vvEPA
United States
Enviromental Protection
Agency
Air and Radiation
(6602J)
EPA 402-K-92-004
August 1993
Radiation:
Risks and Realities
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: Ris,Ks and Realities is Printed on Recycled Paper.
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t comes from outer space, the ground, and even from within
our own bodies. Radiation is all around us and has been
present since the birth of this planet. Naturally-occurring
radioactive materials were discovered in 1896. Less than
50 years later, the physicist Enrico Fermi split the atom, producing the
first man-made radioactive materials. Today, both man-made and
natural radiation are part of our lives. We use radioactive materials for
beneficial purposes, such as generating electricity and diagnosing and
treating medical problems. For example, Americans receive 200 million
x-rays every year. Though radiation offers many
benefits, exposure to it can also threaten our health
and the quality of our environment. We cannot
eliminate radiation from our environment. We can,
however, reduce our risks by controlling our exposure
to it. This booklet discusses the major sources and
uses of radiation, the risks from exposure, and how we can limit
and reduce these risks.
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Matter is composed of atoms. Some atoms are unstable. As these atoms change to become
more stable, they give off invisible energy waves or particles called radiation.
RELATIVE DOSES FROM
RADIATION SOURCES
Mitllram Doses
There are different types of
radiation, some more energetic
than others. One type of radia-
tion, non-ionizing radiation,
has enough energy to move
atoms but not enough to alter
them chemically. This booklet
X-rays and
nuclear medicine
50 millirem (anmial)
Radon in
avaraga
household^
in the U.S.
200 milliran :
(annual) 1
lintestinal
(upper
and lower)
1,400 millirem
Living in
Denver
81 millirem
(anntial)
Natural
radioactivity
in the body
39 mjfiirem
(amnial)
34 milliretrj
(annual)
Mommogram
30 millirety,-'
. ,'fe
7 _
drinking^ivater
11 millirem
'**' ."(annual)
Cosmic
radioactivity
31 millirem (anmtal)
Living at sea level
28 millirem (annuatK
Living near.
a nuclear
power station
mUlirem-fauaaal't
discusses the most energetic
form, known as ionizing radia-
tion, which from here on will be
referred to simply as radiation.
We measure radiation dose in
units called rem1 (small doses
are measured in millirem; one
rem = 1,000 millirem). Scien-
tists estimate that the average
person in the United States
receives a dose of about 360
millirem of radiation per year.
Eighty percent of that exposure
comes from natural sources:
radon gas, the human body,
outer space, and rocks and soil.
The remaining 20 percent
comes from man-made
radiation sources, primarily
medical x-rays.
Over 80 percent of our exposure to
radiation comes from natural sources.
Our own bodies, which contain the
radioactive element potassium,
account for 11 percent of our total
exposure. Another three percent of our
exposure to radiation comes from
consumer products. Many of the
sources of radiation shown here are
discussed in this booklet.
illirem
Tho average annual radiation exposure for a person living in the U.S.A. is 36O millirem.
i Other countries, as well as the
scientific community in the U.S.,
measure radiation dose in units
called sieverts.
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T 1. When radiation penetrates a
human cell, it may damage molecules
in its path.
11
T 2. If a DNA molecule is damaged,
the chromosome containing that DNA
molecule may break apart.
A DMA MOLECULE
A 3. The chromosome may
then recombine abnormally.
This change in chromosome
structure may lead to the
death of the cell or the
formation of a cancerous cell.
RISKS FROM EXPOSURE
TO RADIATION
Radiation is a carcinogen.
In this respect, it is similar to
many hazardous chemicals
found in the environment that
can cause cancer. It may also
cause other adverse health
effects, including genetic defects
in the children of exposed par-
ents or mental retardation in the
children of mothers exposed
during pregnancy. However, the
risk of developing cancer due to
radiation exposure is much
higher than the risk of these
other effects.
Much of our knowledge about
the risks from radiation is based
on studies of over 100,000
survivors of the atomic bombs
at Hiroshima and Nagasaki.
In these studies, which have
continued over the last 40 years,
scientists have been able to
observe the effects of a wide
range of radiation doses, includ-
ing doses comparable to an
average person's lifetime dose
from naturally-occurring back-
ground radiation (about 20,000
millirem). We have learned
many things from these studies.
The most important are:
D The more radiation doss
a person receives, the
greater the chance of
developing cancer.
01 It is the chance of cancer
occurring, not the kind
or severity of cancer, that
increases as the radiation
dose increases.
El Most cancers do not appear
until many years after the
radiation dose is received
(typically 10 to 40 years).
Current evidence suggests that
any exposure to radiation poses
some risk, i.e., there is no level
below which we can say an
exposure poses no risk. For
the entire dose of radiation we
accumulate over a lifetime
from natural background
radiation, the risk of develop-
ing cancer is estimated to be
about one in one hundred.
Based on this estimate, several
percent of all fatal cancers
in the U.S. are caused by
background radiation. The
additional contribution from
all man-made sources of radia-
tion is much smaller.
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Naturally-occurring radiation accounts for approximately 80 percent of our exposure.
Most of our exposure is to indoor radon, followed by radiation from
outer space and from the earth's crust.
Ration accounts for over half of the
radiation dose H* receive. It can enter
a house through cracks in basement
MM//J or floors, construction joints, or
gaps around pipes. Nearly one out of
every IS homes in the United States is
atintated to have elevated radon levels.
RADON
Fifty-five percent of our expo-
sure to natural sources of
radiation usually comes from
radon. Radon is a colorless,
tasteless, and odorless gas that
comes from the decay of ura-
nium found in nearly all soils.
Levels of radon vary throughout
the country. Radon usually
moves from the ground up and
migrates into homes and other
buildings through cracks and
other holes in their founda-
tions. The buildings trap radon
inside, where it accumulates
and may become a health
hazard if the building is not
properly ventilated.
When you breathe air contain-
ing a large amount of radon,
the radiation can damage your
lungs and eventually cause lung
cancer. Scientists believe that
radon is the second leading
cause of lung cancer in the
United States. It is estimated
that 7,000 to 30,000 Americans
die each year from radon-in-
duced lung cancer. Only smok-
ing causes more lung cancer
deaths and smokers exposed to
radon are at higher risk than
nonsmokers.
CONTROLLING THE
RISKS FROM RADON
EXPOSURE
Radon is found all over the
United States. Scientists estimate
that nearly one out of every 15
homes in this country has
radon levels higher than four
picocuries per liter, the level
above which EPA recommends
that homeowners take correc-
tive action. Picocuries per liter
is how radon in the air is
measured. Testing your home
is the only way to know if you
and your family are at risk
from radon.
Testing for radon is easy and
only takes a few minutes of your
time. There are many kinds of
low-cost, "do-it-yourself,"
EPA-approved or state-certified
radon test kits available through
the mail or from retail outlets.
You can also hire a professional
to do the testing. EPA recom-
mends choosing a state-certi-
fied and/or EPA-listed
measurement company.
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f-
If you find high radon concen-
trations, you can reduce them
in a variety of ways. Reduction
methods can be as simple as
sealing cracks in floors and walls
or as complex as installing sys-
tems that use pipes and fans to
draw radon out of the building.
EPA has a National Radon
Program to inform the public
"about radon risks, train radon
mitigation contractors, provide
grants for state radon programs,
and develop standards for
radon-resistant buildings. EPA
works with health organizations,
state radon programs, and other
federal agencies to make the
program as effective as possible.
For more information about
radon, its risks, and what you _
can do to protect yourself, call
1-800-SOS-RADON or contact
your state's radon office and
request a free copy of EPA's
A Citizen's Guide to Radon.
A list of state radon contacts is
provided on the back cover of
this booklet.
RADIATION FROM
THE GROUND AND
OUTER SPACE
Radon gas is not the only
source of natural radioactivity.
We receive about eight percent
of our exposure to radiation
from other radioactive elements
in the earth's crust, such as
thorium and potassium. Radia-
tion levels from these sources
vary in different areas of
the country. .-.""^
Another_eight percent of our
radiation exposure,comes from
outer space. This cosmic radia-
.,.,tion originates in bur galaxy,
other galaxies, and our own pun.
Our exposure to cosmic radia-
tion depends in part on the j
elevation where we live. For- .. .
example, people who live in j
Denver, Colorado, which is j,_".
more than 5,666 fee"f1boveJj|a
level, are exposed to more cos-^-
mic radiation than people living
in Chicago, Illinois. Because
Chicago is only approximately
1,000 feet above sea level, it
has a thicker atmosphere, ^
which can filter out mom cos-
mic radiation thajlPehver's
thinner atmosphere.
Qpjitfolling exposure
forms of natural rai
would not be pra
f-
iftr
ill
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Since the discovery of radiation, people have benefited from the use of radiation in medicine
and industry. Man-made sources of radiation account for about 20 percent of our
total exposure to radiation.
X-rayt are a type of radiation
and are also an important tool in
medical diagnoses. Doctors and
patients fhould weigh the benefits
and riffcs of medical treatment
involving radiation.
RADIATION IN MEDICINE
Radiation used in medicine is
the largest source of man-made
radiation to which people in
the United States are exposed.
Most of our exposure is from
diagnostic x-rays. Physicians use
x-rays in more than half of all
medical diagnoses to determine
the extent of disease or physical
injury. Radiation is also used in
cancer treatments, where pre-
cisely targeted radiation
destroys diseased cells without
killing nearby healthy cells.
Radiopharmaceuticals, another
medical treatment, are used to
locate tumors in a patient's
body and to treat cancer. One-
third of all successful cancer
treatments involve radiation.
CONTROLLING THE
RISKS OF MEDICAL
RADIATION
The Food and Drug Adminis-
tration (FDA) and other
federal and state agencies
regulate medical procedures
that use radiation. EPA and
these agencies also issue
guidance designed to reduce
unnecessary use of radiation
in diagnosis and treatment
and to ensure that technicians,
equipment, and techniques
meet standards that minimize
radiation exposure.
Patients and health care pro-
viders must make the decision
to use radiation on a case-by-
case basis. Since any radiation
exposure carries some risk, it is
necessary to decide whether
the benefits of radiation justify
its use. Before receiving x-rays
or any other type of medical
treatment involving radiation
exposure or dose, it is sensible
to discuss the need for and
benefits of the procedure
and its alternatives with
your physician.
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NUCLEAR POWER
Nuclear power reactors, whicr
use uranium, supply the
United States with about 20
percent of its electricity. Our
ability to produce power using
radioactive materials reduces
our reliance on fossil fuels.
Nuclear power plant opera-
tions account for less than a
hundredth of a percent of the
average American's total
radiation exposure. Workers at
nuclear power plants receive
higher doses of radiation, but
the overall risk to the popula-
tion is extremely low.
CONTROLLING
THE RISKS OF
NUCLEAR POWER
In 1979, EPA issued environ-
mental standards that protect
the public from radiation from
the many kinds of facilities that
contribute to the production of
electricity through the use of
nuclear enegfy. Additionally,
issued ance
^
thejjpelopmentcrfracfiaTio
exjfKure standards for workers
ese standards limit the
gunt of radiatioryjJaTwork-
_ igdjcjfl^Mclear power,
irfflistryrmining, and waste
management may receive.
Finally, in 1989, under the
Clean Air Act, EPA published
standards limiting radionuclide
emissions from all Federal and
industrial facilities.
The Nuclear Regulatory
Commission (NRC) is the fed-
eral agency responsible for
implementing EPA's radiation
exposure standards through
regulation of nuclear power
reactors and many other uses of
radiation. The Department of
Energy (DOE) also implements
these standards at facilities
under their supervision.
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The Department of Energy's nuclear
weapons complex consists of 16 major
sites across the United States, such as
this one in Hanford, Washington.
Many of these sites are contaminated
with radioactive wastes from nuclear
weapons production. EPA is setting
the criteria that DOE and the states
will use to clean up the contamination
at these facilities.
RADIOACTIVE WASTE
Any activity that uses radioactive
materials generates radioactive
waste. Mining, nuclear power,
defense, nuclear medicine, and
scientific research all produce
radioactive waste that must be
disposed of properly. Some ac-
tivities produce low-level waste,
which includes rags, equipment,
and protective clothing con-
taminated with radioactive
material. Others generate more
highly radioactive waste, such
as used fuel from reactors or
waste from the manufacture of
nuclear weapons.
Radioactive waste can remain
radioactive for anywhere from
days to hundreds or even thou-
sands of years. If this waste is
not properly isolated from the
public and the environment, it
may contaminate air, soil, and
water supplies.
CONTROLLING
THE RISKS OF
RADIOACTIVE WASTE
Several federal agencies and
some states control the risks of
radioactive waste by establishing
appropriate disposal regulations
and applying these to disposal
facilities to effectively isolate
the waste. EPA has already
established environmental
standards for the cleanup and
disposal of radioactive mining
wastes. EPA is also responsible
for setting generally applicable
environmental standards for
disposal of other radioactive
wastes, which will be imple-
mented by NRC and DOE.
Federal agencies regulate stor-
age of high-level waste, which
is currently placed in under-
ground tanks or stored in pools
of water. DOE is evaluating
potential disposal sites for
radioactive waste at Yucca
Mountain, Nevada, and
Carlsbad, New Mexico. These
sites would be located thou-
sands of feet underground
and be subject to EPA perfor-
mance requirements issued to
prevent waste from escaping. In
October 1992, Congress passed
the Waste Isolation Pilot Plant
(WIPP) Land Withdrawal Act.
This Act gives EPA the respon-
sibility to oversee DOE in the
testing and operation of the
WIPP. EPA is also charged with
ensuring that WIPP complies
with all federal environmental
laws and regulations.
In addition to these
disposal options, the federal
government is investigating
new technologies and disposal
methods to treat or dispose of
these wastes safely.
CONCLUSION
Natural sources of radioactivity
are all around us, and man-
made radioactive materials are
a vital part of medicine and
industry. Exposure to some
radiation, natural or man-
made, is inevitable. In living
with radiation, we must
understand the risks and
benefits. It is also important to
remember that many federal
and state programs exist to
protect the public from avoid-
able exposures to radiation.
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MANY FEDERAL
AGENCIES AND
THE STATES
HAVE IMPORTANT
ROLES IN
PROTECTION OF
THE PUBLIC AND
THE ENVIRONMENT
FROM RADIATION
STATES
The states have agencies re-
sponsible for regulating the use
of radiation and for addressing
radiation questions and prob-
lems. They are the best first
source of information about
radiation issues which affect
their constituents. The states
regulate the use of x-ray ma-
chines. Some are also licensed
to regulate other sources of
radiation within their state on
behalf of EPA, NRC, or the
Occupational Safety and
Health Administration
(OSHA).
ENVIRONMENTAL
PROTECTION AGENCY
(EPA>
EPA issues standards and guid-
ance to limit human exposure
to radiation. EPA works with
the public, industry, the states
and other government agencies
to inform people about
radiation's risks and to pro-
mote actions that reduce
human exposure. EPA also
measures environmental levels
of radiation and assesses
, jadiation's effects on people: s =
and the environment.
NUCLEAR REGULATORY
COMMISSION (NRC)
NRC implements EPA's and its
own standards for protecting
the public from radiation. NRC
regulates the civilian uses of
iJ-JMVV -.-:; -:-~~ .-:...-_, -- -
|h United
States by: licensing facilities
that possess, use, or dispose of
nuclear materials; establishing
standards governing the activi-
ties of licensees; and inspecting
licensed facilities to ensure ;["
compliance with its require-i
ments. These regulatory func-
tions relate to both nuclear
power plants and to other u:;ers
of nuclear materials for pur-
poses such as nuclear medicine
at hospitals, academic activities
at educational institutions, :
research work, and industrial
applications such as gauges ;ind
testing equipment. j
DEPARTMENT OF
HEALTH AND HUMAN
SERVICES (HHS)
HHS's Food and Drug
Administration's Center for"
Devices and Radiological
Health establishes standardsjfor
x-ray machines and other elfec- '
tronic products to ensure that
human health is protected j
from the radiation produces!'"_ "".
by these products. J
DEPARTMENT OF
ENERGY (DOE)
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DOE is responsible for the .:
development of the disposal
system for spent nuclear fuel"
from the nation's civilian *
nuclear power plants. This ; t-
-. . -" " ~ . I *=-
activity is totally funded by i *:
a tax paid by the users of i w
J «^i.'
nuclear-generated electricity. %
DOE is also responsible for the
management and disposal cf ::;
nuclear waste and other radio-__;
active materials associated vfitib
nuclear weapons production at
federally-owned facilities. The
Department is working to clean
up its present and former
nuclear sites. DOE is cooperat-
ing with state governments and
private industry to clean up
other locations around the
United States that were con-
taminated with radiation as a
result of government programs.
DOE also provides technical
advice and assistance to states
and the private sector in the
management and Disposal of
low-level radioactive waste.
DEPARTMENT OF
DEFENSE (DOD)
- . \ '*- »V>_
While DOE is responsible fqr '._
the, safe handling of radioactive
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matenal at defense production.
facilities, DOD is responsible -
-for the safe handling and "^ -^*
'. storage of nuclear-weapons
-
|a
r-we
St
nuclear energy.
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DOT, in cooperatioh with
NRC and the states, governs
the packaging and transport
of radioactive materials. TJig
Department also regulates
carriers of radioactive materials.
tr!E--5S
10SHA)
0SH3. develops and enforces
"regulations to protect workers
not covered by other agencies
from radiation exposure.
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1 R E G 1 0 IM A L 0 F F 1 C E S ^^^^^^^^^^^^^H
Providing Information
REGION 1
U.S. EPA Region 1
J.F.K. Federal Building
One Congress Street
Boston, MA 02203
617-565-4502
Connecticut
Afrt/Mf
itJIIIfIL
Massachusetts
Ne\v Hampshire
Rhode Island
Vermont
REGION 2
U.S. EPA Region 2
26 Federal Plaza
New York, NT 10278
212-264-4110
Nc\v Jersey
iYeu1 York
Puerto Rico
REGION 3
U.S. EPA Regions
841 Chestnut Street
Philadelphia, PA 19107
215-597-8326
Ddamire
District of Columbia
Man'land
Pennsylvania
\7iginra
West Virginia
on EPA's Radiation
REGION 4
U.S. EPA Region 4
345 Courtland Street, NE
Atlanta, GA 30365
404-347-3907
Alabama
Florida
Georgia
Kentucky
Mississippi
North Carolina
South Carolina
Tennessee
REGION 5
U.S. EPA Region 5
Protection Programs
REGION 7
U.S. EPA Region 7
726 Minnesota Avenue
Kansas City, KS 66101
913-551-7600
Iowa
Kansas
Missouri
Nebraska
REGION 8
U.S. EPA Region 8
999 18th Street
Denver, CO 80202-2405
303-293-1713
Colorado
Montana
77 West Jackson Boulevard ,7 ., _. ,
_, . ' -_,. North Dakota
Chicago, IL 60604
312-886-6175 South Dakota
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
REGION 6
U.S. EPA Region 6
1445 Ross Avenue
Dallas, TX 75202-2733
214-655-7223
Arkansas
Louisiana
Ne\v Mexico
Oklahoma
Texas
Utah
Wyoming
REGION 9
U.S. EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
415-744-1048
Arizona
California
Hawaii
Nevada
REGION 1O
U.S. EPA Region 10
1200 Sixth Avenue
Seattle, WA 98 101
206-442-7660
A In elf fi
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