Oxidative potential of solvent-extractable organic matter of ambient total suspended particulate in Bangkok, Thailand. Issue 3 (9th February 2022)

• Record Type: Journal Article
• Authors: Wang, Jiaqi; Zhao, Shizhen; Jiang, Haoyu; Geng, Xiaofei; Li, Jun; Mao, Shuduan; Ma, Shexia; Bualert, Surat; Zhong, Guangcai; Zhang, Gan
• Is Part Of: Environmental science. Volume 24:Issue 3(2022)
• Page Start: 400
• Page End: 413
• Publication Date: 2022-02-09
• Subjects: Environmental monitoring -- Periodicals; Biological monitoring -- Periodicals; Environmental chemistry -- Periodicals; 363.7363
• DOI: 10.1039/d1em00414j
• Languages: English
• ISSNs: 2050-7887

Abstract

Abstract : This study creatively combined the molecular markers with the source apportionment model, to identify and quantify sources contributing to the oxidative potential of particulate matter in Bangkok, skipping over the inherent mechanism. Abstract : Oxidative stress is a key mechanism by which ambient particulate matter induces adverse health effects. Most studies have focused on the oxidative potential (OP) of water-soluble constituents, while there has been limited work on the OP of solvent-extractable organic matter (EOM OP). In this study, the EOM OP of ambient total suspended particulate (TSP) from Bangkok, Thailand, was determined using the dithiothreitol (DTT) assay. Positive matrix factorization (PMF), combined with chemical analysis of molecular markers, was employed to apportion the contributions of various emission sources to EOM OP. The volume-normalized OP initially increased with organic carbon (OC) concentration and plateaued gradually, while the mass-normalized OP fitted well with OC concentration using a power function. Fossil fuel combustion (62%) and plastic waste burning (23%) were the major contributors to EOM OP, while biomass burning demonstrated only a limited contribution. EOM OP correlated well with each group of polycyclic aromatic hydrocarbons (PAHs), suggesting that secondary formation of quinones associated with fossil fuel combustion and plastic waste burning could be an important pathway of TSP toxicity. This study underscores the importance of considering different emission sources when evaluating potential health impacts and the implementation of air pollution regulations.