Ten out of 15 cities around the world with the worst air quality are Indian cities. Delhi retained its spot to be the most polluted capital in the world for the fourth consecutive year in 2021 with pollution rising 15% over the previous year.
As per the World Air Quality Report 2021 by IQAir, Delhi saw a 14.6% increase in PM2.5 concentrations in 2021 with levels rising to 96.4 µg/m³ (micrograms per cubic meter air. Concentration of air pollutants is measured in micrograms) from 84 µg/m³ in 2020.
According to the air quality ‘life index’ developed by the University of Chicago, all of India’s 1.3 billion people live in areas where the annual average particulate pollution level exceeds the World Health Organisation (WHO) guideline. When measured in the lethal and microscopic PM 2.5 pollutant, the average air pollution is 58.1 micrograms per cubic meter. This means it is 10 times more than the WHO’s air quality guidelines. In fact, no city in India has met the WHO guidelines.
India’s pollution has worsened since 2021. According to a World Air Quality Report released by IQAir, a Swiss firm, northern India is worse.
The report said, “India also continues to feature prominently among the most polluted cities with 35 of the top 50 most polluted cities being in this country. India’s annual average PM2.5 levels reached 58.1 g/m3 in 2021, ending a three-year trend of improving air quality.”
Apart from Delhi, Bhiwadi in Rajasthan followed by Ghaziabad in Uttar Pradesh and Jaunpur also from Uttar Pradesh found themselves at the top 15 of the most polluted cities in the list. The only other cities outside India are Hotan (third place) in China, Faisalabad, Bahawalpur, Peshawar and Lahore from Pakistan.
Here are the 15 most polluted cities in the world:
| Global Rank | Country | State | City | Avg. PM 2.5 |
| 1 | India | Rajasthan | Bhiwadi | 106.2 |
| 2 | India | Uttar Pradesh | Ghaziabad | 102 |
| 3 | China | Xinjiang | Hotan | 101.5 |
| 4 | India | Delhi | Delhi | 96.4 |
| 5 | India | Uttar Pradesh | Jaunpur | 95.3 |
| 6 | Pakistan | Punjab | Faisalabad | 94.2 |
| 7 | India | Uttar Pradesh | Noida | 91.4 |
| 8 | Pakistan | Punjab | Bahawalpur | 91.0 |
| 9 | Pakistan | Khyber Pakhtunkhwa | Peshawar | 89.6 |
| 10 | India | Uttar Pradesh | Bagpat | 89.1 |
| 11 | India | Haryana | Hisar | 89.0 |
| 12 | India | Haryana | Faridabad | 88.9 |
| 13 | India | Uttar Pradesh | Greater Noida | 87.5 |
| 14 | India | Haryana | Rohtak | 86.9 |
| 15 | Pakistan | Punjab | Lahore | 86.5 |
