New Hampshire is marking National Radon Action Month by offering free test kits so residents can check for the harmful gas in their homes.
Radon is a naturally occurring radioactive gas that can build to high levels in homes. State officials said many people don’t think about it because it has no color, taste or odor, but it is the second-leading cause of lung cancer after cigarette smoking.
The Department of Environmental Services is offering free air test kits while supplies last. Applications are available www.des.nh.gov

