Study reveals biological process of how air pollution increases premature birth risk

Time of India

2 days ago

New Delhi: A study has uncovered the biological process by which pregnant women exposed to PM2.5 air pollution could be at a higher risk of premature deliveries.
Researchers from Emory University in the US analysed blood samples from 330 African American pregnant women in the Atlanta metropolitan area.
Women living in downtown and midtown neighbourhoods, where several highways intersect, had a higher level of exposure to pollution over a year, compared to those living on the outskirts of the city, the team said.
Vehicular emissions are a major contributor to PM2.5 pollution.
Two substances -- 'cortexolone' and 'lysoPE(20:3)' -- involved in the relationship between short-term exposure to air pollution and an elevated risk of early births, were identified.
Cortexolone is a glucocorticoid crucial to regulating metabolism, inflammation, and the immune response, while lysoPE(20:3) is a lipid present in cells and important for cell function.
The findings, published in the Environmental Science and Technology journal, highlighted disruptions in how proteins are digested and absorbed -- vital to foetal development and immune function -- which potentially serve as a link between exposure to air pollution and premature deliveries.
The changes were associated with an increased risk of various negative birth outcomes, including premature birth, the researchers said.
"The link between air pollution and premature birth has been well established, but for the first time we were able to look at the detailed pathway and specific fine particles to identify how they are reflected in the increased risk of
adverse birth outcomes
," lead author Donghai Liang, associate professor of environmental health at Emory University, said.
"This is important because if we can figure out the 'why' and 'how' then we can know better how to address it," Liang added.
Of the 330 women participants, 66 (20 per cent) delivered preterm babies -- before 37 weeks of pregnancy -- and 54 (16.4 per cent) delivered early term babies -- occurring between 37 and 38 weeks and 6 days of pregnancy -- both of which are significantly higher than the prevalence in the general US population, the researchers said.
The authors wrote, "We identified significant indirect effects of
cortexolone and lysoPE(20:3
) in mediating the relationship between PM2.5 and early births."
"Perturbations in protein digestion and absorption and aromatic amino acid metabolism may potentially mediate the associations between PM2.5 and early births."
Liang said that while even lower levels of air pollution are harmful, people cannot simply be asked to move away from highly polluted areas.
"So, from a clinical intervention standpoint, it's critical to gain a better understanding of these pathways and molecules affected by pollution. In the future, we may be able to target some of these molecules to develop effective strategies or clinical interventions that could help reduce these adverse health effects," the lead author added. PTI