Questions to the Mayor of London – answered on 1st March 2022.
Are you satisfied with the number of particulate matter (PM) monitoring stations in London, specifically for PM2.5?
London has one of the most comprehensive air quality monitoring networks of any global city. London has the highest number of highest-quality reference monitors of any city in the UK and air quality is constantly monitored at over 120 locations, with 52 automatic reference monitors measuring PM2.5 across 22 boroughs.
Historically there have been fewer PM2.5 monitors as the focus was on pollutants which exceeded the legal limits, such as nitrogen dioxide and PM10. However, as PM2.5 is the pollutant most associated with health effects, my London Local Air Quality Management Framework encourages boroughs to increase PM2.5 monitoring to monitor progress against the WHO PM2.5 guideline which I have committed to meet by 2030. As a result, the number of PM2.5 monitors increased by 49 per cent between 2016 and 2020. My Breathe London Network also supplements the reference monitoring network with low-cost sensors, with 277 currently installed across London that monitor PM2.5.
I will continue to work with the boroughs to improve the provision of real-time air quality data, including for PM2.5.