Breathing Easy: Understanding Air Quality Index
The Air Quality Index (AQI) is a 0-500 scale that converts pollutant concentrations — PM2.5, PM10, NO2, SO2, CO, and ozone — into a single number and color-coded category, from Good (green) to Severe (maroon). The Central Pollution Control Board (CPCB) recorded Delhi’s winter AQI exceeding 400 (“Severe”) on multiple…
