A continuous dichotomous beta gauge monitor was used to characterize the hourly content of PM₂.₅, PM₁₀₋₂.₅, and Black Carbon (BC) over a 12-month period in an urban street canyon of Hong Kong. Hourly vehicle counts for nine vehicle classes and meteorological data were also recorded. The average weekly cycles of PM₂.₅, PM₁₀₋₂.₅, and BC suggested that all species are related to traffic, with high concentrations on workdays and low concentrations over the weekends. PM₂.₅ exhibited two comparable concentrations at 10:00–11:00 (63.4 μg/m³) and 17:00–18:00 (65.0 μg/m³) local time (LT) during workdays, corresponding to the hours when the numbers of diesel-fueled and gasoline-fueled vehicles were at their maximum levels: 3179 and 2907 h⁻¹, respectively. BC is emitted mainly by diesel-fueled vehicles and this showed the highest concentration (31.2 μg/m3) during the midday period (10:00–11:00 LT) on workdays. A poor correlation was found between PM₂.₅ concentration and wind speed (R = 0.51, P-value > 0.001). In contrast, the concentration of PM₁₀₋₂.₅ was found to depend upon wind speed and it increased with obvious statistical significance as wind speed increased (R = 0.98, P-value < 0.0001) Copyright © 2014 Chinese Society of Particuology and Institute of Process Engineering,
CitationCheng, Y., Lee, S. C., Gao, Y., Cui, L., Deng, W., Cao, J. et al. (2015). Real-time measurements of PM₂.₅, PM₁₀₋₂.₅, and BC in an urban street canyon. Particuology, 20, 134-140.
- Hong Kong
- Urban street canyon