13 of world's top 20 most polluted cities in India, Delhi world's most polluted capital city: IQAir

Byrnihat in Assam has been identified as the world's most polluted city, as revealed by the World Air Quality Report 2024 from Swiss air quality technology firm IQAir. The report maintains Delhi's status as the most polluted capital city globally.

Despite these rankings, India is now the fifth most polluted country, a slight improvement from its third-place ranking in 2023, following a 7% decline in PM2.5 concentrations to an average of 50.6 micrograms per cubic metre.

IQAir's report highlights that 13 of the top 20 most polluted cities worldwide are in India, including Mullanpur and Faridabad, alongside Byrnihat and Delhi.

Delhi's PM2.5 concentration remained worrying at an annual average of 91.6 micrograms per cubic metre, only marginally lower than the previous year's 92.7 micrograms. The report underscores the critical health risk posed by air pollution, noting that 35% of Indian cities have PM2.5 levels exceeding ten times the WHO's recommended limit.

Air pollution in India has been associated with a reduction in life expectancy by approximately 5.2 years. The dangerous PM2.5 particles, smaller than 2.5 microns, are linked to severe health issues, including heart disease and cancer.

A study by Lancet Planetary Health noted that between 2009 and 2019, an estimated 1.5 million deaths annually in India were tied to long-term PM2.5 exposure. The primary sources include vehicle emissions, industrial activities, and biomass burning.

Former WHO chief scientist Soumya Swaminathan stressed the need for actionable steps to address air pollution.

"We have the data; now we need action. Some solutions are easy like replacing biomass with LPG. India already has a scheme for this, but we must further subsidise additional cylinders. The first cylinder is free, but the poorest families, especially women, should receive higher subsidies. This will improve their health and reduce outdoor air pollution," she told PTI in an interview.

Swaminathan emphasised a mix of incentives and penalties to encourage cleaner practices. "A mix of incentives and penalties is necessary," she said, advocating for expanded public transport and penalties for certain vehicles as effective measures against urban pollution.

The former Director-General of the Indian Council of Medical Research added, "Finally, strict enforcement of emission laws is crucial. Industries and construction sites must comply with regulations and install equipment to cut emissions instead of taking shortcuts," highlighting the necessity of regulatory compliance to mitigate pollution levels.