Characteristics and sources of carbonaceous aerosols in a semi-arid city: Quantifying anthropogenic and meteorological impacts

Peng Liu; Haijun Zhou; Xi Chun; Zhiqiang Wan; Tao Liu; Bing Sun

doi:10.1016/j.chemosphere.2023.139056

Characteristics and sources of carbonaceous aerosols in a semi-arid city: Quantifying anthropogenic and meteorological impacts

Chemosphere. 2023 Sep:335:139056. doi: 10.1016/j.chemosphere.2023.139056. Epub 2023 May 27.

Authors

Peng Liu¹, Haijun Zhou², Xi Chun³, Zhiqiang Wan⁴, Tao Liu⁵, Bing Sun⁶

Affiliations

¹ College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China. Electronic address: 1203432239@qq.com.
² College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China. Electronic address: hjzhou@imnu.edu.cn.
³ College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China. Electronic address: chunxi@imnu.edu.cn.
⁴ College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China. Electronic address: xiaoqiang1988117@126.com.
⁵ Environmental Monitoring Center Station of Inner Mongolia, Hohhot, 010011, China. Electronic address: 88417230@qq.com.
⁶ Hohhot Environmental Monitoring Branch Station of Inner Mongolia, Hohhot, 010030, China. Electronic address: sunice1979@163.com.

PMID: 37247672
DOI: 10.1016/j.chemosphere.2023.139056

Abstract

Carbonaceous aerosols have great adverse impacts on air quality, human health, and climate. However, there is a limited understanding of carbonaceous aerosols in semi-arid areas. The correlation between carbonaceous aerosols and control measures is still unclear owing to the insufficient information regarding meteorological contribution. To reveal the complex relationship between control measures and carbonaceous aerosols, offline and online observations of carbonaceous aerosols were conducted from October 8, 2019 to October 7, 2020 in Hohhot, a semi-arid city. The characteristics and sources of carbonaceous aerosols and impacts of anthropogenic emissions and meteorological conditions were studied. The annual mean concentrations (± standard deviation) of fine particulate matter (PM_2.5), organic carbon (OC), and elemental carbon (EC) were 42.81 (±40.13), 7.57 (±6.43), and 2.25 (±1.39) μg m^-3, respectively. The highest PM_2.5 and carbonaceous aerosol concentrations were observed in winter, whereas the lowest was observed in summer. The result indicated that coal combustion for heating had a critical role in air quality degradation in Hohhot. A boost regression tree model was applied to quantify the impacts of anthropogenic emissions and meteorological conditions on carbonaceous aerosols. The results suggested that the anthropogenic contributions of PM_2.5, OC, and EC during the COVID-19 lockdown period were 53.0, 15.0, and 2.36 μg m^-3, respectively, while the meteorological contributions were 5.38, 2.49, and -0.62 μg m^-3, respectively. Secondary formation caused by unfavorable meteorological conditions offset the emission reduction during the COVID-19 lockdown period. Coal combustion (46.4% for OC and 35.4% for EC) and vehicular emissions (32.0% for OC and 50.4% for EC) were the predominant contributors of carbonaceous aerosols. The result indicated that Hohhot must regulate coal use and vehicle emissions to reduce carbonaceous aerosol pollution. This study provides new insights and a comprehensive understanding of the complex relationships between control strategies, meteorological conditions, and air quality.

Keywords: Anthropogenic emissions; COVID-19 lockdown; Carbonaceous aerosols; Meteorological conditions.

MeSH terms

Air Pollutants* / analysis
COVID-19*
Carbon / analysis
China
Coal / analysis
Communicable Disease Control
Environmental Monitoring
Humans
Particulate Matter / analysis
Respiratory Aerosols and Droplets
Seasons
Vehicle Emissions / analysis

Substances

Air Pollutants
Particulate Matter
Vehicle Emissions
Coal
Carbon