An Introduction to Air Quality

Welcome to Stratford-on-Avon District Council's air quality webpages. These pages will provide information on air quality for Stratford District, information on pollutant types and health effects, reports on air quality and much more.

In Stratford District the air quality is expected to meet national air quality objectives. However, the major polluting source in the district is road traffic. As such traffic and the consequent congestion is still significant and largely outside the council's control, air quality remains a subject of some local concern.

Nationally, most air pollution is also caused by emissions from motor traffic and urban air quality is once more causing public concern. To increase public awareness, the Government issues daily air quality bulletins via the national media. These bulletins include health advice for those who may be especially affected by high concentrations of air pollutants.

The air pollutants that may cause health effects are ozone, particulate matter (PM10), carbon monoxide (CO), sulphur dioxide (SO2), nitrogen dioxide (NO2) and volatile organic compounds (VOCs). The first five are used by the Environment Agency to classify air quality with reference to the risks to human health. The classifications are:

Low: Effects are unlikely to be noticed even by individuals sensitive to air pollutants.

Moderate: Mild effects, unlikely to require action. May be noticed among sensitive individuals.

High: Sensitive individuals may notice significant effects and action to avoid or reduce these effects may be needed (e.g. reducing exposure by spending less time in polluted areas). Asthmatics will find their 'reliever' inhaler is likely to reverse the effects on the lung.

Very high: The effects on sensitive individuals described for 'High' levels of pollution may worsen.

Although less serious than the smogs of the 1950's, pollution concentrations regularly exceed international health guidelines in some UK towns and cities and reach the classification of Very High.

On 13th December 1991, London experienced the most severe nitrogen dioxide pollution incident since regular monitoring began in 1971. At this time, Friends of the Earth carried out a survey of air pollution standards around the country. They found that even in some less densely populated urban areas, such as Stratford, there were levels of nitrogen dioxide in the air that were potentially harmful to the general public.

An increasing phenomenon being experienced in larger towns and cities in the United Kingdom relates to photochemical smogs due to low level ozone, principally from motor vehicles. The website of the Department for Environment, Food and Rural Affairs contains information regarding smog.

Although there is no scientific evidence that pollution from motor vehicles causes asthma, it is evident that the incidence of asthma in the population is increasing and any asthmatic is more likely to suffer an attack if exposed to high pollution levels arising from motor vehicles.

Stratford on Avon District Council will continue to monitor air quality in its district and to report to government, as is its duty, and to the public, so that they are fully informed.

For further information please contact the Environmental Protection team on 01789 260817, or by emailing envhealth@stratford-dc.gov.uk, or by fax on 01789 260860.