EPA Recommends:

  • If you are planning on buying a home or selling your home, have it tested for radon.
  • For new homes, ask if radon resistant construction features have been used.
  • Fix the home if the radon level is 4 picocuries per liter (pCi/L) or higher.
  • Radon levels less than 4 pCi/L still pose a risk, and in many cases may be reduced.
  • Take steps to prevent device interference when conducting a radon test.

Radon is estimated to cause thousands of cancer deaths in the U.S. each year.



EPA has developed this guide to help home buyers and sellers address 8 key questionsabout radon:

  1. Why Do You Need to Test for Radon?
  2. If You Are Selling a Home, What Should You Do?
  3. If You Are Buying a Home, What Should You Do?
  4. If You Are Buying a Newly-Built Home, What Should You Do?
  5. How Can You Get Reliable Radon Test Results?
    1. Types of Radon Devices
    2. Length of Time to Test
    3. If You Conduct A Short-Term Test
    4. Using Testing Devices Properly (If You Do The Test Yourself)
    5. EPA’s Testing Checklist
    6. Getting Reliable Test Results (If You Hire a Professional Radon Tester)
    7. Interpreting Radon Test Results
  6. What Should You Do If You Find a High Radon Level?
  7. Radon Myths/Facts
  8. Where Can You Get More Information about Radon?

This guide is for anyone buying or selling a home who wants to learn about radon.

Radon is a cancer-causing, radioactive gas

You cannot see radon. And you cannot smell it or taste it. But it may be a problem inyour home. That is because when you breathe air containing radon, you increase your riskof getting lung cancer. In fact, the Surgeon General has warned that radon is the secondleading cause of lung cancer in the United States today. If you smoke and your home hashigh ration levels, your risk of lung cancer is especially high.

You should test for radon

Testing is the only way to find out your home’s radon levels. EPA and the SurgeonGeneral recommend testing all homes below the third floor for radon.

You can fix a radon problem

If you find that you have high radon levels, there are ways to fix a radon problem.Even very high levels can be reduced to acceptable levels.

If you are selling a Home.

EPA recommends that you test your home before putting it on the market and, ifnecessary, lower your radon levels. Save the test results and all information you haveabout steps that were taken to fix any problems. This could be a positive selling point.

If you are buying a Home.

EPA recommends that you obtain the indoor radon level in a home you are consideringbuying. Ask the seller for radon test results. If the home has a radon reduction system,ask the seller for information about the system.

The radon testing guidelines in the “Home Buyer’s and Seller’s Guide toRadon” have been developed specifically to deal with the time sensitive nature ofhome purchases and sales and the potential for radon device interference.

The guidelines in the “Home Buyer’s Guide” are somewhat different from theguidelines in other EPA publications which provide radon testing and reduction informationfor non-real estate situations. The “Home Buyer’s Guide” recommends threeshort-term testing options when long-term testing is not possible. The “Home Buyer’sGuide” also recommends testing a home in the lowest level of the home which iscurrently suitable for occupancy. This is because a buyer may choose to live in a lowerarea of the home than that used by the seller.

1. Why Do You Need To Test For Radon?

Radon Has Been Found In Homes All Over the U.S.

Radon is a radioactive gas that has been found in homes all over the U.S. It comes fromthe natural breakdown of uranium in soil, rock and water and gets into the air youbreathe. Radon typically moves up through the ground to the air above and into your homethrough cracks and other holes in the foundation. Your home can trap radon inside.Sometimes radon enters the home through well water (see page 24 for more information aboutradon in water).

Any home can have a radon problem. This means new and old homes, well-sealed and draftyhomes, and homes with or without basements. In fact, you and your family are most likelyto get your greatest radiation exposure at home. That is where you spend most of yourtime.

Nearly 1 out of every 15 homes in the U.S. is estimated to have elevated radon levels.Elevated levels of radon gas have been found in homes in your state. Contact your stateradon office (see table)for information about radon in your area.

EPA And The Surgeon General Recommend That You Test Your Home

Testing is the only way to know if you and your family are at risk from radon. EPA andthe Surgeon General recommend testing all homes below the third floor for radon.


Do not rely on radon test results taken in other homes in the neighborhood to estimatethe radon level in your home. Homes which are next to each other can have different indoorradon levels. While radon problems may be more common in some areas in the local communityor state, any home may have a problem. Testing your home is the only way to find out whatyour radon levels are.

2. If You Are Selling A Home,What Should You Do?

a. If your home has already been tested for radon.

If you are thinking of selling your home and you have already tested your home forradon, provide your test results to the buyer. Review the testing Checklist  to makesure that the test was done correctly.

No matter what kind of test you took, a potential buyer may ask for a new testespecially if:

  • you took a test and the Checklist items were not met;
  • you have renovated or altered your home since you tested;
  • the buyer plans to live in a lower level of the house than you do, such as a basement which is suitable for occupancy but is not currently lived in; or
  • your state requires disclosure of radon information to buyers.

b. If the home has not yet been tested for radon.

Have a test taken as soon as possible. If you can, test your home before putting it onthe market because this may save time during real estate transactions. You should test inthe lowest level of the home which is suitable for occupancy and finished. This meanstesting in the lowest level that you currently live in or a lower level not currentlyused, but which a buyer could use for living space without renovations. The result of theradon test is important information about your home’s radon level that potential buyersmay want to

You can test your own home or hire an EPA listed or state certified radon tester. Callyour state radon office (see pages 29-31) for a list of these professional radon testers.If you test your own home, carefully follow the Checklist.

3. If You Are Buying A Home,What Should You Do?

a. If the home has already been tested for ration.

If you are thinking of buying a home, you may either decide to accept the test resultsfrom the seller, ask the seller to do another test, or you may ask for a new test to beconducted by an EPA listed or state certified radon tester.

If you decide to accept the seller’s test, make sure that the seller (or whoever tookthe test) followed the testing Checklist and that he orshe can confirm that all the items were followed. If you plan to use the seller’s test,find out as soon as possible from the seller:

  • the results of the previous test; and
  • who conducted the previous test: the homeowner, a radon professional, or some other person; and
  • where in the home the previous test was taken, especially if you may plan to live in a lower level of the home. For example, the test may have been taken on the first floor; however, you may want to live in a basement which is not currently lived in, but which is suitable for occupancy without renovation.
  • what, if any, structural changes or alterations have been made to the house since the test was done. Such changes might affect radon levels.

If you decide that a new test is needed, you should discuss it with the seller as soonas possible. If you decide to use an EPA qualified or state certified radon tester,contact your state radon office (see pages 29-31) for a list of radon testing companies.

b. If the home has not yet been tested for radon.

Make sure that a radon test is done as soon as possible. You should consider includingprovisions in the contract specifying who should conduct the test, what type of test todo, when to do the test, and how the seller and the buyer will share the test results,test costs and, if necessary, when radon reduction measures should be taken and who shouldpay for them.

Make sure that the test is done in the lowest level of the home suitable for occupancy.This means the lowest level that you are going to use as living space which is finished ordoes not require renovations prior to use. A state or local radon official or an EPAlisted or state certified radon tester can help you make some of these decisions.

If you decide to finish or renovate an unfinished area of the home in the future,ration tests should be taken before and after the area is finished. Radon reduction costscould be incurred if high levels are found in that area. Generally, it is less expensiveto install a radon reduction system before or during renovations rather than afterwards.

4. If You AreBuying A Newly-Built Home, What Should You Do?

New homes can be built with radon resistant features that minimize radon entry andallow easier fixing of radon problems that could occur later. These features cost less ifinstalled during construction than if added to an existing home. In most new homes, use ofradon resistant features will keep radon levels to below 2 pCi/L.

Builders can incorporate radon resistant features into the homes they build. Somestates, counties and local jurisdictions may adopt radon resistant construction featuresin their building codes, which builders must then follow. Radon resistant constructionstandards can be applied depending on the radon potential in a particular area. Manybuilders already use radon resistant building features.

New home buyers should ask if radon resistant construction techniques have been builtinto the new home they are considering for purchase. Buyers should also ask whetherinformation about radon is available. For custom-built homes, the buyer should discussradon resistant features with the builder including the cost.

Occupants of newly constructed should have their homes tested for radon. A long-termtest will provide a reading that more representative of the home’s average radon level.However, short-term (as described on page 13) may be used determine if elevated radonlevels exist.

5. How Can You Get ReliableRadon Test Results?

Even though you cannot see or smell radon, it is not hard to find out if you have aradon problem in your home.

a. Types of Radon Devices

Since you cannot see or smell radon, special equipment is needed to detect it. You canbuy radon devices in retail stores when you want to test your own home, send away forradon devices from laboratories that offer mail order services, or you can hire an EPAlisted or state certified radon tester who will test using radon devices that areappropriate for the situation.

Preventing or Detecting Test Interference

There is a potential for test interference in real estate transactions. There are anumber of ways to prevent or detect test interference such as:

  • Print-out report which frequently records radon or decay product levels to detect unusual swings;
  • Motion detectors to determine whether the test device has been moved or testing conditions have changed;
  • Proximity detectors to reveal the presence of people in the room which may correlate to possible changes in radon levels during the test;
  • Record of barometric pressure to identify weather conditions which may have affected the test;
  • Temperature record to help assess whether doors and windows have been opened; and
  • Taping windows shut to ensure closed house conditions (see page 16).

Home buyers and sellers should evaluate these and other features when selecting a radontest alternative. Refer to the “Protocols for Radon and Radon Decay Measurements inHomes” for information about radon testing devices and associated device interferencefeatures.

Some of the most common radon testing devices are listed below. Because new testingdevices may be listed by EPA or your state, you may want to check with your state radonoffice before you test to get the most up-to-date information.

Passive Devices

Passive radon testing devices do not need power to function. They include radondetectors such as charcoal canisters, alpha-track detectors, and charcoal liquidscintillation devices that are available in hardware stores, drug stores, other stores,and by mail, and electret ion chamber detectors generally only available throughlaboratories. They are exposed to the air in the home for a specified period of time andthen sent to a laboratory for analysis. Both short-term and long-term passive devices aregenerally inexpensive. Some of these devices may have features that offer more resistanceto test interference or disturbance than other passive devices. Professional radon testersmay use any of these devices to measure the home’s radon level.

Active Devices

Active radon testing devices require power to function. Active radon detectors such ascontinuous ration monitors and continuous working level monitors require operation bytrained testers. They work by continuously measuring and recording the amount of radon orits decay products in the air of the home. Many of these devices provide a report of thisinformation which can reveal any unusual or abnormal swings in the radon level during thetest period. A professional tester can explain this report to you. In addition, some ofthese devices are specifically designed to deter and detect test interference. Currently,some of the technically advanced active devices offer the most extensive deviceinterference features. Although these tests may cost more, they may ensure a more reliableresult.

General Information for All Devices:

A state or local radon official can explain the differences between devices andrecommend the ones which are most appropriate for your needs and expected testingconditions. In addition, EPA’s Radon Measurement Protocols include technical informationabout the differences between devices.

Make sure the radon device is listed by EPA’s testing program or is state-certified.The device may display the phrase “Meets EPA Requirements” or “EPAlisted.” Your state radon office or a radon tester can tell you more about radontesting devices.

Certain precautions should be followed to avoid interference during the test period.Refer to the Checklistfor more information about how to get a reliable test.

In some areas, companies may offer different types of radon service agreements. Someagreements let you pay a one-time fee that covers both testing, and if needed, radonreduction. Contact your state radon office to find out if these are available in yourstate.

Radon Test Device Placement

The testing device(s) should be placed in the lowest level of the home suitable foroccupancy. This means testing in the lowest level currently lived in or a lower level notcurrently used, such as a basement, which a buyer could use for living space withoutrenovations. The test should be in a room to be used regularly (like a living room,playroom, den or bedroom) but not a kitchen, bathroom or laundry room.


b. Length of Time to Test

There Are Two General Ways To Test Your Home for Radon:


Long-term tests remain in your home for more than 90 days. Alpha track, and electretion chamber detectors are commonly used for this type of testing. A long-term test willgive you a reading that is more likely to tell you your home’s year-round average radonlevel than a short-term test. If time permits (more than 90 days) long-term tests can beused to confirm initial short-term results between 4 pCi/L and 10 pCi/L. When long-termtest results are 4 pCi/L or higher, EPA recommends fixing the home.


The quickest way to test is with short-term tests. Short-term tests remain in your homefrom two days to 90 days, depending on the device. There are two groups of devices whichare more commonly used for short-term testing. The passive device group includes alphatrack detectors, charcoal canisters, charcoal liquid scintillation detectors, and electretion chambers. The active device group consists of different types of continuous monitors.(see pages 11-12 for more information.) Because radon levels tend to vary from day to dayand season to season, a short-term test is less than a long-term test to tell you yourround average radon level. However, if need results quickly, short-term testing be used todecide whether to fix the home.

c. If You Conduct a Short-Term Test .

If you are testing in a real estate transaction and you need results quickly, any ofthe following three ways to conduct Short-Term Tests are acceptable for determiningwhether the home should be fixed. Any real estate test for radon should include steps toprevent or detect device interference (see pages 10-12).



Take an initial short-term test for at least 48 hours. After the first test has beencompleted, take a follow-up short-term test for at Fix the home if the least 48 hours.average of two tests is 4 pCi/L or more. or

Take two short-term tests at the same time in the same location for at least 48 hours.


Fix the home if the average radon level is Test the home with a continuous 4 pCi/L ormore. monitor for at least 48 hours.


There are trade-offs among the short-term test options. One test followed by anothertest (sequential) would most likely give a better representation of the seasonal average.Two tests taken at the same time (simultaneous) would improve the precision of the radontest. Both active and passive devices may have features which help to prevent testinterference. Your state radon office can help you decide which option is the best foryou.

d. UsingTesting Devices Properly (If You Do the Test Yourself)

When you are taking a short-term test, close your windows and outside doors and keepthem closed as much as possible during the test, except for normal entry and exit. If youare taking a short-term test lasting less than 4 days, be sure to close your windows andoutside doors at least 12 hours before beginning the test, too. You should not conductshort-term tests lasting less than 4 days during severe storms or periods of high winds.

Place the test device at least 20 inches above the floor in a location where it willnot be disturbed and where it will be away from drafts, high heat, high humidity, andexterior walls. Leave the test kit in place for as long as the test instructions say. Onceyou have finished the test, reseal the package and send it immediately to the labspecified on the package for analysis. You should receive your test results within a fewweeks. If you need results quickly, you should find out how long results will take and, ifnecessary, request expedited service.


Follow this Checklist carefully so that you get the most accurate radon test results.

Radon testing is not a complicated process, but must be done properly. Otherwise, thetest results may not be accurate and more testing may have to be done. Disturbing orinterfering with the test device or closed-house conditions will invalidate the testresults.

The seller, or an EPA listed or state certified tester, should be able to confirm thatall the items in this Checklist have been followed. If the tester cannot confirm this,another test should be taken.

Before the radon testing:

  • Notify occupants of the importance of proper testing conditions. Give occupants written instructions or this document and explain the directions carefully.
  • If you conduct the test yourself, use a ration measurement device listed by EPA’s Ration Measurement Proficiency (RMP) Program or certified by your state and follow the manufacturer’s instructions that come with the device.
  • If you use a testing professional, only hire an EPA listed or state certified individual and ask to see his or her photo identification. The contractor’s identification number should be clearly visible on the test report.
  • The test should include method(s) to prevent or detect interference with testing conditions or with the testing device itself.
  • Conduct the radon test for a minimum of 48 hours. Certain devices must be exposed for more than the 48 hour minimum.
  • Check to see if an active radon reduction system is in the house. Before taking a short-term test lasting less than 4 days, make sure the fan, if any, is operating at least 24 hours before the beginning of the test.
  • EPA recommends that short-term radon testing which lasts for no more than a week in length, be done under closed-house conditions. Closed-house conditions means keeping all windows closed, keeping doors closed except for normal entry and exit, and not operating fans or other machines which bring in air from outside. Note that fans that are part of a radon reduction system or small exhaust fans operating for only short periods of time may run during the test.
  • When doing short-term testing lasting less than 4 days, it is important to maintain closed-house conditions for at least 12 hours before the beginning of the test and for the entire test period. Do not operate fans or other machines which bring in air from the outside.

During the radon test:

  • Maintain closed-house conditions during the entire time of a short-term test, especially for tests shorter than one week in length.
  • Operate the home’s heating and cooling systems normally during the test. For tests lasting less than one week, only operate air conditioning units which recirculate interior air.
  • Do not disturb the test device at any time during the test.
  • If a radon reduction system is in place, make sure the system is working properly and will be in operation during the entire radon test.

After a radon test:

  • If a high radon level is found, fix the home. Pages 21 to 23 of this guide recommend the next steps you should take, such as contacting a qualified radon reduction contractor to lower the home’s radon level.
  • Be sure that you or the professional radon tester can demonstrate or provide information to ensure that the testing conditions were not violated during the testing period.

f. GettingReliable Results (If You Hire A Professional Radon Tester)

In many cases, home buyers and sellers may decide to have the radon test done by aprofessional radon tester. Make sure that the company you hire is listed in EPA’s RadonMeasurement Proficiency (RMP) Program or your state’s certification program, if it hasone.

EPA’s Radon Measurement Proficiency (RMP) program is designed to help you get reliableradon tests. RMP program participants are required to show their ability to make accuratetests and follow quality assurance and EPA test guidelines. EPA issues RMP reports foryour state. These reports list testing companies and individuals in your area qualified tofollow EPA’s residential radon testing requirements. Make sure you ask to see theprofessional radon tester’s photo I.D. card.

g. Interpreting Radon Test Results

The average indoor radon level is estimated to be about 1.3 pCi/L, and about 0.4 pCi/Lof radon is normally found in the outside air. The U. S. Congress has set a long-term goalthat indoor radon levels be no more than outdoor levels. While this goal is not yettechnologically achievable for all homes, the radon levels in some homes today can bereduced to 2 pCi/L or below.


An EPA listed or state certified radon tester knows the proper conditions, testdevices, and guidelines to get a reliable radon test. A professional radon tester canalso:

  • Evaluate the home and recommend a testing approach designed to make sure you get reliable results;
  • Explain how proper conditions can be maintained during the radon test;
  • Emphasize to occupants of a home that a reliable test result depends on their cooperation because any interference or disturbance with the test or the closed-house conditions, especially, during short-term testing, will invalidate the test result;
  • Analyze and report measurement results to you; and
  • Provide an independent test result by someone who is not involved in the home sale.

Your state radon office may also have information about certification requirements forprofessional radon testers. Contact your State radon office for information about RMP andstate certified contractors. (See pages 29-31 of this guide.)


Your radon test results may be reported in either picocuries per Liter of Air (pCi/L)or Working Levels (WL).

If your test result is in pCi/L, EPA recommends you fix the home if your radon level is4 pCi/L or higher. If the test result is in WL, EPA recommends you fix the home if theworking level is 0.02 WL or higher.

Sometimes short-term tests are less definitive about whether the home is at or above 4pCi/L. This can happen when your results are close to 4 pCi/L. For example, if the averageof the two short-term tests is 4.1 pCi/L, there is about a 50% chance that the year-roundaverage is somewhat below 4 pCi/L. However, EPA believes that any radon exposure carriessome risk; no level of radon is safe. Even radon levels below 4 pCi/L pose some risk, andyou can reduce your risk of lung cancer by lowering your radon level.

Like other environmental pollutants, there is some uncertainty about the magnitude ofradon health risks. However, we know more about radon risks than risks from most othercancer-causing substances. This is because estimates of radon risks are based on studiesin humans (underground miners). Additional studies on more typical populations are underway.

Your radon measurement will give you an idea of your risk of getting lung cancer fromradon. Your chances of getting lung cancer from radon depend mostly on:

  • The home’s radon level; and
  • The amount of time you spend in your home; and
  • Whether you are a smoker or have ever smoked.

Smoking combined with radon is an especially serious health risk. If you smoke or are aformer smoker, the presence of radon greatly increases your risk of lung cancer. If youstop smoking now and lower the radon level in your house, you will reduce your lung cancerrisk.


Radon Level If 1,000 people were exposed to this level over a lifetime. The risk of cancer compares to.** WHAT TO DO: Stop Smoking and…
20 pCi/L About 135 people could get lung cancer <-100 times the risk of drowning Fix your home
10 pCi/L About 71 people could get lung cancer <-100 times the risk of dying in a home Fix your home
8 pCi/L About 57 people could get lung cancer Fix your home
4 pCi/L About 29 people could get lung cancer <-100 times the risk of dying in an airplane crash Fix your home
Consider fixing between 2 and 4 pCi/L
2 pCi/L About 15 people could get lung cancer <-2 times the risk of dying in a car crash
1.3 pCi/L About 9 people could get lung cancer (Average indoor radon level) (Reducing radon levels below 2 pCi/L is difficult)
0.4 pCi/L About 3 people could get lung cancer (Average outdoor radon level)
Note: If you are a former smoker, your risk may be lower.


Radon Level If 1,000 people were exposed to this level over a lifetime. The risk of cancer compares to.** WHAT TO DO: Stop Smoking and…
20 pCi/L About 8 people could get lung cancer <-The risk of being killed in a violent crime Fix your home
10 pCi/L About 4 people could get lung cancer Fix your home
8 pCi/L About 3 people could get lung cancer <-10 times the risk of dying in an airplane crash Fix your home
4 pCi/L About 2 people could get lung cancer <-The risk of drowning Fix your home
Consider fixing between 2 and 4 pCi/L
2 pCi/L About 1 person could get lung cancer <-The risk of dying in a home fire
1.3 pCi/L Less than 1 person could get lung cancer (Average indoor ration level) (Reducing radon levels below 2 pCi/L is difficult)
0.4 pCi/L Less than 1 person could get lung cancer (Average outdoor radon level)
Note: If you are a former smoker, your risk may be higher.

It’s never too late to reduce your risk of lung cancer. Don’t wait to ted and fix aradon problem. If you are a smoker, stop smoking.

6. What Should You Do IfYou Find A High Radon Level?

High Radon Levels Can Be Reduced

EPA recommends that you take action to reduce your home’s indoor radon levels if yourradon test result is 4 pCi/L or higher.

It is preferable to correct a radon problem before placing your home on the marketbecause then you have more time to address a radon problem. If elevated levels are foundduring the real estate transaction, the buyer and seller should discuss the timing andcosts of the radon reduction, as with any other aspect of the home purchase and sale.

The cost of making repairs to reduce radon depends on how your home was built and otherfactors. Most homes can be fixed for about the same cost as other common home repairs,like painting or having a new hot water heater installed. The average cost for acontractor to lower radon levels in a home is about $1,200, although this can range from$500 to about $2,500.

How To Lower The Radon Level In Your Home

A variety of methods can be used to reduce radon in homes. Sealing cracks and otheropenings in the foundation is a basic part of most approaches to radon reduction. EPA doesnot recommend the use of sealing alone to reduce radon because, by itself, sealing has notbeen shown to lower radon levels significantly or consistently. In most cases, systemswith pipes and fans are used to reduce radon. Such systems are called “subslabdepressurization,” and do not require major changes to your home. These systemsprevent radon gas from entering the home from below the concrete floor and the foundation.Similar systems can also be installed in homes with crawl spaces. Radon reductioncontractors may use other methods that may also work in your home. The right systemdepends on the design of your home and other factors. As with any other householdappliance, there would be costs associated with the operation of the radon reductionsystem.

Ways to reduce radon are discussed in EPA’s “Consumer’s Guide to RadonReduction.” Call your state radon office (see pages 29-31) to get a copy.

You should also test your home again after it is fixed to be sure that radon levelshave been reduced. If your living patterns change and you begin occupying a lower level ofyour home (such as a basement) you should retest your home on that level. In addition, itis a good idea to retest your home sometime in the future to be sure radon levels remainlow.


If you are planning any major renovations, such as converting an unfinished basementarea into living space, it is especially important to test the area for radon before youbegin the renovation. If your test results indicate a radon problem, radon resistanttechniques can be inexpensively included as part of the renovation. Because majorrenovations can change the level of radon in any home, always test again after work iscompleted.


Contractors who participate in EPA’s RCP program are qualified to:

  • Review testing guidelines and measurement results and determine if additional measurements are needed;
  • Evaluate the radon problem and provide you with a detailed, writtenproposal on how radon levels will be lowered;
  • Design a radon reduction system;
  • Install the system according to EPA Standards and State or local codes; and
  • Make sure the finished system effectively reduces radon levels to acceptable levels.

Picking someone to fix your radon problem is much like choosing a contractor for otherhome repairs; you may want to get references and more than one estimate. Call your stateradon office for a list of the names of EPA listed or state certified radon contractors inyour area (see pages 29-31 of this guide). Your state radon office may also haveinformation about certification requirements for these contractors.

Selecting A Radon Reduction Contractor

You should use a radon reduction contractor who is listed by EPA’s Radon ContractorProficiency (RCP) Program. This Program tests the technical knowledge of contractors toensure that hey can correct radon problems. RCP contractors must follow specificguidelines which make certain that their work meets minimum quality standards. RCPcontractors carry photo I.D. cards and are listed in RCP Program reports.

Radon reduction contractors are required to take the RCP exam and then follow the RCPMitigation Standards. These standards are available from your state radon office (seepages 29-31). The RCP radon reduction contractor is also required to review radonmeasurement results before beginning radon reduction work.

In addition, the RCP contractor must recommend that the home be tested again by anindependent EPA listed or state certified radon tester after completing radon reductionwork to confirm that elevated levels have been reduced.


Compared to radon entering the home through soft, radon entering the home through waterin most cases will be a small source of risk. Radon gas can enter the home through wellwater. It can be released into the air you breathe when water is used for showering andother household uses. Research suggests that swallowing water with high radon levels maypose risks, too, although risks from swallowing water containing radon are believed to bemuch lower than those from breathing air containing radon.

While radon in water is not a problem in homes served by most public water supplies,radon has been found in well water. If you have tested the air in your home and found aradon problem, and your water comes from a well, have the water tested. If you are on apublic water supply and are concerned that radon may be entering your home through thewater, call your public water supplier. The testing device and procedures used to find outthe radon levels of your home’s water supply are different from the device and proceduresused to test your home’s indoor air levels for radon.

Radon problems in water can be read fly fixed. The most effective treatment is toremove radon from the water before it enters the home. This is called point-of-entrytreatment. Treatment at your water tap is called point-of-use treatment. Point-of-usedevices usually only treat a small portion of your water and are not effective in reducingradon risk in water.

Call your State radon office for a copy of the “Consumer’s Guide to RadonReduction” (see pages 29-31) or call EPA’s Drinking Water Hotline (1 800 426-4791)for more information on radon in water.


Be aware that there is a potential conflict of interest if you use the same company toconduct both the test and the radon reduction of the home. If the same radon testingprofessional also offers to do radon reduction of the home, make sure that the testing isdone according to the Testing Checklist.

EPA’s Radon Proficiency Programs (RMP and RCP) work together to protect home buyers andsellers. Make sure you only hire professional testers and radon reduction contractors whoare EPA qualified or state certified. Always ask to see the contractor’s I.D. card.

You should also consider getting more than one cost estimate and asking for referencesfrom radon testing and radon reduction companies in your area.

Some states have additional certification requirements, and may require the homeownerto sign a waiver if one firm conducts both testing and radon reduction. Contact your stateradon office (see pages 29-31) for more information.


MYTH: Scientists are not sure that radonreally is a problem.

FACT: Although some scientists disputethe precise number of deaths due to radon, the major health organizations (like theCenters for Disease Control, the American Lung Association and the American MedicalAssociation) agree with estimates that radon causes thousands of preventable lung cancerdeaths every year. This is especially true among smokers, since the risk to smokers ismuch greater than to non-smokers.

MYTH: Radon testing devices are notreliable and are difficult to find.

FACT: Radon testing can be conducted byprofessionally trained RMP listed or state certified radon tester.

Active radon devices can continuously gather and periodically record radon levelsreveal any unusual swings in the radon level during the test.

Reliable testing devices are also available through the mail, in hardware stores andother retail outlets. Call your state radon office (see table) for a list of radondevice companies that have met EPA requirements for reliability or are state certified.

MYTH: Radon testing is difficult andtime-consuming.

FACT: Radon testing is easy. You can testyour own home or you can hire an EPA listed or state certified radon tester. Eitherapproach takes only a small amount of the homeowner’s time or effort.

MYTH: Homes with radon problems cannot befixed.

FACT: There are solutions to radonproblems in homes. Thousands of home owners have already lowered elevated radon levels intheir homes. Radon levels can be readily lowered for $500 to $2,500. Call your state radonoffice (see pages 29-31) for a list of contractors that have met EPA requirements or arestate certified.

MYTH: Radon only affects certain types ofhomes.

FACT: Radon can be a problem in all typesof homes such as old homes, new homes, drafty homes, insulated homes, homes with basementsand homes without basements. Construction materials and the way the home has been builtmay also affect radon levels.

MYTH: Radon is only a problem in certainparts of the country.

FACT: High radon levels have been foundin every state. Radon problems do vary from area to area, but the only way to know thehome’s radon level is to test.

MYTH: A neighbor’s test result is aindication of whether your home has a radon problem.

FACT: It is not. Radon levels vary fromhome to home. The only way to know if your home has a radon problem is to test it.

MYTH: Everyone should test his or herwater for radon.

FACT: while radon gets into some homesthrough the water, it is important to first the air in the home for radon. If high radonlevels are found and the home has a well, call the Safe Drinking Water Hotline at 1800-426. 4791, or your state radon office (see table) for more information.

MYTH: It is difficult to sell a homewhere radon problems have been discovered.

FACT: Where radon problems have beenfixed, home sales have not been blocked. The added protection could be a good sellingpoint.

MYTH: I have lived in my home for solong, it does not make sense to take action now.

FACT: You will reduce your risk of lungcancer when you reduce radon levels, even if you have lived with a radon problem for along time.

MYTH: Short-term tests cannot be used formaking a decision about whether to reduce the home’s high radon levels.

FACT: Short-term tests may be used todecide whether to reduce the home’s high radon levels. However, the closer the short-termtesting result is to 4 pCi/L, the less certainty there is about whether the home’syear-round average is above or below that level. Keep in mind that radon levels below 4pCi/L still pose some risk and that radon levels can be reduced in some homes to 2 pCi/Lor below.


Alabama 800/582-1866 205/242-5315
Alaska 800/478-4845 907/465-3019
Arizona 602/255-4845
Arkansas 501/661-2301
California 800/745-7236 916/324-2208
Colorado 800/846-3986 303/692-3057
Connecticut 203/566-3122
Delaware 800/554-4636 302/739-3028
District of Columbia 202/727-7106
Florida 800/543-8279 904/488-1525
Georgia 800/745-0037 404/894-6644
Guam 617/646-8863
Hawaii 808/586-4700
Idaho 800/445-8647 208/334-6584
Illinois 800/325-1245 217/524-5641
Indiana 800/272-9723 317/633-8563
Iowa 800/383-5992 515/281-3478
Kansas 913-296-1561
Kentucky 502/564-3700
Louisiana 800/256-2494 504/925-7042
Maine 800/232-0842 207/287-5676
Maryland 800/872-3666 410/631-3301
Massachusetts 413/586-7525
Michigan 517/335-8037
Minnesota 800/798-9050 612/627-5480
Mississippi 800/626-7739 601/354-6657
Missouri 800/669-7236 314/751-6083
Montana 406/444-3671
Nebraska 800/334-9491 402/471-2168
Nevada 702/687-5394
New Hampshire 800/852-3345xtn 4674 603/271-4674
New Jersey 800/648-0394 609/987-6369
New Mexico 505/827-4300
New York 800/458-1158 518/458-6495
North Carolina 919/571-4141
North Dakota 701/221-5188
Ohio 800/523-4439 614/644-2727
Oklahoma 405/271-5221
Oregon 503/731-4014
Pennsylvania 800/237-2366 717/783-3594
Puerto Rico 809/767-3563
Rhode Island 401/277-2438
South Carolina 800/768-0362 803/734-4631
South Dakota 800/438-3367 605/773-3351
Tennessee 800/232-1139 615/532-0733
Texas 512/834-6688
Utah 801/536-4250
Vermont 800/640-0601 802/865-7730
Virginia 800/468-0138 804/786-5932
Washington 800/323-9727 206/753-4518
West Virginia 800/922-1255 304/558-3526
Wisconsin 800/798-9050 608/267-4796
Wyoming 800/458-5847 307/777-6015

8. Where Can You Get MoreInformation About Radon?

For more information on how to reduce your radon health risk, ask your state radonoffice to send you these guides:

  • Protocols for Radon and Radon Decay Product Measurements in Homes
  • Citizen’s Guide to protecting Yourself and Your Family from Radon
  • Consumer’s Guide to Radon Reduction

If you plan to make repairs yourself, be sure to contact your state radon office (seepages 29-31) for a current copy of EPA’s technical guidance on radon reduction,”Radon Reduction Techniques for Detached Houses — Technical Guidance.”

Contact the EPA’s Drinking Water Hotline (1 800 426-4791) for information on radon inwater.


“Indoor radon gas is a national health problem. Radon causes thousands of deathseach year. Millions of homes have elevated radon levels. Homes should be tested for radon.When elevated levels are confirmed, the problem should be corrected.”

Consumers need to know about the health of a house they are considering purchasing,including whether there is a radon problem, and if so, how to fix it. The Home Buyer’s andSeller’s Guide to Radon provides practical consumer information that every home buyerneeds to know.

Consumer Federation of America

AMERICAN LUNG ASSOCIATION Recommends testing all homes for radon.

United States Environmental Protection Agency, 402-R-93-003, March 1993, Air andRadiation 6604J

For sale by the U.S. Government Printing Office Superintendent of Documents,Mail Stop:SSOP, Washington, DC 20402-9328