Good (Air quality is satisfactory, poses little or no health risk)
Moderate (Air quality is acceptable, healthy one)
Unhealthy for Sensitive Groups (People with heart and breathing problems should avoid outdoor activities)
Unhealthy (Slight irritations may occur, unhealthy for sensitive group)
Very Unhealthy (Heavily polluted, healthy people will be noticebly affected)
Hazardous (Strictly prohibited for elders, strong irritations and symptoms may trigger other illnesses)
The Air Quality Index, popularly known as AQI, is based on measurement of Particulate Matter (PM2.5 and PM10), Ozone (O3), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2) and Carbon Monoxide (CO) emissions. As it raises, an increasingly large percentage of the population is likely to experience increasingly severe adverse health effects.