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Delhi’s air quality fell sharply after Diwali firecrackers. Several stations recorded “severe” pollution. The official AQI was 370, while some private apps showed readings near 1,000.
Context of the News
What Is the AQI?
- It turns many different pollutant readings into one single number
- That number comes with a category and a colour
- The aim is to tell the public, in simple terms, how bad the air is and what it means for health
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Who Made It?
| Item | Detail |
|---|---|
| Launched | 17 September 2014, in New Delhi |
| Under | Swachh Bharat Abhiyan |
| Ministry | MoEFCC |
| Prepared by | Central Pollution Control Board, with IIT Kanpur and an expert committee |
What Are the Six Categories?
| AQI | Category | Colour | Health effect |
|---|---|---|---|
| 0-50 | Good | Green | Almost no effect |
| 51-100 | Satisfactory | Light green | Minor breathing trouble for sensitive people |
| 101-200 | Moderate | Yellow | Breathing trouble for people with lung, asthma or heart problems |
| 201-300 | Poor | Orange | Breathing trouble for most people on long exposure |
| 301-400 | Very Poor | Red | Respiratory illness on long exposure |
| 401-500 | Severe | Dark red | Affects even healthy people. Serious for the ill |
Which Pollutants Are Measured?
Eight in total:
- PM₁₀ and PM₂.₅ — fine dust particles
- NO₂ — nitrogen dioxide
- SO₂ — sulphur dioxide
- CO — carbon monoxide
- O₃ — ozone
- NH₃ — ammonia
- Pb — lead
