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Dangerous Properties of Radon

Radon is a naturally occurring radioactive gas released from uranium found in all soils and rocks. Outdoors, radon is released and dissipates rapidly, causing minimal risk. Dangers arise when construction occurs on areas releasing radon and radon enters buildings through cracks, cavities and construction joints. Given the right geology, atmospheric conditions and inadequate ventilation, radon builds to dangerous levels. Approximately 8 million U.S. homes are estimated to have elevated radon levels, as do many schools and workplaces.

  1. Odorless

    • Being odorless makes radon gas an insidious killer. It cannot be detected except with special radon detector kits, meaning people may inhale it over long time periods without knowing they have been exposed.

    Tasteless

    • Radon can also enter water supplies--in some areas, levels can be high. Having no taste or odor means radon can go undetected. Water drawn from deep underground sources is most likely to be contaminated since radon in surface water dissipates rapidly into the air. Drinking water with high levels of radon can potentially damage stomach cells and is linked to 180 U.S. deaths annually. However, the risk is much less than with inhalation, and most ingested radon is rapidly exhaled.

    Invisible

    • Radon is colorless. This adds to the difficulty of detecting it in air or water. It also means that radon can be inadvertently included within some building materials. For example, wall boards made from phosphogypsum containing radium release radon, a product of radium decay. Such construction materials raise radon levels within buildings significantly. Concerns have also been raised about radon emissions from granite counter tops, a popular material in modern kitchens. The risk from granite counter tops is considered to be low, however.

    Radioactive

    • Inhaling radon particles exposes lung cells to alpha radiation. Alpha radiation does not penetrate human tissues as deeply as gamma radiation, but it does have the potential to permanently alter DNA where it does reach cell nuclei. Studies in Japan after Atom bomb exposure show clear links between radiation exposure and increased incidence of thyroid disease, liver disease, respiratory disease, cancer and stroke. Radiation is measured in becquerels---a measure of disintegration of radioactive atoms per second. Radon levels inside a home or workplace of more than 200 becquerels per cubic meter of air are considered actionable. Radiation levels vary with season, day and even time of day since ventilation of buildings varies with weather conditions and temperature.

    Carcinogenic

    • Exposure to radon increases a person's risk of lung cancer. Our knowledge of lung cancer among uranium miners, combined with studies of home owners in Sweden, suggests that the degree of increased risk rises with the length and intensity of exposure. In the worst exposed homes, radon levels approximate levels in mines The U.S. Environmental Protection Agency cites radon as the second most significant cause of lung cancer after tobacco smoke. Lung cancer is by far the most prevalent health risk of radon exposure. The effect of radon is more damaging in smokers.

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