Levels of and Health Risk Assessment on Commuters Exposed to Aromatic Volatile Organic Compounds in Public transportation Models in Bangkok

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Maneerat Ongwandee

Abstract

This study investigated concentrations of volatile organic compounds (VOCs) in four public transportation modes in Bangkok, Thailand during two rush hour periods (7:00-9:00 a.m. and 4:00-7:00 p.m.). The four modes included an air-conditioned bus (A/C bus), non-air-conditioned bus (non-A/C bus), electric sky train, and a passenger boat traveling along the San Saeb canal. Five studied routes were Paholyothin Road, Sukhumvit Road, Petchburi-Ramkhamheang Road, sky train route, and boat route. In-vehicle air samples were collected within the commuter’s breathing zone using charcoal sorbent tubes, desorbed by carbon disulfide, and then analyzed by a gas chromatography-mass spectrometer. Results show that the transportation modes significantly influenced the abundance of in-vehicle benzene, toluene, ethybenzene, and m,p-xylene (BTEX). Mean concentrations of BTEX were 53.8, 210, 14.6 and 46.0 µg m-3 in A/C bus; 66.1, 200, 18.2 and 74.1 µg m-3 in non-A/C bus; 13.2, 39.5, 0.50 and 0.97 µg m-3 in sky train; and 60.0, 73.7, 2.6 and 7.3 µg m-3 in boat, respectively. Wilcoxon rank sum test indicated that toluene and m,p-xylene in the sky trains were statistically lower than in the other three modes at a p-value of 0.05. The Benzene to toluene (B/T) ratios implied that tail-pipe emissions from gasoline-used vehicles were important contributor to the abundance of in A/C bus VOCs. Furthermore, the lifetime cancer and non-cancer risks for commuters exposed to BTEX were estimated. Results show that all transportation modes had a lifetime cancer risk between 2×10-6 and 2×10-5, while non-cancer risks were below the US EPA reference levels.

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How to Cite
Ongwandee, M. (2017). Levels of and Health Risk Assessment on Commuters Exposed to Aromatic Volatile Organic Compounds in Public transportation Models in Bangkok. Applied Environmental Research, 30(1), 65-78. Retrieved from https://tci-thaijo.org/index.php/aer/article/view/104712
Section
Original Research