Air pollution in London

Air pollution refers to the substances in the air that harm human health, welfare, plant or animal life. Most pollution in London is caused by road transport and domestic and commercial heating systems.

The UK Air Quality Standards Regulations (external website) 2000 sets standards for a variety of pollutants that are considered harmful to human health and the environment. These are based on EU limit values (external website) and are for a range of air pollutants, listed below:

  • Sulphur dioxide (SO2)
  • Nitrogen dioxide (NO2)
  • Oxides of nitrogen (NOX)
  • Particulate matter (PM10 and PM2.5)
  • Lead
  • Benzene
  • Carbon monoxide (CO)
  • Benzo(a)pyrene
  • Ozone (O3)

The majority of these pollutants are now at concentrations within London that do not affect human health. All but one of the pollutant concentrations listed above have decreased between 1996 and 2011.

Monitoring air pollution

London’s air quality is continuously monitored at around 100 different locations. These sites are operated and funded by the London boroughs. The Cleaner Air for London website (external website) records real time and historical monitoring data.

Despite reductions in the majority of pollutants mentioned above, levels of PM10 and NO2 continue to exceed national air quality standards and objectives in some areas of London. The Mayor is working to reduce concentrations of these pollutants however this is particularly challenging as between 30-40% of air pollution is generated from sources outside of Greater London.

For more information about air pollution in London watch the videos from Kings Environment Research Group.