We undertake monitoring of air quality across the district using diffusion tubes, real time monitoring equipment and low cost sensors.
Results are reported annually in our Annual Status Report or can be viewed using the links on this page.
Diffusion tubes are low cost passive samplers that can be easily mounted on lamp posts. They provide an indication of average monthly nitrogen dioxide (NO2) concentrations in different parts of the district. The tubes are changed every month and sent to a laboratory for analysis. We currently expose around 400 diffusion tubes around the district each month.
To improve the accuracy of the diffusion tube measurements we expose some alongside our more accurate real time equipment and apply a bias factor to the results. At some sites we expose three diffusion tubes alongside each other to check their precision.
More information on diffusion tubes and how to use them is available here: Defra information on use of diffusion tubes in LAQM.
You can view the results from our diffusion tube network on this interactive monitoring results map.
To view all the diffusion tube sites press the layer button on the top right hand corner of the map and deselect the CAZ area. To view the results for any diffusion tube use the left mouse button to click on the correct blue triangle and then press on the large right hand arrow to scroll to the results.
Real time monitoring of air quality is currently undertaken at 7 sites across the district. Real time monitoring provides 15 minute averages of pollutant concentrations and is more accurate than diffusion tubes.
All the real time site in Bradford monitor nitrogen dioxide (NO2), three also measure PM10 and PM2.5. The real time stations are manually calibrated twice per month and serviced by the equipment manufacturer twice per year. The data is collected and checked by an independent data management specialist before being published in the Annual Status Report.
The monitoring station at Mayo Avenue forms part of the national monitoring network operated by the Environment Agency. The council undertake local site operator duties at this site.
Data from the Mayo Avenue site can be viewed and downloaded here: national monitoring network data portal.
We have recently established a new network of low cost Zephyr sensors in some areas of the district to provide more information about particulate concentrations near homes and schools.
Zephyrs can provide data in real time but are not as accurate as the larger real time monitoring stations. They are useful for comparing pollutant concentrations in different parts of the district and to see how pollution levels change at different times of the day or week. Data from the Zephyr units is indicative data and isn’t intended for direct comparison with air quality standards and objectives.
The Zephyr network was established using a DEFRA air quality grant bid and forms part of our wider Particulate Reduction Strategy work. Real time data from some of these units will be accessible from this webpage soon.
Where we find levels of air pollution above health-based objectives, we declare Air Quality Management Areas (AQMAs) and draw up Air Quality Action Plans (AQAPs) to improve air quality.
We have also introduced a Clean Air Zone (CAZ) to address exceedances of the limit value for nitrogen dioxide.
