Every year, an estimated 20,000 Americans die of lung cancer caused by exposure to radon — a naturally occurring radioactive gas that often finds its way into indoor air. That's about half the number that die in car crashes. Yet detecting radon and remedying it are easy and inexpensive.

EPA has declared January National Radon Action Month. It's a good time for environmental reporters to look at the many specific ways radon impacts their audience and the things people can do to protect themselves.

While the geological formations in some parts of the country release more radon than the formations in others, radon problems have been found in every county in the US. EPA estimates that about 8 million US homes have radon above the recommended "action level." The Surgeon General has recommended that all homes be tested.

Odorless and colorless, radon seeps into basements through foundation gaps. But homeowners can buy kits at the hardware store to detect it. Problems can usually be remedied with specific kinds of inexpensive ventilation and sealing.

For local media, the story can be covered from many angles beyond the environmental beat. It involves building code, real estate, do-it-yourself, public health, and small business stories.

Radon can also be found in drinking water that comes from wells.

• EPA Release of Jan. 6, 2010. [2]
• EPA Radon Page. [3]
• EPA Map of Radon Zones. [4]
• World Health Organization: International Radon Project. [5]