Fine particulate matter known as PM2.5 that is associated with a variety of negative health outcomes in humans is often found in the air, and new research has revealed a PM2.5 health risk related to pregnancy.
“Most particles form in the atmosphere as a result of complex reactions of chemicals such as sulfur dioxide and nitrogen oxides, which are pollutants emitted from power plants, industries and automobiles,” explained the U.S. Environmental Protection Agency.
Researchers from Harvard T.H. Chan School of Public Health conducted the study, published Friday in the Science Advances journal. Per a press release, it is the first study to examine the impact of PM2.5 on maternal and fetal health at the single-cell level. To do this they used data collected by the EPA to calculate average exposure levels in non-pregnant women and women who were 20 weeks pregnant.
Then, the research team “used an innovative technology” that allowed them to determine how the pollution modified the DNA of participants’ cells. Specifically, they were able to map changes to histones – proteins that help control when cytokines are released.
Cytokines control inflammation in the body and elevated levels can cause health issues. One example is the life-threatening “cytokine storm” condition triggered by COVID-19 and other viral infections.
“Exposure to PM2.5 was associated with higher levels of inflammation among pregnant women, potentially leading to adverse birth outcomes,” said the study press release.
Previously, research revealed associations between exposure to PM2.5 and other maternal and child health complications, including preeclampsia, low birth weight, and developmental delays in early childhood. In early November, Audacy reported on a study from the University of Southern California that identified poor learning and memory in children as another risk linked to air pollution exposure.
“This study represents a substantial step forward in understanding the biological pathways through which PM2.5 exposure affects pregnancy, maternal health, and fetal development. Its advanced methodology represents a significant innovation for how we study immune responses to environmental exposures,” said Kari Nadeau, corresponding author of the Harvard study.
The study found that PM2.5 exposure can influence the histone profiles of pregnant women, disrupting the normal balance of cytokine genes and leading to increased inflammation in both women and fetuses. In pregnant women, this increase in inflammation can correspond with adverse pregnancy outcomes.
“Our findings highlight the importance of minimizing air pollution exposure in pregnant women to protect maternal and fetal health,” said co-author Youn Soo Jung, research associate in the Department of Environmental Health. “Policy interventions to improve air quality, as well as clinical guidelines to help pregnant women reduce their exposure to pollution, could have a direct impact on reducing pregnancy complications.”
Fortunately, average PM2.5 concentrations have decreased over the years nationwide, according to the EPA. From 2000 through last year, they dropped 37%.
Those who want to limit their exposure to air pollution can head to AirNow, a government site that offers air pollution readings and maps.
“Every day the Air Quality Index (AQI) tells you how clean or polluted your outdoor air is, along with associated health effects that may be of concern,” said the EPA. “The AQI translates air quality data into numbers and colors that help people understand when to take action to protect their health.”