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 (NJDEP) 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 Program’s Information Line,
1-800-648-0394, 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, NJDEP data
indicate that subsequent testing would confirm that levels in the home
are 4 pCi/L or more in 80% 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 NJDEP 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 NJDEP 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
|
Radon
Level (in pCi/L)
|
Odds for non-smokers*
of developing lung cancer due to radon if exposed to this level
over a lifetime
|
Odds for smokers*
of developing lung cancer due to radon if exposed to this level
over a lifetime**
|
|
20
|
1 in 27
|
1 in 5
|
|
8
|
1 in 68
|
1 in 13
|
|
4
|
1 in 135
|
1 in 26
|
|
2
|
1 in 270
|
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 NJDEP
Radon Program if you have any questions, if you’d 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
1-800-648-0394 (within New Jersey) or 1-609-984-5425 (outside New
Jersey) -- or you can visit the Radon Program web site at www.njradon.org.
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