The top two causes of lung cancer in the United States are cigarettes and exposure to the natural gas radon, according to the American Cancer Society. The risk of lung cancer is even greater when a smoker has contact with radon gas. That reality makes radon gas a major environmental hazard, especially since about 1 in 15 homes has high radon levels, according to the U.S. Environmental Protection Agency.
Features
The odorless, invisible, tasteless and radioactive gas radon forms when the natural element uranium decays. Found both inside and outside, the gas is a health hazard to humans because of the tiny radioactive alpha particles it emits. Uranium is present in most soil and some rocks and water. The radon gas it produces as it breaks down can enter homes and other buildings through openings in the structure, such as cracks in the basement area, foundation and walls.
History
Interest in the health risks of radon existed before the element was even discovered, according to the American Cancer Society. In 1556, Georgius Agricola, a German scientist, noticed the high number of deaths of Eastern European miners. Three centuries later, autopsies of miners in that region revealed that many had chest tumors subsequently identified as lung cancer. Research conducted in the 1950s confirmed that alpha particles are radioactive, and epidemiologic investigations from the same time period established the link between lung cancer and exposure to radon gas.
Health Risks
The radioactive alpha particles that radon emits can cause health problems after inhalation because their energy is capable of altering DNA permanently, explains the American Cancer Society. The harmful effect occurs when alpha particles come into contact with the nuclei of cells. Although exposure to radiation from alpha particles causes no symptoms right away, the radiation damages lung cells, which increases the risk of developing lung cancer.
Detecting Radon
Because radon gas has no color, odor or taste, the only way to know if it is present in a home or building is to use a radon test kit. Such test kits are available for short-term and long-term evaluation. Examples include charcoal liquid scintillation and continuous monitor short-term kits, which require two to 90 days, and alpha track and electret detector kits, which take longer than 90 days.
Considerations
Average radon levels are approximately 0.4 pCi/L--or 0.4 picocuries in one liter of air--outside and 1.3 pCi/L indoors, according to the EPA. Although no level of radon gas is considered safe, the agency recommends taking action to reduce radon gas levels when testing indicates they are 4 pCi/L or greater. The EPA also advises testing all homes for radon gas every two years and aiming for levels of 2pCi/L or lower. Radon contractors can install systems that pull radon from the home and vent it outdoors.
