Implications for air quality management of changes in air quality during lockdown in Auckland (New Zealand) in response to the 2020 SARS-CoV-2 epidemic

Copyright © 2020 Elsevier B.V. All rights reserved..

The current changes in vehicle movement due to 'lockdown' conditions (imposed in cities worldwide in response to the COVID-19 epidemic) provide opportunities to quantify the local impact of 'controlled interventions' on air quality and establish baseline pollution concentrations in cities. Here, we present a case study from Auckland, New Zealand, an isolated Southern Hemisphere city, which is largely unaffected by long-range pollution transport or industrial sources of air pollution. In this city, traffic flows reduced by 60-80% as a result of a government-led initiative to contain the virus by limiting all transport to only essential services. In this paper, ambient pollutant concentrations of NO2, O3, BC, PM2.5, and PM10 are compared between the lockdown period and comparable periods in the historical air pollution record, while taking into account changes in the local meteorology. We show that this 'natural experiment' in source emission reductions had significant but non-linear impacts on air quality. While emission inventories and receptor modelling approaches confirm the dominance of traffic sources for NOx (86%), and BC (72%) across the city, observations suggest a consequent reduction in NO2 of only 34-57% and a reduction in BC of 55-75%. The observed reductions in PM2.5 (still likely to be dominated by traffic emissions), and PM10 (dominated by sea salt, traffic emissions to a lesser extent, and affected by seasonality) were found to be significantly less (8-17% for PM2.5 and 7-20% for PM10). The impact of this unplanned controlled intervention shows the importance of establishing accurate, local-scale emission inventories, and the potential of the local atmospheric chemistry and meteorology in limiting their accuracy.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:746

Enthalten in:

The Science of the total environment - 746(2020) vom: 01. Dez., Seite 141129

Sprache:

Englisch

Beteiligte Personen:

Patel, Hamesh [VerfasserIn]
Talbot, Nick [VerfasserIn]
Salmond, Jennifer [VerfasserIn]
Dirks, Kim [VerfasserIn]
Xie, Shanju [VerfasserIn]
Davy, Perry [VerfasserIn]

Links:

Volltext

Themen:

Air Pollutants
Atmospheric pollution
Black carbon
Covid-19
Emissions inventories
Journal Article
Particulate
Particulate Matter
Transport

Anmerkungen:

Date Completed 07.10.2020

Date Revised 10.01.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.scitotenv.2020.141129

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM313211809