NEW DELHI: India was the fifth most polluted country in the world in terms of air quality, with Byrnihat in Meghalaya being the most polluted metropolitan area globally last year, according to IQAir’s 2024 World Air Quality Report released Tuesday.
Byrnihat reported an annual average PM2.5 level of 128.2 micrograms per cubic metre (µg/m3) which was more than 25 times higher than WHO-recommended level and over three times more than Indian ambient air quality standards. High air pollution level in the little-known Meghalayan city can be attributed to rapid industrialisation, unregulated emission, construction and deforestation.
Though India improved its overall ranking from third most-polluted in 2023 to fifth last year, it had the dubious record of having six of the world’s 10 most polluted cities and 13 of the 20 most polluted cities globally, with Delhi being the most polluted capital in the world in 2024.

Little known byrnihat

The report that analysed a critical pollutant particulate matter 2.5 (PM2.5) data from over 40,000 air quality monitoring stations across 8,954 locations in 138 countries, finds Chad — a central African country — as the most polluted country last year, followed by Bangladesh, Pakistan, Congo and India by exceeding the WHO standards of acceptable limit of that pollutant multiple times.
Only seven countries — Australia, Bahamas, Barbados, Estonia, Grenada, Iceland and New Zealand — met WHO annual average PM2.5 guideline level of 5 µg/m3.
As far as India is concerned, the report finds that the country with the annual average PM2.5 concentration of 50.6 µg/m3 in 2024 reported more than 10 times higher than the WHO PM2.5 annual guideline and over 26% higher than the acceptable limit of the hazardous pollutant as per Indian national ambient air quality standards.
The report shows that India saw a 7% decline in PM2.5 concentrations in 2024, averaging 50.6 µg/m3 compared to 54.4 µg/m3 in 2023, but the capital, New Delhi, maintained consistently high pollution levels, with annual average of 91.6 µg/m3, nearly unchanged from 92.7 µg/m3 in 2023.
“Overall, 35% of Indian cities reported annual PM2.5 averages exceeding 10 times WHO guideline,” it says. In 2024, air quality data was reported from 371 cities across 11 countries, with India being the most monitored, hosting more than half of central and south Asia region’s stations. The region was home to the top nine most-polluted cities in the world with six of them in India last year.
Citing Air Quality Life Index released by University of Chicago in 2023, IQAir’s report noted that air pollution remains a significant health burden in India, reducing life expectancy by an estimated 5.2 years.
PM2.5, which is smaller than 2.5 micrometers, is considered the most hazardous air pollutant. It can be deposited in lungs, causing respiratory problems and other health issues.