@article {2799,
	title = {Residential Coal Combustion as a Source of Levoglucosan in ChinaResidential Coal Combustion as a Source of Levoglucosan in China},
	journal = {Environmental Science \& Technology},
	volume = {52},
	year = {2018},
	month = {Jun-02-2018},
	pages = {1665 - 1674},
	abstract = {Levoglucosan (LG) has been widely identified as a specific marker for biomass burning (BB) sources and frequently utilized in estimating the BB contribution to atmospheric fine particles all over the world. However, this study provides direct evidence to show that coal combustion (CC) is also a source of LG, especially in the wintertime in Northern China, based on both source testing and ambient measurement. Our results show that low-temperature residential CC could emit LG with emission factors (EF) ranging from 0.3 to 15.9 mg kg{\textendash}1. Ratios of LG to its isomers, mannosan and galactosan, differ between CC and BB emissions, and the wintertime ratios in Beijing ambient PM2.5 and source-specific tracers including carbon isotopic signatures all indicated a significant contribution from CC to ambient levoglucosan in winter in Beijing. The results suggest that LG cannot be used as a distinct source marker for biomass burning in special cases such as some cities in the northern China, where coal is still widely used in the residential and industrial sectors. Biomass burning sources could be overestimated, although such an over-estimation could vary spatially and temporally.},
	issn = {0013-936X},
	doi = {10.1021/acs.est.7b05858},
	url = {https://pubs.acs.org/doi/10.1021/acs.est.7b05858},
	author = {Yan, Caiqing and Zheng, Mei and Sullivan, Amy P. and Shen, Guofeng and Chen, Yingjun and Wang, Shuxiao and Zhao, Bin and Cai, Siyi and Desyaterik, Yury and Li, Xiaoying and Zhou, Tian and Gustafsson, {\"O}rjan and Collett, Jeffrey L.}
}
@article {2778,
	title = {Divergent Evolution of Carbonaceous Aerosols during Dispersal of East Asian Haze},
	journal = {Scientific Reports},
	volume = {7},
	year = {2017},
	month = {Jan-12-2017},
	abstract = {Wintertime East Asia is plagued by severe haze episodes, characterized by large contributions of carbonaceous aerosols. However, the sources and atmospheric transformations of these major components are poorly constrained, hindering development of efficient mitigation strategies and detailed modelling of effects. Here we present dual carbon isotope (δ13C and Δ14C) signatures for black carbon (BC), organic carbon (OC) and water-soluble organic carbon (WSOC) aerosols collected in urban (Beijing and BC for Shanghai) and regional receptors (e.g., Korea Climate Observatory at Gosan) during January 2014. Fossil sources (>50\%) dominate BC at all sites with most stemming from coal combustion, except for Shanghai, where liquid fossil source is largest. During source-to-receptor transport, the δ13C fingerprint becomes enriched for WSOC but depleted for water-insoluble OC (WIOC). This reveals that the atmospheric processing of these two major pools are fundamentally different. The photochemical aging (e.g., photodissociation, photooxidation) during formation and transport can release CO2/CO or short-chain VOCs with lighter carbon, whereas the remaining WSOC becomes increasingly enriched in δ13C. On the other hand, several processes, e.g., secondary formation, rearrangement reaction in the particle phase, and photooxidation can influence WIOC. Taken together, this study highlights high fossil contributions for all carbonaceous aerosol sub-compartments in East Asia, and suggests different transformation pathways for different classes of carbonaceous aerosols.},
	doi = {10.1038/s41598-017-10766-4},
	url = {http://www.nature.com/articles/s41598-017-10766-4},
	author = {Fang, Wenzheng and Andersson, August and Zheng, Mei and Lee, Meehye and Holmstrand, Henry and Kim, Sang-Woo and Du, Ke and Gustafsson, {\"O}rjan}
}
@article { ISI:000299864400020,
	title = {Modern and Fossil Contributions to Polycyclic Aromatic Hydrocarbons in PM2.5 from North Birmingham, Alabama in the Southeastern U.S.},
	journal = {ENVIRONMENTAL SCIENCE \& TECHNOLOGY},
	volume = {46},
	number = {{3}},
	year = {2012},
	month = {FEB 7},
	pages = {1422-1429},
	type = {Article},
	abstract = {Analyzing the radiocarbon (C-14) content of polycyclic aromatic hydrocarbons (PAHs) in atmospheric particulate matter can provide estimates on the source contributions from biomass burning versus fossil fuel. The relative importance of these two sources to ambient PAHs varies considerably across regions and even countries, and hence there is a pressing need to apportion these sources. In this study, we advanced the radiocarbon analysis from bulk carbon to compound class specific radiocarbon analysis (CCSRA) to determine Delta C-14 and delta C-13 values of PAHs in PM2.5 samples for investigating biomass burning and fossil fuel source contributions to PAHs from one of the Southeastern Aerosol Research and Characterization (SEARCH) sites in North Birmingham (BHM), Alabama during winter (December 2004-February 2005) and summer (June-August 2005) by accelerator mass spectrometry. To compare our ambient samples to known sources, we collected and analyzed fenceline samples from the vicinity of a coke plant in BHM. As expected, PAHs from the coke plant fenceline samples had very low radiocarbon levels. Its Delta C-14 varied from -990 to -970 parts per thousand, indicating that 97 to 99\% were of fossil source. PAHs in the ambient PM2.5 had Delta C-14 from -968 to -911 parts per thousand, indicating that 92-97\% of PAHs were from fossil fuel combustion. These levels indicated the dominance of fossil sources of ambient PAHs. The radiocarbon level of ambient PAHs was higher in winter than in summer. Winter samples exhibited depleted delta C-13 value and enriched Delta C-14 value because of the increased contribution of PAHs from biomass burning source. However, biomass burning contributed more to heavier PAHs (modern source accounting for 6-8\%) than fighter ones with a modern contribution of 3\%.},
	issn = {0013-936X},
	doi = {10.1021/es2043189},
	author = {Xu, Li and Zheng, Mei and Ding, Xiang and Edgerton, Eric S. and Reddy, Christopher M.}
}
