| Executive Summary | AEAT-3133 |
This is the third in a series of reports describing the high resolution air quality mapping work carried out at AEA Technology's National Environmental Technology Centre on behalf of the Department of the Environment, Transport and the Regions. Maps of estimated annual mean background concentrations of nitrogen dioxide, oxides of nitrogen, sulphur dioxide, benzene, 1,3-butadiene, carbon monoxide, particles (PM10) and lead for 1996 are presented. These maps are a valuable resource for use within the assessment of local air quality as part of the United Kingdom National Air Quality Strategy. Results from dispersion or other models can be used to estimate the impact of individual sources on local air quality. Ambient air quality near to sources, such as at the edge of a busy road or near to an industrial chimney, can be estimated by calculating the sum of this local impact and the background concentration.
The general approach to mapping pollutant concentrations from a combination of monitoring site measurements and emissions inventory information is described. There have been several significant changes to the mapping methods since the previous compilation of maps was published. These include:
- High resolution emissions inventory maps for the UK have recently become available from the National Atmospheric Emissions Inventory. These maps of the spatial distribution of emissions on a 1 km x 1 km grid have been used to calculate the contribution of sources within a 25 km
2 area to local background air quality. Earlier work made use of surrogate emission statistics such as land-cover information.
There has been a considerable increase in the availability of automatic monitoring data over the last few years. Data from many more sites are available for 1996 than were available for earlier mapping work.
Maps of the concentrations of benzene and 1,3-butadiene have been calculated using estimates of emissions of volatile organic compounds. Carbon monoxide and PM10 maps have been calculated using carbon monoxide and PM10 emissions estimates respectively. The maps of these pollutants that were presented in earlier reports were derived indirectly from maps of the concentration of oxides of nitrogen.
Many of the maps presented in this report are available on-line from the following web sites
/netcen/airqual/
http://www.environment.detr.gov.uk/airq/aqinfo.htm
