Information about the pollutants we monitor in the borough
Pollutants and monitoring methods
Air pollutants are emitted from a variety of both natural and man-made sources. Many everyday activities can have a negative effect on air quality, with an impact on human health, such as from:
- traffic
- burning fossil fuels
- farming
- industry
The pollutants we monitor in ambient air are:
- Nitrogen Dioxide (NO2)
- Particulate Matter (PM10 and PM2.5)
We review the concentration/levels of these pollutants within the borough against National Air Quality Objectives.
For the fine particulate matter fraction (PM2.5) this pollutant is also assessed through national targets and delivered through the National Air Quality Strategy.
Nitrogen Dioxide
Southgates monitoring station
Sources of NO2 include:
- traffic
- combustion of fossil fuels
- industrial processes
Air Quality Monitoring Stations
We monitor the NO2 at the following automatic monitoring stations located at
- South Gates Park, King's Lynn
- Gaywood Clock
These sites measure NO2, mainly from road traffic and background sources and other background sources.
Image of a diffusion tube
Diffusion tubes
These are small plastic tubes that contain a chemical that reacts with NO2. They provide us with an average concentration of NO2 in the air rather than an instantaneous reading like the above stations.
There are currently 72 sites with NO2 diffusion tubes located across the borough. The tubes are usually placed on the front of buildings near a busy road, or at road junctions.
Image of an OSIRIS unit
We change these tubes monthly and get them analysed.
The monthly average NO2 level is used to calculate a yearly average. We then compare this to the annual mean objective level as set in the National Air Quality Objectives.
Particulate Matter
Particulate Matter within the size fractions of less than 10 and 2.5 microns (PM10 and PM2.5) is measured real-time by an Earthsense Zephyr and also by 4 Turnkey Osiris analysers. The Zephyr also monitors NO2 in addition to the particulate matter emissions.
These are indicative sensor type devices and are located at the following locations;
- The Earthsense Zephyr is located along Railway Rd which helps to monitor primarily the traffic pollutants within the Railway Rd AQMA;
- We also have two of the Osiris analysers either side of the docks in North Lynn (Estuary Rd and at Page Stair Lane); and,
- Two Osiris units located around an animal feed mill in Stoke Ferry (Wretton Rd and Buckenham Drive);
Image of the Zephyr unit
Monitoring Results
The real-time air quality monitoring results can be viewed from our data management website which also includes some results from neighbouring local authorities.
Alternatively, you can download the Defra UKAir app to receive notifications, and which is available for both apple and android systems.
The results including the diffusion tubes are also compiled into yearly air quality reports called Annual Status Reports (ASR). They include a summary of the results from each year and trends in the pollutants that we monitor.
The reports are submitted to the Defra’s Local Air Quality Management department who appraise this work. You can view these ASR reports on our air quality information page.