Delhi world's 'most polluted' capital: report

Delhi was the most polluted capital city in the world in 2023, a Swiss-based air-quality monitoring group has found.

India, of which Delhi is the capital, was also ranked as the world's third-most polluted country after neighbours Bangladesh and Pakistan, IQAir said.

The country's air has worsened since 2022, when it was the eighth most polluted country, it added.

The report by IQAir said that India's average level of PM2.5 - fine particulate matter that can clog lungs and cause a host of diseases - was 54.4 micrograms per cubic metre.

Globally, air that has 12 to 15 micrograms per cubic metre of PM2.5 is considered safe to breathe, while air with values above 35 micrograms per cubic metre is considered unhealthy. Delhi's air quality was worse than India's overall air quality with the city having a PM2.5 reading of 92.7 micrograms per cubic metre.

Delhi struggles with bad air around the year, but the air gets particularly toxic during winter.

This happens due to various factors, including burning of crop remains by farmers in nearby states, industrial and vehicular emissions, low wind speeds and bursting of firecrackers during festivals.

Last year, the government shut schools and colleges for several days in a row due to the toxic air.