Influences of Traffic Emissions and Meteorological Conditions on Ambient PM10 and PM2.5 Levels at a Highway Toll Station

Received: September 30, 2010
Revised: September 30, 2010
Accepted: September 30, 2010
Download Citation: RIS|BibTeX|https://doi.org/10.4209/aaqr.2010.04.0025  

Cite this article:
Cheng, Y.H. and Li, Y.S. (2010). Influences of Traffic Emissions and Meteorological Conditions on Ambient PM10 and PM2.5 Levels at a Highway Toll Station. Aerosol Air Qual. Res. 10: 456-462. https://doi.org/10.4209/aaqr.2010.04.0025

ABSTRACT

The PM₁₀ and PM_2.5 levels at a highway toll station were monitored from October to December 2008. Experimental results show that hourly average PM₁₀ and PM_2.5 levels at the highway toll station were 10.6–208.4 μg/m³ and 6.6–187.9μg/m³, respectively. Additionally, the PM_2.5-to-PM₁₀ ratio at the highway toll station was 0.73, indicating that emissions from traffic sources are dominant in PM_2.5 fraction. At the highway toll station, the time variations of the PM₁₀ and PM_2.5 levels were not strongly correlated with traffic volumes; however, traffic on the highway markedly elevated ambient PM₁₀ and PM_2.5 levels. The PM₁₀ and PM_2.5 levels at the highway toll station are higher than those at monitoring stations in the vicinity to the toll station by factors of 1.3–1.4 and 1.4–1.8 times, respectively. The low wind speeds and low mixing-layer heights lead to relatively high PM₁₀ and PM_2.5 levels. Moreover, high wind speed also could have resulted in high PM₁₀ and PM_2.5 levels due to the re-suspension of particulate matter under well dispersed conditions. Measurements indicate that both traffic emissions and meteorological conditions drive PM₁₀ and PM_2.5 levels at the highway toll station.

Keywords: PM10; PM2.5; Meteorological condition; Traffic emission; Highway toll station