• Posted April 13, 2026

Radon Gas Increases Risk Of Ovarian Cancer, Study Says

An invisible radioactive gas could be increasing women’s risk for ovarian cancer, a new study says.

Women living in homes with elevated radon levels have higher odds of developing ovarian cancer, researchers reported April 10 in JAMA Network Open.

“The risks of ovarian cancer, particularly serous ovarian cancer, were significantly higher in the high radon zone,” concluded the research team led by Gary Schwartz, chair of population health at the University of North Dakota School of Medicine & Health Sciences.

These odds were even higher if a woman had a family history of breast cancer, the study found.

About 25% of Americans live in homes with radon levels of more than 4.0 pCi/L, the level at which the U.S. Environmental Protection Agency recommends action to mitigate exposure, researchers said.

“Because serous ovarian cancer is highly fatal, and because radon levels in homes can be reduced, our findings could have large implications for ovarian cancer prevention,” the team wrote.

Radon gas is naturally released from rocks, soil and water. It can get trapped inside homes and build up, contaminating indoor air.

Radon is considered the second-leading cause of lung cancer in the U.S., according to the EPA.

“This study is really the first to report that environmental radon exposure, which is a fairly common environmental hazard, can lead to an increased risk of ovarian cancer in women,” said Dr. Jacqueline Moline, who reviewed the findings. She’s senior vice president and chair of occupational medicine, epidemiology and prevention at Northwell Health in New York City.

"It's something that has been identified as a lung cancer risk for decades, but this is the first time in a very large study that someone has been able to demonstrate that radon can also lead to ovarian cancer,” she said in a news release.

Researchers suspected radon might be involved in ovarian cancer, given that exposure to ionizing radiation had been shown to increase ovarian cancer risk among World War II atomic bomb survivors.

“The largest source of ionizing radiation for most individuals is from radon, a naturally occurring gas produced by the decay of uranium and other radioactive elements present in soil,” researchers wrote.

For the new study, researchers tracked nearly 128,000 women participating in a large-scale health research project.

The team used participants’ home addresses to estimate their radon exposure based on National Geological Survey data. Exposure was classified into into low (<2 pCi/L); medium (2-4 pCi/L); and high zones (>4 pCi/L).

Results showed that women exposed to high radon levels had a 31% increased risk of ovarian cancer, compared to those exposed to low levels.

Women in the high radon zone also were 31% more likely to die from ovarian cancer compared to those in the low zone, researchers found.

"The most important thing is to get your house checked, because it's a simple test that can be done,” Moline said. “If there are elevated levels, they can be remediated. There are various ways that can happen, to get the radon levels down to a safe level.”

Moline noted that researchers also found an interaction between radon and a history of breast cancer when it comes to ovarian cancer risk.

Women with high radon exposure and a family history of breast cancer were 63% more likely to develop ovarian cancer, the study said.

These results indicate that radon might interact with cancer-causing mutations of genes like BRCA, Moline said.

“That's why if you know there's a family history of breast cancer, make sure your home doesn't have radon in it, and if it does, get it taken care of,” Moline said.

More information

The U.S. Centers for Disease Control and Prevention has more about radon.

SOURCES: JAMA Network Open, April 10, 2026; Dr. Jacqueline Moline, senior vice president and chair of the occupational medicine, epidemiology and prevention, Northwell Health, New York City