Impact of dust storms on NPAHS and OPAHs in PM2.5in Jinan, China, in spring 2016: Concentrations, health risks, and sources

Abstract

To better understand the influence of dust storms on nitrogen polycyclic aromatic hydrocarbons (NPAHs) and oxygen polycyclic aromatic hydrocarbons (OPAHs), PM2.5was collected using prebaked quartz filters at Shandong University, Jinan, China, in spring 2016. The concentrations of 16 NPAHs and 5 OPAHs in PM2.5were measured using gas chromatography-mass spectrometry. The highest concentration of NPAHs was recorded during dust storm 1 (DS1; 4.62 ng m–3), which was higher than those recorded during haze (2.28 ng m–3) and on clear days (0.17 ng m–3). The concentrations of 2+3N-FLA and 9N-ANT were considerably higher during haze and dust storms. The total concentration of OPAHs was highest during haze (7.72 ng m–3) and was 2–4.2 times higher than those during DS1, dust storm 2 (DS2), dust storm 3 (DS3) (all 2.38– 3.07 ng m–3) and on clear days (1.82 ng m–3). The three most abundant OPAHs were 9-fluorenone, 9,10-anthraquinone, and naphthalene-1-aldehyde during all studied periods. The 2+3N-FLA/1N-PYR ratio indicated that NPAHs were dominated by secondary generation throughout the sampling period and that dust storm days were more conducive to the secondary generation of NPAHs than were hazy days. During dust storms, NPAHs and OPAHs were influenced by long-distance transport originating in Mongolia and Inner Mongolia. NPAHs and OPAHs in PM2.5were mainly derived from vehicle exhausts, solid fuel combustion, secondary generation, and crustal sources throughout the sampling period. The highest ∑BaPeq value (0.0928 ng m–3) was recorded during DS2. The incremental lifetime cancer risk and total risk on hazy days and the three dust storm episodes were higher than those on clear days.