The Influence of Sandstorms and Long-Range Transport on Polycyclic Aromatic Hydrocarbons (PAHs) in PM2.5 in the High-Altitude Atmosphere of Southern China

Atmosphere

Minmin Yang¹  Yan Wang¹  Qiang Liu³  Aijun Ding³  Yuhua Li² 

[1] School of Environmental Science and Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250100, China; E-Mail:;Shandong Environmental Monitoring Center, 3377 Jingshi Road, Jinan 250101, China; E-Mail:;Institute for Climate and Global Change Research and School of Atmospheric Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing 210023, China; E-Mails:

关键词: polycyclic aromatic hydrocarbons (PAHs);    sandstorm;    emission sources;    long-range transport;    Mount Heng;    free troposphere;   

DOI  :  10.3390/atmos6111633

来源: mdpi

【 摘 要 】

PM_2.5 (Particulate Matter 2.5) samples were collected at Mount Heng and analyzed for polycyclic aromatic hydrocarbons (PAHs). During sampling, a sandstorm from northern China struck Mount Heng and resulted in a mean PM_2.5 concentration of 150.61 μg/m³, which greatly exceeded the concentration measured under normal conditions (no sandstorm: 58.50 μg/m³). The average mass of PAHs in PM_2.5 was 30.70 μg/g, which was much lower than in the non-sandstorm samples (80.80 μg/g). Therefore, the sandstorm increased particle levels but decreased PAH concentrations due to dilution and turbulence. During the sandstorm, the concentrations of 4- and 5-ring PAHs were below their detection limits, and 6-ring PAHs were the most abundant. Under normal conditions, the concentrations of 2-, 3- and 6-ring PAHs were higher, and 4- and 5-ring PAHs were lower relative to the other sampling sites. In general, the PAH contamination was low to medium at Mount Heng. Higher LMW (low molecular weight) concentrations were primarily linked to meteorological conditions, and higher HMW (high molecular weight) concentrations primarily resulted from long-range transport. Analysis of diagnostic ratios indicated that PM_2.5 PAHs had been emitted during the combustion of coal, wood or petroleum. The transport characteristics and origins of the PAHs were investigated using backwards Lagrangian particle dispersion modeling. Under normal conditions, the “footprint” retroplumes and potential source contributions of PAHs for the highest and lowest concentrations indicated that local sources had little effect. In contrast, long-range transport played a vital role in the levels of PM_2.5 and PAHs in the high-altitude atmosphere.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.