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RADON TESTING AND MITIGATION:
THE BASICS
WHAT
IS RADON & WHY IS IT A CONCERN?
Radon
is a radioactive gas that comes from the breakdown of naturally
occurring uranium in soil and rock. It is invisible, odorless
and tasteless, and can only be detected by specialized tests.
Radon enters homes through openings that are in contact with
the ground, such as cracks in the foundation, small openings
around pipes, and sump pits.
Radon, like other radioactive
materials, undergoes radioactive decay that forms decay products.
Radon and its decay products release radioactive energy that
can damage lung tissue in a way that causes the beginning
of lung cancer.
The more radon you
are exposed to, and the longer the exposure, the greater the
risk of eventually developing lung cancer. Radon is the second
leading cause of lung cancer in the United States, resulting
in 15,000 to 22,000 deaths per year.
Testing your home for
radon is easy and homes with high levels of radon can be fixed
(mitigated). The New Jersey Department of Environmental Protection
(DEP) recommends that all homes be tested for radon.
SELECTING
& ARRANGING FOR TESTS
Homeowners can test
for radon themselves or hire a New Jersey certified radon
measurement company to perform the testing. Some certified
radon measurement companies sell test kits, and test kits
are often available in hardware stores or from local health
departments. A list of certified companies, including companies
that can mail you a "do-it-yourself" test, is available through
the NJDEP Radon Programs Information Line, (800)648-0394,
or web site, www.njradon.org.
If you buy your test
from a retail store, make sure that the kit is labeled with
the New Jersey certification number of the company that produced
the test kit (the number will begin with "MEB9" followed
by 4 digits), or you can call the Information Line to confirm
that the company is certified. If you hire a contractor to
do the test, make sure the technician who places and picks
up the test device is certified by the State, by checking
their NJDEP certificate or calling the Radon Information Line.
It is against the law to do radon testing or mitigation without
certification in New Jersey.
Short-Term
Tests:
A single short-term
test of 2-7 days in length can be used to indicate the radon
level in your home. If a single short-term test reveals levels
of 4 pCi/L or more, DEP data indicate that subsequent testing
would confirm that levels in the home are 4 pCi/L or more
in 80 percent of cases. If a second short-term test is conducted
in the same location (either simultaneously or at different
points in time), and the results of the tests are averaged,
the average will provide a slightly more accurate estimate
of radon levels.
A variety of short-term
test devices are available, including charcoal canisters,
electrets, and continuous radon monitors. The DEP Radon
Program considers all short-term test devices used by certified
companies to be equally reliable.
Long-Term
Tests:
A long-term test of
3-12 months will provide your best estimate of average exposure
over time, since radon levels fluctuate daily and by season.
Because gases are drawn to areas of lower pressure, radon
gas will enter the home at a rate that depends on the air
pressure inside the home, which is affected by temperature,
wind conditions, exhaust systems in the home, etc. Long-term
testing should include the winter months, when radon concentrations
are often higher than at other times.
Long-term test devices
are usually either alpha track detectors or electrets; both
tests are considered equally reliable and accurate.
Real
Estate Transactions:
A single short-term
radon test may be used for real estate transactions. An escrow
account, with funds set aside by the seller, can be arranged
for the buyer who prefers to test after closing. The funds
can then be used to mitigate the home if testing reveals concentrations
of 4 pCi/L or more.
If you are a potential
homebuyer and are concerned about the possibility of test
tampering, discuss anti-tampering methods with the radon measurement
contractors you are considering hiring. Also, be sure to check
that the contractor will close and pick up the test, as required
by regulation. Neither the buyer, the homeowner nor the real
estate agent can perform any part of the test, including:
closing the test, picking it up, or sending it to a laboratory.
If a homeowner is testing their home for themselves, they
may do all or part of the test.
CONDUCTING
THE TEST
If you do the test
yourself, the process is very simple. You need only follow
the testing instructions and complete the form that accompanies
the test device. The device should then be mailed without
delay to a laboratory using a pre-addressed envelope enclosed
with the kit.
The following guidelines
should be used by both homeowners and measurement companies.
For both long-term
and short-term tests, the testing device must be placed:
- in the lowest livable
level of the home -- that is, the lowest level of the home
that is used, or could be used, as a living space. This
would include, for example, a first floor without a basement,
and a finished or unfinished basement, but not a crawl space.
- in a location where
it will not be disturbed.
- at least 20 inches
from the floor, at least 4 inches away from other objects
and at least 36 inches away from doors, windows or other
openings to the outside. The tests only need to be placed
one foot away from exterior walls that have no openings.
If suspended from the ceiling, it should be in the general
breathing zone.
Test kits should not
be placed:
- in areas exposed
to direct sunlight, drafts, high heat, or high humidity;
or
- in kitchens, bathrooms,
laundry rooms or closets.
In addition, attic
and window fans, fireplaces and wood stoves (unless they are
the primary heat source) should not be used for the duration
of the test. They will affect air pressure in the house which
will in turn affect radon concentrations. Air conditioning
can be used if it circulates inside air rather than bringing
in air from the outside.
For short-term tests,
it is very important to maintain "closed house conditions,"
since ventilation can increase or decrease radon levels in
unpredictable ways. This means all windows and doors that
let in outside air, on all floors, must be kept closed except
for normal entrances and exits. You need to maintain closed
house conditions until the short-term test is finished. For
tests that last less than four days, closed house conditions
must be started at least 12 hours before you begin the test.
INTERPRETING
YOUR TEST RESULTS
The
test report will usually give your radon reading in picoCuries
per liter (pCi/L). PicoCuries per liter is a measure of how
much radiation is in a liter of air, which is about the size
of a quart. Sometimes results will be given in Working Levels
(WL). You can calculate the pCi/L level by multiplying the
WL reading by 200.
The DEP and the Environmental
Protection Agency (EPA) both recommend that you take action
to mitigate your home if your test results indicate radon
levels of 4.0 pCi/L of radon or more. If you used two
or more short-term tests at the same location, the results
should be averaged.
There is no truly "safe"
level of radon since lung cancer can result from very low
exposures to radon however, the risk decreases as the
radon concentration decreases. If your test result is less
than 4.0 pCi/L, you may want to discuss with mitigation companies
whether the radon level can be brought down still further.
In about half of the homes that have been mitigated in New
Jersey, radon levels have been brought to less than 1 pCi/L.
Radon Risk for Smokers
and Nonsmokers
(Source:
National Academy of Sciences, Biological Effects of Ionizing
Radiation, Sixth Report, 1998)
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Radon
Level (in pCi/L)
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Odds
for non-smokers* of developing lung cancer due
to radon if exposed to this level over a lifetime
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Odds
for smokers* of developing lung cancer due to
radon if exposed to this level over a lifetime**
|
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20
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1
in 27
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1
in 5
|
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8
|
1
in 68
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1
in 13
|
|
4
|
1
in 135
|
1
in 26
|
|
2
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1
in 270
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1
in 52
|
|
0.4***
|
1
in 1,350
|
1
in 260
|
*Smokers are defined
as individuals who have smoked at least 100 cigarettes in
a lifetime; non-smokers have never smoked or smoked less than
100 cigarettes in a lifetime.
**This is in
addition to the risk of lung cancer from smoking itself.
***Average outdoor
radon concentration.
MITIGATING
YOUR HOME
The most common type
of radon mitigation system is the sub-slab depressurization
system. This system uses venting and sealing to lower radon
levels in the home. A pipe is installed that runs from below
the basement flooring to above the roofline, with a fan at
the top that draws radon out from under the slab. Cracks and
openings in the foundation are sealed. The radon is vented
through the pipe to the outside, where it is quickly diluted.
The average price of
such a system is around $1,200, although prices can range
from $500 to $2,500, depending on characteristics of the home
and the underlying soil. You can install the system yourself,
if you are highly experienced in making home repairs, or you
can hire a New Jersey certified radon mitigation company to
do the work for you. New Jersey certified radon mitigation
professionals meet specified education and experience standards
and must take continuing education classes each year to maintain
their certification. It is against the law for uncertified
contractors to do mitigation work in New Jersey.
After your home has
been mitigated, make sure the mitigator does a post-mitigation
test to prove the system is working properly. In addition,
you can contact the Radon Program to obtain a free post-mitigation
test (you will have to provide a copy of your mitigation contract).
Retesting your home every two years will tell you whether
or not your system is still working effectively in reducing
the radon level to below 4 pCi/L. If you believe that your
system was not installed correctly, you can contact the Radon
Program to arrange for a free inspection and test of the system.
QUESTIONS?
Feel free to contact
the DEP Radon Program if you have any questions, if youd
like a copy of the certified radon businesses lists, or if
you have complaints about services provided by radon companies,
through the Information Line at (800)648-0394 (within New
Jersey) or (609)984-5425 (outside New Jersey) -- or you can
visit the Radon Program web site at www.njradon.org.
Radon Main Page
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