Radon and Smoking — Combined Effects
The combined health effects of radon and tobacco exposure are synergistic , so reducing either of the exposures substantially reduces lung cancer risk . The median age of lung cancer diagnosis is 70 years , with approximately 91 percent of cases occurring in people older than age 55 . 6 Studies of radon-exposed underground miners have demonstrated that the minimum latency period for lung cancer is 5 years and that radon exposure occurring 5 to 15 years prior to the development of lung cancer carries the greatest risk per unit exposure . 7 Because approximately 37 percent of U . S . adults have smoked at some time in their life , reducing radon exposure in this segment of the population — even if smoking cessation occurs later in life — can reduce the risk of lung cancer considerably . 8
Lifetime Risk of Lung Cancer Death from Radon Exposure in Homes
RADON LEVEL ( pCi / L )
Risk Is Shown per 100,000 Individuals
NEVER SMOKERS CURRENT SMOKERS GENERAL POPULATION 20 3,600 26,000 11,000 10 1,800 15,000 5,600 8 1,500 12,000 4,500 4 730 6,200 2,300 2 370 3,200 1,200 1.25 230 2,000 730 0.4 73 640 230 Estimated Risks at the EPA Action Level ( 4 pCi / L ) Never Smokers 7 / 1000 | Smokers 62 / 1000