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The
U.S. Surgeon General, Richard Carmona, Issues National
Health Advisory on Radon
The Surgeon General of the United States issued a Health
Advisory in 2005 warning Americans about the health risk
from exposure to radon in indoor air.
The Nation’s Chief Physician urged Americans to test
their homes to find out how much radon they might be
breathing. Dr. Carmona also stressed the need to remedy the
problem as soon as possible when the radon level is 4 pCi/L
or more.
Read the Surgeon General's News Release
Why is radon the public health risk that it is?
EPA estimates that about 20,000 lung cancer deaths each year
in the U.S. are radon-related. Exposure to radon is the
second leading cause of lung cancer after smoking. Radon is
an odorless, tasteless and invisible gas produced by the
decay of naturally occurring uranium in soil and water.
Radon is a form of ionizing radiation and a proven
carcinogen. Lung cancer is the only known effect on human
health from exposure to radon in air. Thus far, there is no
evidence that children are at greater risk of lung cancer
than are adults.
Radon in air is ubiquitous. Radon is found in outdoor air
and in the indoor air of buildings of all kinds. EPA
recommends homes be fixed if the radon level is 4 pCi/L (pico
Curies per Liter) or more. Because there is no known safe
level of exposure to radon, EPA also recommends that
Americans consider fixing their home for radon levels
between 2 pCi/L and 4 pCi/L. The average radon concentration
in the indoor air of America’s homes is about 1.3 pCi/L. It
is upon this level that EPA based its estimate of 20,000
radon-related lung cancers a year upon. It is for this
simple reason that EPA recommends that Americans consider
fixing their homes when the radon level is between 2 pCi/L
and 4 pCi/L. The average concentration of radon in outdoor
air is .4 pCi/L or 1/10th of EPA’s 4 pCi/L action level.
For smokers the risk of lung cancer is significant due to
the synergistic effects of radon and smoking. For this
population about 62 people in a 1,000 will die of
lung-cancer, compared to 7.3 people in a 1,000 for never
smokers. Put another way, a person who never smoked (never
smoker) who is exposed to 1.3 pCi/L has a 2 in 1,000 chance
of lung cancer; while a smoker has a 20 in 1,000 chance of
dying from lung cancer. Figure A compares the risks between
smokers and never smokers; smokers are at a much higher risk
than never smokers, e.g., at 8 pCi/L the risk to smokers is
six times the risk to never smokers.
The radon health risk is underscored by the fact that in
1988 Congress added Title III on Indoor Radon Abatement to
the Toxic Substances Control Act. It codified and funded
EPA’s then fledgling radon program. Also that year, the
Office of the U.S. Surgeon General issued a warning about
radon urging Americans to test their homes and to reduce the
radon level when necessary (U.S. Surgeon General).
Unfortunately, many Americans presume that because the
action level is 4 pCi/L, a radon level of less than 4 pCi/L
is ‘safe’. This perception is altogether too common in the
residential real estate market. In managing any risk, we
should be concerned with the greatest risk. For most
Americans, their greatest exposure to radon is in their
homes; especially in rooms that are below grade (e.g.,
basements), rooms that are in contact with the ground and
those rooms immediately above them.
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