National Air Quality Index
Also called: AQI · Topic: Geographical Issues: Pollution, Urban Waste, Slums and Land Degradation · NCERT: Beyond NCERT
Meaning
The National Air Quality Index (AQI) is a single number that tells people how clean or dirty the air is. It was launched in April 2015. It combines the levels of eight pollutants into one figure: PM10, PM2.5, NO₂, SO₂, CO, ozone, ammonia and lead. PM10 and PM2.5 are tiny dust and smoke particles. The number falls into six bands: Good (0–50), Satisfactory, Moderately polluted, Poor, Very Poor and Severe (401–500). Because it is easy to read, people can decide when to stay indoors, and the government can trigger emergency steps.
Example
In Delhi in winter, the AQI often reaches Very Poor or Severe. Each band links to a stage of GRAP (Graded Response Action Plan), from dust control up to bans on construction.
Don't confuse with
- National Ambient Air Quality Standards: these are the legal limits for each pollutant. AQI is a public scale that turns the measured levels into one easy number.
Related concepts
- National Ambient Air Quality Standards
- Non-attainment city
- National Clean Air Programme
- Graded Response Action Plan
- Commission for Air Quality Management