Air Pollution - what it means for your health
How does the air pollution banding system work?
The system is a way of telling people of the daily changes in air pollution. It is especially helpful to those affected by air pollution, as it can help them adjust their medication or activities for the day.
The system uses a numerical index grouped into four bands to describe levels of air pollution. The bands, or levels, are 1 - 3 (low), 4 - 6 (moderate), 7 - 9 (high) and 10 (very high).
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Information on each of the five main pollutants with short-term health effects is gathered every hour from over 110 automatic monitoring sites. The five main pollutants are:
The air pollution level reported in the forecasts and summaries is the highest for any single pollutant. For example, if all but one of the pollutants in a region were 1-3 (low), with just a single pollutant registering 7 (high), the summary would describe air pollution as 7 (high). In the UK, very high levels of air pollution are rare. That is why the 'very high' band is only a single number - 10. |
The service also issues special messages when air pollution levels are high. These report where and when exceedences occur and explain their likely cause. They also give a forecast of levels and specific health advice to sensitive people in the area affected.
Page (HTML version) published 17 November 2002;
Page last modified
3 November, 2006