Jefferson County Public Health wants people to test their homes for a harmful natural gas.
Public Health is giving away 100 free radon testing kits in Watertown.
About half of the homes in the county that have been tested had high levels of the gas.
Radon is the leading cause of lung cancer for non-smokers, so public health officials say it's important to test your home.
"It's odorless. You can't know unless you test and it causes about 20,000 lung cancer deaths a year in the U.S. So it's really important to know, and it's a simple mitigation, you can simply get rid of it in most cases," said Faith Lustik, Public Health planner.
If you can't pick up a radon test kit at Jefferson County Public Health, you can purchase it on the state's website.