Office of Air and Radiation (6101)
EPA Document #402-K92-001
Published: May 1992
Co-sponsored by The U.S. Environmental
Protection Agency,
U.S. Department of Health and Human Services (Centers for Disease Control),
and the
U.S. Public Health Service
EPA Recommends:
- Test your home for radon -- it's easy and
inexpensive.
- Fix your home if your 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.
 |
Radon is
estimated to cause about 14,000 deaths per year. However, this number
could range from 7,000 to 30,000 deaths per year The numbers of deaths
from other causes are taken from 1990 National Safety Council reports. |
Overview
How Does Radon Get Into Your Home?
How to Test Your Home
What Your Test Results Mean
-- Radon and Home Sales
-- Radon in Water
How to Lower the Radon Levels in Your Home
The Risk of Living With Radon
Radon Risk Charts
Radon Myths
State Radon Contacts
Overview
Radon is a cancer-causing, radioactive
gas.
You can't see radon. And you can't smell it
or taste it. But it may be a problem in your home.
Radon is estimated to cause many thousands of
deaths each year. That's because when you breathe air containing radon, you
can get lung cancer. In fact, the Surgeon General has warned that radon is
the second leading cause of lung cancer in the United States today. Only
smoking causes more lung cancer deaths. If you smoke and your home has
high radon levels, your risk of lung cancer is especially high.
Radon can be found all over the U.S.
Radon comes from the natural (radioactive)
breakdown of uranium in soil, rock and water and gets into the air you
breathe. Radon can be found all over the U.S. It can get into any type of
building - homes, offices, and schools - and build up to high levels. But
you and your family are most likely to get your greatest exposure at home.
That's where you spend most of your time.
You should test for radon.
Testing is the only way to know if you and
your family are at risk from radon. EPA and the Surgeon General recommend
testing all homes below the third floor for radon. EPA also recommends
testing in schools.
Testing is inexpensive and easy
- it should only take a few minutes of your time. Millions of Americans have
already tested their homes for radon.
You can fix a radon problem.
There are simple ways to fix a radon problem
that aren't too costly. Even very high levels can be reduced to acceptable
levels.
How Does Radon Get Into
Your Home?
Radon is a radioactive gas. It comes from
the natural decay of uranium that is found in nearly all soils. It typically
moves up through the ground to the air above and into your home through cracks
and other holes in the foundation. Your home traps radon inside, where it can
build up. Any home may have a radon problem. This means new and old homes,
well-sealed and drafty homes, and homes with or without basements.
Radon from soil gas is the main cause of radon
problems. Sometimes radon enters the home through well water (see "Radon
in Water" below). In a small number of homes, the building materials can
give off radon, too. However, building materials rarely cause radon problems
by themselves.
| RADON GETS
IN THROUGH: |
1. Cracks in solid floors
2. Construction joints
3. Cracks in walls
4. Gaps in suspended floors
5. Gaps around service pipes
6. Cavities inside walls
7. The water supply |
 |
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 state
radon office for general information about radon in your area. While radon
problems may be more common in some areas, any home may have a problem. The
only way to know about your home is to test.
Radon can be a problem in schools and
workplaces, too. Ask your state radon office
about radon problems in schools and workplaces in your area.
How to Test
Your Home
You can't see radon, but it's not
hard to find out if you have a radon problem in your home. All you need to do
is test for radon. Testing is easy and should only take a few minutes of your
time.
The amount of radon in the air is
measured in "picoCuries per liter of air," or "pCi/L."
Sometimes test results are expressed in Working Levels (WL) rather than
picoCuries per liter (pCi/L). There are many kinds of low-cost
"do-it-yourself" radon test kits you can get through the mail and in
hardware stores and other retail outlets. If you prefer, or if you are
buying or selling a home, you can hire a trained contractor to do the testing
for you. EPA recommends that you contact your State radon office state
radon office for a list of these testers. You can also contact one
or both of the known private radon proficiency programs for lists of privately
certified radon professionals in your area. For more information on
these two programs, visit http://www.epa.gov/radonpro/.
Click
here to order a test kit
| There
are Two General Ways to Test for Radon: |
 |
|
| SHORT-TERM
TESTING: The quickest way to test is with short-term tests.
Short-term tests remain in your home for two days to 90 days,
depending on the device. "Charcoal canisters," "alpha
track," "electret ion chamber," "continuous
monitors," and "charcoal liquid scintillation"
detectors are most commonly used for short-term testing. Because radon
levels tend to vary from day to day and season to season, a short-term
test is less likely than a long-term test to tell you your year-round
average radon level. If you need results quickly, however, a
short-term test followed by a second short-term test may be used to
decide whether to fix your home.
LONG-TERM TESTING:
Long-term tests remain in your home for more than 90 days. "Alpha
track" and "electret" detectors are commonly used for
this type of testing. A long-term test will give you a reading that is
more likely to tell you your home's year-round average radon level
than a short-term test.
|
How To Use a Test Kit:
Follow the instructions that come
with your test kit. If you are doing a short-term test, close your windows and
outside doors and keep them closed as much as possible during the test. (If
you are doing a short-term test lasting just 2 or 3 days, be sure to close
your windows and outside doors at least 12 hours before beginning the
test, too. You should not conduct short-term tests lasting just 2 or 3 days
during unusually severe storms or periods of unusually high winds.) The test
kit should be placed in the lowest lived-in level of the home (for example,
the basement if it is frequently used, otherwise the first floor). It should
be put in a room that is used regularly (like a living room, playroom, den or
bedroom) but not your kitchen or bathroom. Place the kit at least 20 inches
above the floor in a location where it won't be disturbed - away from drafts,
high heat, high humidity, and exterior walls. Leave the kit in place for as
long as the package says. Once you've finished the test, reseal the package
and send it to the lab specified on the package right away for study. You
should receive your test results within a few weeks.
Testing is easy and should only
take a few minutes of your time.
Click
here to order a test kit
EPA Recommends the Following
Testing Steps:
- Take a short-term test. If your result is 4
pCi/L or higher (0.02 Working Levels [WL] or higher) take a follow-up test
(Step 2) to be sure.
- Follow up with either a long-term test or a
second short-term test. For a better understanding of your year-round
average radon level, take a long-term test. If you need results quickly,
take a second short-term test. The higher your initial short-term test
result, the more certain you can be that you should take a short-term
rather than a long-term follow up test. If your first short-term test
result is several times the action level - for example, about 10 pCi/L or
higher - you should take a second short-term test immediately
- If you followed up with a long-term test:
Fix your home if your long-term test result is 4 pCi/L or more (0.02
Working Levels [WL] or higher). If you followed up with a seconds
short-term test: The higher your short-term results, the more certain you
can be that you should fix your home. Consider fixing your home if the
average of your first and second test is 4 pCi/L or higher (0.02 Working
Levels [WL] or higher).
What Your
Test Results Mean
The average indoor radon level is
estimated to be about 1.3 pCi/L, and about 0.4 pCi/L of radon is normally
found in the outside air. The U.S. Congress has set a long-term goal that
indoor radon levels be no more than outdoor levels. While this goal is not yet
technologically achievable in all cases, most homes today can be reduced to 2
pCi/L or below.
Sometimes short-term tests are
less definitive about whether or not your home is above 4 pCi/L. This can
happen when your results are close to 4 pCi/L. For example, if the average of
your two short-term test results is 4.1 pCi/L, there is about a 50% chance
that your year-round average is somewhat below 4 pCi/L. However, EPA believes
that any radon exposure carries some risk - no level of radon is safe. Even
radon levels below 4 pCi/L pose some risk, and you can reduce your risk of
lung cancer by lowering your radon level.
If your living patterns change and
you begin occupying a lower level of your home (such as a basement) you should
retest your home on that level.
Even if your test result is below
4 pCi/L, you may want to test again sometime in the future.
Radon and
Home Sales
More and more, home buyers and
renters are asking about radon levels before they buy or rent a home. Because
real estate sales happen quickly, there is often little time to deal with
radon and other issues. The best thing to do is to test for radon NOW and save
the results in case the buyer is interested in them. Fix a problem if it
exists so it won't complicate your home sale. If you are planning to move,
call your state radon office for EPA's
pamphlet "Home Buyer's and Seller's Guide to Radon,"
which addresses some common questions. During home sales:
- Buyers often ask if a home has been tested,
and if elevated levels were reduced.
- Buyers frequently want tests made by someone
who is not involved in the home sale. Your state office (see below) has a
list of qualified testers.
- Buyers might want to know the radon levels
in areas of the home (like a basement they plan to finish) that the seller
might not otherwise test.
Today many homes are built to
prevent radon from coming in. Your state or local area may require these
radon-resistant construction features. Radon-resistant
construction features usually keep radon levels in new homes below 2
pCi/L. If you are buying or renting a new home, ask the owner or builder if it
has radon-resistant features.
Test your home now and save
your results. If you find high radon levels, fix your home before you decide
to sell it.
Radon in
Water
Compared
with radon entering the home through soil, radon entering the home through
water will in most cases be a small source of risk. Radon gas can enter the
home through well water. It can be released into the air you breathe when
water is used for showering and other household uses. Research suggests that
swallowing water with high radon levels may pose risks, too, although risks
from swallowing water containing radon are believed to be much lower than
those from breathing air containing radon.
While radon in water is not a
problem in homes served by most public water supplies, it has been found in
well water. If you've tested the air in your home and found a radon problem,
and your water comes from a well, contact a lab certified to measure radiation
in water to have your water tested. If you're on a public water supply and are
concerned that radon may be entering your home through the water, call your
public water supplier.
Radon problems in water can be
readily fixed. The most effective treatment is to remove radon from the water
before it enters the home. This is called point-of-entry treatment. Treatment
at your water tap is called point-of-use treatment. Unfortunately,
point-of-use treatment will not reduce most of the inhalation risk from radon.
If you've tested the air in
your home and found a radon problem, and your water comes from a well, have
your water tested.
If high radon levels are found and
the home has a well, you can find publications and documents developed by
EPA's Office of Ground Water and Drinking Water relating to radon in drinking
water and the radon in drinking water rule at http://www.epa.gov/safewater/radon.html.
How to Lower
the Radon Level in Your Home
Since there is no known safe level
of radon, there can always be some risk. But the risk can be reduced by
lowering the radon level in your home.
A variety of methods are used to
reduce radon in your home. In some cases, sealing cracks in floors and walls
may help to reduce radon. In other cases, simple systems using pipes and fans
may be used to reduce radon. Such systems are called "sub-slab
depressurization," and do not require major changes to your home. These
systems remove radon gas from below the concrete floor and the foundation
before it can enter the home. Similar systems can also be installed in houses
with crawl spaces. Radon contractors use other methods that may also work in
your home. The right system depends on the design of your home and other
factors.
Ways to reduce radon in your home
are discussed in EPA's "Consumer's Guide to Radon
Reduction." You can get a copy from your state
radon office.
The
cost of making repairs to reduce radon depends on how your home was built and
the extent of the radon problem. 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 house costs about $1,200 for a contractor to
fix, although this can range from about $500 to about $2,500.
Lowering high radon levels
requires technical knowledge and special skills. You should use a contractor
who is trained to fix radon problems. A trained mitigation contractor
can study the radon problem in your home and help you pick the right treatment
method.
Check our radon
proficiency web site or contact your state
radon office for privately certified or state certified radon mitigation
contractors in your area. Picking someone to fix your radon problem is much
like choosing a contractor for other home repairs - you may want to get
references and more than one estimate.
If you plan to fix the problem in
your home yourself, you should first contact your state
radon office for EPA's technical guide, "Radon Reduction Techniques
for Detached Houses."
You should also test your home
again after it is fixed to be sure that radon levels have been reduced. Most
radon reduction systems include a monitor that will alert you if the system
needs servicing. In addition, it's a good idea to retest your home sometime in
the future to be sure radon levels remain low.
Most homes can be fixed for
about the same cost as other common home repairs.
Radon and Home
Renovations
If you are planning any major structural renovation, such as
converting an unfinished basement area into living space, it is
especially important to test the area for radon before you begin the
renovation. If your test results indicate a radon problem
radon-resistant techniques can be inexpensively included as part of
the renovation. Because major renovations can change the level of
radon in any home, always test again after work is completed. Most
homes can be fixed for about the same cost as other common home
repairs. |
The Risk of
Living With Radon
Radon gas decays into radioactive
particles that can get trapped in your lungs when you breathe. As they break
down further, these particles release small bursts of energy. This can damage
lung tissue and lead to lung cancer over the course of your lifetime. Not
everyone exposed to elevated levels of radon will develop lung cancer. And the
amount of time between exposure and the onset of the disease may be many
years.
Like other environmental
pollutants, there is some uncertainty about the magnitude of radon health
risks. However, we know more about radon risks than risks from most other
cancer-causing substances. This is because estimates of radon risks are based
on studies of cancer in humans (underground miners). Additional studies on
more typical populations are under way.
Smoking combined with radon is an
especially serious health risk. Stop smoking and lower your radon level to
reduce your lung cancer risk.
Children
have been reported to have greater risk than adults of certain types of cancer
from radiation, but there are currently no conclusive data on whether children
are at greater risk than adults from radon.
Your chances of getting lung
cancer from radon depend mostly on:
- How much radon is in your home
- The amount of time you spend in your home
- Whether you are a smoker or have ever smoked
Scientists are more certain
about radon risks than risks from most other cancer-causing substances.
| RADON
RISK IF YOU SMOKE |
| Radon
Level |
If
1,000 people who smoked were exposed to this level over a lifetime... |
The
risk of cancer from radon exposure 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
fire |
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 |
| 2 pCi/L |
About 15 people could get lung cancer |
2 times the risk of dying in a car crash |
Consider fixing between 2 and 4 pCi/L |
| 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) |
(Reducing radon levels below 2 pCi/L is
difficult.) |
| Note: If you are a
former smoker, your risk may be lower. |
| RADON
RISK IF YOU HAVE NEVER SMOKED |
| Radon
Level |
If
1,000 people who smoked were exposed to this level over a lifetime... |
The
risk of cancer from radon exposure compares to... |
WHAT
TO DO: |
| 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 |
| 2 pCi/L |
About 1 person could get lung cancer |
The risk of dying in a home fire |
Consider fixing between 2 and 4 pCi/L |
| 1.3 pCi/L |
Less than 1 person could get lung cancer |
(Average indoor radon 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) |
(Reducing radon levels below 2 pCi/L is
difficult.) |
| 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 test and fix a radon problem.
If you are a smoker, stop smoking.
Some Common
Myths About Radon
MYTH: Scientists are not sure
that radon really is a problem.
FACT: Although
some scientists dispute the precise number of deaths due to radon, all the
major health organizations (like the Centers for Disease Control and
Prevention, the American Lung Association and the American Medical
Association) agree with estimates that radon causes thousands of preventable
lung cancer deaths every year. This is especially true among smokers, since
the risk to smokers is much greater than to non-smokers.
MYTH: Radon testing devices
are not reliable and are difficult to find.
FACT: Radon
testing can be conducted by a professionally trained or state-certified radon
tester.
Active radon devices can continuously gather and periodically record radon
levels to reveal any unusual swings in the radon level during the test.
Reliable testing devices are also available through the mail, in hardware
stores and other retail outlets. Call your state
radon office for a list of radon device companies or visit our radon
proficiency program web site for information on two privately run national
radon proficiency programs.
MYTH: Radon testing is
difficult and time-consuming.
FACT: Radon
testing is easy. You can test your own home or you can hire a professionally
certified or state-certified radon tester. Either approach takes only a small
amount of the homeowner's time or effort.
MYTH: Homes with radon
problems cannot be fixed.
FACT: There are
solutions to radon problems in homes. Thousands of home owners have already
lowered elevated radon levels in their homes. Radon levels can be readily
lowered for $500 to $2,500. Call your state radon
office or visit our radon
proficiency program web site for information on how to acquire the
services of a qualified professional.
MYTH: Radon affects only
certain types of homes.
FACT: Radon can
be a problem in all types of homes such as old homes, new homes, drafty homes,
insulated homes, homes with basements and homes without basements.
Construction materials and the way the home has been built may also affect
radon levels.
MYTH: Radon is only a problem
in certain parts of the country.
FACT: High radon
levels have been found in every state. Radon problems do vary from area to
area, but the only way to know the home's radon level is to test.
MYTH: A neighbor's test result
is a good indication of whether your home has a radon problem.
FACT: It is not.
Radon levels vary from home to home. The only way to know if your home has a
radon problem is to test it.
MYTH: Everyone should test his
or her water for radon.
FACT: While radon
gets into some homes through the water, it is important to first test the air
in the home for radon. If high radon levels are found and the home has a well,
call the Safe Drinking Water Hotline at 1 800-426-4791, or your
state radon office for more information.
MYTH: It is difficult to sell
a home where radon problems have been discovered.
FACT: Where radon
problems have been fixed, home sales have not been blocked. The added
protection could be a good selling point.
MYTH: I have lived in my home
for so long, it does not make sense to take action now.
FACT: You will
reduce your risk of lung cancer when you reduce radon levels, even if you have
lived with a radon problem for a long time.
MYTH: Short-term tests cannot
be used for making a decision about whether to reduce the home's high radon
levels.
FACT: Short-term tests may be
used to decide whether to reduce the home's high radon levels. However, the
closer the short-term testing result is to 4 pCi/L, the less certainty there
is about whether the home's year-round average is above or below that level.
Keep in mind that radon levels below 4 pCi/L still pose some risk and that
radon levels can be reduced in some homes to 2 pCi/L or below.
State Radon and Indoor
Air Quality Contacts
National Radon Hotline:
1 800/SOS-RADON
For other Indoor Air Hotlines: [www.epa.gov/iaq/iaqxline.html]
For Further
Information
For more information on how to reduce your
radon health risk, call your state radon office
for copies of these guides:
If you plan to make repairs yourself, be sure
to contact your state radon office or visit
our publications site for a current copy of EPA's technical guidance on radon
mitigation, "Application of Radon Reduction Techniques for Detached
Houses. "
|
SURGEON GENERAL HEALTH ADVISORY:
"Indoor radon gas is a national
health problem. Radon causes thousands of deaths each year. Millions
of homes have elevated radon levels. Homes should be tested for radon.
When elevated levels are confirmed, the problem should be
corrected."
|
This guide ("A Citizen's Guide to
Radon" - EPA Document #402-K92-001) is for sale by the:
U.S. Government Printing Office
Superintendent of Documents, Mail Stop: SSOP,
Washington, DC 20402-9328
ISBN 0-16-036222-9
Last Modified: June 12, 2000
http://www.epa.gov/iaq/radon/pubs/citguide.html
