Delhi Emerges as the Most Polluted Region in India
Delhi has once again been named India’s most polluted region, according to a new satellite-driven air quality study by the Centre for Research on Energy and Clean Air (CREA). The National Capital Region recorded an annual mean PM2.5 concentration of 101 µg/m³ (March 2024 – February 2025).
This is:
- 2.5 times higher than India’s national air quality limit of 40 µg/m³
- 20 times higher than the WHO’s safe guideline of 5 µg/m³
The data confirms Delhi’s position as one of the world’s worst-affected capitals in terms of air pollution.
What Is PM2.5 and Why It Is Dangerous
PM2.5 refers to particulate matter 2.5 micrometres or smaller — fine enough to penetrate:
- Deep into the lungs
- The bloodstream
- Vital organs
These particles come from:
- Vehicle emissions
- Industrial smoke
- Coal burning
- Open burning of waste
- Dust storms
- Winter smog caused by temperature inversion
High PM2.5 exposure is linked to heart disease, lung disease, childhood asthma, reduced lung growth, and premature deaths.
Delhi Tops the List, But the Crisis Is Nationwide
After Delhi, several regions showed extremely high annual PM2.5 averages:
- Chandigarh – 70 µg/m³
- Haryana – 63 µg/m³
- Tripura – 62 µg/m³
- Assam – 60 µg/m³
- Bihar – 59 µg/m³
- West Bengal – 57 µg/m³
- Punjab – 56 µg/m³
All of these exceed the Indian limit of 40 µg/m³.
Overall:
- 447 out of 749 districts (60%) failed India’s national air quality standard.
- Pollution hot spots were concentrated in northern and eastern India.
States With the Most Districts Breaching Limits
The most severely affected states include:
- Delhi – 100% of districts exceed limits
- Assam – 100%
- Punjab – 100%
- Haryana – 100%
- Chandigarh – 100%
- Himachal Pradesh – 100%
- Meghalaya – 100%
- Tripura – 100%
Other states with overwhelming exceedances:
- Bihar – 37 of 38 districts
- West Bengal – 22 of 23
- Gujarat – 32 of 33
- Rajasthan – 30 of 33
- Jharkhand – 21 of 24
India’s Pollution Crisis in Global Perspective
The severity of air pollution in India is consistent across global rankings:
- 39 of the world’s 50 most polluted cities in 2023 were in India
- Delhi, Begusarai, Guwahati, and New Delhi topped global lists
- India remains consistently among the top three most polluted countries
- Delhi regularly ranks as the world’s most polluted capital
These global rankings rely on ground data, while CREA’s report uses satellite observations — but both paint the same picture.
Nationwide Air Quality Emergency
The report highlights that India’s pollution problem is:
- Chronic
- Nationwide
- Not limited to winter smog
- Not limited to a single region
CREA stresses the urgent need for:
- Stronger central and state-level enforcement
- Coordinated action across states
- Faster transition to clean energy
- More extensive monitoring in remote districts
- Year-round pollution control strategies, not just seasonal measures
