A study of more than 700 counties across multiple U.S. states found a link between childhood leukemia and levels of decaying radon gas, including those lower than the federal guideline for mitigation.
The findings are important because there are few established risk factors for cancer in children and the role of the environment has not been explored much, said Oregon State University's Matthew Bozigar, who led the research. Radon, a naturally occurring gas, is a product of the radioactive decay of uranium, which is present in certain rocks and soils. Upon escaping from the ground, radon itself decays and emits radioactive particles that can get within the body and collect in many tissues, where they can damage or destroy the cells' DNA, which can cause cancer.
Odorless, tasteless and colorless, radon gas dilutes quickly in open air and is generally harmless before it decays, but indoors or in areas with poor air exchange, it can easily concentrate to dangerous levels and is recognized as a significant risk factor for lung cancer. Radon, measured with small, passive detectors and mitigated through passive or active ventilation in basements and crawl spaces, has not been linked to other cancers, according to the World Health Organization. But in an 18-year statistical modeling study of 727 counties spread among 14 states, Bozigar and collaborators not only found a connection between childhood leukemia and radon, but at concentrations below the Environmental Protection Agency's .