Air Quality

We are currently reviewing and updating Brent's draft Air Quality Action Plan! Find out more about the project

What are the pollutants of concern in my area?

We take action to limit the levels of eight key pollutants and meet targets to reduce air pollution. Since 1997 we have worked to improve air quality and now the main pollutants of concern are Nitrogen dioxide (NO2) and particulates (PM10 and PM 2.5).


PollutantTarget setCurrent Status in Brent
Nitrogen Dioxide - 1 hour mean 200 µg m-3 not to be exceeded more than 18 times a year Target met in most areas where this is measured.
Nitrogen Dioxide - Annual mean 40 µg m-3 Target not met in most areas where this is measured.
Particles (PM10) - 24 hour mean 50 µg m-3 not to be exceeded more than 35 times a year Target met in most areas where this is measured.
Particles (PM10) - Annual mean 40 µg m-3 Target met in most areas where this is measured.
Particles (PM2.5) - Annual mean None No Target is set. Action taken to reduce Particles PM10 will lead to a reduction in PM2.5. The council will quantify this reduction where possible.


Where we are monitoring?

We have monitoring stations located in Harlesden, Kingsbury, Neasden, Kensal Rise and Brent Park which operate 24 hours a day.  We also have a network of 27 diffusion tubes measuring levels of nitrogen dioxide across the borough.

Why monitor air pollution?

  • The law requires the monitoring of pollution levels and the results can be used to make informed policy decisions.
  • Monitoring air pollution can help us understand how pollutants behave and their relationship with the weather, location and human activities.
  • Residents benefit from easily available, accurate and up to date information on the quality of the air they breathe.

Where do the pollutants come from?

Nitric oxide (NO) is produced during high temperature burning of fuel (e.g. road vehicles, heaters and cookers). When this mixes with air, nitrogen dioxide (NO2) is formed. Levels are highest in urban areas as it is a traffic-related pollutant.

The principal source of particulate matter (PM10 or PM2.5) in Brent is road traffic emissions, particularly from diesel vehicles. It is also emitted from industrial combustion plants and public power generation, commercial and residential combustion, and some non-combustion processes (e.g. waste transfer sites).

What is being done about it?

The Environment Act 2005 requires us to declare an air quality management area (AQMA) for any part of the borough in which it appears that air quality standards or objectives are not being met.

We first declared some AQMAs in 2001 for the pollutants nitrogen dioxide and particulates. Areas included in the AQMAs were last extended in 2006. As the most recent borough-wide monitoring shows, NO2 continued to exceed the standard. This means that the AQMA designation is still required.

To find out more about Brent's work with schools to raise awareness of air pollution please read our reports.