Relationships between outdoor and personal exposure of carbonaceous species and polycyclic aromatic hydrocarbons (PAHs) in fine particulate matter (PM_2.5) at Hong Kong

Personal and ambient fine particulate matter (PM2.5) samples were simultaneously collected at Hong Kong during winter in 2014. Mass concentration, organic carbon (OC), elemental carbon (EC), and polycyclic aromatic hydrocarbons (PAHs) relationships were analyzed. The correlations of personal and ambient concentrations of PM2.5, OC, and EC indicated the ambient concentrations were the factors showing influences on the personal exposures. Personal to ambient (P/A) ratios in PM2.5, OC, and EC were all > 1, suggesting influences between indoor sources and/or personal activities. Significant higher ambient ΣPAHs concentrations with P/A ratios were nevertheless < 1. The Σ15 U.S. EPA priority PAHs accounted for 50.6% and 70.8% of ΣPAHs in personal and ambient samples, respectively. The ratios of indicator compounds confirmed the origin of PAHs in personal PM2.5, which were found to be associated predominantly with traffic emissions and the influence by the indoor sources.