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, and therefore human health, such as:
- farming
- energy generation
- transport
- industry
The pollutants we monitor are:
- Nitrogen Dioxide (NO2)
- Particulate Matter (PM10)
We review the concentration/levels of these pollutants within the borough against National Air Quality Objectives.
Nitrogen Dioxide
Air Quality Monitoring Stations
We have automatic pollution monitoring stations at the following locations:
- South Gates Park, King's Lynn
- Gaywood Clock

Southgates monitoring station
These sites measure NO2, mainly from road traffic and background sources.
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.
Sources of NO2 include:
- combustion of fossil fuels
- use of motor vehicles
- industrial processes
There are currently 75 diffusion tubes located across the borough. The tubes are usually placed on the front of buildings near a busy road, or at road junctions.
We change these monthly and get them analysed.
The monthly average NO2 level is used to calculate a yearly average. We then compare this to the yearly average objective level in the National Air Quality Objectives.

Image of a diffusion tube
The results are used, with other data, to compile yearly air quality reports called Annual Status Reports. These are submitted to the Department for Environment, Food and Rural Affairs (DEFRA). You can view the reports on our air quality information page.
- Diffusion tube results 2023
- Diffusion tube results 2022
- Diffusion tube results 2021
- Diffusion tube results 2020
Particulate Matter

Image of an OSIRIS unit
Particulate Matter (PM10) is currently measured automatically using a TEOM located in Self’s Field, Stoke Ferry. The results from this monitoring will be used to produce a detailed report in autumn 2019.
Additionally, particulate matter is measured at the following locations within the borough using OSIRIS units:
- Estuary Road, King's Lynn
- Page Stair Lane, King's Lynn
- Wretton Road, Stoke Ferry
- Buckenham Drive, Stoke Ferry
The PM10 measured is mainly from local industrial activities.
COVID-19 and air quality trends

We've created a document that compares the likely impacts of traffic movements before and during the COVID-19 lockdown. Find out more on our air quality trends document.
A10 Main Road Air Pollution
Following recent enquires about air quality levels along the A10 main road running through West Winch and North Runcton, we have provided an update here.
Viewing our data
The monitoring data collected from all stations is available to view from our data management website.
Or you can download the UKAir app available for both apple and android.