(Singapore) Air pollution, from human emissions or other sources, such as wildfires, is linked to some 135 million premature deaths worldwide between 1980 and 2020, a Singapore university study finds published Monday.

Weather phenomena like El Niño and the Indian Ocean Dipole – another natural climate phenomenon resulting from a difference in sea surface temperatures – have worsened the effects of pollutants by increasing their concentration in the air, explains the Nanyang Technological University (NTU) in Singapore.  

The problem of fine particles “has been associated with approximately 135 million premature deaths globally” between 1980 and 2020, the university said in a press release on the study, published by the journal Environment International.

Fine PM2.5 particles (less than 2.5 microns in diameter) are harmful to human health if inhaled because they are small enough to reach the bloodstream. They come from vehicles and industrial emissions, as well as natural sources such as fires or dust storms.

Weather events helped increase these deaths by 14%, the study found.

Asia has the “highest number of premature deaths attributable to PM2.5 pollution” with more than 98 million deaths, mainly in China and India, she said.  

Pakistan, Bangladesh, Indonesia and Japan also have many premature deaths, between two and five million people.  

The study is one of the most comprehensive to date regarding air quality and climate, based on 40 years of data to provide an overview of the effects of fine particles on health.

“Our findings show that changes in climate can make air pollution worse,” said Steve Yim, associate professor at NTU’s Asian School of Environment, who led the study.

Researchers from universities in Hong Kong, the United Kingdom and China took part in the study.

According to the World Health Organization, the “combined effects of ambient and indoor air pollution” are linked to 6.7 million premature deaths each year worldwide.