As China cleans up its act, India's cities named the world's most polluted

School children take out march to express their distress on the alarming levels of pollution in the city, in New Delhi, India. Photo / AP file

India's capital city of New Delhi, choked by rising automobile emissions and construction dust, was named the world's most polluted megacity by the World Health Organisation.

The WHO analysed the levels of the pollutant PM10 in the air in cities with populations above 14 million between 2010 and 2016.

Greater Cairo was the second most polluted large city, with India's other great mega-city of Mumbai ranked fourth on the list and Beijing fifth.

When the health organisation studied data for the smaller and more deadly PM2.5 particulate matter, 14 of the top 15 most polluted cities were in India, with the industrial hub of Kanpur ranked number 1.

Nine out of 10 people around the globe were breathing polluted air, the study said, and that air pollution is responsible for the deaths of seven million people worldwide each year, most of them living in Asia and Africa. Of those deaths, 3.8 million were from indoor air pollution from unhealthy cook stoves, a huge problem in India.

The report comes at a time when former perennial offender China, in response to citizen outrage, has taken steps to clean up its air, closing or reforming factories and reducing its coal consumption in favour of renewable energy. The moves helped improve air quality in Beijing and elsewhere, but at a cost - many poor people were denied coal heat during winter or lost jobs.

The WHO's head of public health, Maria Neira, told Reuters that India should follow China's lead.

"There was a big step at the government level declaring war on air pollution," Neira said. "One of the reasons for that is that the health argument was very strongly presented, and the fact that citizens were really breathing air that was totally unacceptable.

"We would be very happy if we would see a similar movement now in India, which is one of the countries for which we are particularly concerned, although there are good initiatives which can be put in place quickly, still the levels are very high and we would like to see a similar decision and leadership," Neira told Reuters.

Unlike China's muscular reforms, India's efforts to address its growing air pollution problem have been more scattershot, such as the last year's temporary ban by the Supreme Court on fireworks in Delhi during Diwali, the Hindu festival of lights. The court had temporarily blocked the sales of fireworks after the previous year's revelry helped contribute to a toxic air emergency that lasted for days.

The WHO did praise an Indian Government program that has provided 37 million poor women with free gas connections to help them switch from coal or dung-fired clay ovens to cooking gas.

New WHO data: 9 out of 10 people worldwide breathe polluted air https://t.co/W9OiazKkqF #AirPollution pic.twitter.com/x2ikHK4D9x

— World Health Organization (WHO) (@WHO) May 2, 2018

The WHO says India is home to the world's 14 most polluted cities. Indian environment ministry officials say the findings are embarrassing, but not surprising. See more: https://t.co/57rdtfY3M5 pic.twitter.com/AAT6izpTqF

— Reuters (@Reuters) May 2, 2018

These 14 cities in India rank among world's polluted

Here's your 10-point cheatsheet to this story: https://t.co/Sl5WvOzdYx#pollution pic.twitter.com/ESorEdBnSl

— NDTV (@ndtv) May 2, 2018

World’s 14 most polluted cities are in India. https://t.co/x0nBLOgD0H pic.twitter.com/svm0Cmyvu1

— Sadanand Dhume (@dhume) May 2, 2018

14 Indian cities in WHO’s 20 most-polluted! pic.twitter.com/9L37hj7yY1

— Porinju Veliyath (@porinju) May 2, 2018