Understanding Your Radon Test Results

General Information

Radon is a radioactive gas produced by the natural breakdown of uranium (which is present in soil and in rock formations throughout this country). Studies have shown that exposure to radon contributes to the incidence of lung cancer. This relationship between radon exposure and lung cancer is the primary basis for the EPA’s radon policy. The EPA advises you to take action to reduce the level of radon in your air if it exceeds 4.0 pci/L (picocuries per liter of air) in the lowest lived-in level of your home. The EPA is in the process of setting a national standard for a maximum recommended radon concentration in water through the Safe Drinking Water Act.

Radon in your Air

Radon gas rises through underground rocks and soil and collects around and under the foundation of your home. Radon enters your home through cracks and/or holes in the foundation. The highest concentration of radon will be found in the level of the home closest to the ground (usually the basement). The radon concentration decreases at each successive level above the basement.

Radon in your Water

Just as oxygen gas dissolves into lake water, radon gas dissolves into your well water underground. When radon is present in your water, there are two ways that it can affect your health.

  1. Radon escapes into the air when you wash your dishes or laundry, or when you shower or use the kitchen or bathroom sink. The more water you use, the more radon gas will escape into your air. In this case, radon from your water contributes to the level of radon in your air.
  2. Radon is ingested when you drink your water. The health effects from radon ingestion are currently being studied, and a federally recommended maximum level of radon in water is expected soon.

How Should I React to my Reported Radon Air Concentration?

  1. The EPA has advised homeowners to take action to reduce the radon in their home if the concentration in the lowest lived-in level exceeds 4.0 pci/L. This number was statistically generated based on a lifetime exposure of 18 hoursper day. When considering the risk you face from your reported radon concentration, remember to compare the amount of time you spend in the level of your home where the measurement was made to the 18 hour per day factor. You may wish to measure the radon in other levels of the home.
  2. The statistical risk factor is based on the entire population, but everyone has a different susceptibility to cancer. Your risk of getting cancer is also based on genetic factors, the environment you live in, and on your general health and lifestyle. For instance, the EPA and other health agencies have found that people who smoke are especially at risk from radon exposure.

How Should I React to my Reported Radon Water Concentration?

  1. The EPA is considering an upper limit of radon in public water supplies. When the level is agreed upon and finalized, it will provide us with a nationally recommended maximum level for our own water wells.
  2. Each New England state currently recommends an action level where private well owners should investigate water treatment to remove radon. The current action levels (picocuries per liter of water) by state are:
New Hampshire 2,000 Maine 4,000 Connecticut 5,000
Massachusetts 10,000 Vermont 4,000 Rhode Island 4,000

What if my Reported Radon Concentration Exceeds the Recommended Levels?

Consider the information above and make a personal ‘risk assessment’. You need to consider whether or not you are comfortable with the radon level you are faced with. If you are not, you should consider making repairs and/or installing a radon reduction system. You might make your own repairs. There are also companies that specialize in radon mitigation. We recommend you contact your state radon program for information and advice. You can also find information at the EPA website. Two national organization web sites list accredited radon mitigation companies. Follow the links to radon mitigation. (nrsb.org) (nrpp.info/) The good news about radon problems is that they can be reduced. If you install a radon reduction system, keep up with recommended maintenance and occasionally retest for radon to be sure the system is working.