Nearly 90 per cent of the 200 cities beset by the world’s highest levels of deadly micro-pollution are in China and India, with most of the rest in Pakistan and Indonesia, researchers reported on Tuesday.
Taking population into account, Bangladesh emerged as the country with the worst so-called PM2.5 pollution, followed by Pakistan, Mongolia, Afghanistan and India, according to the 2019 World Air Quality Report, jointly released by IQAir Group and Greenpeace. China ranks 11th.
Particulate matter of 2.5 microns or less in diameter — roughly 1/30 the width of a human hair — is the most dangerous type of airborne pollution.
Microscopic flecks are small enough to enter the bloodstream via the respiratory system, leading to asthma, lung cancer and heart disease.
Among the world’s megacities of 10 million or more people, the most PM2.5-toxic in 2019 was the Indian capital New Delhi, followed by Lahore in Pakistan, Dhaka in Bangladesh, Kolkata in India, Linyi and Tianjin in China, and Jakarta, Indonesia.
Next on the list was Wuhan — the epicentre of the new coronavirus outbreak — along with Chengdu and Beijing.
New Delhi on top, Dhaka third, says IQAir and Greenpeace study for 2019
The IQAir report is based on data from nearly 5,000 cities worldwide.
Most of the seven million premature deaths attributed by the World Health Organization (WHO) to air pollution are caused by PM2.5 particles, which originate in sandstorms, agriculture, industry, wildfires and especially the burning of fossil fuels.
“Air pollution is the world’s leading environmental health threat,” said IQAir CEO Frank Hammes. “Ninety per cent of the global population is breathing unsafe air.” China’s average urban PM2.5 concentration dropped 20 per cent in 2018 and 2019, but last year it still counted 117 of the 200 most polluted cities in the world.