Multi-group organic pollutants in urban and suburban atmospheric particulate matter (PM2.5): Temporal variation, meteorological impact, and sources

Abstract

Several adverse health impacts have been attributed to particulate matter-PM_2.5, defined as having a diameter of less than 2.5 µm. The World Health Organization has determined that 5 µg m⁻³ is the 24-h limit threshold. PM_2.5 comes from various primary sources and is also created by secondary atmospheric processes. Finding responsible sources can help regulate by focusing on the biological processes that underlie the observed health impacts. Determining the chemical composition of PM_2.5 is the first phase in allocating PM_2.5 to various sources. This study outlines the procedure for organic speciation of PM_2.5—solvent-extractable polycyclic aromatic hydrocarbons (PAHs), n-alkanes, n-alkanoic acids, and levoglucosan. Daily PM_2.5 aerosol samples were collected between July 2014 and September 2015 in Ankara, Turkey. Seasonal average concentrations of measured species ranged from 13.51 to 65.04 ng m⁻³ for PAHs, 36 to 150 ng m⁻³ for n-alkanes, 24 to 47 ng m⁻³ for n-alkanoic acids, 0.44 to 3.6 ng m⁻³ for levoglucosan. n-Alkanes are the most abundant group at both urban and suburban sites. Concentrations of all groups were higher during winter, which is associated with emissions from space heating and lower mixing height in winter months. The diagnostic ratios between specific atmospheric concentrations of tracers depicted that the particulate organic compounds are mainly from anthropogenic sources like vehicular emission, biogenic combustion, and food cooking.