Ethylene Oxide Exposure During Pregnancy May Increase Risk of Childhood Heart Disease: Study

Researchers warn prenatal exposure to ethylene oxide used to sterilize medical equipment could cause a number of serious health conditions in children.

A new study suggests that pregnant women exposed to ethylene oxide are more likely to have babies with lower birth weight and a reduced head circumference, which may increase the risk of developing heart disease and type 2 diabetes, among other serious medical conditions.

Ethylene oxide is used in many household products, as well as during the sterilization process for some medical devices, including those made of metals, glass or containing multiple layers and small crevices.

Expectant mothers are most often exposed to ethylene oxide through household items, including certain cleaning agents, air fresheners and personal care items. However, some pregnant women may also face risks from occupational exposure, especially among those in the healthcare industry, where workers may be exposed during equipment sterilizations.

In findings of a new study published in the September 2024 issue of the journal Epidemiology, researcher Barbara Harding from the Barcelona Institute for Global Health (ISGlobal) warns about the negative impact prenatal exposure to ethylene oxide can have on a child’s early development.

Ethylene Oxide Dangers for Pregnant Women

A number of serious and life-threatening health risks have already been linked to ethylene oxide exposure. Inhaling the gas can irritate the lungs, throat, eyes and nose, and direct exposure is also known to increase the risk of breast and lymphoid cancers. Researchers have also warned that it can cause damage to the brain and nervous system.

There have been several high-profile ethylene oxide leaks in recent years, which have also caused widespread exposure near certain manufacturing or sterilization plans. As a result, federal agencies have outlined new regulations to help protect vulnerable populations.

Since there are safer alternatives available to clean medical equipment, experts have also been calling for the healthcare industry to move away from use of ethylene oxide.  However, it is still used to sterilize about half of the medical equipment made in the U.S.

In this new ISGlobal study, researchers determined the levels of ethylene oxide exposure during pregnancy by measuring amounts of the toxic chemical in babies’ cord blood, which is the blood that remains in placentas and umbilical cords after birth.

The researchers discovered that newborns with elevated levels of ethylene oxide in their cord blood were at increased risk of low birth weight and smaller head circumference, which can lead to heart disease, type 2 diabetes, osteoporosis and delayed neurodevelopment, a condition that can cause cerebral palsy, ADHD and language and speech problems.

Harding and her team isolated the effects of ethylene oxide exposure on pregnant women and newborns by using data from the NewGeneris project, a 2009 European study on prenatal diets and children’s health.

Looking at the effects of ethylene oxide in the cord blood of 1,106 newborns from the U.K., Norway, Greece, Spain and Denmark, researchers were able to determine precisely how much ethylene oxide the baby was exposed to during the final months of pregnancy.

This revealed that children with higher levels of ethylene oxide in their cord blood had birth weights that were lower, which was in direct proportion to the amount of ethylene oxide they were exposed to. Those with the greatest exposure had the lowest birth weights.

“We found that increasing levels of [ethylene oxide hemoglobin] adducts in cord blood were associated with decreasing birth weight and head circumference,” Harding said. “Reduced head circumference has been linked to delayed neurodevelopment, and reduced birth weight increases the risk of cardiovascular disease, type 2 diabetes, and osteoporosis.”

Women exposed to higher levels of ethylene oxide during pregnancy are already known to have a higher risk of miscarriage and premature birth.

EPA Is Taking Action Against Ethylene Oxide Exposure

In March, the U.S. Environmental Protection Agency (EPA) announced that it had finalized amendments to the National Emission Standards for Hazardous Air Pollutants for Ethylene Oxide Commercial Sterilizers, which the agency says are the strongest measures yet to reduce ethylene oxide risks. This may help reduce the lifetime risk of cancer for nearly 13 million residents across the U.S.

The EPA first proposed new ethylene oxide standards in 2023, following several high-profile ethylene oxide plant shutdowns caused by massive gas leaks that flooded the areas with the toxic gas.

Ethylene Oxide leaks occurred in 2019 at the Sterigenics plant near Atlanta and other facilities in Michigan and Illinois. The facilities were shut down temporarily to address the leaks, but multiple lawsuits were subsequently filed over health risks from exposure to the gas.

Following the leaks, the FDA began hosting a series of meetings as town halls to discuss ethylene oxide restrictions, alternative sterilization methods and reducing ethylene oxide use overall.

Lawsuits filed over ethylene oxide leaks at Sterigenics facilities were brought by a number of workers and nearby residents who developed breast cancer, non-Hodgkin’s lymphoma and other health problems due to exposure. The lawsuits resulted in a $408 million settlement last year to resolve claims brought by residents in surrounding communities.