The answer is Radon gas.
Radon is an odorless, tasteless, radioactive gas which comes from the natural decay of uranium in the ground. Because uranium is found virtually everywhere in the earth’s crust radon is also found almost everywhere. As the gas forms its moves through the ground and into the air above. Radon can move through small cracks in the foundation of a home, get trapped, and build up over time. In general most people receive more radiation exposure from the radon than from all other sources.
Radon was first identified as a possible cancer causing agent when it was noticed that uranium miners died of lung cancer at higher rates than normal. There results were confirmed when it was shown that rodents who were exposed to high radon levels formed higher rates of lung tumors.
Because radon is a gas it can be breathed into the lungs where it undergoes radioactive decay. Radon-222 has a half-life of 3.8 days and emits an alpha particle as it decays to polonium-218. The particles produced and damage DNA in the lung tissue and cause lung cancer over long periods of time.
Radon is the second leading cause of lung cancer, second only to smoking, and is estimated to cause about 21,000 lung cancer deaths per year. In fact, studies show that radon is the leading cause of lung cancer in people who have never smoked. Because of the dangers of Radon it is now possible to buy home testing kits.
© 2016 Steve Farmer
