Monitoring air quality in Coventry
Coventry, like many towns and cities in the UK, can have poor air quality, particularly close to areas with high levels of traffic.
The Environment Act 1995 introduced local air quality management (LAQM) which says all local authorities must assess air quality within their district. If the air quality in any area is not good enough, the local authority must declare an air quality management area (AQMA) and prepare an Action Plan to improve the air quality.
An Air Quality Management Area (AQMA) for the whole of Coventry was declared in 2009 because of high levels of nitrogen dioxide (NO2).
As the whole city was named, we are able to make a detailed plan for air quality across Coventry, giving more power to tackle problem areas and help improve the air quality.
The National Air Quality Strategy (NAQS) 2007 aims to protect human health by setting objectives and targets for key pollutants. These include fine particulates (PM10 and PM2.5), nitrogen dioxide, and sulphur dioxide.
We carry out checks around the city to find areas of poor air quality. The main pollutants of concern in Coventry are nitrogen dioxide (NO2) and particulate matter of less than 2.5 microns (less than 0.0025th of a millimetre) in diameter.
Environmental Protection monitor pollution levels with a variety of methods.
Nitrogen dioxide is measured by small plastic tubes with a metal grid at one end which is coated with a chemical to absorb the nitrogen dioxide. The tubes are replaced every 4-5 weeks and sent for analysis at a laboratory. Because of their low cost, these tubes can be used in a wide area and we have about 60 around the city on busy roads and junctions. However, the tubes only help find annual averages as tube results have an uncertainty of +/- 25% they undergo a series of calculations in line with Defra Technical Guidance TG16 to produce the annual average result.
The team reviews information from the tubes on a regular basis to help keep a check on air quality.
Map of the location of the diffusion tubes around Coventry. The sites where Nitrogen Dioxide levels are less than 40µg/m3 are marked in green, and those that are over are marked in red.
AQ Mesh monitors
We are currently trialling two AQ Mesh monitors at one location in the city. These are small, battery-operated units that measure nitrogen dioxide. We are investigating procuring more of these monitors in order to monitor at more locations in the future.
Reviewing and assessing air quality
The Environmental Protection Team use information from the monitoring sites across Coventry to check air quality levels in the city against national standards and come up with plans if any problems are found.
The pollutants we assess are named in the air quality strategy for England, Scotland, Wales and Northern Ireland. All local authorities in the UK have to follow a 10-year air quality timetable which started in May 2003.
Defra has recently changed the way that we report on air quality so that instead of five different reports, a single Annual Status Report (ASR) is now required. An ASR must include a public-facing executive summary, a clear statement of improvement measures being taken, an update on progress, information on how the main pollutants are being measured, modelled and assessed, how the plan links with transport and public health activities and to identify any new hot spots of pollution. The ASR must be published by 30 June for the first year and thereafter by 30 April each year.
Air quality and transportAddress: PO Box 15