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Radon FAQs

Frequently Asked Questions (FAQ)

What is radon?

Radon is a radioactive gas found in soil and rock.  You can't see, smell, or taste it.

Why is radon dangerous to human health?

Radon can cause lung cancer and is thought to be responsible for over 13% of lung cancer deaths. Radon gas moves up through the soil and can be drawn into your home. Once inside, radon becomes trapped and can build up to unsafe levels. As you inhale radon gas, small particles get trapped in your lungs and release tiny bursts of energy (radiation) called alpha particles. This damages your lung tissue and can lead to lung cancer over time.

How does lung cancer impact the health of Americans?

Lung cancer is the #1 cancer killer in the U.S. The National Cancer Institute found that while 9 in 10 people diagnosed with skin cancer live at least five years after diagnosis, only 1 in 6 people diagnosed with lung cancer are still alive five years after diagnosis. One reason lung cancer is so deadly is that it is hard to find in its early stages. Symptoms usually do not appear until the cancer has spread to other parts of the body.

Should people who smoke tobacco be especially concerned?

Yes. Only smoking causes more lung cancer deaths than radon. If you smoke and your home has high radon levels, your risk of lung cancer is especially high.

Visit The Risk of Living with Radon, found in EPA's A Citizen's Guide to Radon, to see risk comparison of smoking and radon.

Besides lung cancer, does radon cause any other human health effects?

Breathing radon does not cause any short-term human health symptoms such as shortness of breath, coughing, headaches, or fever. There is no conclusive evidence that children are at greater risk than adults from radon. Currently, there is also no conclusive evidence that radon exposure leads to an increased risk of contracting other cancers or diseases.

Can people be screened or tested for radon exposure?

At this time, Oregon Health Authority (OHA) is not aware of any standard medical screenings that determine lung damage related to radon exposure. The best way to find out your risk of radon exposure is to test your home.

The Centers for Disease Control (CDC) does provide information on screening tests that are available for lung cancer. It is recommended for those who have a history of smoking and are between the ages of 55-80 years old.

Are there some areas in Oregon that have higher radon levels than others?

Yes. There are some areas of Oregon that have been found to have higher radon levels. NW Oregon, including the Columbia Gorge and Willamette River Valley, tends to be the areas of greatest known concern for radon exposure. The geology for much of Eastern Oregon would suggest high risk, but unfortunately, not enough radon testing has been done to know what the actual risk is in much of the state.

However, you should not assume that your home will have low/high radon levels based on what the already reported (or unreported) levels in your neighborhood.

The only way to know whether your home has elevated radon levels is to test it.

How can I get an inexpensive radon test kit?

Kits can be found at hardware stores for $15 to $30. Check and see if the cost of the analysis is included in the test kit price. Some test kits charge for analysis in addition. You can also find test kits at either of the following:

I’m selling/buying a home – How do I get radon results quickly?

Currently, radon testing is not required for real estate transactions under Oregon law. It is still a good idea to test for radon for the health of the people who live there.

Radon measurement (testing) companies are often hired when the results are needed quickly (like in the 10-day inspection period of a home sale). A list of radon Measurement Companies in Oregon is on our website

If your radon concern is related to a real estate transaction, you may be interested in EPA’s Home Buyer's and Seller's Guide to Radon (pdf).

How can I find a radon measurement (testing) company in Oregon?

A list of radon Measurement Companies in Oregon is on our website. Assuming you follow the basic instructions on a test kit that you purchased yourself, the accuracy of your results will be very close to that of a professional test result, and significantly less expensive.

Can I test my home for elevated radon myself?

Yes. Testing your home is simple and inexpensive. Please see our Testing for Radon Gas webpage for more information on radon testing.

I don't need to test because I live in a new house and I don't have a basement, right?

Not necessarily true - elevated radon levels can occur in just about any house in all areas of Oregon. The only way to know is to test your home.

What are the different types of radon test kits?

There are two general ways to test for radon:

  • Short-term test kits - Remain in your home for two to 90 days and are usually less expensive. These tests allow you to gain results quickly, but they only measure a small window of time.
  • Long-term test kits - Remain in your home for at least 90 days, and are usually more reliable to determine your homes year-round average radon level.

To understand which type of test kit is right for you, we suggest reading the advantages and disadvantages of each type of kit at Types of Radon Gas Testing.

What is a safe level of radon?

There is no safe level of radon. However, the Environmental Protection Agency (EPA) has set an action level of 4.0 pCi/L in homes and schools. The World Health Organization recommends that a home be mitigated when its confirmed radon level is 2.7 pCi/L or above.

Above all, the goal of radon reduction is risk reduction. To find out more on why you should test and why 4.0 pCi/L is the EPA recommended action level, go to National Radon Program Services webpage.

I just found out my home has confirmed elevated radon levels. Should I tell my healthcare provider?

Receiving high radon test results (i.e. 4.0 pCi/L or above) may be discouraging if you've lived in the home for a long time. Try not to be alarmed. The next step is to mitigate. It is also recommended that you inform your family physician of the radon exposure to inform their medical decision-making in the future.

National Radon Program Services has additional information on lung cancer screening and radon exposure. Breathing Easier shows how healthcare providers can discuss radon with their patients.

My home has confirmed elevated radon levels. How do I “fix” (or mitigate) it?

Reducing radon levels in your home requires technical knowledge and skill, and typically involves hiring a radon mitigation contractor. The most common approach to mitigating a radon problem is referred to as sub-slab depressurization or sub-slab suction. This technique draws radon-filled air from beneath the foundation through a pipe using a continuously running fan, and vents the radon outside. Sealing cracks and holes in the foundation makes this technique more effective. You can learn more about residential radon mitigation from EPA-funded National Radon Program Services.

You can see a diagram of the sub-slab depressurization system here.

Which radon mitigation companies does OHA recommend?

OHA cannot make recommendations of any particular radon company or service.

A list of radon Mitigation Companies in Oregon is on our website. Companies on this list have at least one radon mitigation technician on staff who has been certified by the National Radon Proficiency Program (NRPP) or the National Radon Safety Board (NRSB). Current listings of certified mitigation technicians in Oregon can be found at their respective websites, and

This list should be used for informational purposes only and is not intended to be an endorsement by the Oregon Health Authority of any mitigation company. The private companies listed on the webpage are provided as a convenience. The State of Oregon does not regulate, certify, endorse or sponsor their products, services or information.

These organizations are not the only sources of radon services.

What should I consider when choosing a radon mitigation company?

We recommend that you consider the following:

  • Use a certified or qualified radon mitigation professional. You can find a list of qualified professionals here.
  • Choose a contractor to fix a radon problem just as you would choose someone to do other home repairs - get estimates and ask for/check references. Consider knowledge, experience, pricing and the mitigation techniques they plan to use.
  • Ask if they can guarantee (in a written contract) that the radon in your home will be reduced to a certain level.

The EPA's Consumer's Guide to Radon Reduction has provided a checklist to help guide you when evaluating and comparing contractors and also specific questions to ask.

*Oregon does not have state regulations that govern how companies mitigate radon. Most mitigation companies follow technical standards/recommendations made by the EPA or the American Association of Radon Scientists & Technologists, Inc. (AARST). Many radon mitigation companies in Oregon reduce radon levels by using a method called sub-slab depressurization (see diagram on the left-hand side of the page).

Is financial assistance (loans) available to help homeowners pay for radon mitigation?

U.S. Dept. of Housing & Urban Development (HUD) has the Section 203(k) program that may be used to finance radon mitigation systems. To locate an approved lender, search HUD’s Lender List or call HUD’s customer service at 1-800-225-5342.

Nationally, some carriers of employee health savings accounts (HSAs) now consider radon mitigation as a qualified medical expense; check with your HSA about this possibility for you. At this time, the State of Oregon does not offer financial assistance to homeowners for radon mitigation.

Can I put in my home’s radon mitigation system myself?

It is possible (and legal in Oregon) for a homeowner to put in a radon mitigation system into their home themselves. We don’t recommend it unless you have specialized radon mitigation knowledge. Radon mitigation is not just a matter of putting a hole in the ground that’s attached to a fan. Constructing an effective system requires in-depth knowledge of air-pressure differences and the use of special equipment to test them. Those considering a DIY approach should understand that if mitigation is done incorrectly, it is possible to make your radon problem worse.

What about radon in well water?

Your water supply is also a source for the radon in your home's indoor air, but radon entering your home through the soil is usually a much larger risk. Most of your risk from radon in the water comes from radon released into the air when water is used for showering and other household purposes. A radon in water problem is more likely when its source is groundwater (private well or public water supply system that used groundwater). If you have tested the air in your home and found a radon problem, and your water comes from a well, have your water tested.

If you've already tested your home and private well, and have a radon in water problem, it can be fixed. For more information, see the Citizens Guide to Radon - Radon in Water. You can also call the Environmental Protection Agency's Drinking Water Hotline at (800) 426-4791.

What about radon in granite countertops?

Radon in natural stone and building materials, such as granite countertops, may contain low levels of uranium. However, these are typically not major contributors to the radon levels in a home. Most of the time radon is coming from the soil beneath the home. No approved sampling or testing methods exist to test granite for radon at this time. See EPA's Granite Countertops and Radiation.

When radon decays into particles in a dusty place like an attic, do I need to take special precautions when cleaning?

Exposure periods in attics would likely be very short. Radon levels in attics are not a concern in almost all circumstances. Radon decay products coming from the radon are short-lived radioactive elements (with half-lives of minutes to fractions of a second) and will plate out to surfaces in the environment or attach to dust particles in the air. Cleaning any space with high levels of dust would warrant a dust mask to reduce exposure to the dust particles, but the risk from radon decay products would be far less significant than what might be in the dust, such as fiberglass, or other fibers coming from what is being disturbed in the attic.

Does radon pose a threat to organic produce in a home garden?

No. Radon does not pose a risk through uptake from the soil into vegetables or other plants. Eating plants with radon in them has not shown to be any risk. Radon decay in the digestive tract poses a fundamentally insignificant risk due to the very low exposure potential for DNA/cell damage when compared to the lungs.

What is Radon Resistant New Construction (RRNC)?

Under Oregon statute (ORS 455.365), RRNC is required in all public buildings (including schools) and residences built after April 1, 2013, in seven Oregon counties (Baker, Clackamas, Hood River, Multnomah, Polk, Washington and Yamhill). The 2017 Oregon Residential Specialty Code defines the standards approved by the Residential Structures Code Program within the Oregon Building Codes Division.

The intent of RRNC is for new homes, schools, and other buildings to be built to prevent radon from accumulating at harmful levels. The builder installs specific components of radon mitigation system while the building is still under construction. The additional cost at the time of construction is considered minimal compared to after construction is completed. This intervention is a primary prevention strategy. RRNC reduces the risk and incidence of lung cancer by removing radon risk entirely.

RRNC techniques greatly reduce the lung cancer risk that may occur from radon in the home. It is important to note that RRNC buildings may still have elevated levels of radon. Radon testing should still be done after construction is completed.

What about radon in schools?

School buildings are the second leading source of radon exposure for students and school employees.

The EPA began investigating radon in schools in 1988. The initial studies show that there were elevated levels of radon in schools in every state. A later study, the National School Radon Survey, showed that 19.3% of all U.S. schools (nearly one in five) have at least one frequently occupied room with short-term radon levels above the U.S. EPA action level: (≥4.0 pCi/L).

Under ORS 332.341 and 332.345, school districts were required to submit a testing plan for schools to Oregon Health Authority (OHA) by September 1, 2016. Testing must be done before January 1, 2021.

Visit Testing in Oregon Schools page for more information.

Should students, staff, and visitors be allowed in school buildings that have rooms with confirmed radon levels at 4.0 pCi/L or higher?

According to EPA, how quickly to mitigate depends on the urgency of the situation as dictated by the radon level detected. Very elevated radon concentrations (e.g., several times the action level or around 10 pCi/L) demand a quicker response. In addition, if radon levels are near 100 pCi/L or greater, school officials should call their State Radon Contact and consider relocating until the levels can be reduced.

Radon averages 1.3 pCi/L inside structures and 0.4 pCi/L inside homes and buildings across our country. It is impossible to “get away” completely from radon. The overall goal of radon reduction is risk reduction. Large buildings have many rooms and the radon levels in each room may vary. Sometimes those levels can be quite different from each other.

We have started follow-up testing at my home or school after the first radon test was high. What do I do in the meantime to reduce risk?

Radon levels in a home or school can vary dramatically over the course of a year or even a day. That's why initial, short-term tests with a result of 4.0 pCi/L or more must be followed by a second test so you have a firm basis for decision making.

The central health concern is radon exposure over an extended period of time, not during relatively short periods like while testing for radon. Similarly, an individual's lifetime radon exposure depends on radon levels at all locations where they regularly spend time (i.e. school and work). Here are a few short-term risk reduction practices you can perform while testing your home or school for radon:

  • If you are a smoker, stop smoking. Or at least cease smoking inside the areas where you found high radon levels.
  • If the high levels were found at home, check in with your neighborhood school about their testing plan.
  • If the high levels were found at school, encourage local residents to test their homes.

What about students with special needs, chronic conditions or who are medically fragile? Are there radon guidelines specific to these populations?

Neither EPA nor OHA has specific guidance on radon for these populations. Breathing radon does not cause any short-term human health symptoms such as shortness of breath, coughing, headaches or fever. Children (who have higher respiration rates than adults) have been reported to have greater risk than adults for certain types of cancer from radiation.

However, no conclusive data exists at this time on whether children are at greater risk than adults from radon. There is no conclusive data at this time that radon exposure causes illnesses other than lung cancer.

What is the best time of the year to test my home for radon?

The best time to test for radon is during the heating season (winter months). This when you would expect to find the highest radon levels in your home. That is because a closed house keeps radon from escaping outside. When indoor air is warmer than outside air, it creates a vacuum effect that pushes the warm air out and replaces it with naturally occurring radon from the soil under the home.

What if I suspect/find elevated radon levels in a home that I rent? What are my tenant rights related to radon?

Find out if the home has been tested by asking your landlord. If your landlord has tested previously, you can request a copy of the results. If the home has not been tested, you can ask the owner to test or you can test yourself. Find out more about types of testing on our Testing for Radon page.

Take a look at the EPA's A Radon Guide for Tenants. This is a valuable resource that summarizes the steps above and how to move forward with reducing your risk if high levels of radon are found.

Oregon does not have any specific radon standards or regulations for rental homes at this time. However, if you or your landlord need more information on measurement and/or mitigation, please contact us.

What are the HUD Requirements for Radon?

The U.S. Department of Housing and Urban Development (HUD) has policy and notification requirements pertaining to radon, found here

The Oregon HUD Office has information about tentant rights and resources

The EPA, HUD and AARST worked together to establish requirements for radon testing and mitigation in multifamily housing. Effective May 28, 2016, HUD’s Multifamily Accelerated Processing (MAP) Guide was updated to include revisions to the radon testing and mitigation policy outlined in Mortgagee Letter 2013-07. These updates supersede Mortgagee Letter 2013-07. More information is available here