How Is Air Pollution Being Measured?

Wrexham County Borough Councils Public Protection Department monitors air pollution in two ways, automatic and non-automatic.

Automatic Monitoring

There are two automatic monitoring stations within the County Borough. One is situated near to Wrexham Town (Victoria Road) and the other is located near the Wrexham Industrial Estate (Isycoed). Details and current Air Quality levels of the two sites can be found by following either of the two links below:

Welsh Air Quality Forum
Wrexham County Borough Council website

Both Stations continuously monitor for Oxides of Nitrogen (NOx), Sulphur Dioxide (SO2) and Particulate Matter (PM10). Though the technique for monitoring PM10 is not real time and hence only historic information can be viewed for either site by following this link www.welshairquality.co.uk/data_and_statistics.php (external link) and completing the required information.

The Victoria Road station is part of the Automatic Urban and Rural Network (AURN) which is a network of Air Quality stations that as well as Wales, also covers England, Scotland and Northern Ireland. The Isycoed station is a member of the Welsh Air Quality network.


The Automatic Urban and Rural Network Station at Victoria Road


Inside of the Automatic Urban and Rural Network Station

Non Automatic Monitoring

There are several methods of non-automatic monitoring (also known as passive) and Wrexham County Borough Council uses three different types of technology:

  • Diffusion Tubes
  • Partisol plus PM10 monitor
  • Dust Frisbee

Diffusion Tubes

Diffusion tubes are a simple and cost effective way to measure pollutants over a period of time (usually one month) and the Housing and Public Protection Department uses these tubes to monitor four types of pollution:

  • Nitrogen Dioxide (type of tube shown on the left in the picture below)
  • Sulphur Dioxide
  • Ozone
  • Benzene (type of tube shown on the right in the picture below)

Over twenty diffusion tubes are exposed all over the County Borough each month. At the end of each month the exposed tubes are sent off to an independent laboratory for analysis and the most recent results as well as older data can be viewed.

Particulate PM10 Monitor

Particulate matter (PM10) is measured at one fixed location and two transient locations in the County Borough using Partisol Plus monitors. These Partisol’s draw air onto a pre-weighed filter over a twenty-four hour period. The exposed filter is then re-weighed and a simple calculation will determine the amount of Particulate Matter in the surrounding area.


Partisol Plus PM10 Monitor

Dust Frisbee

The Housing and Public Protection Department currently utilises two dust frisbee’s to monitor for dust within the County Borough. This technique monitors for larger dust sizes than the Partisol Plus PM10 monitors described above, and focuses more on the nuisance levels than the health implications specified in the Air Quality Standards.

The frisbee’s work by collecting dust falling out of the atmosphere onto the frisbee section, which is then washed down into a collection bottle by rain. The bottle is then sent off to an independent laboratory where the dust is filtered from the rainwater and weighed. A simple calculation then allows for the determination of the amount of dust in the monitoring area on a daily basis.


Dust Frisbee

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