|
Frequently Asked Questions About Radon
- Definition
Radon is a gaseous radioactive
element having the symbol Rn, the atomic number 86, an atomic weight of 222, a
melting point of 71ºC, a boiling point of 62ºC, and 18
radioactive isotopes; it is a toxic, colorless gas; it can be condensed to a
transparent liquid and to an opaque, glowing solid; it is derived from the
radioactive decay of radium and is used in cancer treatment, as a tracer in
leak detection, and in radiography.*)
- Sources of Radon
Earth and rock beneath the
home; well water; building materials. *)
- What are the Health Effects From Exposure to
Radon?
No immediate symptoms. Cronic exposure is estimated to
contribute to between 7,000 and 30,000 lung cancer deaths each year. Smokers
are at higher risk of developing Radon-induced lung cancer. The only health
effect which has been definitively linked with radon exposure is lung cancer.
Lung cancer would usually occur years (5-25) after exposure. There is no
evidence that other respiratory diseases, such as asthma, are caused by radon
exposure and there is no evidence that children are at any greater risk of
radon induced lung cancer than adults. *)
- What is the Average Level of Radon Found in a
Home?
Based on a national residential radon survey completed in 1991,
the average indoor radon level is 1.3 picocuries per liter (pCi/L) in the
United States. The average outdoor level is about 0.4 pCi/L. *)
- How is a home mitigated?
In the northeast,
sub-slab and sub-membrane depressurization systems are the preferred methods.
These systems are easily installed and offer low maintenance and energy costs.
- Does the fan run continuously?
Yes. In order
for the system to remain effective, the fan must continually depressurize the
sub-material. Most fans will use $3.00 to $5.00 of electricity per month.
- What does a mitigation system cost?
Typically
$1,500 to $1,800 including warranty, all electrical work is completed by a
state licensed electrician, post mitigation testing, and we guarantee the level
of Rn below 4.0 pCi/l. If after the initial mitigation the levels are still
elevated, NERC will return and perform additional work at no cost to you.
- What's the Debate on Radon?
There is no debate
about radon being a lung carcinogen in humans. All major national and
international organizations that have examined the health risks of radon agree
that it is a lung carcinogen. The scientific community continues to conduct
research to refine our understanding of the precise number of deaths
attributable to radon. EPA and the National Cancer Institute (NCI) have
independently placed that number at about 15,000 lung cancer deaths each year
in the United States.
A few scientists have questioned whether low
radon levels, such as those found in residences, increase the risk of lung
cancer because some small studies of radon and lung cancer in residences have
produced varied results. Some have shown a relationship between radon and lung
cancer, some have not. However, the national and international scientific
communities are in agreement that all of these residential studies have been
too small to provide conclusive information about radon health risks. All major
scientific organizations continue to believe that approximately 10% of lung
cancers in the United States -- or about 15,000 lung cancer deaths annually --
are attributable to radon. *)
- How do we know radon is a carcinogen?
The
World Health Organization (WHO) and the US Department of Health and Human
Services, as well as EPA, have classified radon as a "Class A" known human
carcinogen, because of the wealth of biological and epidemiological evidence
and data showing the connection between exposure to radon and lung cancer in
humans.
The World Health Organization, the National Academy of Sciences
and other scientific organizations agree that studies of the miners are the
best scientific information for estimating radon health risks in homes. The
Lubin/Boice meta-analysis paper also concludes that the miners studies are the
best data source for analyzing residential radon risk. Based on the miner data,
NCI has previously estimated that 15,000 people die of lung cancer from
residential radon each year in the U.S.
There have been many studies
conducted by many different organizations in many nations around the world to
examine the relationship of radon exposure and human lung cancer. The largest
and most recent of these was an international study, led by the National Cancer
Institute (NCI), which examined the data on 68,000 underground miners who were
exposed to a wide range of radon levels. The studies of miners are very useful
because the subjects are humans, not rats, as in many cancer research studies.
These miners are dying of lung cancer at 5 times the rate expected for the
general population.
Over many years scientists around the world have
conducted exhaustive research to verify the cause-effect relationship between
radon exposure and the observed increased lung cancer deaths in these miners
and to eliminate other possible causes. In addition, there is an overlap
between radon exposures received by miners who got lung cancer and the
exposures people would receive over their lifetime in a home at EPA's action
level of 4 pCi/L, i.e., there are no large extrapolations involved in
estimating radon risks in homes. *)
*)
Source: U.S. Environmental Protaction
Agency |