Air Pollution Guide » Why monitor air pollution?

Pollution Guide Key Points:
  • Air pollution monitoring can help us understand how pollutants behave and their relationship with the weather.
  • Monitoring data can be used to validate pollution modelling, used to test 'what if' scenarios.
  • National and European law requires the monitoring of pollution levels. Results can be used to make informed policy decisions.
  • Members of the public benefit from easily available, accurate and up to date information on the quality of the air they breathe.
Once emitted, the behaviour of air pollution is dictated by the weather. As the weather in this country is extremely variable, the behaviour of pollution is extremely variable. The situation is complicated further by atmospheric chemistry; pollutants react with other gases in the atmosphere and deposit onto surfaces such as roads and buildings.
At present, our scientific understanding of air pollution is not sufficient to be able to accurately predict air quality at all times throughout the country. This is where monitoring can be used to fill the gap in understanding.
Monitoring provides raw measurements of air pollutant concentrations, which can then be analysed and interpreted. This information can then be applied in many ways.
Analysis of monitoring data allows us to assess how bad air pollution is from day to day, which areas are worse than others and whether levels are rising or falling. We can see how pollutants interact with each other and how they relate to traffic levels or industrial activity. By analysing the relationship between meteorology and air quality, we can predict which weather conditions will give rise to pollution episodes.
Another important use is in the validation of computer models. Models are used to test 'what if' scenarios. For example, 'how much will air quality improve if traffic numbers reduce by 20%?' or 'what effect will building a power station near a certain town have?'. The accuracy of these models can only be tested by comparison with actual monitoring data.
All of this information can then be used by the Government to make informed policy decisions. Environmental policy is constantly being updated in the light of scientific research.
Increased awareness in air quality issues has lead to the demand for more thorough and accessible information. Members of the public worried about pollution or with health problems worsened by pollution can benefit from such information. Up-to-date information taken from monitoring sites across the country can be broadcast to the public via television, teletext, dedicated help lines, or the Internet.
Many laws now require government and local authorities to ensure that air pollution does not exceed certain legal limits. EC law sets standards (known as Directives) for some pollutants and requires national governments to monitor air quality to show that the standards are not exceeded. The Government's National Air Quality Strategy makes it the responsibility of local authorities to use monitoring information to assess air quality in order to show that Air Quality Standards will not be exceeded in their area by certain deadlines.
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