Radon Seasonal Levels

Radon is one of the most dangerous of indoor air pollutants. It is especially dangerous because it is virtually undetectable. It is odorless, tasteless and colorless. According to the National Cancer Institute, radon is the second leading cause of lung cancer deaths in the U.S. If radon levels are high in your home, the more time you spend inside increases your risk. However, radon concentrations may show seasonal variations due to environmental and lifestyle factors.

Source

Radon is a naturally-occurring substance. This radioactive gas is a byproduct of the decay of uranium which is found in the Earth's crust. Concentrations of uranium vary geographically, with the greatest amounts found in the northern United States through the East Coast. Even if you live in an area where concentrations are low, the U.S. Environmental Protection Agency (EPA) warns any building may have a radon issue.

Seasonal Variations

Radon seeps into your home from the area around it. The soil can emit radon around your home. The concentrations will vary seasonally, based on the amount of seepage occurring and the ventilation in your home. Presumably, the amount of radon will be highest during the winter months, when you are least likely to have windows open in your home. Ventilation will dissipate the radon in the air. However, a similar scenario may occur in summer as well if you run your air conditioning through the summer months. If your unit is a closed air system, radon concentrations likely will increase.

Considerations

Environmental factors play a role in seasonal fluctuations of radon. A 2008 paper presented at the American Association of Radon Scientists and Technologists International Symposium found climate conditions in winter favored the greatest seasonal concentrations of radon. Ice or snow cover prevents radon in the soil from escaping into the atmosphere. Also, air pressure differences between indoor structures and the soil cause radon to be drawn indoors.

Radon Testing

One way you can detect seasonal and average radon levels is through testing. There are two types of tests: short-term and long-term. Short-term tests run anywhere from two to 90 days, depending upon the test. During short-term testing, you replicate winter conditions by keeping windows and doors closed to contain radon indoors. The test shows the radon for that particular time period. For a more accurate assessment, use a long-term test, which will last longer than 90 days.

Prevention/Solution

If testing reveals high levels of radon, you should hire a radon mitigation contractor. The EPA provides a convenient search function on its website to help you locate a certified professional in your area. The contractor will likely find ways to prevent radon entering your home. He or she may suggest sealing your foundation, windows and doors in your home to prevent seepage from the soil. The contractor may also recommend the installation of a radon reduction system.