New Delhi: Thirteen of the world’s 20 most polluted cities are in India, with Byrnihat in Assam topping the list, according to a new report published on Tuesday.
The World Air Quality Report 2024 by Swiss air quality technology company IQAir said Delhi remains the most polluted capital city globally, while India ranked as the world’s fifth most polluted country in 2024, an improvement from its third rank in 2023. Four cities in Pakistan and one in China are among the top 20 polluted cities.
The report said India saw a 7% decline in PM2.5 concentrations in 2024, averaging 50.6 micrograms per cubic metre, compared to 54.4 micrograms per cubic metre in 2023. Yet, 13 of the world’s 20 most polluted cities are in India.
The air pollution in Delhi has worsened, with the annual average PM2.5 concentration rising from 102.4 micrograms per cubic metre in 2023 to 108.3 micrograms per cubic metre in 2024.
The Indian cities in the list of world’s top 20 most polluted cities are Byrnihat, Delhi, Punjab’s Mullanpur, Faridabad, Loni, Gurugram, Ganganagar, Greater Noida, Bhiwadi, Muzaffarnagar, Hanumangarh and Noida.
Overall, 35% of the Indian cities reported annual PM2.5 levels exceeding 10 times the World Health Organisation (WHO) limit of 5 micrograms per cubic metre, the report said.
The high level of pollution in Byrnihat, a town on the Assam-Meghalaya border, is due to emissions from local factories, including distilleries, iron and steel plants.
Delhi grapples with high air pollution year-round and the problem worsens in winter when unfavourable meteorological conditions, combined with vehicular emissions, paddy-straw burning, firecrackers and other local pollution sources, make the air quality hazardous.
Air pollution remains a serious health risk in India, reducing life expectancy by an estimated 5.2 years. According to a Lancet Planetary Health study published last year, about 1.5 million deaths in India every year from 2009 to 2019 were potentially linked to long-term exposure to PM2.5 pollution.
PM2.5 refers to tiny air pollution particles smaller than 2.5 microns, which can enter the lungs and bloodstream, leading to breathing problems, heart disease and even cancer. The sources include vehicle exhaust, industrial emissions and the burning of wood or crop waste.
Former WHO chief scientist and health ministry adviser Soumya Swaminathan said India has made progress in air quality data collection but lacks sufficient action.
