Radon Toxicity

Radon is a radioactive gas and one of the most important sources of ionizing radiation to humans. Radon exposure is the leading cause of lung cancer in nonsmokers. It is estimated to cause around 21,000 deaths annually, and the World Health Organization estimates that 3 to 15% of all lung cancer worldwide is due to radon toxicity. Radon is tasteless, odorless, and colorless, with no warning signs of exposure. Naturally occurring in the environment, it is the decay product of uranium-238 and radium-226 and can be found in the soil, rocks, and ground worldwide. Its main decay product has a half-life of 3.5 days, so there is substantial time for diffusion to take place in homes, particularly basements. It can also exist in water supplies and remain entrapped in homes. It tends to build up in large quantities in areas with poor ventilation, and high levels can eventually cause health concerns, particularly lung cancer. As an extremely dense and highly radioactive gas, it can damage the respiratory epithelium by emitting alpha particles. Recently, a statistically significant linear relationship has been found between increased radon concentrations and an increased risk for lung cancer. In 1988, the International Agency for Research on Cancer categorized radon and its decay products as IARC Group 1 carcinogens.  Given that it is imperceptible by color, taste, or smell and causes no obvious symptoms of irritation or exposure, measuring radon levels is the only way to know if a high exposure level exists. Abatement and mitigation within the home can decrease the risk of exposure and cancer development from the radiation emitted.