. >> reporter: the specialist terry howell says it can accumulate in old and new homes and office buildings, high rises and schools. and exposure to raidon can pose a serious health risk. >> most people think smoking is primarily the cause of lung cancer and they are right. but raidon is the second most common cause. >> reporter: smokers lungs arey mighted and because your neighbor doesn't have it in their home doesn't mean you are in the clear. >> it's in every state virtually every county. there's some areas that have higher concentrations than others and unless you test you don't know where they are. >> reporter: the epa website has testing kids. >> if the radon test results are above the recommended action level, you should consider contacting a professional. >> reporter: and fix any problems as soon as possible. for today's health minute, i am elizabeth cohen. >>> the holiday season, it's easy to get lost in the lights and sounds and parties and presents and it's easy to forget billions will wake up each morning hope to survive the night. >> beginning this friday, abc news will take a

. >> reporter: radon specialist terry howell says it can accumulate in both old and new homes. also in office buildings. highrises, even schools. and exposure to radon can pose a serious health risk. >> most people think that smoking is primarily the cause of lung cancer and they are right but radon seems to be the second most common cause. >> reporter: smoking increases the risk of cancer from radon because smokers' lungs are already compromised. just because your neighbor doesn't have radon in their home doesn't mean you're in the clear. >> radon is in every state, virtually every county, there's some areas that have higher concentrations than others. unless you test for it you don't know where those are. >> reporter: the epa web site has instructions on testing kits and potential fixes. >> if your radon test results come back above the epa recommended action level then you should consider contacting a professional. >> reporter: and fix any problems as soon as possible. for today's health minute, i'm elizabeth cohen. >> back-to-back fire alarms, just horrible news in east bal