Reading the air quality index
Change the amount of fine dust (PM2.5) in the air and watch the air quality index move from good to severe. Learn what each band means for your health and where the dust comes from.
Core concept
The air quality index (AQI) turns the amount of fine particles (PM2.5) into a number from 0 to 500; India's scale has six bands, good, satisfactory, moderate, poor, very poor and severe, each with its own health advice
Topic: Pollution of air and water
Air carries tiny particles of dust, smoke and soot. The most harmful are PM2.5: particles smaller than 2.5 micrometres, so small that they pass deep into the lungs and even into the blood. Their amount is measured in micrograms in each cubic metre of air (µg/m³), averaged over a day. To make this easy to read, the amount is turned into an air quality index from 0 to 500. India's AQI has six bands: good (0–50), satisfactory (51–100), moderate (101–200), poor (201–300), very poor (301–400) and severe (401–500). In cities across South Asia, much of the PM2.5 comes from vehicles, brick kilns, factories, burning rubbish and burning crop stubble after the harvest.
What you will learn
- Explain what PM2.5 is and why it harms health.
- Read the AQI band for a PM2.5 reading.
- Name the main sources of PM2.5 and ways to reduce it.
Before you start
- Know that air can be polluted by smoke and dust.
Materials
- The AQI of your town from a newspaper or a public website
Equipment
- None
Procedure
- Record the AQI for 45 µg/m³ of PM2.5.
- Record clean air of 10 µg/m³.
- Record 110 µg/m³ and 350 µg/m³.
How this simulation is simplified
- PM2.5 is a 24-hour average; the bands follow India's national AQI (CPCB) for PM2.5.