摘要:

Particulate PAHs are of significant concern due to their carcinogenic and mutagenic properties. In order to investigate the characteristics and sources of particulate PAHs during heavy pollution episodes, PM2.5 samples were collected in Beijing and Dezhou in the North China Plain from November 17th, 2018 to January 19th, 2019. 26 species of PAHs in PM2.5 during six heavy pollution episodes were measured by gas chromatography-mass spectrometer (GC-MS). The results showed that: (1) The total concentration of PAHs during six heavy pollution episodes ranged from 62 to 191 ng/m3 in Dezhou, and from 61 to 129 ng/m3 in Beijing. (2) The ratios of ∑26PAHs/PM2.5 were higher in Beijing, although PM2.5 concentrations were lower. (3) The dominant components of PAHs were benzo[b]fluoranthene, benzo[a]pyrene (Bap), benzo[a]anthracene, methyl-fluoranthene and retene, accounting for about 50% of ∑26PAHs. (4) The diagnostic ratios indicated vehicle exhaust, coal combustion and biomass burning were the main sources of PAHs at both sites. A more obvious influence of biomass burning in Dezhou was found via a tracer-based approach and using the ratio of PAHs to levoglucosan in fresh biomass burning aerosols. (5) The Bap toxic equivalent concentrations (TEQ) were 6.5-17.2 ng/m3, with higher values in Dezhou than those in Beijing. The BaP concentration ranged from 5.2 to 13.1 ng/m3 and exceeded BaP standard (24 h average: 2.5 ng/m3) in China (Ambient Air Quality Standard, GB 3095-2012), indicating a potential hazardous effect on human health. The studies have shown that both sites have similar distribution characteristics and sources, while the enrichment ratios of ∑26PAHs/PM2.5 in Beijing were higher. PAHs emission control needs to be further strengthened to reduce the risk of human exposure to heavy pollution episodes and the PM2.5 pollution levels. © 2021, Editorial Board, Research of Environmental Sciences. All right reserved.

附注:

Export Date: 7 June 2021