Frequently Asked Questions: Indoor Exposures - Radon
Select a question below, or scroll to see all available information.
- What is radon?
- What are health risks of radon exposure?
- Should I test my home for radon?
- Are levels of radon below 4pCi/L considered safe?
- If my neighbor's home has low levels of radon can I assume my home is safe?
- How can I fix my radon problem?
- What are some ways radon can be prevented while building a new home?
|Q: hat is radon?|
Radon (Rn) is a naturally occurring
radioactive gas produced by the breakdown of uranium in soil, rock, and
water. Because the air pressure inside a home is often lower than the
pressure in the soil underneath and surrounding a home’s foundation, a
home acts as a vacuum and draws the gas through foundation cracks and
other openings. Radon levels are
often represented as picocuries per liter of air or pCi/L. The average
indoor air radon level is 1.3 pCi/L of air. The average outdoor ambient
level is 0.4 pCi/L. Radon is odorless and colorless. On a
are the health risks of radon exposure?
inside the home, radon and it’s decay products can be inhaled into the
lungs, resulting in cellular damage that can lead to disease. Radon
exposure is the 2nd leading cause of lung cancer (tobacco
smoke being #1) and it is estimated that in the
A: The only way to know your radon level is to test. Tests can be either short term (2-90 days) or long term (> 90days). Short term tests are inexpensive and available at the Health Department and local hardware stores. Test kits are also available at the radon hotline 1-800-SOS-RADON (767-7236).
A: The EPA has established that a level of 4pCi/L is the action level or the level above which homes should be fixed. Does this mean that it is safe if you are at 3.9pCi/L? The answer is no. There is no safe level of radiation. A radon level of 4.0pCi/L is equal to 200 chest x-rays per year or 16 cigarettes per day. The U.S. Congress has set a long-term goal that indoor radon levels be no more than outdoor levels, about 0.4 pCi/L.
A: Radon levels can vary wildly between homes. Variability in the housing techniques, age, materials, heating/air conditioning systems, geological features, venting, floor spaces, additions, foundation, plumbing, etc. all can influence levels. The only way to know your radon levels is to test.
|Q: How can I fix my radon problem?|
Locate a qualified radon
There are a variety of techniques used by contractors to mitigate radon levels including subslab suction, sump hole suction, submembrane suction in crawlspaces, sealing cracks, house pressurization, and air-to-air heat exchange. Since the house acts as a vacuum and draws radon inside, often times the most effective way to mitigate radon is to simply apply stronger suction to the soil underneath the house and vent it through a pipe to the outside air above the home.
|Q: What are some ways radon can be prevented while building a new home?|
Build the home to be radon
resistant. A number of the same approaches used in mitigating (sealing,
passive and active depressurization, etc.) can be more easily applied
during the initial phases of construction than after a home has been
built. Radon-resistant new construction has many advantages over
remediation including aesthetics and efficiency. Additionally, the EPA
has recently developed a new building label called Indoor airPLUS. The
building practices incorporated as part of this label maximize radon
reductions, moisture control, HVAC, and pest control. From the EPA’s
“By constructing homes that meet EPA's Indoor airPLUS specifications, builders can distinguish themselves by being among the first recognized by EPA to offer homes designed to truly deliver better indoor air quality. Participating builders can expect higher levels of quality assurance, improved reputation, reduced callback and warranty costs, and less business risk. Partners are also eligible to use Indoor airPLUS marketing materials and tools to help promote their qualified homes, access technical and marketing assistance, and receive awards. Go to http://www.epa.gov/indoorairplus to find out more information
Also see the publication: Building Radon Out: A Step-by-Step Guide On How To Build Radon-Resistant Homes on the EPA website (http://www.epa.gov/radon).