Exposure to high and even moderate concentrations of radon can raise the risk of stroke, according to a new study.
Radon is an odorless and invisible radioactive gas naturally released from rocks, soil, and water. The gas can make its way into homes through cracks in basement walls and floors, as well as construction joints and gaps around pipes.
"Our research found an increased risk of stroke among participants exposed to radon above — and as many as two picocuries per liter (pCi/L) below — concentrations that usually trigger Environmental Protection Agency recommendations to install a home radon mitigation system," study author Eric A. Whitsel, MD, MPH, of the University of North Carolina in Chapel Hill, said in a statement.
The study involved 158,910 women with an average age of 63 who did not have a stroke at the start of the study. During an average follow-up of 13 years, there were 6,979 strokes among participants.
To determine the link between stroke and radon exposures, the researchers linked the participants' home addresses to radon concentration data from the U.S. Geological Survey and the U.S. Environmental Protection Agency (EPA).
Participants were divided into three groups. The highest group lived in areas where average radon concentrations were more than four picocuries per liter (pCi/L), exceeding the EPA's recommendations.
The middle group had homes in areas with average concentrations between two and four pCi/L. The lowest group lived in areas with average concentrations of less than two pCi/L.
The participants in the highest group had a 14% higher risk of stroke compared to those in the lowest group. Those in the middle group had a 6% increased risk.
"It's important to note that we found an increased stroke risk among those exposed to radon concentrations as much as two pCi/L below the current lung cancer-based threshold for recommending radon mitigation," Whitsel said.
However, the results should be generalized with caution, as the study included only females who were middle-aged and older and primarily white.
Moreover, the study does not prove that exposure to radon causes stroke; it only shows an association, emphasizing the need for further research.
Test your home for radon
Radon is responsible for about 21,000 lung cancer deaths in the United States every year. About 2,900 of these deaths occur among people who have never smoked, making radon the number one cause of lung cancer among non-smokers.
Testing your home is the only way to know your level of exposure, according to the EPA. Contact your state radon program for help in finding qualified professionals in your area.
According to the Centers for Disease Control, you should test your home for radon:
- If it's never been tested or radon levels are unknown
- When preparing to buy or sell
- Before and after any renovations, especially after making any repairs to reduce radon levels
- Before making any lifestyle changes in the home that would cause someone to spend more time in the basement or lower level (like converting a basement to a bedroom)
Although more studies are needed to determine if radon increases the risk of stroke, the relationship between the gas and lung cancer is well-established.
- Neurology. Radon exposure and incident stroke risk in the women's health initiative.
- American Academy of Neurology. Exposure to even moderate levels of radon linked to increased risk of stroke.
- U.S. Environmental Protection Agency. Radon.
- CDC. Test Your Home.