Air Pollution Levels in Delhi Drop by 49% Amid Lockdown, Skies Turn Azure Blue
AQI captures various air pollutants, such as particulate matter (PM), nitrogen oxide, sulphur dioxide, ozone, carbon monoxide and so on. The ones that are of most concern is particulate matter with a diameter of 2.5 and 10 microns. These are too small to be filtered out of the body.