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Indoor
Air Quality and Radon
Radon Fact Sheet
What is Radon?
Radon is a naturally occurring, invisible, odorless gas that comes
from deposits of uranium in soil, rock and water. It is harmlessly
dispersed in outdoor air, but when trapped in buildings, it can be
harmful, especially at elevated levels. Radon is a radioactive decay
product of radium, which is itself a decay product of uranium. Uranium
and radium are both common elements in the soil.
Where is Radon found?
The primary source of high levels of radon in homes is the
surrounding soil. Radon has been found in elevated levels in homes in
every state. The US Environmental Protection Agency estimates that as
many as one in 15 homes across the US has elevated radon levels.
How does Radon get into my house?
Warm air rises. When this happens in your home, it creates a
vacuum in the lower areas of the house. Nature abhors a vacuum, so
something must rush in to fill it. In the case of your home, air seeps
in from the soil around and under the house, and some air is sucked in
through openings (cracks, doors, windows) on the lower levels. Radon
gas enters the same way air and other soil gases enter the home;
through cracks in the foundation floor or walls, hollow-block walls,
and openings around floor drains, pipes and sump pumps.
What are the health effects of
Radon?
Exposure to radon is the second leading cause of cancer in the
US Radon can be inhaled into the lungs, where it undergoes
radioactive decay. As it decays, radon releases tiny bursts of energy
called alpha particles, which can harm sensitive lung tissue by
damaging the DNA. This damaged DNA can lead to lung cancer.
How is Radon measured?
Radon is measured in picocuries per liter of air (pCi/L), a
measurement of radioactivity. The EPA and the Center for Disease
Control and Prevention recommend that homes with radon levels over 4
pCi/L be fixed.
How do I find out if my house has
Elevated Levels of Radon?
Testing your home for radon is as simple as opening a package,
placing a radon detector in a designated area, and after the
prescribed number of days, sealing the detector back in the package.
Fixing a radon problem is usually just a matter of caulking cracks
along basement foundations, sealing leaks around pipes, and taking
other steps to prevent radon from entering the house through places
where it is in contact with the ground.
"I don't have a basement, I
probably don't have a Radon problem."
Radon can seep in from soil anywhere around or under a home,
regardless of whether your home has a basement, a crawl space, or is
built slab-on-grade. The US Environmental Protection Agency (EPA)
and the Surgeon General recommend radon testing for all types of homes
at or below the third floor.
"I don't live in an area
designated as a high Radon zone, so my home won't have a
problem."
The US EPA and the US Geologic Survey conducted a survey of radon
potential across the United States. They broke the country down into
three zones according to their potential for high indoor radon levels,
with Zone I having the highest radon potential. It is true that homes
in Zones I and 2 have a statistically high chance of having elevated
levels of radon. However, the fact is that elevated levels of radon
have been found in homes in all fifty states. The only way to know
whether radon exists in elevated levels in your home is to test.
"Two of my neighbors have
tested their homes for Radon and they don't have high levels, so I
probably don't either."
Radon levels can vary considerably from house to house, even on the
same street. It is nearly impossible to predict the exact nature of
geologic soil deposits and the extent to which soil gases will seep
into and be retained by a specific house. The only way to know whether
radon exists in elevated levels in your home, and to protect your
family from radon, is to test.
"There doesn't seem to be much
proof that Radon is a serious health problem."
The science on radon has been formidable over the years, but never
before have we had such overwhelming scientific consensus that
exposure to elevated levels of radon causes lung cancer in humans. In
February of 1998, the National Academy of Sciences (NAS) presented the
findings of their Biological Effects of Ionizing Radiation (BEIR) IV
Report: "The Health Effects of Exposure to Indoor Radon".
This new report by the NAS is the most definitive accumulation of
scientific data on indoor radon. The report confirms that radon is the
second leading cause of lung cancer in the US and that it is a
serious public health problem. The study supports US EPA estimates
that radon causes about 15,000 lung cancer deaths per year.
"I don't have time to test for Radon!"
Testing is as simple as opening a package, placing a radon detector in
your home in a designated area, and after the prescribed number of
days, sealing the detector back in the package and mailing it to a
lab. The whole process only takes a few minutes of your time.
Radon Hotline (202) 535-2302
