13 out of 20 world’s most polluted cities are from India; Byrnihat, Delhi top list

New Delhi: Delhi is among the 20 most polluted cities in the world. According to the 2024 World Air Quality Report, Byrnihat topped the global pollution list, with Delhi coming second.

The 13 Indian cities on the list are Byrnihat, Delhi, Mullanpur (Punjab), Faridabad, Loni, New Delhi, Gurugram, Ganganagar, Greater Noida, Bhiwadi, Muzaffarnagar, Hanumangarh and Noida.

The other four countries featured on the list are Chad, Bangladesh, Pakistan and the Democratic Republic of Congo.

The report, released by Swiss air quality technology company IQAir, evaluates PM2.5 air quality data from 8,954 cities across 138 countries. It’s based on measurements from over 40,000 air quality monitoring stations and low-cost sensors operated by government bodies, research institutions, non-profit organisations and scientists.

Where is India on the list?

India is the fifth most polluted country in the world, with an average Air Quality Index (AQI) of 50.6 μg/m3—10 times higher than the World Health Organization’s (WHO) annual PM2.5 guideline value of 5 μg/m3. In 2023, it was the third most polluted country.

Byrnihat, on the Assam-Meghalaya border, is the most polluted metropolitan area in 2024, with an annual average PM2.5 concentration of 128.2 μg/m3. A major reason for the pollution is emissions from local factories, including distilleries and iron and steel plants.

According to the report, India saw a 7 per cent decline in PM2.5 concentrations in 2024, averaging 50.6 micrograms per cubic meter, compared to 54.4 micrograms per cubic meter in 2023.

Delhi remains worse

Air pollution in Delhi worsened, with the annual average PM2.5 concentration rising from 102.4 micrograms per cubic meter in 2023 to 108.3 micrograms per cubic meter in 2024.

In October, air quality deteriorated in Manipur, while November saw extreme pollution levels in Delhi, Punjab, Chandigarh, Haryana and Himachal Pradesh, with crop stubble burning remaining a major contributor to PM2.5 levels, accounting for 60 per cent of pollution during peak periods.

How is air quality in other countries?

Only 12 countries, regions and territories recorded PM2.5 concentrations below the WHO annual PM2.5 guideline of 5.0 µg/m³, most of which were in the Latin America and Caribbean or Oceania region. However, in 2024, 17 per cent of cities included in the report met the WHO annual PM2.5 guideline level, up from 9 per cent in 2023, according to the report.