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DOI	10.1016/j.atmosenv.2020.117881
	Physicochemical properties and cytotoxicity of brown carbon produced under different combustion conditions
	Atwi K.; Mondal A.; Pant J.; Cheng Z.; El Hajj O.; Ijeli I.; Handa H.; Saleh R.
发表日期	2021
ISSN	1352-2310
卷号	244
英文摘要	Light-absorbing organic particulate matter (PM), or brown carbon (BrC), may constitute an important fraction of combustion PM. Here, we investigate the effect of combustion conditions on the molecular sizes of BrC, their light-absorption properties, and their cytotoxicity. We used toluene in a combustion reactor with highly controlled conditions to produce two different types of BrC under two conditions corresponding to smoldering and near-flaming combustion, with temperatures of 670 °C and 1035 °C, respectively. We performed online measurements of the size distributions and light-absorption properties of the BrC. The BrC produced at 1035 °C was more light absorbing, with an imaginary component of the refractive index at 532 nm (k532) an order of magnitude larger than that of the BrC produced at 670 °C. We also collected samples for offline chemical characterization using laser desorption ionization (LDI) mass spectrometry. The LDI mass spectra showed that the BrC produced at 1035 °C was composed of species with significantly larger molecular sizes than the BrC produced at 670 °C. Using human lung epithelial cells, we conducted in vitro cytotoxicity analysis on the two types of BrC with doses ranging from 3.5 to 136.0 μg of BrC/ml. After 24-h exposure, the viability of the cells was assessed using a WST-8 assay. The cytotoxicity analysis showed that, for both BrC samples, the cells exhibited a clear dose-dependent response with significant BrC cytotoxicity that plateaued at the higher doses. However, while the viability of cells exposed to the BrC produced at 1035 °C reached a minimum of around 65% at the highest dose, the BrC produced at 670 °C proved to be significantly more toxic, with the viability dropping asymptotically to 25%. The results presented here suggest that organic PM of smaller molecular sizes produced under lower temperature, smoldering combustion could be significantly more toxic than that of larger molecular sizes produced under higher temperature, flaming conditions. The use of a single-molecule fuel in a highly controlled combustion setup distinguishes this work from experiments that rely on real-life sources and combustion setups, where different combustion conditions could be occurring simultaneously and clouding the conclusions. © 2020 Elsevier Ltd
关键词	Brown carbon Combustion conditions Cytotoxicity Particulate matter
语种	英语
scopus关键词	Carbon; Cells; Combustion; Cytology; Cytotoxicity; Light absorption; Mass spectrometry; Physicochemical properties; Refractive index; Absorption property; Chemical characterization; Combustion condition; Controlled conditions; Laser desorption ionization; On-line measurement; Organic particulate matters; Smoldering combustion; Bromine compounds; carbon; toluene; brown carbon; combustion; desorption; ecotoxicology; ionization; laser method; molecular analysis; organic matter; particulate matter; physicochemical property; refractive index; spectral analysis; toluene; Article; atmospheric radioactivity; cell viability; combustion; cytotoxicity; human; human cell; in vitro study; laser desorption ionization mass spectrometry; light absorption; lung epithelium; molecular size; particle size; particulate matter; physical chemistry; priority journal; refraction index; temperature; warming
来源期刊	ATMOSPHERIC ENVIRONMENT
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248876
作者单位	Air Quality and Climate Research Laboratory, School of Environmental, Civil, Agricultural and Mechanical Engineering, University of Georgia, Athens, GA, United States; Handa Biomaterials Research Lab, School of Materials, Chemical and Biomedical Engineering, University of Georgia, Athens, GA, United States
推荐引用方式 GB/T 7714	Atwi K.,Mondal A.,Pant J.,et al. Physicochemical properties and cytotoxicity of brown carbon produced under different combustion conditions[J],2021,244.
APA	Atwi K..,Mondal A..,Pant J..,Cheng Z..,El Hajj O..,...&Saleh R..(2021).Physicochemical properties and cytotoxicity of brown carbon produced under different combustion conditions.ATMOSPHERIC ENVIRONMENT,244.
MLA	Atwi K.,et al."Physicochemical properties and cytotoxicity of brown carbon produced under different combustion conditions".ATMOSPHERIC ENVIRONMENT 244(2021).