Air Quality in West Dorset

Air quality objectives have been set by the Government for the protection of health and councils must check air quality against these objectives once every three years. Where objectives are unlikely to be met, councils must designate Air Quality Management Areas (AQMA's) and draw up action plans to reach the objective which have been set for the following air pollutants: Benzene, 1,3 butadiene, fine particles (PM10), carbon monoxide, sulphur dioxide, nitrogen dioxide and lead. This page provides residents and visitors with information concerning air quality in the district including the latest monitoring results, air quality reports and details of the air quality management areas.

Current levels of air quality in West Dorset

The latest Draft Progress Report and Detailed Assessment 2011 (pdf, 6Mb) (opens in a new window) shows that air quality across the district is generally good, however there are three areas, in Dorchester, Bridport and Chideock where the annual mean objective for nitrogen dioxide (NO₂) is exceeded. This is due to road traffic emmisions.

The report identifies that two air quality management areas (AQMA's) have already been declared in Chideock along the A35 and Dorchester along High East Street and action plans have been produced to improve the air quality here. In Chideock monitoring has shown that the only areas with exceedences are on the south side of the A35 going out of the village towards Lyme Regis as such this draft report recommends that the boundary of the AQMA is amended to include only the exceedance area. East Road, Bridport has also shown exceeded levels of NO₂, however at present there is no intention to declare an AQMA, although this will be reviewed following consultation.

Monitoring air quality

The council Summary of West Dorset District Council's Monitoring Results from our Nitrogen Dioxide Diffusion Tube Survey (pdf, 126kb) (opens in a new window) . We operate one high resolution continuous analyser (since 2009) and a low resolution diffusion tube survey (since 1996), encompassing approximately 25 monitoring locations.

Monitoring sites are generally indicative of where the public might be exposed over the averaging period of the objective. In the case of the annual objective for nitrogen dioxide, at the facades of houses facing the road. In the past we have monitored nitrogen dioxide in some towns and villages across the district.

However, following a review of our monitoring locations in December 2009 we now only monitor nitrogen dioxide in Dorchester, Chideock and Bridport. Note that the annual mean objective concentration for nitrogen dioxide is 40µg/m³.

Radon in West Dorset
A few parts of West Dorset are in a 'radon affected area', where a small sample shows that more than 1 per cent of homes are estimated to have levels of radon at or above the action level.
Air quality in Chideock
This page tells you about air quality in Chideock.
Air quality in Dorchester
An Air Quality Management Area (AQMA) was declared in 2009 along High East Street, Dorchester, as nitrogen dioxide levels were above the annual mean objective set by Government. This page provides information on the AQMA in Dorchester, the actions that we are taking to improve the air quality here and the latest monitoring results.