Pollution is being linked to between 2.7 million preterm births globally, according to a new study out of the Stockholm Environment Institute.
That accounts for around 18 per cent of total preterm births, or babies born before 37 weeks of pregnancy. And it can get as high as 23 per cent, depending on how you categorize pollution, Chris Malley, lead author on the study, told Global News.
READ MORE: Air pollution affecting 1 in 7 children worldwide: UNICEF
The highest numbers of preterm births linked to pollution were found in South Asia (1.4 million) and East Asia (473,000), with West Africa, North Africa and the Middle East not far behind.
In Canada, the number of premature births linked to pollution ranged between 600 and 2,450 or between 2-8 per cent of all preterm births.
While the air pollution studied in the paper is made up of all “fine particulate matter” in the air including natural particulates like desert dust and sea salt, the areas where the study sees the highest numbers of preterm births are in areas with human-created pollutants.
The numbers are from 2010, the last year data was available globally for pollution and preterm births.
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The study said out of all 135 million births in the world that year, one in 10 were born prematurely. It’s the leading cause of neonatal death, and can lead to complications in childbirth.
“If we can get it (the number of preterm births) down, the potential to affect human life expectancy would be substantial,” Malley said.
He said that now we know about the link, the question becomes: How can we reduce exposure to air pollution to reduce the amount of pre-term births?
READ MORE: 6.5 million deaths worldwide linked to air pollution: report
Since factors include diesel emissions, and agriculture (such as burning a crop), Malley says “it’s important to take action on all these sources.”
Malley did warn that there were some limitations to the study. Firstly, because of a lack of research in certain regions led his team to rely on European and North American studies on exposure to air pollution. Secondly, he said the study was only based on outdoor air pollution, and doesn’t count indoor air pollution caused by things like cooking with a solid-fuel stove (ex. wood burning). But the Guardian reports that experts who reviewed the paper called the numbers “conservative.”