Air Pollution Monitoring and Trends
Bristol City Council has an extensive monitoring network that compares well with other cities.
Over 100 sites around the city measure nitrogen dioxide, including continuous analysers which publish data in real time to our open data platform.
The map below shows the location of the current monitoring sites and annual mean concentrations of nitrogen dioxide at the diffusion tube sites (circles).
Amber circles indicate where a diffusion tube reads over 40 μgm-3 (microgrammes per metre cubed), which is the EU and UK limit. Red circles show where concentrations exceed 60 μgm-3. This means that concentrations of the hourly mean could exceed the hourly limit of 200 μgm-3. The data are from 2017. Click on the circles to see the concentration in 2017 and the trends since 2010.
You can also see the ClairCity project version of the map which includes data from neighbouring councils.
For more information on monitoring and to access the data, visit our open data portal for air quality.
In response to citizens’ concerns Bristol City Council has expanded this monitoring network to include all the schools within the Air Quality Management Area and other schools in the city which are close to a busy road.
Trends in nitrogen dioxide have remained stable over the last 20 years, but show slight improvement over the last five years. At some locations annual mean concentrations exceed 60 ugm-3 and widespread breaches of the annual mean objective for nitrogen dioxide exist (red and amber dots in the map above).
Monitoring PM (Particulate Matter – particles too small to see)
Bristol does not breach legal limits on particulate matter. However public health experts are increasingly concerned that there may be “no safe limit” to particulate matter and so Bristol City Council is in the process of working up a monitoring campaign to establish sources and scale of the problem.
Community monitoring, sometimes called “citizen sensing”, is becoming increasingly popular. It can raise awareness about air quality and help to engage people about the issue. We believe citizen sensing can bring people together to work out how we solve the generation of pollution and the actions needed to prevent air pollution. Currently these monitors cannot be used for compliance testing as they are not accurate enough. Bristol City Council encourages and supports well-run citizen sensing as an engagement tool.