Maternal Air Pollution Exposure Worsens Asthma Severity for Offspring
Study also finds exposure leads to epigenetic changes that can persist for generations.
Session: C19—Spatial and Single-Cell Analysis of Lung Disease: Bridging Early Mechanisms to Therapeutic Gaps
An Epigenetic Association Between Heightened Airway Hyperreactivity and Maternal Exposure to Particulate Air Pollution
Date and Time: Tuesday, May 20, 2025, 9:15 a.m.
Location: Room 3006/3008 (West Building, Level 3), Moscone Center
ATS 2025, San Francisco – A mother’s exposure to air pollution during pregnancy can increase asthma risk in her adult offspring, according to a new mouse study published at the ATS 2025 International Conference. Researchers also found that offspring had lasting epigenetic changes affecting their lungs and immune response.
While previous research has suggested that maternal air pollution exposure may increase childhood asthma risk, the study provides new insights into how epigenetic mechanisms may be driving this effect. It also indicates that, even if an individual is never directly exposed to air pollution themselves, their health can still be impacted if their mother was exposed during pregnancy.
“This highlights the importance of protecting pregnant women from air pollution, as its effects can persist across generations,” said Razia Zakarya, PhD, Wendy McCormick Research Fellow, University of Technology Sydney, and a researcher at the Epigenetics of Chronic Disease Group, Woolcock Institute of Medical Research.
The link between air pollution and asthma prevalence, severity, and hospitalizations is well established. However, there is a need to better understand the molecular pathways driving this connection, so they can be targeted for prevention and treatment. In particular, the “molecular memory” involved in prenatal exposure is not well understood, Dr. Zakarya noted.
For the new paper, researchers studied the effects of maternal air pollution in mice. In the first stage, they exposed one group of pregnant mice to air pollution particulates, and another group to harmless saline. They then separated their offspring into groups with and without asthma.
Adult mice whose mothers had been exposed to air pollution while pregnant had stronger airway constriction in response to allergens, making their asthma symptoms worse than their counterparts.
The team also found that thousands of genes in the lungs of these offspring were expressed differently than those from unexposed mothers. In addition, they found maternal air pollution exposure altered the offspring’s DNA methylation patterns — an epigenetic modification that controls gene activity.
“This suggests an epigenetic ‘memory effect’ of prenatal air pollution exposure that persists into adulthood, affecting the way genes related to lung function and immune response are regulated,” Dr. Zakarya said.
Notably, the levels of air pollution tested in the study meet WHO air quality guidelines for “safe,” she said, suggesting that guidelines may need to be revisited.
Next, the team plans to follow up on the study with future research focusing on whether similar epigenetic changes occur in human populations. They also hope to study how these changes might be reversed or mitigated.
###
You may also be interested in these abstracts.
CONTACT FOR MEDIA:
Dacia Morris
Caroline Zielinski