Scientists have long known that exposure to air pollution during pregnancy increases the risks of preterm or low birth weight deliveries.
The impact of exposure to pollution
The new findings suggest that exposure to pollution is highest in low- and middle-income countries and especially from indoor sources.
In 2019, for example, about half of the world’s population breathed in household air pollution from cooking fires. In addition, 92% of the world’s population lived in areas where air quality did not meet the recommendations of the World Health Organization.
Preterm births: ABOUT THE STUDY
For this latest report, published in PLOS Medicine, the researchers analyzed data from 124 studies on air pollution, birth weight and preterm birth. They wanted to be sure to distinguish exposures to indoor air pollution, which is often overlooked. (Preterm delivery is defined as before 37 weeks of pregnancy; low birth weight is around 5.5 pounds, or less than 2500 grams.)
Most of the studies they evaluated came from the United States, Europe, and Australia, with a scattering of findings from India, China, South America, and sub-Saharan Africa.
The researchers specifically included reports from Africa and Asia because indoor fire cooking is more common in these regions.
One third of the air pollution that causes preterm labor came from outside air
About a third of the air pollution that causes preterm labor came from outside air. So most of it was due to indoor air pollution, mainly in low-income countries.
The results showed that air pollution accounted for 16% of all babies born with low birth weight and 36% of preterm deliveries. The findings imply that one in three preterm births could be prevented by eliminating exposure to air pollution during pregnancy.
In sub-Saharan African countries, for example, more than half of all preterm births (52.5%) were attributable to exposure to air pollution. Keeping air pollution to a minimum risk level could reduce both preterm births and the incidence of low birth weight by 78% in this region, the study authors estimate.
Low birth weight and preterm delivery increase the risk of death before one year of age and can have additional lifelong consequences.
These babies are more likely to have intellectual and developmental disabilities and other disabilities, such as vision, lung, or hearing problems. Asthma, digestive difficulties, and infections are also more common in premature babies.
UNAM researchers make progress in nanovaccine against COVID-19
How safe is it to combine COVID-19 vaccines?
GRAPH: 78% of the adult population in Mexico has a vaccine against COVID
THAT? Study proves COVID is a seasonal infection, like the flu