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Radon is the second leading cause of lung cancer. A new study finds that exposure to this invisible, odorless gas is also linked to an increased risk of stroke.
The study, which examined exposures in middle-aged to older female participants, found an increased risk of stroke among those exposed to high or even moderate concentrations of the gas compared to those exposed to concentrations the weakest.
The study, published in the January 31, 2024 online issue of Neurology, does not prove that exposure to radon causes stroke; it only shows an association.
Radon is a naturally occurring radioactive gas produced when metals like uranium or radium break down in rocks and soil. Gas can enter homes through cracks in basement walls and floors, construction joints, and gaps around pipes.
“Radon is an indoor air pollutant that can only be detected by tests measuring gas concentrations in homes,” said study author Eric A. Whitsel, MD, MPH, of the University of North Carolina at Chapel Hill.
“Our research found an increased risk of stroke among participants exposed to radon above – and up to two picocuries per liter (pCi/L) below – concentrations that typically trigger Environmental Protection Agency recommendations Protection Agency to install a radon mitigation system in the home.”
The study included 158,910 participants with an average age of 63 who had not suffered a stroke at the start of the study. They were followed for an average of 13 years. During the study, 6,979 strokes were recorded among participants.
To determine radon exposure, researchers linked participants’ home addresses to data on radon concentrations from the U.S. Geological Survey and the U.S. Environmental Protection Agency (EPA).
The EPA recommends that average indoor radon concentrations not exceed four picocuries per liter (pCi/L). For concentrations this high, the EPA recommends installing a radon mitigation system to reduce radon levels in the home.
The participants were divided into three groups. The highest group lived in areas where average radon concentrations were greater than four pCi/L. The intermediate group lived in areas where average concentrations were between two and four pCi/L. The lowest group lived in areas where average concentrations were below two pCi/L.
In the group with the highest radon exposures, there were 349 strokes per 100,000 person-years, compared to 343 strokes in the middle group and 333 strokes in the group with the highest exposure. weak. Person-years represent both the number of people participating in the study and the time each person spends on the study.
After adjusting for factors such as smoking, diabetes and high blood pressure, researchers found that participants in the highest group had a 14% increased risk of stroke compared to those in the highest group. weak. People in the middle group had a 6% increased risk.
“Importantly, we found an increased risk of stroke in people exposed to radon concentrations up to two pCi/L below the current lung cancer-based threshold for recommending mitigation radon,” Whitsel said. “Further studies are needed to confirm our findings. Confirmation would present an opportunity to improve public health by addressing an emerging risk factor for stroke.”
A limitation of the study was that it only included participants who were middle-aged or older and primarily white, so the results might not be the same for other populations.
More information:
Neurology (2024).
Provided by the American Academy of Neurology
Quote: Exposure to even moderate levels of radon linked to increased risk of stroke (January 31, 2024) retrieved January 31, 2024 from
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