Real-time measurements of PM2.5, PM10-2.5, and BC in an urban street canyon

Yan Cheng, Shuncheng Lee, Yuan Gao, Long Cui, Wenjing Deng, Junji Cao, Zhenxing Shen, Jian Sun

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)


A continuous dichotomous beta gauge monitor was used to characterize the hourly content of PM<sub>2.5</sub>, PM<sub>10-2.5</sub>, 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 PM<sub>2.5</sub>, PM<sub>10-2.5</sub>, and BC suggested that all species are related to traffic, with high concentrations on workdays and low concentrations over the weekends. PM<sub>2.5</sub> exhibited two comparable concentrations at 10:00-11:00 (63.4 μg/m<sup>3</sup>) and 17:00-18:00 (65.0 μg/m<sup>3</sup>) 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<sup>-1</sup>, respectively. BC is emitted mainly by diesel-fueled vehicles and this showed the highest concentration (31.2 μg/m<sup>3</sup>) during the midday period (10:00-11:00 LT) on workdays. A poor correlation was found between PM<sub>2.5</sub> concentration and wind speed (R = 0.51, P-value > 0.001). In contrast, the concentration of PM<sub>10-2.5</sub> 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).
Original languageEnglish
Pages (from-to)134-140
Number of pages7
Publication statusPublished - 1 Jan 2015


  • BC
  • Hong Kong
  • PM&lt;inf&gt;10-2.5&lt;/inf&gt;
  • PM&lt;inf&gt;2.5&lt;/inf&gt;
  • Urban street canyon

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Materials Science(all)
  • Condensed Matter Physics

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