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.htmll.
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.htmll]
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.htmll
