Guide to Radon

Read this PE Fact document to learn about the dangers of radon and how to prevent it from invading homes and buildings.

The second leading cause of lung cancer in the U.S. today is radon. The Environmental Protection Agency (EPA) estimates that exposure to radon causes roughly 21,000 fatal cases of lung cancer each year in the U.S. For every 1,000 non-smokers exposed to levels of radon that are double the EPA's recommended action level, approximately 15 will develop lung cancer. The odds of getting lung cancer jump to 120 victims per 1000 for smokers exposed to the same level of radon.

Even though the EPA's estimates clearly show that radon is deadly, this carcinogen is easily overlooked because it is imperceptible to humans. Another hazardous problem with radon is that people are typically exposed to it where they feel most safe – their homes. According to the EPA, approximately one out of every 15 homes in the U.S. has radon levels that are higher than tolerable.

Fortunately, this fatal problem is actually quite easy and relatively cheap for property owners to fix. The key to dealing with radon is awareness. Merely knowing what radon is, how to check for it and what to do if levels are too high are three easy steps in keeping your risk of dangerous exposure to a minimum.

What is Radon

Radon is a radioactive gas that is created through the breakdown of uranium inside the earth. It is invisible, odorless and tasteless, with no immediate health symptoms.

The primary way radon gas enters buildings is through holes and cracks in the foundation. Once inside, the levels of the gas become concentrated from being trapped. The EPA has suggested that an appropriate action level for radon is 4 picoCuries per liter (pCi/L). They recommend that quick action be taken to reduce the level of radon for any concentration above 4pCi/L.

According to the EPA, here are some examples of where radon can enter a structure:

• Cracks in solid floors
• Construction joints
• Cracks in walls
• Gaps in suspended floors
• Gaps around service pipes
• Cavities inside walls
• Water supply

Cracks in the foundation and walls should not be the only concern since radon can also enter a building through its water supply. This doubles the risk because there is a possibility of being exposed through inhalation as well as ingestion. According to a report published by the National Academy of Sciences (NAS) in 1999, drinking water contaminated by radon is the cause of 168 deaths from cancer each year. 89 percent of these deaths were from lung cancer due to inhaling radon released from the water, and 11 percent were from stomach cancer caused by drinking the poisonous water.

Radon-contaminated drinking water is found much more frequently in groundwater supplied systems (private and public wells) rather than surface water supplied systems.

How to Detect Radon

There are two simple test methods to detect and monitor radon gas, whether it is entering through the foundation or through the water supply. Passive radon monitoring is the most common test used. This test consists of placing passive monitors in certain areas of the building for a designated period of time and then sending them to a laboratory for testing.

There are short-term and long-term versions of the passive radon test. There is no special training necessary to perform these tests, so it is easy for property owners to execute them properly. Most hardware and home improvement stores carry radon test kits. They are also available through online retailers. If you are uncomfortable performing the tests by yourself, you can contact your state radon office to hire a qualified professional.

Short-term tests are the quickest method of passively monitoring radon in a facility. The sample media is placed in the test area for anywhere from two to 90 days before being sent into a laboratory for analysis. The test results are then mailed back to the kit owner.

Since radon levels are rarely consistent, changing seasonally or even daily, short-term tests may not give accurate results concerning the buildings radon level year-round. Long-term radon kits give a much better estimate of year-round radon levels.

Long-term test kits are very similar to short-term tests except that they are placed in the building for over 90 days. This extended period of time allows for a more precise measurement of the year-round radon level because it is not as affected by daily fluctuations.

The EPA established the following strategy to help property owners execute a passive radon monitoring program effectively:

Step 1. Take a short-term test. If your result is at or above 4 pCi/L, take another test (step 2) to be sure.

Step 2. Follow up with either a long-term test or a second short-term test.

• Take a long-term test for a more accurate indication of your year-round average radon level.
• If you need fast results, take a second short-term test.

The higher your original short-term test result, the more positive you can be that you should take another short-term rather than a long-term follow up test. You should take a second short-term test immediately if your first short-term test is more than twice the EPA's 4 pCi/L action level.

Step 3. If you follow up with a long-term test: Fix your home if your long-term test result is 4 pCi/L or more. If you follow up with a second short-term test: The higher your short term results, the more likely you should fix your home. You should also consider fixing your home if the average of the two short-term tests is 4 pCi/L or higher.

The alternative method for detecting radon gas is to use active monitors. Active monitors need a power source in order to provide a readout of radon levels instantaneously. Some units are capable of calculating short-term as well as long-term radon levels. Active radon monitors are usually more expensive than passive monitors but the prices are gradually dropping.

In most cases, you should perform your radon monitoring in the lowest occupied level of a facility. You should receive instructions concerning where to place the detector with the radon monitor you purchase.

The Centers for Disease Control and Prevention (CDC) suggests the following regarding radon in drinking water, "Before you test your water for radon, you should test the air. If the indoor radon level is high and you use groundwater, test your water. If the radon level is low in the air, there is no need to test your water. Test results are expressed in picoCuries of radon per liter of water (pCi/L). In general, 10,000 pCi/L of radon in water contributes roughly 1 pCi/L of airborne radon throughout the house. The U.S. Environmental Protection Agency (EPA) currently advises consumers to take action if the total household air level is above 4 pCi/L."

Solving Radon Problems

Even though the EPA believes that "no level of radon is safe," they established the level of dangerous exposure to radon at 4 pCi/L. Any concentration below that does not require immediate attention. You should re-test for radon at least every two years or anytime structural changes are made on a building.

What if the monitor reports radon levels of 4 pCi/L or higher? The EPA suggests that you contact your state radon office to get names of local, qualified or state certified radon contractors. The EPA advocates using radon remediation professionals because, "Lowering high radon levels requires technical knowledge and special skills. You should use a contractor who is trained to fix radon problems. A qualified contractor can study the radon problem in your home and help you pick the right method."

There are many techniques that can help reduce radon in your facility. The first step with most remediation plans is to close up any cracks and holes in the foundation of the building. Any cracks found in concrete floors or walls of the basements must be sealed. Caulk designed to repair concrete will do the job. If the building has a sump crock, the crock will need to be sealed and vented to the outside.

In cases where radon levels are reasonably low, sealing the cracks in the foundation and venting the sump crock may be enough to knock the concentration down below 4 pCi/L. However, the EPA does not suggest fixing the problem by using sealing alone because, "by itself, sealing has not been shown to lower radon levels significantly or consistently."

There are two ways qualified professionals solve radon problems in your home. One technique is to prevent radon from ever entering your home while the other reduces radon levels after it has already been detected inside. The EPA recommends using preventative measures that stop the radon from entering the building altogether. One example of this is soil suction. This technique draws radon out from underneath the foundation and vents it out to the air above the house where it will quickly diffuse, preventing it from entering the house.

The EPA's "Consumer's Guide to Radon Reduction" booklet has detailed descriptions of numerous techniques of radon remediation. It also provides cost estimates for the installation and operation of several radon removal systems. Installation costs typically range from $200 to $3,000.00. Operation costs usually run from $50.00 to $700.00 annually.

Problems with radon-contaminated water can be fixed through either point-of entry or point-of-use treatment systems. The CDC recommends the point-of-entry method. The CDC states, "…, it is important to treat the water where it enters your home (point-of-entry device) so that all water will be treated. Point-of-use devices such as those installed on a tap or under a sink will only treat a small portion of your water and are not effective in reducing radon in your water."

The EPA urges anyone with questions about radon in their water supply, both testing and treatment, to contact their state radon office or the EPA's Drinking Water Hotline at (800) 426-4791.

Commonly Asked Questions

Q. Are there requirements for test kits and the laboratories that analyze them?

A. Since you cannot see or smell radon, special equipment is needed to detect it. When you're ready to test your home, contact your state radon office for information on locating qualified test kits or qualified radon testers as some states have certain requirements to meet for their state programs. You can also order test kits and obtain information from www.sosradon.org.

Q. If I want to get my home tested for Radon, can anyone fix the problem? Who do I call?

A. EPA recommends that you use a certified or qualified radon mitigation contractor trained to fix radon problems. You can determine a service provider's qualifications to perform radon measurements or to mitigate your home in several ways. First, check with your state radon office. Many states require radon professionals to be licensed, certified, or registered, and to install radon mitigation systems that meet state requirements. Most states can provide you with a list of knowledgeable radon service providers doing business in the state. In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential, and if they follow industry consensus standards such as the American Society for Testing and Materials, ASTM, Standard Practice for Installing Radon Mitigation Systems in Existing Low-Rise Residential Buildings, E2121. You can contact private proficiency programs for lists of privately certified professionals in your area. Such programs usually provide members with a photo ID card, which indicates their qualifications and the ID card's expiration date. For more information on private proficiency programs, visit www.epa.gov/radon/radontest.html, or contact your state radon office.

Please Note: The information contained in this publication is intended for general information purposes only. This publication is not a substitute for review of the applicable government regulations and standards, and should not be construed as legal advice or opinion. Readers with specific questions should refer to the cited regulation or consult with an attorney.