Cause of High Radon Levels - Radon is an odorless, invisible, radioactive gas that rises from decaying uranium in the ground into the air we breathe. The decay process of uranium is very slow, which means the production of radon gas in soil is constant and won’t stop in any of our lifetimes.
When radon gas rises from the ground outdoors, it doesn’t create a health risk. However, radon also rises through the foundation of buildings and can cause serious health issues for people inside. Radon is the leading cause of lung cancer in nonsmokers in the U.S. and results in roughly 21,000 lung cancer deaths annually.
What Level of Radon Is Safe?
Radon is measured in picocuries per liter of air (pCi/L). According to the Environmental Protection Agency (EPA), the national average concentration of radon in outdoor air is 0.4 pCi/L. While technically no radon exposure is completely safe, 0.4 pCi/L is not considered a “high” or an “actionable” concentration of radon. However, once radon reaches 2.0 pCi/L in a building, the EPA recommends that residents consider action to reduce radon exposure. The World Health Organization (WHO) suggests taking action at 2.7 pCi/L, but even with this slight threshold difference, one thing is certain: We want to expose ourselves to as little radioactive gas as possible.
What Factors Impact How Much Radon Enters a Building?
The amount of uranium in the soil beneath a building is the primary factor that affects indoor radon levels. If uranium is present in the soil, there are a few additional factors that directly impact how high the radon concentration can be in a home:
- How porous or permeable the soil is below the home. Radon travels through most ground materials, but travels easier through a material like gravel compared to a material like clay.
- The time of year. The air pressure in a home is the driving force behind radon rising from deep in the soil into a building. Because the air pressure in a building changes with different seasons, conditions, and weather patterns, radon levels can vary throughout the year. For more information about how winter weather increases radon levels, check out this blog post.
- The building’s ventilation rate. Nowadays, homes are built more “airtight” to improve energy efficiency, but this can also trap more radon inside.
How To Reduce High Radon Levels
Installing a radon mitigation system is the only permanent solution to lower radon levels in a building. Radon mitigation systems are designed to stop most of the radon in the soil from entering the home in the first place, not remove the radon from inside the building. However, if you stop radon from entering a building, the indoor radon level significantly drops off.
Typically, a radon mitigation system consists of a 3- to 4-inch PVC pipe that runs from the soil beneath the home up to the roof. It contains a suction fan that continuously draws the radon from the soil and safely vents it above the building. Once a system is installed, we recommend retesting the home to ensure radon levels have been adequately reduced. After the building reaches an acceptable radon level, we suggest retesting the home every two years to catch any potential increase in radon levels that would require additional mitigation efforts.
How To Test a Home for Radon
Utah Radon Services offers one free, simple, at-home test for every resident in Utah. Click here to request your test. If your home tests high, we will gladly walk you through the process of mitigation.