МакедонскиAir quality index
Air quality index is used to describe the air quality in simple terms and an easy-to-understand color scale. It is based on hourly means of pollutant concentrations and gives an overall characterisation of the actual air quality.
The index takes into account the concentrations of sulphur dioxide (SO2), nitrogen dioxide (NO2), respirable particles (PM10), fine particles (PM2,5), ozone (O3) and carbon monoxide (CO). The measured concentrations are compared with the current air quality guidelines.
This air quality index has been developed in Common Information to European Air (CITEAIR) projects funded by the European Union (http://www.airqualitynow.eu/index.php)
Color codes corresponding to the concentration levels
| SO2 | NO2 | PM10 | PM2.5 | O3 | CO | |
| Very high | 500- | 400- | 180- | 110- | 240- | 20- |
| High | 350-500 | 200-400 | 90-180 | 55-110 | 180-240 | 10-20 |
| Medium | 100-350 | 100-200 | 50-90 | 30-55 | 120-180 | 7.5-10 |
| Low | 50-100 | 50-100 | 25-50 | 15-30 | 60-120 | 5-7.5 |
| Very low | 0-50 | 0-50 | 0-25 | 0-15 | 0-60 | 0-5 |
Concentrations are in µg/m3 except for CO in mg/m3
