Welcome to the UK Air Quality Data and Statistics Database. These pages contain options for you to enter queries to the database and retrieve statistics relating to Air Quality in the UK from the present back to 1960.

The database contains tables of measured concentration data and statistics from the monitoring networks operated on behalf of the Defra and the Devolved Administrations. Estimates of emissions - the amount of pollution produced by a range of activities can be obtained from the National Atmospheric Emissions Inventory (NAEI).

Further environmental statistics on air quality and other topics are available from Defra's e-Digest of Environmental Statistics at http://www.defra.gov.uk/evidence/statistics/environment/index.htm

The data stored here fall under three categories:

Monitoring data

There are over 1500 sites across the UK which monitor air quality. They are organised into networks that gather a particular kind of information, using a particular method. The pollutants measured and method used by each network depend on the reason for setting up the network, and what the data is to be used for. There are two major types - automatic and non-automatic networks.

Automatic Networks produce hourly pollutant concentrations, with data being collected from individual sites by modem. The data go back as far as 1972 at some sites. Site Information Archive gives detailed information for each site presently in operation.

Non-automatic Networks measure less frequently - either daily, weekly or monthly - and samples are collected by some physical means (such as diffusion tube or filter). These samples are then subjected to chemical analysis, and final pollutant concentrations calculated from these results.

Details of the NO₂ diffusion monitoring sites are available here.

Descriptive Statistics

For each monitoring site you can select a range of statistics which are relevant to the particular monitoring method. Basic statistics are annual mean, maximum and minimum values, with daily means, monthly means and a range of percentile values available where these are meaningful.

Exceedence Statistics

The Air Quality Strategy for England, Scotland, Wales and Northern Ireland sets out health-based standards for eight main air pollutants and objectives for their achievement throughout the UK by 2005. It identifies the action that needs to be taken at international, national and local level, and provides a framework which allows relevant parties, such as industry, business and local government to identify the contributions they can make to ensuring that its objectives are met.

The strategy also includes standards which have been adopted for the protection of vegetation and ecosystems. Click here for a list of the National Air Quality Strategy Objectives

The objectives in The Air Quality Strategy are either equivalent to or more stringent than limit values which have been set in European Directives on Air Quality.

Click here for a table of the limit values in European Directives

On a day-to-day basis UK air quality data are reported to the public by using a health-effects based system of four bands and a 1-10 index. This provides detail about air pollution level in a simple way, similar to the sun index or pollen index.Click here for information on the Air Pollution Index and Banding System

Part of the Government's plans to ensure a better quality of life are Indicators of Sustainable Devolopment. The Air Quality indicator measures the average number of days per site on which pollution levels were above National Air Quality Standards. The Standards represent defined levels which avoid significant risks to health. As levels increase above the Standard, the likelihood of effects on health increases. For example, levels of ozone in the 'high' band may cause cough and discomfort on deep breathing during exercise in some people.Click here for information on Air Quality Indicator Statistics

National Vegetation and Ecosystems Objectives are adopted for the protection of vegetation and ecosystems.

You can select any of these exceedence statistics for a range of time periods, pollutants and locations.

Data Output

There are three options for the output of the query, according to the size of the data request. Small enquiries can be shown on your screen using minimum HTML, moderately sized enquiries can be e-mailed to you as an attachment in comma separated format, or the largest enquiries will be left on an ftp site, also in comma separated format, for you to collect. The data on the ftp site will be wiped within seven days if it is not retrieved.

The comma-separated format should make it easy to load the file into a spreadsheet once saved to your local machine. If the program does not recognise the format automatically, you will need to set the file type to "Text" and the separator as "Comma" for Lotus, or rename the file to [NAME].csv for Excel.