In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 22, No. 18 ( 2022-09-19), p. 12153-12166
Abstract:
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.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-22-12153-2022
DOI:
10.5194/acp-22-12153-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
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