Medical scientists have found a statistically significant link between levels of residential radon and risks for several cancers of the blood, particularly in women, say researchers from the American Cancer Society. Radon, a gas that is the naturally occurring decay product of radium, has been long substantiated as a cause of lung cancer. The cancer society lists it as the second-leading cause of lung cancer in the United States.

Studies to date on radon gas and cancers such as leukemia, lymphoma and multiple myeloma have shown inconsistent results. But a statistical analysis of the data from the society’s own Cancer Prevention Study-II Nutrition Cohort, which had 140,652 participants, found 3,019 cancers of the blood. They traced the fate of these patients over 19 years of follow-up.

More than 171,000 new cases of hematologic cancer and more than 58,000 deaths are expected in the United States in 2016. These cancers are the most expensive to treat, experts from the society said in a statement Friday. The new research is reported in the online edition of the journal Environmental Research.

The team, led by cancer society epidemiologist Lauren Teras, found that women living in counties with the highest concentrations of radon had a 63 percent higher risk of these cancers compared with women who lived in counties with the lowest radon levels. Teras and her colleagues also found evidence of a dose-response relationship: the greater the radon concentration, the more likely one of these forms of cancer will occur.

But Teras and her team said even with the new finding, the risk is not worrisome.

“The overall lifetime risk of hematological cancers in the United States is about 2 percent, so even a 60 percent relative increase would still mean a relatively small absolute risk,” she said, noting “radon is already associated with lung cancer, and if other studies confirm the link to blood cancers, we think it would warrant strengthened public health efforts to mitigate residential radon risks.”

Teras suggested that radon may have an effect on the bone marrow, the site in the body where blood cells are produced. That possibility, however, has yet to be confirmed.

The gas is most prevalent in regions with rich underground stores of certain natural radioactive elements, but there are other sources as well, experts said Friday.

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.