Most polluted cities: 13 Indian cities among top 20. Know which city is the worst - it’s not Delhi, Mumbai or Pune

A global air quality report, ‘The World Air Quality Report 2024,’ by Swiss firm IQAir, was released Tuesday. The report revealed that 13 Indian cities are among the world's 20 most polluted cities. Notably, the most polluted city was neither Delhi, Mumbai, nor Pune. Meghalaya’s Byrnihat took the crown as the most polluted city.

The The World Air Quality Report 2024 ranked Byrnihat, a town on the Assam-Meghalaya border, as the world's most polluted city, with an alarming PM 2.5 level of 128 micrograms per cubic meter.

Meanwhile, Delhi was ranked the most polluted capital, and India ranked the world's fifth most polluted nation.

Byrnihat: India's most polluted city

Byrnihat's extreme pollution levels stem from heavy industrial activities, including distilleries and iron and steel plants.

These industries release massive amounts of toxic gases into the air, deteriorating air quality.

The heavy movement of trucks transporting goods between Assam and Meghalaya further worsens the air quality.

Byrnihat’s deteriorating air quality has also severely impacted the local people.

In January, locals protested against rising pollution levels and its impact on their health. In response, earlier this month, authorities shut down seven industrial units in Byrnihat for violating environmental regulations, reported Shillong Times.

The state government recently directed the pollution control board to carry out inspections and take strict action against defaulting industries.

Delhi: World's most polluted capital

Delhi continues to battle severe air pollution, with its PM2.5 levels rising from 102.4 micrograms per cubic metre in 2023 to 108.3 micrograms per cubic metre in 2024.

The city's pollution crisis worsens in winter due to a mix of vehicular emissions, stubble burning, firecrackers and unfavourable weather conditions.

Thirteen Indian cities among world's 20 most polluted

India's pollution crisis extends beyond Byrnihat and Delhi, with 13 Indian cities making it to the list of the world's top 20 most polluted cities. These include: Byrnihat, Delhi, Punjab's Mullanpur, Faridabad, Loni, Gurugram, Ganganagar, Greater Noida, Bhiwadi, Muzaffarnagar, Hanumangarh and Noida.

In 2023, India was ranked the world's third most polluted nation, but in 2024, it dropped to fifth, with a slight 7 per cent improvement in PM2.5 levels. However, 35 per cent of Indian cities still report air pollution levels exceeding WHO's safety limits by more than tenfold.

According to the World Air Quality Report 2024, India's average PM2.5 concentration fell from 54.4 micrograms per cubic meter in 2023 to 50.6 micrograms per cubic meter in 2024.

Meanwhile, four cities in neighbouring Pakistan and one in China also ranked among the world's top 20 polluted cities.

What is PM2.5 and why is it dangerous?

PM2.5 refers to tiny air pollution particles smaller than 2.5 microns, which can enter the lungs and bloodstream and lead to breathing problems, heart disease, and even cancer.

Major sources include industrial emissions, vehicle exhaust, and the burning of wood or crop waste.