Temporal and spatial distribution characteristics and source origins of volatile organic compounds in a megacity of Sichuan Basin, China

Qinwen Tan; Hefan Liu; Shaodong Xie; Li Zhou; Tianli Song; Guangming Shi; Wenju Jiang; Fumo Yang; Fusheng Wei

doi:10.1016/j.envres.2020.109478

Temporal and spatial distribution characteristics and source origins of volatile organic compounds in a megacity of Sichuan Basin, China

Environ Res. 2020 Jun:185:109478. doi: 10.1016/j.envres.2020.109478. Epub 2020 Apr 4.

Authors

Qinwen Tan¹, Hefan Liu², Shaodong Xie³, Li Zhou⁴, Tianli Song⁵, Guangming Shi⁵, Wenju Jiang⁵, Fumo Yang⁶, Fusheng Wei⁵

Affiliations

¹ College of Architecture and Environment, Sichuan University, Chengdu, China; Chengdu Academy of Environmental Sciences, Chengdu, China.
² Chengdu Academy of Environmental Sciences, Chengdu, China.
³ State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, China.
⁴ College of Architecture and Environment, Sichuan University, Chengdu, China. Electronic address: lizhou@scu.edu.cn.
⁵ College of Architecture and Environment, Sichuan University, Chengdu, China.
⁶ College of Architecture and Environment, Sichuan University, Chengdu, China. Electronic address: fmyang@scu.edu.cn.

PMID: 32276165
DOI: 10.1016/j.envres.2020.109478

Abstract

As important pollution gases and represented precursors of both ozone and second organic aerosol (SOA), the component characteristics, source origins, environmental health and emission control of volatile organic compounds (VOCs), are gaining more and more attention in Chinese megacities. In order to understand the concentration, composition and temporal and spatial distribution characteristics of VOCs in the atmosphere of Chengdu, a megacity located in Sichuan basin in southwest China, the offline sampling measurements of VOCs were carried out at 28 different field sites covering all the districts and counties of Chengdu during special periods from May 2016 to January 2017. Speciated VOCs measurement was performed by the GC-FID/MS, and 99 species were identified. The averaged total VOC mixing ratios of each sampling site were in the range from 35.03 to 180.57 ppbv. Based on these observational data, the distribution characteristics of VOCs in different months and different regions of Chengdu were clarified. The VOCs data were used to estimate the potential amount of ozone, secondary aerosol formation and health risk assessment in Chengdu. Furthermore, the positive matrix factorization (PMF) model was used to identify the dominant emission sources and evaluate their contribution to VOCs in the city. The two main sources of VOCs in Chengdu were motor vehicle exhaust and solvent utilization. These accounted for 43% of all emission sources. In the summertime, due to higher temperatures and stronger sunlight, the contribution of natural sources and secondary emissions were also relatively high, which were supported by the regional emission inventories. Finally, the controlling direction of VOCs and O₃ pollution in Chengdu was discussed, and the VOCs pollution control strategy was proposed for the near future.

Keywords: Chengdu; Impact assessment; Source appointment; Temporal and spatial distribution; VOCs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Air Pollutants* / analysis
China
Cities
Environmental Monitoring
Ozone* / analysis
Volatile Organic Compounds* / analysis

Substances

Air Pollutants
Volatile Organic Compounds
Ozone