title: Effects of day-of-week trends and vehicle types on PM2.5-bounded carbonaceous compositions.
abstract: Carbonaceous compositions of PM2.5 were measured in the heart of Bangkok from 17th November 2010 to 19th January 2012, and a data set of 94 samples was constructed. Effects of day-of-week trends and vehicle types on PM2.5-bound TC, OC, and EC were carefully investigated. In this study, OC was the most important contributor to the total PM2.5 mass concentration. The average PM2.5-bound OC content measured at CHAOS (18.8 ± 9.18 μg m(-3)) was approximately 11 times higher than at Chaumont, Switzerland (1.7 μg m(-3)), but approximately five times lower than at Xi'an, China (93.0 μg m(-3)). The application of diagnostic binary ratios of OC/EC and estimations of secondary organic carbon (SOC) coupled with autocorrelation plots (Box and Jenkins) highlight the enhanced impacts of traffic emissions, especially from diesel vehicles, on PM2.5-bound carbonaceous compositions on weekdays relative to weekends. Hierarchical cluster analysis (HCA) coupled with principal component analysis (PCA) underline the importance of diesel emissions as the primary contributors of carbonaceous aerosols, particularly during weekdays.
authors.affiliation: NIDA Center for Research & Development of Disaster Prevention & Management, School of Social and Environmental Development, National Institute of Development Administration (NIDA), 118 Moo 3, Sereethai Road, Klong-Chan, Bangkapi, Bangkok 10240, Thailand; SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi'an 710075, China. Electronic address: pongpiajun@gmail.com.
authors.forename: Siwatt
authors.initials: S
authors.lastname: Pongpiachan
authors.affiliation: Department of Microbiology, Faculty of Sciences, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Charnwit
authors.initials: C
authors.lastname: Kositanont
authors.affiliation: Faculty of Education, Valaya Alongkorn Rajabhat University under the Royal Patronage (VRU), No.1 Moo 20, Phaholyothin Road, Klong luang, Pathumthani 13180, Thailand.
authors.forename: Jittree
authors.initials: J
authors.lastname: Palakun
authors.affiliation: SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi'an 710075, China.
authors.forename: Suixin
authors.initials: S
authors.lastname: Liu
authors.affiliation: SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi'an 710075, China.
authors.forename: Kin Fai
authors.initials: KF
authors.lastname: Ho
authors.affiliation: SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences (IEECAS), Xi'an 710075, China.
authors.forename: Junji
authors.initials: J
authors.lastname: Cao
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D002681:China; D004784:Environmental Monitoring; D052638:Particulate Matter / Q000032:analysis*; D025341:Principal Component Analysis; D012621:Seasons
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: Bangkok; Carbonaceous compositions; Day-of-week trends; Vehicle types