Our system also receives monitoring data from other pollutants from our partners. To combine data, we use AQI, or Air Quality Index, is a system for translating sometimes confusing or unintuitive pollutant concentration measurements, into one easy-to-understand scale to clearly represent the health risk posed by ambient air pollution. The index formula usually considers up to 6 main pollutants (PM2.5, PM10, carbon monoxide, sulfur dioxide, nitrogen dioxide and ground level ozone), and calculates the respective health risk (or AQI number) for each one at any given time. The overall AQI number at a given moment is dictated by the "riskiest" pollutant, with the highest AQI number.
The index ranges from 0 to 500, where high index values indicate higher levels of air pollution and higher potential for adverse health effects. Any value larger than 300, for example, is considered to be hazardous, while an AQI value of 0-50, on the other hand, represents good air quality.