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Radon Risk Levels
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The Public Health Division recommends that all residences be tested for radon regardless of the risk level assigned to the home’s geographic location. Homeowners can easily do testing themselves by following these steps recommended by EPA. If the confirmed average radon concentration exceeds 4 pCi/liter, the Public Health Division and the Environmental Protection Agency recommend that measures be taken to lower the concentration below that level.

The data presented in the links below was compiled by the Oregon Public Health Division. It contains both long-term radon tests (more than 90 days) and short-term radon tests (2-90 days) that have been conducted primarily by homeowners. Indoor radon concentrations can be influenced by weather, season, geology, type of construction and heating, ventilation and air conditioning systems. Therefore, radon levels may not be consistent among a group of homes, even those next door to each other.

To understand how the radon risk scores (green/yellow/red rankings) were determined, please review the last page of Table of Radon Risk Levels in Oregon by Zip Code (pdf). Indoor radon concentrations are influenced by weather, season, geology, and type of construction as well as heating, ventilation and air conditioning systems. The maps and table provided here should not be used to substitute for radon testing of an individual home.

Additional information on testing, measurement services or mitigation contractors can be obtained from the Oregon Public Health Division, Radon Information Line (971) 673-0440.