Radon gas is considered a key risk factor for developing lung cancer, but new research has found that even moderate exposure to this invisible, odorless gas is also associated with an increased risk of stroke. The results of the study have been published in Neurology, the medical journal of the American Academy of Neurology, and do not prove that radon exposure causes stroke, but only show an association.
Radon is a naturally occurring radioactive gas that is produced when metals such as uranium and radium break down in rocks and soil. The gas can enter homes through cracks in basement walls and floors, construction joints, and gaps around pipes, becoming an indoor air pollutant that can only be detected by tests that measure gas concentrations in homes, explained Dr. Eric A. Whitsel of the University of North Carolina at Chapel Hill and author of the study.
“Our research found an increased risk of stroke among participants exposed to higher radon concentrations (and up to two picocuries per liter (pCi/L) lower) that typically trigger Environmental Protection Agency recommendations to install a reduction system.” of radon in the home.
The researchers looked at the impact of midlife exposures on older women who participated in the study and found an increased risk of stroke among those who had been exposed to high and even moderate concentrations of the gas, compared to those who had been exposed. exposed to lower concentrations.
A new risk factor for stroke
The research involved 158,910 women with an average age of 63 years who had not suffered a stroke at the beginning of the study, and who were followed for an average of 13 years. During the study, 6,979 strokes occurred among participants.
To determine radon exposures, researchers linked these women’s addresses to radon concentration data from the U.S. Geological Survey and the U.S. Environmental Protection Agency (EPA). The EPA recommends that average indoor radon concentrations should not exceed four picocuries per liter (pCi/L). For concentrations this high, the EPA recommends installing a radon reduction system to reduce radon levels in the home.
Participants in the group with the highest radon exposure had a 14% increased risk of stroke compared to those in the lowest group
The participants were divided into three groups. The highest group had their homes in areas where average radon concentrations were more than four pCi/L. The middle group lived in areas with medium concentrations, between two and four pCi/L. The lowest group lived in areas with average concentrations less than two pCi/L.
In the group with the highest radon exposures, there were 349 strokes per 100,000 person-years compared with 343 attacks in the middle group and 333 attacks in the group with the lowest exposure. Person-years represent both the number of people in the study and the amount of time each person spends in the study.
After adjusting for factors such as smoking, diabetes and hypertension, the researchers found that participants in the highest radon exposure group had a 14% increased risk of stroke compared to those in the lowest radon exposure group. Those in the middle group had a 6% higher risk.
“Importantly, we found an increased risk of stroke among those exposed to radon concentrations up to two pCi/L below the current lung cancer-based threshold for recommending radon reduction,” Whitsel said. “More studies are needed to confirm our findings. Confirmation would offer an opportunity to improve public health by addressing an emerging risk factor for stroke.”
