What is Radon?

Radon is a cancer causing, radioactive gas. You cannot see it, smell it or taste it. Radon is produced by the natural breakdown of uranium in soil, rock and water. High levels of radon have been found in every state in the US. One in fifteen homes in the US have radon levels above 4 picocuries per liter (4pCi/L), the EPA action level.

Effects of Radon?

Radon is the second leading cause of lung cancer in the United States. Of the 160,000 lung cancer deaths annually in the United States, about 12% are due to radon exposure. The remainder is due to smoking. According to the National Academy of Sciences, radon is estimated to cause about 21,000 deaths per year.

How it enters the body?

Radon and its decay products are inhaled, and the decay products become lodged in the lungs where they can radiate the cells lining the respiratory system. The radioactive decay products of the radon emit alpha particles that are damaging to these tissues. Exposure to elevated levels of radon greatly enhances the risk of lung cancer. Even small exposures to radon can result in increased cancer risk. Smoking combined with radon poses a very serious risk. The effect of radon among smokers is about 9 times higher than in non-smokers.

Sources of Radon?

Radon gas can enter a home from the soil under the house by process of diffusion through concrete floors and walls, and through cracks in the concrete slab, floors, or walls and through floor drains, sump pumps, construction joints and cracks or pores in hollow-block walls. Normal pressure differences between the house and the soil can create a slight vacuum in the basement, which can draw radon from the soil into the building. The design, construction and ventilation of the home can affect the radon levels of the home. Well water can be another source of indoor radon. Radon released by well water during showering or other activities may release radon gas into the home. Radon in water is a much smaller factor in radon exposure than radon in soil. Radon exposure outdoors is much less of a risk than indoors because the radon is diluted to low concentrations by the large volume of air.

Where to test?

The EPA recommends that all residences below the third-floor level be tested for radon. In addition, the EPA also recommends testing all rooms in contact with the ground or over crawlspaces in schools. If you have tested your home, you should retest every two years since radon levels can change with structural changes in the home. If you decide to use a lower floor of your home, such as a basement, you should test this level before occupancy. In addition, you should always test prior to the purchase of a home.


How to test?

Using a test kit that meets the EPA requirements, place the test kit in the lowest level of the home suitable for occupancy, at least 20 inches above the floor. The test kit should not be placed in the bathroom or kitchen, where the humidity and use of fans could affect the test results. If a short-term test lasting less than 4 days is conducted, doors and windows should be closed 12 hours prior to and throughout the testing period. If the test lasts up to 7 days closed house conditions are recommended. Short term testing should not be done during severe storms or periods of unusually high winds.

Radon levels high?

You have tested your home for radon and confirmed that you have elevated radon levels — 4 picocuries per liter (pCi/L) or higher. The EPA recommends that you take action to reduce your home's radon levels if your radon test result is 4 pCi/L or higher. High radon levels can be reduced through mitigation.