Volume 13, No. 4, August 2013, Pages 1331-1347 PDF(1.25 MB)
Volatile Organic Compounds in Roadside Environment of Hong Kong
Kin Fai Ho1,2, Steven Sai Hang Ho2,3,4, Shun Cheng Lee5, Peter Kwok Keung Louie6, Junji Cao2, Wenjing Deng7
1 School of Public Health and Primary Care, The Chinese University of Hong Kong, Shatin, Hong Kong, China
2 SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China
3 Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, USA
4 Hong Kong Premium Services and Research Laboratory, Lai Chi Kok, Kowloon, Hong Kong, China
5 Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
6 Hong Kong Environmental Protection Department, Hong Kong, China
7 Department of Science and Environmental Studies, The Hong Kong Institute of Education, Tai Po, Hong Kong, China
Vehicular exhaust emissions are one of major sources of anthropogenic volatile organic compounds (VOCs) in urban areas of Pearl River Delta Region (PRDR). Six types of vehicle emission (VE)-dominated samples were collected at representative locations in Hong Kong in the winter of 2003. A total of 111 VOC species were quantified in the samples collected. n-Butane (31%) was the most abundant species in liquefied petroleum gas (LPG)-fueled VE-dominated samples, followed by propane (26%) and i-butane (25%). Toluene was the most abundant species in gasoline-fueled VE-dominated samples (16%), comprising about half of the quantified aromatic content. While ethene and ethyne have the greatest abundance in all diesel-fueled VE-dominated VOCs profiles (except at Tuen Mun Bus Depot). VOCs were also quantified at three roadside locations in Hong Kong. And ethene was the most abundant VOCs at roadside locations which accounted for 9.5 to 29% of the total quantified VOCs, except at Hong Kong Polytechnic University roadside monitoring station (PUX). Moreover, several VOCs were clearly in abundances in the roadside samples, namely toluene, ethyne, propane, i-butane, n-butane and i-pentane. Generally, strong and fair correlations were determined from the marker species of fuel vapor (i.e., LPG, gasoline, and diesel), which show significant fuel evaporation from vehicles in roadside environment of Hong Kong. Maximum incremental reactivity (MIR) was also calculated to evaluate the contributions of individual VOCs to ozone (O3) formation potential. The largest contributors to O3 production at Mong Kok roadside station (MKX) and Lok Ma Chau roadside station (LMX) were toluene (17 and 15% of the measured VOC reactivity, respectively), ethene (14 and 17% of the measured VOC reactivity, respectively), and propene (7 and 8% of the measured VOC reactivity, respectively), indicating the important roles of alkenes and aromatics in the ambient O3 formation.
VOCs; Roadside; Diesel; Gasoline; LPG; Vehicular emissions; Chemical profiles.