Radon FAQs

Radon is a colorless and odorless gas that can enter homes and other buildings. Elevated concentrations over long periods of exposure can increase the potential for lung cancer.
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Radon is a colorless and odorless gas that can enter homes and other buildings. Elevated concentrations over long periods of exposure can increase the potential for lung cancer.
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Radon is a known human carcinogen. It is very easily detected, measured and mitigated. The benefit of reducing health risks in relation to the costs of doing so is very good. Simple, inexpensive tests allow people to measure their radon exposure and decide if radon should be reduced through mitigation repairs.
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The US EPA and the US Surgeon General’s office have established that people should avoid long-term exposure to radon concentrations greater than 4.0 pico curies per liter of air (4.0 pCi/L) or concentrations of radon decay products greater than .02 Working Levels (.02 WL).
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Radon is a colorless and odorless gas that can enter homes and other buildings. Elevated concentrations over long periods of exposure can increase the potential for lung cancer.

That is between you and your listing agent. No Arizona law requires radon testing.

There is no Arizona law that requires a seller to reduce indoor radon. If radon tests reveal elevated levels, any decision to mitigate is usually a result of negotiations between the buyer and seller.

The testing procedure recommended helps measure the radon potential of the home. To save time, a short-term test of minimum duration (48 hours) is usually conducted. The proper location for the test is in the lowest livable portion of the home. If there is an unfinished basement that may be occupied later, it would be the proper location for the test device. The test should be done with the doors and windows closed in order to determine the "worst case" potential.
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What were the actual radon readings? The US EPA recommends that homes at or above 4 pCi/L or .02 WL be mitigated, if tested using EPA guidance. You may need to obtain a copy of the test report to determine the estimated health risk. Reducing radon in a home that contains radon below 4.0 pCi/L may be difficult or impractical, although there is still some risk associated with concentrations below that recommended "action level."

Radon is quite variable from house to house, even in the same subdivision. The only way to know the level of radon in a house to test it.

The US Surgeon General and the EPA have identified radon as a Type A human carcinogen. After you have tested a home, you can use research-based information on health risk to make an informed decision about whether to purchase or mitigate a property.Want to know more?
 

Surveys have shown that roughly one out of fourteen homes in Arizona may have radon concentrations at or above the recommended action level of 4.0 pCi/L. That is similar to the national average. The incidence of radon is quite variablefrom one area to another, and even from home to home. The only way to know is to test.
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Although there are maps that portray areas of higher potential, they are not precise enough to indicate whether an individual home will have radon above recommended levels.

There is no state or local law in Arizona that requires radon testing at the time of resale. However, the EPA and the US Surgeon General recommend that all homes be tested; and a radon test can be easily done as part of a home inspection process.

You should discuss this with your agent. Radon testing is not mandatory in Arizona.

All homes contain some amount of radon. Radon levels can be reliably reduced to less than 4.0 pCi/L. Effective and durable systems have been developed for reducing radon.

Yes. There are trained contractors who can install mitigation systems. If you talk to one of these contractors you should request a written proposal that includes guarantees resulting concentrations will be less than 4.0 pCi/L.
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Proven techniques exist for reducing radon levels in homes to below 4.0 pCi/L. If you decide to buy the house, you can ask that the seller fix it before you move in, or you can move in with assurance that radon levels can be reduced afterward.

Be specific about an acceptable radon level. It is also a good idea to say who will be doing the radon test and who will pay for it. If elevated radon levels are found, will mitigation be acceptable? Who will pay for the repairs? If mitigation is necessary, who will perform the work and who will determine whether the mitigation was successful?
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The Arizona Radiation Regulatory Agency (ARRA) does not regulate or certify radon testers or mitigation specialists.

Contractors are licensed and regulated in Arizona by the Arizona Registrar of Contractors (ROC). Radon testers or mitigation specialists may need to be licensed by the ROC. You can contact the ROC as follows:

Within Maricopa County: (602) 542-1525
Toll free: 1-877-MY AZROC (1-877-692-9762) 
Website: www.azroc.gov

There are national certification programs that require participants to successfully complete training courses and follow established EPA protocols. EPA recommends that you hire a contractor that is certified. To find qualified radon contractors, EPA recommends that you contact one or both of the two privately run national certification programs listed below. You can find a listing of certified individuals through their websites as follows:

National Environmental Health Association
National Radon Proficiency Program (NEHA NRPP)
Address: PO Box 2109, Fletcher, NC 28732
Phone: (800) 269-4174; (828) 890-4117
Fax: (828) 890-4161
Email: angel@neha-nrpp.org
Website: neha-nrpp.org

National Radon Safety Board (NRSB) 
Address: PO Box 703, Athens, TX 75751
Phone: (866) 329-3474
Fax: (903) 675-3748
Email: info@nrsb.org
Website: www.nrsb.org

Yes. Do-it-yourself home radon test kits are easy to use and are readily available. If you feel comfortable placing a device in a room and mailing the device to a laboratory, then you are certainly capable of performing a home radon test. Just remember to write down the date and time the test begins and ends. However, when the test is for the purpose of a real estate transaction, it is usually suggested that a certified professional conduct the test.

You can purchase a do-it-yourself kit from some hardware stores or other retail outlets. Most of the kits range in price from $10 to $20. The cost usually includes the test device, the price of postage to mail the detector back to the laboratory, and the written report you receive by return mail.

When you purchase the test kit, look at the packaging to ensure the manufacturer is certified by one of the national certification programs (NEHA NRPP or NRSB).

There are several devices on the market. EPA recommends that you begin with a short-term test device placed in the home for a minimum of two days. The devices in most home test kits are actually small containers of activated charcoal. Look for kits approved by one of the national certification programs (NEHA NRPP or NRSB).

If you perform the short-term test and the results are higher than 4.0 pCi/L, the EPA recommends you take further action. The next step should be to retest the home on a long term basis, ideally for a year, then decide if mitigation is necessary.

However, if the initial short-term test finds radon levels are significantly elevated, such as 10 pCi/L or more, you may want to repeat the short term test using a different test device to confirm the radon is still elevated. You can then average the two results and base your mitigation on the average.

The health risk from radon is cumulative, increasing over time if the radon level is elevated but not corrected. The health risks from radon occur over a long period of time and radon concentrations vary from season to season. An average radon level, measured over all four seasons, is a better indicator of actual health risk over time.

On the other hand, if your initial readings are significantly elevated, you should take action to quickly confirm these readings and then proceed to mitigate the home. Again, you may want to repeat the short-term test, using a different test device to confirm the radon is still elevated, then average the two results and base your mitigation on the average.

If the test is being conducted for a real estate transaction, you will want the test device placed in the lowest livable part of the home. Otherwise, the test device should be placed in the lowest lived-in area of the home. A crawl space is not an appropriate location. If the lowest level of the home is a basement and you spend time there, then that is a good place to test. However, if you spend essentially no time in the basement, you will want to test the lowest lived-in level, preferably in a bedroom or a family room. Avoid placing the test device in a kitchen, closet, or bathroom.
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Yes, durable and effective techniques have been developed that can economically reduce radon in new or existing homes and other buildings.
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In Arizona, the cost of a radon mitigation system installed by a certified contractor can be $2,000 or more, although EPA often cites a national average of $1,200 to $1,500. The actual cost may depend on the contractor, the construction, and foundation type of the home, location of the home site, and aesthetic factors. For instance, a vent-pipe system routed outside of the home may cost less to install than one routed through an interior closet and attic space. EPA suggests that you obtain bids from certified contractors and compare costs.

Yes, a nationally certified contractor has received technical training and education, follows EPA protocols and has successfully passed a proficiency examination.
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Merely sealing the openings into a home will not reliably reduce radon. A system that draws the radon from beneath the foundation and exhausts it to the outside is the preferred approach. If you do choose to attempt to reduce radon by sealing, be sure to use proper materials and to retest the home to verify adequate radon reductions.
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There’s no reliable to sample the soil ahead of time and predict what the radon levels will be in a house after it is completed. This is primarily because there is so much disturbance of the soil during construction. When soil is excavated to provide space for a concrete foundation, new pathways are created for radon and other gases to travel through the ground. In turn, that affects how radon will travel below the floor of the new home and the ease with which radon can enter. It is also difficult to accurately predict how construction features that make a home energy-efficient will impact indoor radon concentrations.

Studies of indoor radon concentrations and surveys of underlying geology indicate radon potential can differ from one area to another. Radon is quite variable and homes with radon concentrations above recommended levels have been found in different parts of every state. EPA recommends that radon-resistant construction features be included in new homes where the average radon level in existing homes exceeds 4.0 picocuries per liter of air (pCi/L). For example, counties identified as "Zone 1" areas by the EPA's National Map of Radon Potential meet the criteria. However, none of Arizona's 15 counties fall into the "Zone 1" category, based on existing survey data.

It is not currently a requirement in Arizona that radon resistant construction techniques be utilized. You need to ask your builder if he or she plans to install such features. A few builders have included passive mitigation systems in homes within some residential areas, but most builders do not routinely install them.

The builder or a radon contractor can cover the floor of the crawl space with a flexible plastic sheet forming a gas-resistant barrier. Radon and other soil gases that collect beneath the plastic can be collected and exhausted to the outside, using a piece of perforated pipe that is placed below the plastic and connected to a riser pipe that exits above the roofline. The plastic used to cover the crawl space floor should be a high-density material secured to the foundation walls with caulking, for a proper seal.

The U.S. EPA has free publications that explain proven ways to make new homes radon-resistant. One such publication is entitled "Building Radon Out" (EPA/402-K-01-002). This and other helpful publications can be found at the EPA radon information website.

Depending upon the construction and the size of the house, it can be very affordable to incorporate radon-resistant features in the construction of the home. It can be as little as $300 if done by the builder or subcontractors when the home is constructed.

Properly installed, radon-resistant construction features can help ensure against potential future radon concerns. However, you should not automatically assume the system is effective. The only way to be sure is to test the house for radon after you move in. 
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If the radon levels are higher than desired, a small durable exhaust fan can be added to the passive vent pipe, substantially increasing the system's ability to draw radon from beneath the floor of the home. 
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In addition to removing radon, moisture can also be removed from the soil, which can assist in drying out basements and can help avoid mold and mildew in crawl spaces.