13 out of 20 most polluted cities today are in India. Delhi is not one of them

India placed 13 cities among the world's 20 most polluted urban centres, while Delhi remained outside the list. The real-time ranking underlined sharp variations in air quality across cities and hours.

In Short

• Bulandshahr ranked third globally with an unhealthy US AQI of 198
• Agartala followed fourth, while Pali and Muzaffarnagar each recorded 174
• Indonesia's Palangkaraya topped the ranking with a severe AQI reading of 242

India dominated a global ranking of the world's most polluted cities on Monday afternoon, with 13 of the 20 cities recording the highest air pollution levels on the global list.

However, Delhi, often associated with India's worsening air quality, did not feature in the list at the time of the ranking.

Data from AQI.in, accessed at around 3:30 pm IST on October 19, showed Bulandshahr in Uttar Pradesh ranked third globally, with a US AQI reading of 198, categorised as unhealthy. Agartala in Tripura followed in fourth place with an AQI of 181.

Other Indian cities in the top 20 included Pali in Rajasthan and Muzaffarnagar in Uttar Pradesh, both recording AQI readings of 174. Burhanpur in Madhya Pradesh also reported 174, while Rohtak in Haryana recorded 172.

Kota in Rajasthan registered an AQI of 170, followed by Mumbai at 167, Hapur at 166, Hisar at 165, Bikaner at 165 and Bareilly at 164. These readings placed the cities among the world's most polluted urban locations in the ranking.

WHICH IS THE MOST POLLUTED CITY IN THE WORLD?

Indonesia accounted for several cities near the top of the list.

Palangkaraya in Central Kalimantan ranked first with a US AQI of 242, categorised as severe, while Palembang recorded 207, also in the severe category.

Sampit and Jambi were ranked fifth and sixth, with readings of 180 and 176, respectively. Putrajaya, Kuala Lumpur and Petaling Jaya in Malaysia also featured in the top 20.

DELHI'S AIR QUALITY REMAINS A CONCERN

Although Delhi did not appear in the global top 20 city ranking, its air quality had deteriorated overnight. The historical AQI graph for the capital showed the US AQI reaching a maximum of 191 at 7:31 am on October 19, before declining through the day.

The graph recorded a minimum of 126 at 5:01 pm on October 18. Delhi's AQI subsequently fell from the morning peak, reaching readings in the 130s by the afternoon of October 19.

The readings highlight how air pollution can vary considerably between cities and across hours. A city's position in a real-time ranking is only a snapshot and can change as weather conditions, emissions and atmospheric circulation evolve.

The AQI.in ranking uses the US Air Quality Index, under which readings between 151 and 200 fall in the unhealthy category, while values above 200 indicate very unhealthy or severe pollution depending on the scale's specific bands.

Even when a city falls outside a global ranking, elevated pollution can still pose health risks, particularly for children, older adults and people with respiratory or cardiovascular conditions.

- Ends