Thirty-nine out of the 50 most polluted cities in the world are in India, a report published on Tuesday by Swiss air quality technology company IQAir said.

Lahore in Pakistan and Hotan in China were found to be the top two most polluted cities in the world. They were followed by Rajasthan’s Bhiwadi and Delhi, where the level of PM 2.5 stood at 92.7 micrograms and 92.6 micrograms.

Other Indian cities on the list included Darbhanga, Asopur, Patna, Ghaziabad, Dharuhera, Chapra, Muzaffarnagar, Greater Noida, Bahadurgarh and Faridabad.

Source: IQAir

Particulate matter smaller than 2.5 microns (or about a ten-thousandth of an inch) is particularly dangerous to human health. Such particles are small enough to travel deep into the respiratory system, potentially impairing lung function.

The National Ambient Air Quality Standards require PM2.5 concentration to be less than 60 micrograms per cubic metre of air in any given 24-hour period to be considered safe. The World Health Organisation recommends it to be 75 micrograms per cubic metre of air.

Seven cities in India – Tarakeswar, Digboi, Aladu, Kattupalli, Polampalle, Kharsawana and Muttayyapuram – were also among the 15 least polluted regional cities in South Asia.

India 8th most polluted country in the world

India ranked 8th in the list of the world’s most polluted countries in terms of air quality, the report said. In 2021, it was in the fifth position.

Chad, Iraq, Pakistan, Bahrain, Bangladesh, Burkina Faso, Kuwait, Egypt and Tajikistan were also on the list of ten most polluted countries.

Source: IQAir

“India’s annual average PM2.5 level in 2022 was 53.3 µg/m3, only slightly lower than the 2021 average of 58.1,” IQAir said in its World Air Quality Report in 2022. “Roughly 60% of the cities in India included in this report experienced annual PM2.5 levels of at least seven times higher than the WHO guidelines.”

The Swiss company noted that while Air quality monitoring has increased in India, it still lacks the ability to track the progress of reduction strategies through an effective and reliable emissions inventory.

It also underlined the need for a “comprehensive national emission database” to determine sectoral emission reductions.