Cambridge Environmental Research Consultants (CERC) using the ADMS-Urban model as part of the Breathe London pilot project. Map displays modelled annual mean concentrations for 2019.
The map uses a detailed model to display an estimate of NOx and PM2.5 pollution levels in London for major different sources of pollution – like diesel cars and construction – in 2019. The map allows users to see a calculation of the pollution that people breathe, depending on where they are in the city and separated out by source category. The modelled data, which takes into account factors like wind and weather, is available on a 10 metre grid across London and provides the annual pollution concentrations experienced at 1m above ground level.
The colour scales displayed change depending on the pollutant and source selected. The scales were chosen to visualise where each selected source or grouped sources are responsible for more or less pollution in London. The colours are not meant to identify where legal limits of pollution have been breached.
Measurements from air quality monitoring stations are only able to report pollution levels at specific locations. The map’s detailed model fills in the gaps, providing a picture of air quality across the whole of Greater London. By using emissions data from across the city, the model also provides details on where the pollution is coming from. For example, the map can display how much PM2.5 pollution is coming from vehicle tailpipes and specifically which vehicle types.
Nitrogen oxides (NOx) are a sum of nitric oxide (NO) and nitrogen dioxide (NO2) which, along with fine particulate matter (PM2.5), are the main air pollutants of concern in London. They are harmful to human health and are associated with adverse health outcomes like asthma, strokes and cancer. London also has detailed emissions inventories for NOx and PM2.5; the model needs these inventories to produce the maps.
Annual averages give a good indication of the average level of a pollutant and long-term exposure, which may lead to chronic health effects. High annual mean levels of pollution can also indicate higher levels of short-term exposure, which could lead to acute health effects as well.
London air pollution sources
Map by CERC Measured at
Sensor name.
Sensor name.
Particulate Matter (PM2.5)
The graph shows daily average concentrations of PM2.5 in London. Also displayed are the World Health Organization's Air Quality Guidelines for PM2.5; evidence-based targets for air quality management to protect populations from the adverse health effects of air pollution.
