter months. The analyses of tracer organic compounds also indicated combustion sources, i.e., biomass burning and fossil fuel combustion, as the predominant contributors to ambient air PM (62, 59 and 69%, in PM10, PM2.5 and PM1, respectively). Organic dust was a significant source of PM10 (33%) while its contribution was found to be minor in the finest fractions (9 and 2% in PM2.5 and PM1, respectively). Results of δ13C corroborated a significant contribution of combustion sources, traffic or biomass fuel as well as a higher influence of mineral (calcite) powder in larger particles.