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What is Radon? |
Radon is one of the natural elements present on
earth.
It is a colorless, odorless radioactive gas formed as a result
of the radioactive decay of radium which, in turn, results from
the decay of uranium.
Most soils and rocks emit some radon although concentrations
vary widely among towns and neighborhoods.
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Why worry about radon? |
Long-term exposure to high levels of radon can
lead to the development of lung cancer.
The National Academy of Sciences, on February 18, 1998, released
a summary of the findings of the sixth committee on the
Biological Effects of Ionizing Radiation (BEIR VI) on the health
risks associated with radon in indoor air. The committee
concluded that, annually, between 15,400 and 21,800 lung cancer
deaths in the United States can be attributed to breathing high
indoor air radon. The Executive Summary of the BEIR VI report
can be found on the worldwide web at http://www.epa.gov/iaq/radon/beirvi1.html.
Despite these predicted risks government agencies still find it
difficult to convince people to test their homes.
The State of Connecticut Department of Public Health (DPH) still
strongly urges all Connecticut residents to test their homes for
radon and mitigate the home if elevated radon concentrations are
confirmed.<Top>
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How does radon enter my
home? |
Being a gas, radon easily can find its way out
of rocks and soils, mix with other soil gases and enter homes
and other buildings through cracks and openings in foundations.
Some radon can also enter homes through drinking water supplies.
Radon can then enter the air after leaving the water during
showering, cooking, and other water use activities.
Water from private wells may contain much higher levels of radon
than public wells.
It is important to note that radon from soil gas is the primary
source of radon in most homes. All homes and buildings contain
some levels of radon. Radon concentrations can even be detected
in outdoor air.<Top>
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Radon Reduction Techniques |
Various mitigation techniques are available to
reduce indoor air radon concentrations. Homes with radon levels
in excess of the 4.0 pCi/L (action level) but less than 7 pCi/L
may be temporarily corrected by sealing cracks and openings in
the foundation.
Please note: Sealing cracks is a temporary solution until the
home can be mitigated by a qualified contractor. The Connecticut
Department of Public Health does not recommend sealing of cracks
as a permanent solution and should not be used as the sole radon
reduction technique.
Most homes can be successfully mitigated with a technique known
as sub-slab depressurization. This system utilizes four inch PVC
piping and a special fan to collect and transport soil gases
including radon from under the foundation and exhaust them above
the roof eave.
There are a number of other mitigation techniques available for
use in different home construction styles.
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What are the proposed
standards, guidelines for radon in air and water? |
Both the EPA and the DPH use an "action level"
of 4 pCi/L for radon in air.
This action level was selected in the 1980s to provide a goal
that most contractors could achieve with existing mitigation
systems. It does not completely protect one from the risk of
developing lung cancer.
Compare this action level with the average levels found in
Connecticut homes of 2.1 pCi/L in basements and 1.3 pCi/L in
living areas.
The Safe Drinking Water Act (SDWA), as amended in 1996, required
the US Environmental Protection Agency (EPA) to establish a
maximum contaminant level (MCL) for radon in public drinking
water, but also provides for a higher alternative maximum
contaminant level (AMCL) accompanied by a multimedia mitigation
(MMM) program to address radon risks in indoor air.
The proposed Radon in Drinking Water Rule will be published in
the Federal Register. Written public comments must be received
at EPA by 60 days after the publication date.
For detailed information, EPA has posted the proposed rule on
the worldwide web at:
http://www.epa.gov/safewater/radon.html
In the absences of a radon MCL, the Connecticut Department of
Public Health (DPH) recognized the need to establish a guideline
that homeowners could use to make an informed decision whether
to treat their private well water supply. The DPH recommends to
homeowners served by a private well to consider treatment if
their average annual (two or more samples in one year) radon in
water is 5,000 pCi/L or greater.
Once EPA has promulgated a regulatory standard for radon in
water the DPH will explore the feasibility of adopting the
standards for the Connecticut Private Well Water Regulations.
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Can the radon in my
drinking water contribute to my risk for developing cancer? |
Different factors will affect your risk for
developing lung cancer from radon.
These include: the levels of radon that you have been exposed
to, the number of years that you have been exposed to high
levels of radon, your smoking history, and the number and type
of sources of radon in all of the buildings that you have lived
and worked in.
In most homes and other buildings the primary lung cancer risk
results from breathing air contaminated with soil gas containing
radon.
In some homes that use private wells, radon in water can
contribute to the radon exposure and resulting lung cancer risk.
Occupants of these homes will be inhaling radon gas that leaves
the water during showering and other water uses.
While it is easy to understand how inhaling radon from the air
can expose lung tissue, occupants exposed to radon while
drinking the water may also increase lung exposure. This may
occur as a result of radon being absorbed in the stomach and
carried to the lungs by the blood stream.
There is still controversy on risk associated with ingested
radon and there is continuing research in this area.
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How can I reduce radon in
my drinking water? |
Two systems are currently available for treating
private well radon problems. (Public utilities will be required
to monitor and treat their water once the radon MCL becomes
law.)
The whole house granular-activated carbon (GAC) filter systems
can be used to treat radon in water levels below 10,000 pCi/L.
Although these GAC systems are less expensive to install (prices
range from $1,000 to 1,500) the carbon "bed" must be changed
each year to avoid radioactive disposal concerns and a reduction
in treatment ability.
An aeration system (prices range from $2,500 to 4,500) is needed
for levels in excess of these levels. Both of these systems are
under constant development and a number of variations of each
system exist on the market.
Be certain that you are purchasing a system that will be able to
effectively treat the highest level of radon that you can expect
in your well.<Top> |
