Preliminary measurements of aromatic VOCs in public transportation modes in Guangzhou, China.

This study examined the exposure level of aromatic volatile organic compounds (VOCs) in public transportation modes in Guangzhou, China. A total of 40 VOC samples were conducted in four popular public commuting modes (subway, taxis, non-air-conditioned buses and air-conditioned buses) while traversing in urban areas of Guangzhou. Traffic-related VOCs (benzene, toluene, ethylbenzene, m/p-xylene and o-xylene) were collected on adsorbent tubes and analyzed by thermal desorption (TD) and gas chromatography/mass-selective detector (GC/MSD) technique. The results indicate that commuter exposure to VOCs is greatly influenced by the choice of public transport. For the benzene measured, the mean exposure level in taxis (33.6 microg/m(3)) was the highest and was followed by air-conditioned buses (13.5 microg/m(3)) and non-air-conditioned buses (11.3 microg/m(3)). The exposure level in the subway (7.6 microg/m(3)) is clearly lower than that in roadway transports. The inter-microenvironment variations of other target compounds were similar to that of benzene. The target VOCs were well correlated to each other in all the measured transports. The concentration profile of the measured transport was also investigated and was found to be similar to each other. Based on the experiment results, the average B/T/E/X found in this study was about (1.0/4.3/0.7/1.4). In this study, the VOC levels measured in evening peak hours were only slightly higher than those in afternoon non-peak hours. This is due to the insignificant change of traffic volume on the measured routes between these two set times. The out-dated vehicle emission controls and slow-moving traffic conditions may be the major reasons leading elevated in-vehicle exposure level in some public commuting journeys.

[1]  B. Festy,et al.  Exposure of City Residents to Carbon Monoxide and Monocyclic Aromatic Hydrocarbons during Commuting Trips in the Paris Metropolitan Area , 1995 .

[2]  Kun-Ho Park,et al.  Commuter exposure to volatile organic compounds under different driving conditions , 1999 .

[3]  Dongquan He,et al.  Assessment of Vehicular Pollution in China , 2001, Journal of the Air & Waste Management Association.

[4]  R M Harrison,et al.  Concentrations and sources of VOCs in urban domestic and public microenvironments. , 2001, Environmental science & technology.

[5]  G. Petersson,et al.  Exposure to Volatile Hydrocarbons in Commuter Trains and Diesel Buses , 1996 .

[6]  Chang-Chuan Chan,et al.  Office workers's exposure to volatile organic compounds while commuting and working in Taipei City , 1994 .

[7]  W. Jo,et al.  Public bus and taxicab drivers' work-time exposure to aromatic volatile organic compounds. , 2001, Environmental research.

[8]  W. Jo,et al.  Vehicle occupants' exposure to aromatic volatile organic compounds while commuting on an urban-suburban route in Korea. , 1996, Journal of the Air & Waste Management Association.

[9]  Julia Meaton,et al.  ASSESSMENT OF EXPOSURE TO TRAFFIC-RELATED FUMES DURING THE JOURNEY TO WORK , 1998 .

[10]  John D. Spengler,et al.  Driver exposure to volatile organic compounds, carbon monoxide, ozone and nitrogen dioxide under different driving conditions , 1991 .

[11]  Peter F. Nelson,et al.  Exposure to emissions of 1,3-butadiene and benzene in the cabins of moving motor vehicles and buses in Sydney, Australia , 1997 .

[12]  Christopher Y.H. Chao,et al.  Quantification of indoor VOCs in twenty mechanically ventilated buildings in Hong Kong , 2001 .

[13]  Roy M. Harrison,et al.  Roadside and in-vehicle concentrations of monoaromatic hydrocarbons , 1999 .

[14]  W. Wilson,et al.  Ambient Concentrations and Elemental Compositions of PM10 and PM2.5 in Four Chinese Cities , 1999 .