Marylebone Road Monitoring Station

Monitoring and predicting air pollution

Get free air pollution alerts

Between three and eight times a year, London’s air pollution is particularly high. On these days, you can protect yourself and others by avoiding the car and using back streets to walk and cycle instead.

Transport for London now broadcast air quality advice across London whenever pollution is high or very high. You will see notifications at Tube stations, bus stops, river piers, on digital signs along major roads and Transport for London is publishing information on its website.

Sign up for free pollution alerts on the airTEXT website.

See air quality updates on London Air.

Your views: how can we clean up our air?

The Mayor, Sadiq Khan, launched the third phase of his air quality consultation to find out what Londoners think. The consultation opened April 4th and closed June 25th. 

Find out more about the consultations and the results.

Measuring air pollution

We predict London’s air pollution levels using a model that estimates how pollution will spread over time and distance. The pollutants modelled for the Mayor’s Air Quality Strategy are nitrogen dioxide (NO2) and particulate matter (PM10 and PM2.5) as these are often linked with health problems. The EU has also set target levels for these pollutants that each member state must achieve.

Every year we put together the London Atmospheric Emission Inventory (LAEI). Visit the London Datastore to access the latest copy.

This database has information on emissions from all sources in Greater London that can be identified. The current LAEI includes emissions data for the ‘base year’ 2013 and projections for years 2020, 2025 and 2030. We are constantly working to improve the data and share it with all London boroughs for free.

Monitoring air pollution

London’s air quality is constantly monitored at around 100 different locations. These sites are operated and funded by London boroughs. The London Air website, provided by King's College London, records real time and historical monitoring data. To add to this, Ricardo Energy and Environment manage the data sets for 18 sites - more information is on the Air Quality England website.

Despite cuts in most pollutants, levels of PM10 and NO2 are still too high in some areas of London. We are working hard to reduce concentrations of these pollutants. However, around 30-40 per cent of air pollution comes from outside Greater London.

To find out more about London’s air pollution watch the videos from Kings Environment Research Group.