Solution:
The Air Quality Index (AQI) is a measure of air quality that is used to report the level of air pollution in a particular area. The AQI considers five major air pollutants, namely particulate matter (PM2.5 and PM10), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO).
The AQI ranges from 0 to 500, and higher AQI values indicate higher levels of air pollution. AQI values below 50 are considered good, while AQI values above 300 are considered hazardous to health.
In Delhi, an AQI reading between 201-300 is classified as "unhealthy" and can cause health effects on sensitive groups of people, such as children, the elderly, and people with respiratory and cardiovascular diseases.
