Data and Statistics
Welcome to the Gibraltar Air Quality Data and Statistics Database. These pages contain options for you to retrieve data relating to Air Quality in Gibraltar.
The database contains tables of measured concentration data and statistics from the air quality monitoring sites operated by the Environmental Agency. Estimates of emissions - the amount of pollution produced by a range of activities are calculated under Gibraltar’s emissions inventories. The emission estimates are relatively high in uncertainty.
Statistics shown in this database are produced to high professional standards set out in the UK National Statistics Code of Practice. They undergo regular quality assurance reviews to ensure that they meet customer needs and are independently compiled.
Automatic Networks produce hourly pollutant concentrations, with data being collected electronically from individual sites. Gibraltar air quality monitoring started in February 2005 although there are some non-automatic data going back to 2000. By clicking on the map on the Home Page of this web site you can get detailed information for each automatic 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. More detailed information about non-automatic monitoring in Gibraltar is also available.
A range of simple statistics are routinely calculated by the database for the automatic monitoring data each night. These include:
- Daily mean, maximum and minimum values for all pollutants.
- 8-hour running mean values for ozone and carbon monoxide.
- Daily maximum 8-hour running means for ozone.
There are three options for the output of your database download, 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.
Exceedance statistics provide information about concentrations above a specific threshold value. The exact concentration and the metric used varies by pollutant and purpose. A selection of commonly used examples are:
- UK Air Quality Objectives
- Critical Loads
- The health-effects based system of four bands and a 1-10 index
- Indicators of Sustainable development - the average number of days per site on which pollution levels were above National Air Quality Standards