Molecular Composition, Seasonal Variation, and Size Distribution of n-Alkanes, PAHs, and Saccharides in a Medium-Sized City of Guanzhong Plain, Northwest China: Evaluation of Control Measures Executed in the Past Decade
Open Access
- 9 February 2023
- Vol. 11 (2), 164
- https://doi.org/10.3390/toxics11020164
Abstract
Baoji is a medium-sized city in the Guanzhong Plain of northwest China. The compositions of three important organic groups, namely n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and saccharides in atmospheric aerosol with different aerodynamic diameters in power were determined. Both seasonal and daily trends of the target organic chemical groups were demonstrated. The concentration levels of total quantified n-alkanes and saccharides in total suspended particles (TSP) in winter were 541 ± 39 and 651 ± 74 ng·m−3, respectively, much higher than those of the other three seasons. A high total quantified PAHs concentration level of 59.6 ± 6.4 ng·m−3 was also seen in wintertime. n-Alkanes showed a bimodal percent distribution in spring, autumn, and winter. Two peaks were found with the particle sizes of 0.7 μm < Dp < 2.1 μm and 3.3 μm < Dp < 4.7 μm, respectively. In summer, a unimodal was seen with a peak of 4.7 μm < Dp < 5.8 μm. Dehydrated saccharides and PAHs present a unimodal size distribution peaking at the aerodynamic diameters of 0.7 µm < Dp < 2.1 µm. In contrast to glucose and fructose, they mainly exist in the coarse mode particles and have the highest concentrations at aerodynamic diameters of 4.7 µm < Dp < 9.0 µm. The geometric mean diameters (GMD) of n-alkanes and saccharides of the fine particles in winter were higher than in the other seasons. Compared with the data in 2008, the fossil fuel-derived n-alkanes and PAHs in winter decreased by nearly an order of magnitude in 2017. Both the carbon preference index (CPI) of n-alkanes and the diagnostic ratios of PAHs suggest that coal combustion and vehicle exhaust were the major pollution sources of the organic groups in the two decades. It should be noted that the contribution of traffic emissions greatly increased from 2008 to 2017, consistently with a large raise of registered vehicles in Baoji city. The overall results confirm that the control measures conducted by the local government in the recent decade mitigated the air pollution in this city.Funding Information
- Shaanxi Provincial Natural Science (2019JM-120)
- National Nature Science Foundation of China (41977332)
- Youth Innovation Promotion Association CAS (2020407)
- Key Laboratory of Aerosol Chemical Physics, Chinese Academy of Sciences (KLACP2004)
This publication has 54 references indexed in Scilit:
- Particle size distribution of n-alkanes and polycyclic aromatic hydrocarbons (PAHS) in urban and industrial aerosol of Algiers, AlgeriaEnvironmental Science and Pollution Research, 2013
- Abundance, composition and source of atmospheric PM2.5 at a remote site in the Tibetan Plateau, ChinaTellus B: Chemical and Physical Meteorology, 2013
- A seasonal study of polycyclic aromatic hydrocarbons in PM2.5 and PM2.5–10 in five typical cities of Liaoning Province, ChinaJournal of Hazardous Materials, 2010
- Dicarboxylic acids, metals and isotopic compositions of C and N in atmospheric aerosols from inland China: implications for dust and coal burning emission and secondary aerosol formationAtmospheric Chemistry and Physics, 2010
- Contribution of fungi to primary biogenic aerosols in the atmosphere: wet and dry discharged spores, carbohydrates, and inorganic ionsAtmospheric Chemistry and Physics, 2007
- Organic composition of PM2.5 and size-segregated aerosols and their sources during the 2002 Bay Regional Atmospheric Chemistry Experiment (BRACE), Florida, USAAtmospheric Environment, 2007
- Engineering the Structural Stability and Functional Properties of the GI Domain into the Intrinsically Unfolded GII Domain of the Yeast Linker Histone Hho1pJournal of Molecular Biology, 2005
- Composition and major sources of organic compounds of aerosol particulate matter sampled during the ACE‐Asia campaignPublished by American Geophysical Union (AGU) ,2004
- Particle size distribution of organic primary and secondary aerosol constituents in urban, background marine, and forest atmosphereJournal of Geophysical Research: Atmospheres, 2002
- Methods for detecting carcinogens and mutagens with the salmonella/mammalian-microsome mutagenicity testMutation Research/Environmental Mutagenesis and Related Subjects, 1975