This booklet ori radon has
been developed for physicians
by (he U.S. Environmental
Protection Agency in consultation
with the American Medical
Association (AMA). Its purpose is
to enlist physicians in the nation-
al effort to inform the American
public about the serious health
risk posed by indoor radon gas.
Lung cancer's very high associated mortality rate is even more tragic because a significant portion of
king cancer is preventable. While smoking remains the number one cause of lung cancer, radon presents
a significant second risk factor. That is why, in addition to encouraging patients to stop smoking, it is
important for physicians to inquire about and encourage patients to test for radon levels in their homes.
One way to do this is for physicans to join those health care professionals and organizat ions who have
begun to include questions about the radon level in patients' homes on standardized patient history
Because the public views physicians as advisors on health and prevention of disease, physicians are in
a unique position to play a vital role in informing the public about the common and serious risk of
radon, and in educating their patients in testing procedures and remediation methods for correcting
elevated indoor radon levels, thereby helping to reduce the number of lung cancer deaths.
Free radon information materials (posters, pamphlets, videos) are available from your state radon
office (see page 16) to assist you in educating your patients about radon.

Table off Contents
Executive Summary				....			.	2
Wliat is Radon?	.			.		3
Characteristics and Sources of Radon							,	3
The Health Risk 					4
How does Radon Induce Cancer?.,												4
What is the Evidence?					,v.					..			4
Is Occupational Exposure to Radon Comparable to Residential Exposure?	7
What About Smoking and Radon Exposure?..,,															7
The Solution..							9
Why Should Every Home be Tested?							9
How Do You Obtain a Reliable Test Result?	,...,								9
Radon Testing Methods					.												9
Radon Test Devices......									......10
How to Test.....	...																	10
Interpreting Radon Test Results												II
Basis for the 4 pCi/L Radon "Action Level"..													 11
Radon Reduction Methods											....			11
Other Indoor Air Pollutants...,								13
Environmental Tobacco Smoke (ETS)									 13
Biological .Air Pollutants		..........	................									14
Volatile Organic Compounds (VOCs)...,.....,..							14
Other Combustion Products...										,.......,.14
Most Commonly Asked Questions about Radon	15
State Radon Contacts.......									16
Additional Information Sources and Suggested Reading List	17

Executive Summary
According to the
Indoor radon gas is o serious
health problem in our nation that
con be addressed by individual
action. Unless people become
aware of the danger radon
poses, they will not act. Millions
of homes are estimated to hove
elevated radon levels. Fortun-
ately, the solution to this problem
is straight-forward. Like the haz-
ards from smoking, the health
risks of radon can be reduced.
Radon Causes Thousands of Preventable
Lung Cancer Deaths Each Year
Each year in the United States exposure to indoor
radon gas causes thousands of preventable lung can-
cer deaths. In fact. the Surgeon General has warned
that radon is the second leading cause of lung cancer
in the United States. Extensive epidemiological evi-
dence from studies of underground miners, comple-
mented by animal data, indicates that radon causes
lung cancer in both smokers and nonsmokers,
although malignancy is especially likely to occur in
cigarette smokers. Exposure to both smoking and
radon greatly enhances the risk of lung cancer. The
carcinogenicity of radon is supported by a consensus
of opinion among national and international health
organizations. By informing "patients about the health
risk posed by radon exposure and providing practical
advice about radon testing and mitigation, physicians
can have a tremendous positive impact on the nation-
al effort to prevent radon-induced lung cancer.
'Radon is estimated to cause about
14,000 deaths per year—however, this
number could range from 7,000 to
30,000 deaths per year. The numbers
of deaths from other causes are taken
from the 1990 National Safety
Council reports.
5000 -
Radon is Easy to Detect
and Reduce in a Home
The danger posed by radon can be detected rather
easily through inexpensive do-it-yourself testing or
through a trained radon contractor. Radon test kits
can be purchased hy mail order or in hardware stores
and other retail outlets. Because of the serious heal! h
risk posed by radon, the U.S. Environmental
Protection Agency (EPA) recommends that all homes
be tested for radon below the third floor.
If an elevated radon level is discovered in a home, il
can be corrected. It is recommended that a confirmed
radon level of 4 picoeuries per liter (pCi/L) of air or
higher be reduced to decrease the risk of developing
lung cancer. The cost of radon mitigation in a typical
home ranges from about $500 to about $2,500. Your
state radon information office (see page 16) can pro-
vide general advice about radon testing and mitiga-
tion, as well as specific information about qualified
radon contractors in your state.
"Physicians are often the only science
professional known to their patients and
are almost always a trusted source of
information about science in general and
health in particular. Radon does increase
the risk of lung cancer, and physicians
have an obligation to educate their
patients about the health risk
associated with radon."
Jerod M. Loeb, Assistant Vice-President for Science, Technology and
Public Health of the American Medical Association
Drunk Driving RADON* Drownings Fires Airline Crashes

Radon-222 is a radioactive gas released during the
natural decay of thorium and uranium, which are
common, naturally occurring elements found in vary-
ing amounts in rock and soil. Odorless, invisible, and
without taste, radon cannot be detected with the
human senses.
Outdoors, where it is diluted to low concentrations
in the air, radon poses significantly less risk than
indoors. In the indoor air environment, however,
radon can accumulate to significant levels. The mag-
nitude of radon concentration indoors depends pri-
marily on a building's construction and the amount of
radon iit the underlying soil. The soil composition
under and around a house affects radon levels and
the ease with which radon migrates toward a house.
Normal pressure differences between the house and
the soil can create a sliglu vacuum in the home that
can draw radon gas from the soil into the building.
Radon gas can enter a home from the soil through
cracks in concrete floors and walls, floor drains, sump
pumps, construction joints, and tiny cracks or pores
iti hollow-block walls, Radon levels are generally high-
est in basements and ground floor rooms that are in
contact with the soil. Factors such as the design, con-
struction, and ventilation of the home affect the path-
ways and forces that can draw radon indoors.
Another source of radon indoors may be air released
by well water during showering and other household
activities. Compared to radon entering the home
through soil, radon entering the home through water
will in most cases hr a small source of risk.
What is Radon?
Radon-222 decays into radioactive elements, two of
which—polonium-218 and poIonium-214—emit alpha
particles, which are highly effective in damaging lung
tissues. These alpha-emitting radon decay products
have been implicated in a causal relationship with
lung cancer in humans.
Characteristics and Sources off Radon
A Cracks in concrete slabs
B Spaces behind brick veneer walls that
rest on uncapped hoi low-block
C Pores and cracks in concrete blocks
D Floor-wall joints
E Exposed soil, as in a sump
F Weeping (drain) tile, if drained to open
G Mortar joints
H Loose fitting pipe penetrations
I Open tops of block walls
J Building materials such as some rocks
K Water (from some wellsl

The Health Risk
How does Radon Induce Cancer?
If inhaled, radon decay products (poionium-218 and
polonium-214, solid form), unattached or attached to
the surface of aerosols, dusts, and smoke particles,
become deeply lodged or trapped in the lungs, where
t hey can radiate and penetrate the cells of mucous
membranes, bronchi, and other pulmonary tissues,
The ionizing radiation energy affecting the bronchial
epithelial cells is believed to initiate the process of
carcinogenesis. Although radon-related lung cancers
are mainly seen in the upper airways, radon increases
the incidence of all histological types of lung cancer,
including small cell carcinoma, adenocarcinoma, and
squamous cell carcinoma. Lung cancer due to inhala-
tion of radon decay products constitutes the only
known risk associated with radon. In studies done on
miners, variables such as age, duration of exposure,
time since initiation of exposure, and especially the
use of tobacco have been found to influence individ-
ual risk. In fact, the use of tobacco multiplies the risk
of radon-induced lung cancer enormously.
What is the Evidence?
More is known about the health risk of radon expo-
sure to humans than about most other human car-
cinogens. This knowledge is based on extensive epi-
demiological studies of thousands of underground
miners, carried out over more than 50 years world-
wide, including miners in the United States and
Canada. In addition to the miner data, experimental
exposures of animals confirm that radon and its
decay products can cause lung cancer.
The research on lung cancer mortality in miners
exposed to radon progeny is substantial and consis-
tent, Studies of thousands of miners, some with fol-
iow-up periods of 30 years and more, have been con-
ducted in metal, fluorspar, shale, and uranium mines
in the United States, Canada, Australia, China, and
Europe. These studies have consistently shown
an increase in lung cancer occurrence with
exposure to radon decay products, despite differ-
ences in study populations and methodologies.
The mirier studies produced some interesting findings,
¦ At equal cumulative exposures, low exposures in
the range of EPA's 4 pCi/L action level over
longer periods produced greater lung cancer risk
than high exposures over short periods.
¦	Increased lung cancer risk with radon exposure
has been observed even after controlling for, or in
t he absence of, other mine exposures such as
asbestos, silica, diesel fumes, arsenic, chromium,
nickel, and ore dust,
¦	Increased lung cancer risk has been observed in
miners at relatively low cumulative exposures in
the range of EPA's 4 pCi/L action level (Sevc

Kunz, Tomasik et al, Health Physics 54(1):27-46,1988;
Millies Wheeler et al, Proceedings of International
Conference on Occupation Radiation Safety in
Mining, Vol. 1, Canadian Nuclear Association; Radford
and .St. Clair Renard, New England Journal of
Medicine 310(23): 1485-1494, 1984; Woodward, Roder
el al, "Cancer Causes and Control" 2:213-220, 1991).
¦ Nonsmoking miners exposed to radon have been
observed to have an increased risk of lung cancer.
The following table lists seven of the major epi-
demiological studies of underground miners and
their reported relative risk coefficients.
Study Population
Relative Risk
Czech Uranium Miners
Thomas el al. 1985
Sevc et al 1988
Ontario Uranium
Muller 1 984
New Mexico Uranium
Samet et al. 1991
Swedish Iron Miners
Radford & St. Clair Renard 1984
NAS 1988
Colorado Plateau
Uranium Miners
Thomas et al. 1985
NAS 1988
Eldorado (Beaverlodge)
Uranium Miners
Howe et al. 1 986
NAS 1988
Fluorospar Miners
Morrison et al. 1988
"The excess relative "sk coeWieaent used m EPA's risk assessment (1 3WWIMJ is that derrved by the NAS BElR IV report based on their anafysis of studies of underground miners
o Working level month (WLM) is the
cumulative exposure equivalent to
one working level (WL) for a working
month (170 hours). A WL is any com-
bination of short-lived radon dough
ters in one liter of air that will result in
the emission of 1.3 x 105 MeV of
potential alpha energy. A home
exposure of 4 pCi/L for 70 years
would approximately equal a cumula-
tive exposure of 54 WLM (assuming
75% occupancy).
fa The relative risk coefficient is the
fractional increase above the baseline
lung cancer incidence or mortality
rate per WLM, For example, the
Czech Uranium Miner demonstrated
o 1.92% increased lung cancer risk
for every WLM of exposure. Exposure
to 5 WLM would therefore increase
lung cancer risk by 9.6% over base-
c Estimate based on reanalysis of the
data by the NAS with the cooperation
of the principal investigators.

A detailed discussion of the strengths and weak-
nesses of the various miner studies can be found in
the EPA's Technical Support Document for the 1992
Citizen's Guide to Radon, available from your state
radon office, or the BEIR IV Report (National
Academy of Sciences (NAS) 1988).
Animal experiments conducted ill the United States
and France also have confirmed the carcinogenicity
of radon and have provided insight into the nature of
the exposure-response relationship, as well as the
modifying effects of the exposure rate. To date these
animal studies have produced several relevant find-
¦	I-fealth effects observed in animals exposed to
radon and radon decay products include lung car-
cinomas, pulmonary fibrosis, emphysema, and a
shortening of life-span (U.S. DOE/Office of
Energy Research 1988a),
¦	The incidence of respiratory tract tumors
increased with an increase in cumulative expo-
sure and with a decrease in rate of exposure
(NAS 1988).
¦	Increased incidence of respiratory tract tumors
was observed in rats at cumulative exposures as
low as 20 WLM (NAS 1988).
¦	Exposure to ore dust or diesel fumes simultane-
ously with radon did not increase the incidence of
lung tumors above that produced by radon proge-
ny exposures alone (DOE/Office of Energy
Research 1988a).
¦	Lifetime lung-tumor risk coefficients that have
been observed in animals are similar to the life-
time lung-cancer risk coefficients observed in
human studies (DOE/Office of Energy Research
¦	In a study of rats exposed to radon progeny and
uranium ore dust simultaneously, it. was observed
that the risk of lung cancer was elevated at expo-
sure levels similar to those found in homes. The
risk decreased in proportion to the decrease in
radon-progeny exposure (Cross et al. 1991).
In 1988, a panel of world experts convened by the
World Health Organization's International Agency for
Research on Cancer unanimously agreed that there is
sufficient, evidence to conclude that radon causes
cancer in humans and in laboratory animals (IARC,
1988). Scientific committees assembled by the
National Academy of Sciences (NAS, 1988), the
International Commission on Radiological Protection
(ICRP, 1987), and the National Council on Radiation
Protection and Measurement (NCRP, 1984) also have
reviewed the available data and agreed that radon
exposure causes human lung cancer.
Recognizing that radon is a significant public health
risk, scientific and professional organizations such as
the American Medical Association, the American
Lung Association, and the National Medical
Association have developed programs to reduce the
health risks of radon. The National Institute for
Occupational Safety and Health (NIOSH) reviewed
the epidemiological data and recommended that the
annual radon progeny exposure limit for the mining
industry be lowered (NIOSH 1987).

Is Occupational Exposure to Radon
Comparable to Residential Exposure?
Because questions have been raised about the
appropriateness of using the epidemiological studies
of underground miners as a basis for estimating the
risk radon poses to the general population, the EPA
commissioned the National Academy of Sciences
(NAS) to investigate the difference between under-
ground miners and members of the general public in
the doses they receive per unit exposure due to
inhaled radon progeny.
The NAS report, published in 1991 (National
Academy of Sciences, 1991, Comparative Dosimetry
of Radon in Mines and Homes. National Academy
Press, Washington, DC.), concluded that it is reason-
able to extrapolate from the miner data to a residen-
tial situation, but that the effective dose per unit of
exposure for people in their homes is approximately
30 percent less than for the miners, in its analysis,
NAS considered variables such as the amount and
type of dust to which the radon decay particles would
attach, the breathing rate of working miners com-
pared to that of people at home, and the presence of
women and children in the homes.
EPA has adjusted its residential risk estimates
accordingly. The result is still considerable- EPA now
estimates that approximately 14,000 lung cancer
deaths in the United States per year are due to resi-
dential radon exposures, with an uncertainty range of
7,000 to 30,000. As more data are gathered about res-
idential radon exposures, the risk estimates may be
adjusted further. Enough data exists now, however, to
be able to say with certainty that thousands of pre-
ventable lung cancer deaths annually in the
United States are attributable to indoor resi-
dential exposure to radon.
More information about residential exposure to
radon is needed to answer important questions about
radon's effect on women and children—groups not
included in the occupational studies of miners.
Although children have been reported to be at
greater risk than adults of developing certain types of
cancer from radiation, currently there is no conclu-
sive evidence that radon exposure places children at
any greater risk. Some miner studies and animal stud-
ies indicate that for the same total exposure, a lower
exposure over a longer time is more hazardous than
short, high exposures. These findings increase con-
cerns about residential radon exposures.
Epidemiological case control studies are underway in
the U.S. and Europe, the pooler! results of which
should enhance the understanding of the risk of resi-
dential exposure to radon.
What about Smoking and Radon Exposure?
Some people ask whether the lung cancer deaths
attributed to radon exposure actually may be the
result of smoking. A 1989 study by researchers from
the National Institute for Occupational Safety and
Health, the Centers for Disease Control, the Harvard
School of Public Health, and the University of
California at Davis demonstrated a greatly increased
lung cancer risk in nonsmoking uranium miners
exposed to high radon concentrations: compared to
typical non-smoking populations, these miners had 9
to 12 times the risk of developing lung cancer
(Roscoe et al, JAMA 262(5): 629-633, 1989).
Evidence from some of the epidemiological studies
of underground miners, primarily U.S. uranium min-

ers, indicates that radon exposure and smoking may risk of lung cancer; however, exposure to both
have a synergistic relationship. Either smoking or greatly enhances that risk,
radon exposure can independently increase the
Radon Risk comparison for Smokers and Nonsmokers
Radon Level
If 1,000 people who smoked
were exposed to this level
over a lifetime...
If 1,000 people who never
smoked were exposed to this level
over a lifetime...
20 pCi/L
(740 Bq/m')*
About 1 35 people could get
lung cancer
Abou-t 8 people could get
lung cancer
10 pCi/L
(370 Bq/m3)
About 71 people could get
lung cancer
About 4 people could get
lung cancer
8 pCi/L
(296 Bq/m )
About 57 people could get
lung cancer
About 3 people could get
lung cancer
4 pCi/L
(1 48 Bq/m3)
About 29 people could get
lung cancer
About 2 people could get
lung cancer
2 pCi/L
(74 Bq/m )
About 15 people could get
lung cancer
About 1 person could get
lung cancer
1.3 pCi/L
(48.1 Bq/m)
About 9 people could get
lung cancer
Less than 1 person could get
lung cancer
0.4 pCi/L
(14.8 Bq/m)
About 3 people could get
lung cancer
Less than 1 person could get
lung cancer
* Bq/m3= Bequerel/meter3

Why Should Every Home be Tested?
The EPA and the U.S. Surgeon General recommend
testing all homes below the third floor for radon. Data
gathered by the EPA national radon survey indicate
that elevated radon levels are present in about six
million homes throughout the United States. In
every state there are homes with dangerously high
radon levels. Because the radon concentration inside
a home is due to factors relating to its structure and
geographic location, each individual home must be
tested to determine its radon level. Tvvo adjacent
houses may have radically different radon levels. And
any kind of home can have elevated levels—new or
old, drafty or well-sealed, and basement or non-base-
How do You Obtain a Reliable Test Result?
Although radon cannot be seen or smelled, with the
proper equipment its presence is relatively easy to
The EPA operates a voluntary Radon Measurement
Proficiency (RMP) Program that evaluates radon
measurement companies and the test services they
offer. EPA recommends that testing services be pur-
chased from one of the organizations listed by EPA or
certified by the state. Most companies indicate U.S.
EPA or RMP approval on the test kit box by dis-
playing the phrase, "Meets EPA Requirements."
A list of radon measurement companies and individu-
als the EPA has determined to be "proficient" can be
obtained from the State Radon Office. (See page 16.)
A test kit obtained from a qualified company, if used
according to directions, should provide accurate
Tke Solution
Radon Testing Methods
The quickest way to test for radon is with a short-
term "do-it-vourself radon test kit, available by mail
order and in many retail outlets or by hiring an EPA
qualified or state-certified radon tester. Common
short-term test devices are charcoal canisters, alpha
track detectors, liquid scintillation detectors, eleetret
ion chambers, and continuous monitors. A short-term
testing device remains in the home for 2 to 90 days,
depending on the type of device. Because radon lev-
els tend to vary from day-to-day and season-to-sea-
son, a long-term test is more likely than a short-term
test to measure the home's year-round average radon
level. If results are needed quickly, however, a short-
term test followed by a second short-term test may
be used to determine the severity of the radon prob-
Long-term test devices, comparable in cost to
devices for short-term testing, remain in the home for
more than three months. A long-term test is more
likely to indicate the home's year-round average
radon level than a short-term test. Alpha track detec-
tors and elect ret ion detectors are the most common
long-term test devices.

i?flladon Test Devices
Charcoal canisters and liquid scintilJation detectors contain
small quantities of activated charcoal. Radon and its decay
pmducts arc adsorbed onto the charcoal and are measured by
counting with a sodium iodide detector or a tiqvid scintilla-
tion counter.
Alpha track detectors contain a small sheet of plastic that is
exposed for a period of one to three months. Alpha particles
etch the plastic as they strike it. These marks are then chemi-
cally treated and counted in the laboratoi~y to determine the
ixidon concentration.
Electret ion detectors contain an electroslically charged
Teflon disk. Ions generated by the decay of radon strike and
reduce the surface milage of the disk. By measuring the voltage
reduction, the radon concentration can be calculated.
Continuous monitors are active devices which need power to
function. They require operation by trained testers and work
by continuously measuring and recording the amount of tvdon
in the home.
Charcoal Canister
Eleetret Ion
:!f$w To Test
During a short-term test, doors and windows are
closed 12 hours prior to testing and throughout the
testing period. (A short-term test lasting two or three
days should not be conducted during unusually
severe storms or periods of unusually high winds.)
The test kit is placed in the lowest lived-in level of t he
home, at least 20 inches above the floor, in a room
that is used regularly, but not in the kitchen or bath-
room where high humidity or the operation of an
exhaust fan could affect the validity of the test. At the
end of the test period, the kit is mailed to a laboratory
for analysis; result s are mailed back in a few weeks.
In some cases, such as real estate transactions,
trained EPA-listed or state-certified contractors con-
duct the radon test. The EPA's pamphlet Home
Buyer's and Seller's Guide to Radon, which
addresses issues during real estate transactions, is
available from state radon offices.

Interpreting Radon test
A.	if the short-term test result is 4 pCi/L or
higher, conduct a follow-up test to confirm
the results.
B.	Follow-up with either a long-term test or a
second short-t erm test.
For a better understanding of the home's
year-round average radon level, take a long-
term test.
If results are needed quickly, take a second
short-term test.
The higher the initial short-term result, the
more certain the homeowner can be to con-
duct a short-term rather than a long-term fol-
low-up test. If the first short-term test result is
several times the action level—for example,
about 10 pCi/L or higher—a second short-
term test should be taken immediately.
C.	If the long-term follow-up test result is 4
pCi/L or more, fix the home.
If the homeowner followed up with a
second short-term test: the higher the
short-term results, the more certain the
homeowner can be that the home should be
fixed. The homeowner should consider fixing
the home if the average of the first and sec-
ond test is 4 pCi/L or higher.
Basis for the 4 pCi/L Radon "Action Level"
No radon level is considered "safe." The risk of
developing lung cancer is directly proportional to the
levels and duration of exposure to radon: the higher
the radon concentration, the higher the lung cancer
risk. The 4 pCi/L "Action Level" is based on current
mitigation technology. Today mitigation technology
can almost always reduce high radon concentration
levels to below 4 pCi/L and to 2 pCi/L or below 70-80
percent of t he time. The average radon level in homes
is about 1.25 pCi/L. Although Congress passed legisla-
tion in 1988 establishing a national goal that indoor
radon levels not exceed ambient outdoor radon levels
(0.2-0,7 pCi/L), this goal is not yet technologically
Radon Reduction Methods
Radon in soil is drawn indoors by the differential
between the relatively low air pressure in the house
and the higher air pressure in the soil. Therefore,
radon reduction strategies fall into two basic cate-
gories: those that prevent the entry of radon gas into
the home, and those that attempt to remove the
radon once it has entered the home. In most, situa-
tions, the first approach—preventing radon entry—is
the most effective.
Although sealing cracks and other openings in the
foundation is a basic part of most approaches to
radon reduction, sealing alone is not recommended; it
is best done in conjunction with other mitigation
techniques to enhance their effectiveness.
The most popular radon mitigation technology is
called "sub-slab depressurization" or "slib-slab suc-
tion," The "sub-slab depressurization" technique

removes radon-laden air from beneath the foundation
and vents it outside the home by installing a fan and
inserting a pipe through the foundation into the
aggregate below, running it to a point outside the
shell of the house. A similar technique, "sub-mem-
brane depressurization," which is effective in build-
ings with earth-floored crawlspaces or basements,
uses a plastic barrier over the soil as a collection
cover. Another depressurization technique for pre-
venting radon entry, "blockwall depressurization,"
Seal Around
•Entry Points
Radon Sxhaust
Pipe (typically
hidden in closet or
between walls!.
System Failure
uses a fan and duct work to draw suction on the hol-
low interior cavities of a concrete block wall. By
keeping the air pressure within the block wall lower
than the air pressure in the basement, the soil gas is
removed before it can enter the basement .
Reducing radon levels requires technical knowledge
and special skills. The EPA operates a Radon
Contractor Proficiency (RCP) Program that evaluates
radon reduction contractors. As with t he Radon
Measurement Proficiency (RMP) Program, the EPA
sends a list of RCP contractors to state radon offices
{see page 16). Selecting a radon contractor is much
like choosing a contractor for other home repairs; it
makes sense to get references and more than one
estimate. The average cost to correct a radon prob-
lem in a home is about $1,200, although it can range
from about $500 to about $2,500. A free copy of A
Consumer's Guide to Radon Reduction is available
from state radon offices. People who choose to fix
their homes themselves should refer to the EPA's
technical guide, Radon Reduction Techn iques for
Detached Houses, available from state radon offices.
After the radon reduction procedure is complete,
the home should be ret est ed Most radon reduction
systems include a monitor that will alert the home-
owner if the system needs servicing.

Other Indoor Air Pollutants
Preventive Measures that can be
taken ta reduce your exposure to
indoor air pollutants include the
Environmental Tobacco Smoke (ETS)
•	Don'f smoke around others, particularly children.
•	Every organization dealing with children should
have a smoking policy that effectively protects
children from ETS.
•	In the work place, prohibit smoking indoors or
provide separately ventilated smoking areas.
•	If smoking is permitted in restaurants and bars,
placement of smoking areas should be designated
fa minimize nonsmoker exposure.
Biological Air Pollutants
•	Provide adequate outdoor qir ventilation.
•	Keep equipment water reservoirs clean.
•	Maintain relative humidity below 50 percent.
•	Eliminate standing water, wash bedding and soft
toys frequently inhol water.
•	Vacuum carpets and upholstered furniture
Volatile Organic Compounds (VOCs)
•	Remove the source.
•	Avoid use.
•	Increase ventilation when using products.
Other Combustion Products
•	Vent furnaces, water heaters ond clothes dryers to
the outdoors.
•	Periodic professional inspections and maintenance
of major appliances.
•	Regularly clean Fireplace and waod/coal stove
Environmental Tobacco Smoke (ETS)
The U.S. Environmental Protection Agency has
classified environmental tobacco smoke (ETS) as a
Group A (known human) carcinogen. EPA estimates
that approximately 3,000 lung cancer deaths in the
United States per year among nonsmokers are due to
ETS. The U.S. Surgeon General, the National
Research Council, and the National Institute for
Occupational Safety and Health have all concluded
that passive smoking can cause lung cancer in other-
wise healthy adults who never smoked.
Children's lungs are even more susceptible to harm-
ful effects from ETS. In infants and young children up
to three years, exposure to ETS causes an approxi-
mate doubling in the incidence of pneumonia, bron-
chitis, and bronchiolitis. There is also strong evidence
of increased middle ear effusion and reduced lung
function and lung growth. Several recent studies link
ETS with increased incidence and prevalence of asth-
ma and increased severity of asthmatic symptoms in
children of mothers who smoke heavily.
Environmental tobacco smoke is a complex mixture
of more than 4,000 chemicals found in both vapor and
particle phases, many known toxic and carcinogenic
agents. ETS consists of both "sidestream" smoke, the
emission from the burning erici of the cigarette, and
exhaled "mainstream smoke," the smoke inhaled by
the active smoker.

Biological Air Pollutants
Dust mites, molds, animal dander, and other biolog-
icals are found in some degree in every home and
workplace. High relative humidity is the primary fac-
tor encouraging biological agents to grow and be
released into the air. Biological agents are known to
cause three types of human diseases: infections,
where pathogens invade human tissues; hypersensi-
tivity diseases, where specific activation of the
immune system causes disease; and toxicoses, where
biologically produced chemical toxins cause direct
toxic effects.
Volatile Organic Compounds (VOCs)
Volatile Organic Compounds (VOCs) are emitted as
vapors or gases at ordinary temperatures from a vari-
ety of sources. Many are toxic, including benzene,
carbon tetrachloride, and formaldehyde. VOCs can be
found in paint, upholstery, spray cans, copy machine
toners, clothing, and other sources. Health effects
range from irritation of the eyes and respiratory sys-
tem to kidney or liver damage, cancer, or birth
Other Combustion Products
Aside from ETS, the major combustion pollutants—
carbon monoxide (CO), nitrogen dioxide (N02), and
sulfur dioxide (S02)—that may be present at harmful
levels in t he home or workplace stem chiefly from
malfunctioning or misusing heating devices. An addi-
tional source of exposure may be motor vehicle emis-
sions as a result of a garage or loading dock located
near air intake vents. Symptoms may mimic influenza
and include fatigue, nausea, dizziness, headaches,
cognitive impairment, and tachycardia during the
heating season.
For more information on these and other indoor air
pollutants, call EPA's indoor Air Quality Information
Clearinghouse (1-800-438-4318) for Indoor Air
Pollution: An Introduction for Health Professionals
and The Inside Story: A Guide to Indoor Air

Most Commonly Asked Questions About Radon
Where does radon come from?
A, Radon is a naturally occurring gas that results
from the breakdown of uranium commonly found
in soil.
How does radon enter my home?
A. Radon comes up through the soil and rocks
surrounding your home and seeps through
cracks in concrete walls and floors, floor drains,
sump pumps, joints, and hollow block walls.
Why haven't I heard of the radon
danger until recently?
A. Radon has always existed. However, it was
not until the 1980s that dangerous radon levels
were found inside homes across the U.S.
What are the health risks?
A, Radon is the second leading cause of lung
If I have a radon problem, cam It he
A, Yes. The use of trained personnel is recom-
mended. State radon offices can recommend
qualified contractors. In some cases, the problem
can be treated by the homeowners if they have
experience with other kinds of home repair.
Will my neighbor's radon measure-
ment indicate whether or not 1
have a radon problem?
A. No. Radon levels vary from house to house.
The only way to know if you have a radon prob-
lem is to conduct, a test-
How can I get a reliable radon
test kit?
A. Kits can be purchased through the mail or
from your local grocery or hardware store or
other retail outlets. Look for a test kit from a
company that is State-certified or EPA-listed.
How do I know if I have radon m
my home?
Am By testing with an EPA-listed or State-certi-
fied easy-to-use, inexpensive test kit as soon as
possible, or by hiring an EPA-listed or State-cer-
tified contractor to test your home for you.

State Radon Contacts
Alabama	800/582-1866
Alaska	800/478-4845
Arizona	602/2554845
Arkansas	501/661-2301
California	800/745-7236
Colorado	800/846-3986
Connecticut	203/566-3122
Delaware	800/554-4636
DC	202/727-5728
Florida	800/543-8279
Georgia	800/745-0037
Hawaii	808/586-4700
Idaho	800/445-8647
Illinois	800/325-1245
Indiana	800/272-9723
Iowa	800/383-5992
Kansas	913/296-1561
Kentucky	502/564-3700
Louisiana	800/256-2494
New Hampshire.
New Jersey	
New Mexico	
New York	
North Carolina...
North Dakota	
.800/852-3345 x4674
Pennsylvania	800/237-2366
Rhode Island	401/277-2438
South Carolina	800/768-0362
South Dakota	800/438-3367
Tennessee	800/232-1139
Texas	512/834-6688
Utah	801/538-6734
Vermont	800/640-0601
Virginia	800/468-0138
Washington	800/323-9727
West Virginia	800/922-1255
Wisconsin	608/267-4795
Wyoming	800/458-5847
Guam	617/646-8863
Puerto Rico	809/767-3563
Virgin Islands	800/468-0138
National Radon Hotline

Additional Information Sources and Suggested Reading List
The following free materials are available from your
state radon office.
•	Reducing Radon Risk
•	A Citizen's Guide lo Radon (1892 Edition):
The Guide to Protecting Yourself and Your
Family /row Radon (available in Spanish)
» Tech n ical Support Docu men t for the 1992
Citizen's Guide to Radon
•	Home Buyer's and Sellers Guide to Radon
•	Radon it/ Schools
•	Consumer's Guide to Radon Reduction
For additional indoor air publications, call EPA's
Indoor Air Quality Information Clearinghouse
•	The Inside Story:A Guide to Indoor Air Quality
•	Indoor Air Pollution: An Introduction for Health
Profess io n a Is
•	Secondhand Smoke
Your state radon
office has other
materials, including
free posters, to
display in your office.
Suggested Reading List:
Council on Scientific Affairs. 1987. American Medical
Association (AMA). Radon in Homes. Journal of t lie
American Medical Association. 258: <568-672.
Council on Scientific Affairs. Health Effects of
Radon Exposure. Archives of Internal Medicine.
151: (574-677.
Lubin, J.M., Samet and Weinberg, C. 1990. Design Issues
in Epidemiologic studies of Indoor Exposure to Rn and
Risk of Lung Cancer. Health 1'hvsics. 59(0): 807-817.
National Academy of Sciences. 1991. Comparative
Dosimetry of Radon in Mines and I ionics. National
Acedemy Press, Washington. DC.
National Academy of Sciences. 1988, Healt h Risk of
Radon and Other Internally Deposited Aloha Emitters:
BE1R IV. National Academy Press, Washington. DC.
Roscoe. R.J.. et al. 1989. Lung Cancer Mortality Among
Non-Smoking Cranium Miners Exposed to Radon
Daughters, Journal of the American Medical
Association. 262(5): (>29-0-33.
Samet. J.M., Stojwijk, J. and Rose, S. 1991a. Summary:
International Workshop on Residential Rn Epidemiology.
Health physics, 00(2): 223-227.
Samet, J.M. and Hornung, R. 1990, Workshop on Indoor
Air Quality: Review of radon and Lung Cancer Risk. Risk
Analysis. 10(1): 65-75,
U.S. DOE/Offiee of Energy Research, 1989. Internaional
Workshop on Residential Radon Epidemiology:
Wo r k sh on 1 *roc c e d in gs. Commission of European
Communities, Radiation Protection Program. CONF-

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