Radon is after smoking the second leading cause of lung cancer. Among non-smokers, radon is the No. 1 cause of lung cancer deaths. The National Academy of Sciences estimates that radon causes about 19,000 lung cancer deaths in the U.S. each year. That's more than fires, drownings and airplane crashes combined. How radon causes cancer Radon gas spontaneously decays into minute solid particles, which lodge in the lungs and emit radiation for over 20 years.
Alpha radiation damages the DNA in living cells, causing cancerous and genetic mutations.
The onset of carcinoma may take decades. The average person receives more effective radiation exposure from radon than from all other natural or man-made sources combined. Children are particularly susceptible to radiation. Public warnings are regularly issued about carcinogens at levels thousand times less lethal than the average radon level in American homes. Most lung cancer deaths from radon are preventable.