Radon scarcely justifies the alarm. It is odorless, colorless, tasteless, a noble gas in the periodic table of the elements, the byproduct of the decay of uranium. Since uranium is widespread, the gas escapes constantly into the atmosphere. It is moderately soluble, so well water passing through uranium-bearing rocks emits radon upon contact with the air. They in turn decay, releasing alpha particles that can penetrate lung cells, damaging DNA and other cellular components.
Humans have the capacity to repair damaged DNA and do so regularly.
The agency, however, claims that the ionizing radiation produces irreversible damage that will lead inexorably to lung cancer. The miners themselves smoked, unknowingly increasing the cancer risk. Radon, however, remained a concern of homeowners in Western Mountain states until 1984 when Stanley Watras, an engineer, set off alarm bells by walking into a nuclear plant under construction in Pennsylvania. The EPA's approach fanned the flames. Miners who had inhaled radon showed a high incidence of lung cancer, so it was inferred that radon in the home posed a similar threat, despite much lower concentrations and quite different conditions.