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Changes in air quality in Mexico City, London and Delhi in response to various stages and levels of lockdowns and easing of restrictions during COVID-19 pandemic☆☆☆
- Source :
- Environmental Pollution (Barking, Essex : 1987)
- Publication Year :
- 2021
- Publisher :
- The Authors. Published by Elsevier Ltd., 2021.
-
Abstract
- The impacts of COVID-19 lockdown restrictions have provided a valuable global experiment into the extent of improvements in air quality possible with reductions in vehicle movements. Mexico City, London and Delhi all share the problem of air quality failing WHO guideline limits, each with unique situations and influencing factors. We determine, discuss and compare the air quality changes across these cities during the COVID-19, to understand how the findings may support future improvements in their air quality and associated health of citizens. We analysed ground-level PM10, PM2.5, NO2, O3 and CO changes in each city for the period 1st January to August 31, 2020 under different phases of lockdown, with respect to daily average concentrations over the same period for 2017 to 2019. We found major reductions in PM10, PM2.5, NO2 and CO across the three cities for the lockdown phases and increases in O3 in London and Mexico City but not Delhi. The differences were due to the O3 production criteria across the cities, for Delhi production depends on the VOC-limited photochemical regime. Levels of reductions were commensurate with the degree of lockdown. In Mexico City, the greatest reduction in measured concentration was in CO in the initial lockdown phase (40%), in London the greatest decrease was for NO2 in the later part of the lockdown (49%), and in Delhi the greatest decrease was in PM10, and PM2.5 in the initial lockdown phase (61% and 50%, respectively). Reduction in pollutant concentrations agreed with reductions in vehicle movements. In the initial lockdown phase vehicle movements reduced by up to 59% in Mexico City and 63% in London. The cities demonstrated a range of air quality changes in their differing geographical areas and land use types. Local meteorology and pollution events, such as forest fires, also impacted the results.<br />Graphical abstract Image 1
- Subjects :
- Pollution
Coronavirus disease 2019 (COVID-19)
Health, Toxicology and Mutagenesis
media_common.quotation_subject
Air pollution
India
F800
Toxicology
medicine.disease_cause
Article
Mexico city
Environmental monitoring
Pandemic
Lockdown
London
medicine
Delhi
Humans
Cities
Socioeconomics
Air quality index
Mexico
Pandemics
media_common
Air Pollutants
Land use
SARS-CoV-2
Covid-19 restrictions
COVID-19
General Medicine
Geography
Mexico City
Communicable Disease Control
Particulate Matter
Environmental Monitoring
Subjects
Details
- Language :
- English
- ISSN :
- 18736424 and 02697491
- Volume :
- 285
- Database :
- OpenAIRE
- Journal :
- Environmental Pollution (Barking, Essex : 1987)
- Accession number :
- edsair.doi.dedup.....f4c77f2dc9233d4e8fbf14007527904a