Characterization of ambient-generated exposure to fine particles using sulfate as a tracer in the Chinese megacity of Guangzhou

Xiao-Cui Chen; Heiko J Jahn; Guenter Engling; Tony J Ward; Alexander Kraemer; Kin-Fai Ho; Chuen-Yu Chan

doi:10.1016/j.scitotenv.2016.10.241

Characterization of ambient-generated exposure to fine particles using sulfate as a tracer in the Chinese megacity of Guangzhou

Sci Total Environ. 2017 Feb 15:580:347-357. doi: 10.1016/j.scitotenv.2016.10.241. Epub 2016 Dec 10.

Authors

Xiao-Cui Chen¹, Heiko J Jahn², Guenter Engling³, Tony J Ward⁴, Alexander Kraemer², Kin-Fai Ho⁵, Chuen-Yu Chan⁶

Affiliations

¹ The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: chenxcui@cuhk.edu.hk.
² Department of Public Health Medicine, School of Public Health, Bielefeld University, Bielefeld, Germany.
³ Division of Atmospheric Sciences, Desert Research Institute, Reno, NV, USA; Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan.
⁴ School of Public and Community Health Sciences, University of Montana, Missoula, MT, USA.
⁵ The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
⁶ Key Laboratory of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.

PMID: 27955968
DOI: 10.1016/j.scitotenv.2016.10.241

Abstract

Total personal exposures can differ from the concentrations measured at stationary ambient monitoring sites. To provide further insight into factors affecting exposure to particles, chemical tracers were used to separate total personal exposure into its ambient and non-ambient components. Simultaneous measurements of ambient and personal exposure to fine particles (PM_2.5) were conducted in eight districts of Guangzhou, a megacity in South China, during the winter of 2011. Considerable significant correlations (Spearman's Rho, r_s) between personal exposures and ambient concentrations of sulfate (SO₄^2-; r_s>0.68) were found in contrast to elemental carbon (EC; r_s>0.37). The average fraction of personal SO₄^2- to ambient SO₄^2- resulting in an adjusted ambient exposure factor of α=0.72 and a slope of 0.73 was determined from linear regression analysis when there were minimal indoor sources of SO₄^2-. From all data pooled across the districts, the estimated average ambient-generated and non-ambient-generated exposure to PM_2.5 were 55.3μg/m³ (SD=23.4μg/m³) and 18.1μg/m³ (SD=29.1μg/m³), respectively. A significant association was found between ambient-generated exposure and ambient PM_2.5 concentrations (Pearson's r=0.51, p<0.001). As expected, the non-ambient generated exposure was not related to the ambient concentrations. This study highlights the importance of both ambient and non-ambient components of total personal exposure in the megacity of Guangzhou. Our results support the use of SO₄^2- as a tracer of personal exposure to PM_2.5 of ambient origin in environmental and epidemiological studies.

Keywords: EC; Environmental monitoring; Fine aerosol particles (PM(2.5)); Personal exposure; SO(4)(2−).