But at lower concentrations, like at home, every emitted particle counts. Radioactivity is dangerous at any level and even the low levels of radon gas outdoors are not harmless. The higher the radon level in one's home, the higher the radioactive dose to the family. Due to the synergistic effect of the two leading carcinogens, smoking and radon, the risk to smokers is 5 times higher than to never-smokers. A given radon concentration will kill 5 times more smokers than non-smokers.
Radon is the most studied of all carcinogens.
The government, being sued by nuclear plant workers dying of various cancers, was denying for many years that low-level radiation causes cancer. Finally, a large-scale epidemiological study, the most substantial ever, was conducted on the lung cancer risk of radon in homes. The Iowa Radon Lung Cancer Study, led by the University of Iowa, took five years and its results were published in May, 2000. It conclusively proves that indoor radon causes excess lung cancers and that the risks are proportional to the radon exposure. All rights reserved.