What is Considered a High Radon Level?

N. Swensson

Radon is a colorless, odorless gas that is naturally present in the ground. Homes in areas with large deposits of radon underground can have higher levels of the gas, especially in basement areas where walls are underground. While any amount of exposure to radon gas is potentially unsafe, the United States Environmental Protection Agency (EPA) recommends that homeowners install a radon mitigation system if levels are 4 picocuries per liter (pCi/L) or higher.

Radon can work its way up through the floors and walls of a basement.
Radon can work its way up through the floors and walls of a basement.

Over time, exposure to a high radon level may cause lung cancer. It is relatively easy and inexpensive to conduct a home radon test. In some cases, radon tests are conducted as part of the sale of a home.

Difficulty breathing is a symptom of radon poisoning.
Difficulty breathing is a symptom of radon poisoning.

A home test is typically very inexpensive. These tests are often available from local environmental organizations or home improvement stores and take just a few days to complete. After the sample has been collected, it is mailed to a laboratory and results will typically be available in a week or two. If the home is found to have a high radon level, the EPA recommends installing a radon removal system.

The cost of installing a mitigation system will vary depending on the amount of radon present and the home's layout. A number of professional contractors provide radon removal services. In some cases, contractors will conduct their own initial testing to confirm the high radon level found in the home test. If the results are not the same, a longer-term professional test may be recommended, since radon levels can vary in a home and a number of factors can affect the results.

A radon removal system is most often located in the basement. A long pipe is inserted into the floor and draws air out from around the home's foundation, and then a fan moves the radon through the pipe to the outside for venting. The cost of the removal system depends on the extent of the problem and the home's specific characteristics. Contractors will often provide a guarantee that their system will reduce a high radon level to an acceptable level, which they will likely define as less than 4 pCi/L. They should usually back this guarantee with a second air quality test after the system is installed.

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Discussion Comments


I would like to see your data to support your claims, anon291392.


The threat of radon is not as great as the EPA would like you to believe unless you live in a underground mine. The EPA says that "the results do not conclusively demonstrate an excess risk in homes with elevated radon and are inadequate as a basis for quantitative risk estimation. Thus estimates of risk for indoor exposures must still be extrapolated using models derived from the miner data."

That's right. They're using "Miner Data". Not a great comparison, in my opinion. Someone is making money on this deal. And it's at the cost of uninformed citizens. The radon test is a policy practice not supported by science.

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