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Reduction of air pollution levels. Auckland Council air quality monitoring network. Lockdown level 4

Shanju Xie
Auckland Council Research and Evaluation Unit, RIMU
Publication date:  


This document provides an initial overview of key changes measured in the Auckland Council air quality monitoring network over the full covid-19 alert level 4 lockdown period, 26 March-27 April 2020. 


•Traffic pollutant nitrogen dioxide (NO2) levels declined across all the sites, immediately on day one of the Level 4 alert and stayed lower throughout the lockdown period with the largest drop at Takapuna (58%) and Henderson (57%).

•Particulate matter (​PM10 and PM2.5) levels did not show such a consistent pattern due to contribution from non-traffic sources (e.g., dust or sea salt), resulting in reduction at some sites and little change at other sites.

•The city centre (Queen Street) showed a marked drop in NO2, PM10 and PM2.5 levels, by 33%,12% and 11%, respectively.

Air pollution in the Auckland region has been monitored by Auckland Council since the late 1990s at representative monitoring sites across the region. Data from our monitoring network is used to assess compliance with the National Environmental Standards for Air Quality (NES-AQ).

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See also

Change in pollution levels seen in the Auckland Council air quality monitoring network for week one of COVID-19 Alert Level 3 (28 April-4 May)

May 2020