Characteristics of Organic and Elemental Carbon in PM2.5 and PM0.25 in Indoor and Outdoor Environments of a Middle School: Secondary Formation of Organic Carbon and Sources Identification

Atmosphere

Hongmei Xu⁴  Benjamin Guinot²  Zhenxing Shen⁴  Kin Fai Ho¹  Xinyi Niu³  Shun Xiao³  Ru-Jin Huang³  Junji Cao³  Guohui Li⁵ 

[1] School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China; E-Mail:;Laboratoire d’Aerologie, Observatory Midi-Pyrenees, CNRS—University of Toulouse, Toulouse 31400, France; E-Mail:;Key Lab of Aerosol Chemistry & Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China; E-Mails:;Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; E-Mail:;Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China; E-Mail

关键词: OC and EC;    SOC formation;    very fine particles (VFP);    TC sources;    indoor and outdoor;    school;    Xi’an;    China;   

DOI  :  10.3390/atmos6030361

来源: mdpi

【 摘 要 】

Secondary organic carbon (SOC) formation and its effects on human health require better understanding in Chinese megacities characterized by a severe particulate pollution and robust economic reform. This study investigated organic carbon (OC) and elemental carbon (EC) in PM_2.5 and PM_0.25 collected 8–20 March 2012. Samples were collected inside and outside a classroom in a middle school at Xi’an. On average, OC and EC accounted for 20%–30% of the particulate matter (PM) mass concentration. By applying the EC-tracer method, SOC’s contribution to OC in both PM size fractions was demonstrated. The observed changes in SOC:OC ratios can be attributed to variations in the primary production processes, the photochemical reactions, the intensity of free radicals, and the meteorological conditions. Total carbon (TC) source apportionment by formula derivation showed that coal combustion, motor vehicle exhaust, and secondary formation were the major sources of carbonaceous aerosol. Coal combustion appeared to be the largest contributor to TC (50%), followed by motor vehicle exhaust (25%) and SOC (18%) in both size fractions.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.