Environment
14 October 2008


Air Pollutants

The National Air Quality Strategy 1997 was established to control and protect air quality in the United Kingdom. Air Quality Standards were created for eight main air pollutants that are known to harm human health. The eight pollutants are as follows:

  • Benzene
  • Carbon monoxide
  • Nitrogen Oxides
  • Particulates (PM10)
  • 1,3-Butadiene
  • Lead
  • Ozone
  • Sulphur dioxide

The standards set for each pollutant are concentrations over a given time period that are considered to be acceptable in light of what is known about the effects of each pollutant on health and on the environment. They can also be used as a benchmark to see if air pollution is getting better or worse.

In order to simplify the interpretation of air quality monitoring results for the general public the government has created the air pollution public information service. The service uses four bands to describe levels of air pollution.

  • Low
  • Moderate
  • High
  • Very High

To help define these bands further each parameter has a numerical index and a health descriptor attached that advises of the possible health effects of the current air quality. This information is as follows:

Banding Index Health Descriptor
Low 1 Effects are unlikely to be noticed even by individuals who know they are sensitive to air pollutants.24k1200k
2
3
Moderate 4 Mild effects, unlikely to require action, may be noticed amongst sensitive individuals
5
6
High 7 Sensitive individuals may notice significant effects and action to avoid or reduce these effects may be needed (e.g. reducing exposure by spending less time in polluted areas outdoors). Asthmatics will find that their ‘reliever’ inhaler is likely to reverse the effects on the lung.
8
9
Very High 10 The effects on sensitive individuals described for ‘High’ levels of pollution may worsen.