Chemical characteristics and sources of PM2.5 in Hohhot, a semi-arid city in northern China: insight from the COVID-19 lockdown
Atmospheric Chemistry and Physics
; 22(18):12153-12166, 2022.
Article
in English
| ProQuest Central | ID: covidwho-2040263
ABSTRACT
A knowledge gap exists concerning how chemical composition and sources respond to implemented policy control measures for aerosols, particularly in a semi-arid region. To address this, a single year's offline measurement was conducted in Hohhot, a semi-arid city in northern China, to reveal the driving factors of severe air pollution in a semi-arid region and assess the impact of the COVID-19 lockdown measures on chemical characteristics and sources of PM2.5. Organic matter, mineral dust, sulfate and nitrate accounted for 31.5 %, 14.2 %, 13.4 % and 12.3 % of the total PM2.5 mass, respectively. Coal combustion, vehicular emission, crustal source and secondary inorganic aerosols were the main sources of PM2.5 in Hohhot, at 38.3 %, 35.0 %, 13.5 %, and 11.4 %, respectively. Due to the coupling effect of emission reduction and improved atmospheric conditions, the concentration of secondary inorganic components, organic matter and elemental carbon declined substantially from the pre-lockdown (pre-LD) period to the lockdown (LD) and post-lockdown (post-LD) periods. The source contribution of secondary inorganic aerosols increased (from 21.1 % to 37.8 %), whereas the contribution of vehicular emission reduced (from 35.5 % to 4.4 %) due to lockdown measures. The rapid generation of secondary inorganic components caused by unfavorable meteorological conditions during lockdown led to serious pollution. This study elucidates the complex relationship between air quality and environmental policy.
Meteorology; Air quality; Aerosols; Atmospheric pollution; Organic matter; Coal combustion; Air pollution; Environmental policy; COVID-19; Sulfates; Industrial plant emissions; Emissions control; Precipitation; Semiarid zones; Quartz; Carbon; Arid regions; Particulate matter sources; Coronaviruses; Pollutants; Secondary aerosols; Humidity; Arid zones; Atmospheric conditions; Coal; Oceanic crust; Chemical composition; Outdoor air quality; Vehicle emissions; Environmental policies; Meteorological conditions; Semiarid lands; Atmospheric particulates; Components; Particulate matter; Semi arid areas; Cities; Beijing China; Mongolia; United States--US; China; Germany
Full text:
Available
Collection:
Databases of international organizations
Database:
ProQuest Central
Language:
English
Journal:
Atmospheric Chemistry and Physics
Year:
2022
Document Type:
Article
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