A new report has found that air pollution could be contributing to millions of premature births around the world, with Africa and Asia particularly affected. Premature birth, which affects 15 million babies annually who are born prior to 37 weeks of gestation, is the leading cause of death in children under 5 years old, according to World Health Organization data. It affects about 1 in every 10 babies born worldwide. The WHO also says that it can lead to problems with vision, hearing, and learning disabilities.
Researchers with the Stockholm Environment Institute (SEI), as well as the London School of Hygiene and Tropical Medicine and the University of Colorado, concluded that 3.5 million of these premature births, in 183 countries, could be caused by the presence of fine particulate matter. Two experts referred to these figures as “conservative.”
Fine particulate matter refers to pollution particles, smaller than 2.5 micrometers in diameter, that are small enough to lodge deep in the lungs, causing respiratory and heart problems.
According to Dr. Paul Jarris, chief medical officer with the March of Dimes:
“Preterm birth and associated conditions are one of the biggest killers of children in the US and worldwide. Yet, there’s a lot of things we don’t know about what causes preterm birth, so every bit of information we can get is helpful.”
“We have known for a long time that air pollution contributes to asthma and heart disease in adults. What I think people fail to recognize is that so many of these risk factors impact babies before they are even born, Jarris added.
Earlier research has examined the way air pollution could affect babies in utero, in terms of birth weight and premature birth. The SEI research used data from 2010 to project how those factors affect global rates of premature births.
SEI researcher Chris Malley, one of the lead authors of the study, explained:
“By showing in our study that 18% of preterm births are associated with air pollution, we are quantifying the health impacts of fine particulate matter on babies before they are born.”
South Asia and Africa account for 60 percent of premature births worldwide, and were also a focus of the SEI report.
Other factors thought to influence premature birth include infection, smoking and drug use, poverty, and physical activity. The report is among the first to add air pollution to this list.
The researchers that the study demonstrates that “reduction of maternal exposure [to air pollution] through emission reduction strategies should be considered alongside mitigation of other risk factors associated with preterm births.”