New Delhi: Delhi has been ranked the fourth most polluted city in the world in 2025 and continues to hold the position of the most polluted capital globally, according to the latest IQAir World Air Quality Report.
The report revealed that Delhi recorded an annual average PM2.5 concentration of 99.6 micrograms per cubic meter, which is nearly 20 times higher than the safe limit recommended by the World Health Organization (WHO).
The findings highlight the persistent air pollution crisis in the national capital despite several policy interventions aimed at improving air quality.
India Dominates Global Pollution Rankings
India featured prominently in the global pollution rankings released by IQAir. The report noted that:
- Three of the five most polluted cities in the world are located in India
- 29 Indian cities are among the top 50 most polluted cities globally
This reflects the scale of the country’s air quality challenge, particularly in densely populated urban regions.
Most Polluted Cities in the World
According to the report, Loni in Uttar Pradesh emerged as the most polluted city worldwide, recording an average PM2.5 concentration of 112.5 micrograms per cubic meter.
The other cities at the top of the pollution rankings include:
- Loni (Uttar Pradesh, India) – 112.5 µg/m³
- Hotan (China)
- Byrnihat (Meghalaya, India)
- Delhi (India)
The report also noted that the 25 most polluted cities globally are concentrated in South Asia, primarily across India, Pakistan, and China.
Delhi Tops List of Most Polluted Capitals
Among capital cities, New Delhi once again ranked as the most polluted capital in the world, recording an average PM2.5 level of 82.2 micrograms per cubic meter.
Other highly polluted capitals include:
- Dhaka (Bangladesh)
- Dushanbe (Tajikistan)
Although both Delhi and New Delhi showed slight improvements compared to 2024, pollution levels remain dangerously high and far above international safety standards.
India Ranked Sixth Most Polluted Country
At the national level, India ranked as the sixth most polluted country globally in 2025, with an average PM2.5 level of 48.9 micrograms per cubic meter.
This represents a 3 percent improvement from the previous year, but the levels still exceed both global guidelines and India’s own air quality standards.
Experts warn that despite minor improvements, pollution remains a major public health concern affecting millions of people across the country.
Over 115 Indian Cities Exceed Air Quality Standards
Air quality experts have raised concerns about the widespread nature of the problem. According to analysts from the Centre for Research on Energy and Clean Air, more than 115 Indian cities exceed even India’s relatively lenient air pollution standards.
They stressed the importance of addressing gaseous pollutants and emissions from vehicles, industries, and construction activities, which continue to contribute significantly to urban pollution.
NCR Cities Also Among Most Polluted
Several cities in the National Capital Region (NCR) also ranked among the most polluted globally. These include:
- Ghaziabad
- Noida
- Greater Noida
- Gurugram
The findings indicate that air pollution is not limited to Delhi alone but represents a regional environmental crisis affecting the entire NCR belt.
Global Air Pollution Crisis
The IQAir World Air Quality Report analysed PM2.5 data from more than 9,400 cities across 143 countries, providing one of the most comprehensive assessments of air quality worldwide.
The report underscores the growing global challenge of air pollution, which continues to pose serious risks to human health, climate, and urban sustainability.
