A study by Vital Strategies, a public health advisory group, analyzed more than half a million news articles and social media posts on air pollution in 11 countries across southern Asia between 2015 and 2018.

"We see a lot of air pollution content in relation to the environment, climate change or deforestation, but not a lot that links it to health," said Aanchal Mehta, the report's lead author.

Air pollution kills about 7 million people prematurely each year, according to the World Health Organization (WHO), with 1.5 million of those deaths in South and Southeast Asia.

Nine out of 10 people breathe polluted air, according to the WHO, a problem that affects more cities in Asia than anywhere else in the world.

The health impact of air pollution is linked to strokes, lung cancer and heart disease - and is now equal to the effects of smoking tobacco, health experts say.

As well as news articles, the Vital Strategies researchers analyzed social media posts, blogs and online forums.

The study found that the public debate on air pollution largely focused on vehicle emissions, which resulted in policymakers looking only at one cause of the problem.

But in much of South and Southeast Asia, those emissions are not the biggest or only source of air pollution, said Mehta.

Other major causes, which vary from country to country, include coal power plants, construction, festival fireworks, forest clearing, and burning of crops, firewood and waste.

Most of the news and social media posts highlighted the more immediate effects of air pollution, like itchy eyes and coughing, rather than the risks from chronic exposure.

"This points to the fact that people don't attribute or understand that air pollution has longer-term health impacts," Singapore-based Mehta told the Thomson Reuters Foundation.

Emotionally-charged content, such as on children's health, gained the most engagement, which could help in the development of strategies to tackle air pollution, researchers noted.

More government awareness campaigns were needed on the chronic risks linked to air pollution, Mehta said.

"There is a dire need to look at long-term, practical and effective solutions to the issue of air pollution," Oswar Mungkasa, Jakarta's deputy governor for spatial planning and environment, said in a statement on the report.

REUTERS

Read: WHO: 7 Million People Per Year Die due to Air Pollution