Radon Testing for Portland-Area Homes: Why Test and How It Works

Radon is one of the few home hazards you can't see, smell or hear. It is a radioactive gas that forms naturally as uranium in soil and rock breaks down, and it can seep into a house through cracks in the foundation, gaps around pipes and open crawlspaces. Once inside, it can build up, especially in lower levels with little air movement.

Why it matters

The U.S. Environmental Protection Agency names radon the leading cause of lung cancer among people who have never smoked, and the second leading cause overall. The risk comes from breathing elevated levels over many years, which is why it is worth knowing the level in the home where your family will live.

Is radon a concern around Portland?

Yes, in places. Parts of north and northeast Portland are known for higher readings, and the Oregon Health Authority encourages every Oregon household to test. Radon levels can differ a great deal between two houses on the same street, so a neighbor's result tells you very little about yours. The only way to know is to test the house itself.

What the numbers mean

Radon is measured in picocuries per liter of air (pCi/L).

• 4 pCi/L or higher: the EPA recommends fixing the home.
• Between 2 and 4 pCi/L: the EPA suggests considering a fix.
• Below 2 pCi/L: generally no action is recommended.

How a short-term test works

A short-term test runs for at least 48 hours in the lowest lived-in level of the home. For a reliable result, windows and outside doors should stay closed as much as possible during the test and for 12 hours before it starts, apart from normal coming and going. Fans that bring in outside air should be off, and the test device should be left where it is placed.

If you are buying, we recommend scheduling the radon test together with the home inspection. It costs less when bundled than on its own (see the pricing page), and the result arrives while you are still inside your inspection window.

What if the result is high?

High radon is a fixable problem. Radon mitigation, usually a pipe and fan that draws gas from under the house and vents it above the roof, is a well-understood repair done by mitigation contractors. Buyers often negotiate the cost with the seller. After a system is installed, test again to confirm it is working.

Book a radon test

TRUELINE offers radon testing across the Portland metro and Willamette Valley. You can schedule online or call us at 971-712-6868.