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The City of Portland, Oregon

Fire & Rescue

Always Ready, Always There

Phone: 503-823-3700

Fax: 503-823-3710

55 SW Ash Street, Portland, OR 97204

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Protect Your Family From Radon

Each of us is exposed to a certain amount of radiation each day, most of which comes from natural sources such as radon. Radon accounts for the largest percentage -- more than half -- of radiation exposure that the average person in the United States receives.

What is Radon?

Radon is a naturally occurring radioactive gas that is odorless, tasteless, and colorless.  Radon gas is found throughout the world in varying concentrations. Radon forms naturally from the radioactive decay of Uranium in rock, soil, and water.  When radon gas is formed, it migrates through the soil to the air above.

Why is Radon Harmful?

Radon breaks down into solid particles know as radon decay products. These decay particles can become trapped in the lungs and may damage tissue by emitting radiation. Over time, exposure to elevated levels of radon increases a person's risk of developing lung cancer. This is the only known health effect. For smokers, this lung cancer risk is even higher.

Can Radon Enter My Home?

The major source of radon in a home comes from the ground beneath it. Radon moves up through the soil and enters through cracks and holes in the foundation. Radon gas can become trapped in a home and build to unhealthy levels. Radon can also enter a home through the water supply. Radon can be released into the air during showers and other household uses. However, radon from the water supply is most often minimal compared to ground sources. Any home can have a radon problem, including newly built, well-insulated, and homes with or without a basement.

Should I Test My Home for Radon?

The U.S. Surgeon General recommends that all homes be tested for radon. The U.S. Environmental Protection Agency (EPA) recommends taking a short-term test first that take from two to 90 days and allow for quick results.  If your short-term results come back between 4 and 8pCi/L, the EPA suggests following up with a long-term test to confirm your results.  Long-term tests run from 91 days to a year and can offer a more accurate measurement.  If your short-term results come back over 8 pCi/L, perform another short-term test to confirm the results.

RECOMMENDATION: If your test results are 4 pCi/L or higher, the EPA recommends that you take immediate measure to lower radon levels in your home.

Testing Your Home for Radon

To determine if you have high levels of radon in your home, you have a couple options:


  • Hire a Radon Measurement Company to Test Your Home
  • Perform a Radon Measurement Test Yourself: Radon detectors are inexpensive and easy to install. They are generally available in two types: alpha track detectors, which are used for long-term measurements, and charcoal canisters, which are used for short-term measurements. These devices are placed in living areas for a specific time period and then are sent to a laboratory for analysis. Before purchasing, verify that the radon detector meets the current requirements of the national certifying organizations such as the National Radon Safety Board (NRSB) or the National Environmental Health Association (NEHA) and is approved by the Environmental Protection Agency (EPA).

Where Can I Purchase Radon Detectors?

Link here for contact information and a list of measurement companies that can provide radon kits and/or perform radon measurement services in Oregon. You can also purchase a radon measurement test kit from your local hardward or home improvement stores.

The American Lung Association of Oregon provides test kits for a cost that includes shipping the test results to a laboratory and laboratory results being mailed back you. Click here to learn more. 

Please note that Portland Fire & Rescue does not have radon kits for purchase or donation.

What If the Test Reveals High Level of Radon?

The important thing is not to panic.  Radon levels can fluctuate widely over time.  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 fan, and vents the radon outside. Sealing cracks and holes in the foundation makes this technique more effective.

Click here for a list of mitigation companies servicing Oregon that have been certified by NEHA or NRSB. Current listings of certified companies can also be found at their respective web sites, and


Link here to the State of Oregon's Radiation Protection Services - Radon Gas official website for additional radon information and resources. 

Updated 05/27/10