10% are at risk of radon exposure

Up to 460,000 people, or about 10% of the population, are at risk of exposure to radon, a radioactive gas that causes lung cancer.

That’s according to a new risk map based on not just indoor radon data, but also geological data, giving a more detailed breakdown of the radon risk facing the public.

Traditionally such maps, produced by the Environmental Protection Agency (EPA), are solely based on indoor radon measurements.