Volume 13, No. 2, April 2013, Pages 709-720 PDF(1.3 MB)
Influences of Commuting Mode, Air Conditioning Mode and Meteorological Parameters on Fine Particle (PM2.5) Exposure Levels in Traffic Microenvironments
Da-Lei Wu1, Mang Lin1, Chuen-Yu Chan1,2, Wei-Zhong Li3, Jun Tao4, You-Ping Li1,5, Xue-Fang Sang1, Chun-Wei Bu1
1 School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China
2 Faculty of Science and Engineering, University of Nottingham Ningbo, Ningbo 315100, China
3 Institute of Environmental Science, Nanhai District, Foshan 528299, China
4 South China Institute of Environmental Sciences, Guangzhou 510655, China
5 College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637009, China
With the aim of determining the impacts of various factors on commuter exposure to fine particulate matter (PM2.5), a series of field studies were carried out to measure commuter exposure to PM2.5 on six major commuting modes (in-cabin mode: bus, taxi and metro; on-roadway mode: walking, bicycle and motorcycle) in a highly industrialized city in the Pearl River Delta, China. The results showed that the exposure level was greatly influenced by the commuter mode, with the on-roadway mode showing a higher PM2.5 concentration (76 μg/m3). An experiment with the taxi mode suggested that the use of air-conditioning can effectively reduce exposure levels in most cases (by at least 83%). Apart from traffic-related emissions, ambient PM2.5 concentration also had important impacts on exposure levels in most commuting modes, which was further ascertained by the seasonal variations in exposure levels and their significant correlations (p < 0.05) with meteorological parameters (temperature, relative humidity, wind speed and direction). The results of a General Linear Model analysis show that temperature, traffic mode and wind speed were significant factors that explained 27.3% of variability for the in-cabin mode, while relative humidity and wind speed were the significant determinants for the on-roadway mode, which contributed 14.1% of variability. In addition, wind direction was also an important determinant for both in-cabin and on-roadway modes. This study has some valuable implications that can help commuters to adopt appropriate travel behavior to reduce their personal exposure to such pollutants.
Commuter; Exposure; Traffic modes; PM2.5.