Drivers and impacts of decreasing concentrations of atmospheric volatile organic compounds (VOCs) in Beijing during 2016-2020

Yafei Liu; Shijie Yin; Siqing Zhang; Wei Ma; Xin Zhang; Peipei Qiu; Chenlu Li; Guangpeng Wang; Dongli Hou; Xiang Zhang; Junling An; Yele Sun; Jie Li; Ziyin Zhang; Jing Chen; Hezhong Tian; Xingang Liu; Lianyou Liu

doi:10.1016/j.scitotenv.2023.167847

Drivers and impacts of decreasing concentrations of atmospheric volatile organic compounds (VOCs) in Beijing during 2016-2020

Sci Total Environ. 2024 Jan 1:906:167847. doi: 10.1016/j.scitotenv.2023.167847. Epub 2023 Oct 14.

Authors

Yafei Liu¹, Shijie Yin², Siqing Zhang², Wei Ma³, Xin Zhang⁴, Peipei Qiu⁴, Chenlu Li², Guangpeng Wang⁵, Dongli Hou⁶, Xiang Zhang⁶, Junling An⁷, Yele Sun⁷, Jie Li⁷, Ziyin Zhang⁸, Jing Chen², Hezhong Tian², Xingang Liu⁹, Lianyou Liu¹⁰

Affiliations

¹ State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China; Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
² State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China.
³ Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
⁴ State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
⁵ Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China.
⁶ Ecology Environment Monitoring Center of Hebei Province, Shijiazhuang 050000, China.
⁷ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
⁸ Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089, China.
⁹ State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China. Electronic address: lxgstar@126.com.
¹⁰ Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China. Electronic address: lyliu@bnu.edu.cn.

PMID: 37844645
DOI: 10.1016/j.scitotenv.2023.167847

Abstract

China has implemented various policies and measures for controlling air pollutants. However, our knowledge of the long-term trends in ambient volatile organic compounds (VOCs) after the implementation of these action plans in China remains limited. To address this, we conducted a five-year analysis (2016-2020) of VOC compositions and concentrations in Beijing. The annual VOC concentration decreased from 44.0 ± 28.8 to 26.2 ± 16.4 ppbv, with alkanes being the most prevalent group. The annual average concentrations of alkenes, alkynes, and aromatics have experienced a significant decrease of over 50 %. Seasonal variations indicated higher VOC concentrations in winter and autumn, with more significant reductions observed in winter and autumn. The impact of meteorological conditions caused variations in VOC reductions during the Chinese Spring Festival. Satellite-based measurements of formaldehyde (HCHO) columns confirmed the reduction of VOC emissions during the Coronavirus (COVID-19) lockdown. The normalized annual average VOC concentration decreased by 2.9ppbv yr^-1 from 2016 to 2020, and emission reduction contributed to 58.8 % of VOC reduction from 2016 to 2020 after meteorological normalization, indicating the effectiveness of implemented control measures. Based on receptor model, vehicle emissions and industrial sources were identified as the largest contributors to VOC concentrations. Vehicle emissions, liquefied petroleum gas/natural gas (LPG/NG) use, and coal combustion were major drivers of VOC reduction. Potential source region analysis revealed that air masses transported from northwestern and southern regions significantly contributed to VOC concentrations in Beijing. The range of source regions shrunk in both northwestern and southern regions with the reduction in VOC concentrations. The annual variations of ozone formation potential indicated a significant decrease in VOC reactivities through emission control. These results could provide insights into future emission control and coordinated efforts to improve PM_2.5 and ozone levels in China.

Keywords: Emission reduction; Long-term variations; Photochemical reactivities; VOCs; Weather normalization.