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A Publication of .the
Environmental Health Center
National Safety Council
1019 19th Street, N.W., Suite 401
Washington, DiC. 20036
(202) 293-2270
Product No. 82343-0000
May 1996
National
Safety
Council
from the U.S.
under Grant No. X-
The contents of h* docu
ereprce portions o, this guidebook
of the National Safety Council."
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R Guide to Radon
The Nation's Second
Leading Cause of
Lung Cancer
A publicatio n of the
Environmental Health Center
National Safety Council
1019 19th Streelt, NW#401
Washington, DC 20036
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How Radon
Table of Contents
Acknowledgements
Introduction
Chapter 1 -- Understanding Radon
What is Radon?
Radiation Basics
Radon Geology
Damag
as the Lung
Where is Rs don?
Map of Radon Zones
How Does Radon
Who is at Risk?
The Federal Role
3nter Homes?
Chapter 2 --Tjesting and Reducing Exposure
Methods and Reliability of Tests
Testing Reli ability Considerations
Latent 4ealth Risks
Chapter 3 -- tyisput
Quantifying
Estimating tie
Fretting over'F
Target Wor&Radoh
Risks for Sr nokers vs
Dispelling Popular
Is EPA Being Overfy Cautious?
Or is the
Agenq
ng the Radon Risks
Cancer Deaths
Number of Lung i
Routine' Risks?
Homes First?
i. Nonsmokers
Misconceptions
Leaving People at Risk?
Chapter 4 -- Other Radon and Indoor Air Issues
Radon in Schools
Real Estate Transactions
New Construction
Other Indoor Air Quality Issues
What Can Be Done About It?
Chapter 5 -- Sourc
Organizations
State Rado i Contacts
for Further Information
v
1
5
5
5
7
8
9
12
14
15
18
22
22
26
30
30
31
33
34
34
35
35
36
37
37
38
39
45
47
49
49
52
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54
Regional Training Centers 56
EPA Documents and Videos 57
International Contacts 60
Appendix A - Radon Questions and Answers 61
Appendix B -- Summary Table of Indoor Air
Pollutants 68
Glossary 70
Figures
Figure I - Hypothetical Newspaper Headline 2
Figure 2 - Sources of Background Radiation
for the U.S. Population 6
Figure 3 - How Soil Conditions Can Affect Radon
Pathways into Neighboring Houses 7
Figure 4 - Map of Radon Zones 13
Figure 5 - Radon Awareness and Testing 20
Figure 6-House Foundation Types 26
Figure 7 - Radon-Resistant Techniques for
New Home Construction: Passive System 43
Figure 8 - Radon-Resistant Techniques for
New Home Construction: Active System 44
Figure 9 - Suspected Causes of Building-
Associated Illness 46
Tables
Table 1 - Ranking of Environmental Hazards 3
Table 2 - State/EPA Residential Radon Screening
Survey Cumulative Results 10
Table 3 - Radon Exposure Risks (for Smokers
and Nonsmokers) I 16
Table 4 - Estimated Lifetime Risk of Premature :
Death 22
Table 5 - Estimated Installation and Operating
Costs for Various Radon Mitigation
Techniques (1991) 27
Table 6 - State Legislation and Realtor
Association Recommendations Regarding Radon 40
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Rcknouuledgements
This publication is adapted from Reporting on Radon: A
Journalist's Guide to Covering the Nation's Second Leading Cause of
Lung Cancer, published in 1989 by the Nationals'afe'ty Council's
Environmental Health Center (EHC) with support from the U.S. Environ-
mental Protection Agency, Office of Air and Radiation.
The National Safety Council is a not-for-profit, nongovernmental
public service organization founded in 1913. The Environmental Health
Center was established as a division of the Council in 1988 "to foster
improved public understanding of significant environmental health risks
and challenges facing modern society."
The Environmental Health Center's early efforts focused largely on
initiatives with print and broadcast media as the principal means by
which the public receives information on environmental issues. Since
its earliest program activities, EHC has expanded its role - "to foster
improved public understanding" - through a number of other informa-
tion dissemination activities, including public education and outreach,
emergency planning and management, and environmental journalism.
This guide is one of a continuing series of environmental journal-
ism and information dissemination activities undertaken by the Envi-
ronmental Health Center. EHC has published reporters' guides oh
covering chemicals in the community^ solid waste, ocean and coastal
issues, and understanding the science of climate change. It publishes
several newsletters including Environment Writer, a monthly newsletter
aimed exclusively at print and electronic journalists covering environ-
mental health and pollution control issues. EHC also has operated the
national radon hotline (1-800-SOS-RADON) since July 1992 under a
cooperative agreement with EPA. Through the hotline, EHC distributes
information on radon to the general public and distributes radon test
kits. '" "
Bud Ward
Executive Director
Environmental Health Center
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Introduction
Finding a cure for cancer would be big news. Even a cure for one
kind of cancer would make banner headlines. But when it comes to
cancer prevention, as in avoiding radon-induced lung cancers, the
situation is different. Radon stories challenge many fundamental
concepts of journalism's ongoing effort to define "What is news?"
Peter Sandman, a prominent risk communications specialist,
recites a dozen factors affecting how the public perceives environmen-
tal health risks. Collectively, they explain why apathy rather than
outrage tends to characterize the public's response to this heath risk.
They also help explain why many feel that radon-induced lung cancers
are among the most under-reported cancer risks.
Consider a few of the factors Sandman cites about radon:
There is no villain. No one puts radon into the environment. No
industry emits or releases or spills radon into the environment. Radon
occurs naturally, at varying levels, in most rocks and soils. It can
enter individual homes and buildings through cracks and fissures
common to many structures. Those cracks and fissures are the "fault"
of no one in particular.
There is no "victim." You can't point to a lung cancer victim and
conclude that radon was the cause of death. No cancer deaths come
with a "Radon-Induced" label. Radon's effects are delayed rather than
immediate (see page 16); they show up as lung cancer only after
years of exposure. In any single case, showing a cause-and-effect
relationship is impossible. Dr. Susan Conrath, a radiation health
scientist with EPA, points out that, "while fat is well-known as a
leading contributor to colon and breast cancer, it is hard to pin-point fat
as the cause for any given cancer. We just know statistically that fat
is often the culprit."
There is usually no immediate emergency. In most cases, there's
no additional cancer risk from radon by waiting a day, a week, or more
before reducing the radon concentrations in one's environment. "I can
do it tomorrow, so I won't do it today ...."
"Control" of the problem rests with the individual. The risk is
controlled not by some outside force upon whom pressures can be
brought, but rather by the individual. Call it human nature: Because
the timing is up to the individual, the problem often goes unaddressed.
The threat is unseen and unfelt, and the risk can occur in that
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Page 2
fl Guide to Radon
most unlikely and most trusted of places ...at home. Radon is
invisible. People can't see, taste, or smell it. It doesn't repulse them
physically or offend their senses. Rather, it lurks silently in the
background, working its mischief only through prolonged exposure.
And it does so in that haven where people feel most safe ... the home.
That fact creates a psychological barrier against seeing a familiar
situation as a risky one.
Consider this farcical example: You arise one morning to a banner
headline in your local daily: "Out-of-State Trucker Indicted in
Miflintown for Radon Dumping." Imagine the story's kicker: "Hundreds
of 55-GalIon Radon Drums Dumped along 1-77 (see Figure 1)."
Now imagine the lead paragraphs:
"A Steubenberg trucking company president was indicted yester-
day by a Wayne County grand jury for allegedly disposing of hundreds
of drums of highly radioactive radon along the county's busiest inter-
state highway.
"the illegal midnight dumping is expected to lead to hundreds of
increased incidences of lung cancer in the densely populated I-77
corridor. A county health official estimates that costs of cleanup will
Figure 1
Hypothetical Newspaper Headline
Weather
Today, cloudy. Hghl showcra. High 55.
Tonight, rain. fat. Low 46. Tomorrow,
some SUB, wanner, • few shower*. High 67,
Vol. XII No 3
Monday, June 19,1995
75 cents
Out-of-State Trucker Indicted in
Miflintown for Radon Dumping
Hundreds ofSS-Gatton Radon Drums Dumped along I~77
A Slcubcnbcrg trucking
ly president \vas Indicted
by & Wayne County
rorallcdgcdlydlspos-
indrcds of drums of
tactivc radon along
busiest interstate
midnight duinp-
to lend to hun-
Inddcnccs of
densely popu-
lor. A county
estimated that
tnup will exceed $71)0
lilllon over the next decode,
Tlicrc Is no victim. Youcmil
IQ lung cancer victims and
conclude tint radon was the cause
of dcalti. Cnnccr deaths come
with no "Ration-Induced" label.
Rndon's effects are chronic rather
than acute. They siww up as lung
cnncer only after decades. In
Ihosc cases, discovering a causc-
and-cncci rdailonsliip Is almost
iniposslblt;.
Tlicre is usually no immcdi-
alc emergency, and "control" of
the problems lies wltli the Indi-
vidual. In most cases, there Is no
additional cancer risk from radon
by walling n day or a week or
more before reducing the radon
concailrniions in one's environ-
ment. The; risk here is (contp, 2)
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Introduction
Page 3
exceed $700 million over the next decade."
You'll never see that headline or that lead paragraph in any
reputable newspaper. That's not how radon works; there's no villain or
spectacular incident.
Consumer Reports magazine asked in the November 1992 issue,
"Which of these hazards is estimated to pose the greatest public
health risk: a) Toxic waste dumps; b) Oil spills; c) Radon; or d)
Pesticide residues in food? It comes as no surprise that many of the
magazine's respondents failed to identify the "correct" answer - c)
Radon. Study after study has suggested that the public at large -
perhaps reacting to how the general circulation mediei cover environ-
mental health issues - generally under-estimates the cancer risk
potential of elevated radon levels (see Table 1 for a comparison of
public vs. scientific ranking of risks).
The irony is that the radon health risk issue has arisen at a time
when much of the public feels powerless to address and manage
many of the environmental health risks they perceive as most harmful
to them. And yet here is one that they can control. Radon is the
nation's second leading cause of lung cancer, but informed citizens
Table 1
Ranking of Environmental Hazards
Public Ranking*
1. Active hazardous waste
sites
2. Abandoned hazardous
waste sites
3. Destruction of the ozone layer
4. Accidental oil spills
5. Water pollution - industrial
sources
6. Worker exposure to toxic
chemicals
18. Pesticide residues on food
26. Indoor air pollution
29. Radon
Scientific Rankimg**
1. Radon (tied)
1. Worker exposure to chemicals (tied)
3. Pesticide residues on food
4. Consumer exposure to
chemicals (tied)
4. Indoor air pollutants
other than radon (tied)
7. Depletion of stratospheric ozone
8. Abandoned hazardous waste sites
13. Active hazardous waste sites
23. Point source discharges
to surface water
26. Accidental oil spils
*Ranking out of 30 environmental problems.
"Ranking out of 31 environmental problem areas based on cancer risk.
Sources: 1992 Roper Poll; U.S. Environmental Protection Agency, Unfinished
Business, 1987.
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Page 4
fl Guide to Radon
1 ' i Jt "'i I1 "'' ' i' " ' •'• * |IM i11' '' '(I''1!1! » II'1' « 1
' ' "'.-'"'I , '.''•''. : : I'?' "'•:;I'ill-"J "?':"'"! 11'" 11 J'"' ' •!;•.' "^" -!; " *">'•':» ?. i I"1,*
can easily assess and, if necessary, reduce their own exposure nsKs
and at relatively low cost, too. They can do so without having to
endure difficult lifestyle changes.
A Guide to Radon has key information that can help public
officials, reporters and others communicate effectively about radon.
this guide also raises the question of whether radon is an under-
reported news story precisely because it challenges traditional
approaches to evaluating the newsworthiness of environmental health
issues. , ., [
One point is obvious: the public depends on the media for its
understanding of environmental health risk issues. Citizens will
underf tand an issue no better than the reporter does. A second
ess'e'ntialpoint: informed''citizens", actively involvedin environmental
risk policies, are the key to making environmental programs work in
the first place. The media's role in that process is critical.
That point — that informed citizens can help to manage environ-
mental risks — is particularly relevant to radon, because its risks can
be individually controlled. A public besieged with countless threats
over which they have little control will find radon an exception.
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Chapter 1
Understanding Radon
UUhat is Radon?
Radon-222 is a radioactive gas. Humans can neither see, smell,
nor taste it, but it turns up almost everywhere.
Radon occurs naturally in rocks and soil. Radon atoms are
uranium's direct descendants. When atoms of uranium-238 decay,
they produce several generations of other radioactive} elements. The
fifth generation is radium, which in turn decays into radon.
Though great concentrations of uranium are rare, traces of it are
common in ordinary rock and soil throughout much of the U.S. and in
many regions of the world. Concentrations vary greatly from place to
place depending on the underlying geology.
Radiation Basics
Radiation is all around us and comes from a variety of natural and
man-made sources. It comes from outer space, from the ground, from
within the human body, from consumer products, and from x-rays.
Naturally occurring radioactive materials were discovered in 1896,
and the first man-made radioactive materials were produced less than
50 years later. There are different types of radiation; the most energetic
form (discussed here) is known as ionizing radiation.
Radiation dose is measured in rem. The average person in
the U.S. receives about 360 millirem (1 rem= 1,000 rnillirem) of radiation
per year, according to the U.S. Environmental Protection Agency (EPA).
Eighty (80) percent comes from natural sources and 20 percent from
man-made sources, primarily medical x-rays (see Figure 2).
Radiation is a carcinogen and may also cause other adverse health
effects including genetic defects in the children of exposed parents or
mental retardation in the children of mothers exposed during pregnancy.
Much of the current knowledge.about the
risks of radiation comes from studies of the more than 100,000 survivors
of the atomic bombs at Hiroshima and Nagasaki.
The risk of developing cancer due to radiation exposure is much
higherthan the risk of the other effects mentioned above. The cancer
risk increases the more radiation a person receives. Most cancers do
not appear until many years (typically 10 to 40 years) after the radiation
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Page 6
fl Guide to Radon
Figure 2
Sources of Background Radiation
for the U.S. Population
Radon 54.4%
Consumer
Products 3%
Nuclear
Medicine 4%
Terrestrial 7.9%
Cosmic 7.9%
Internal 10.9%
Other 1%
Medical X-rays 10.9%
Source: National Council on Radiation Protection & Measurement.
dose is received.
When radiation penetrates a human cell, it may damage mol-
eculesi in its path. If a DNA molecule is damaged, the chromosome
containing that DNA molecule may break apart. The chromosome
may then recombine abnormally. This change in chromosome struc-
Immediate versus Delayed Effects
An important part of understanding radon involves just when its
health effects are manifested. In scientific jargon, effects that occur
within days or weeks are termed immediate. Effects, such as
cancer, which occur long after exposures are termed latent or
delayed. Even the highest residential radon exposure levels may
induce latent or delayed - not immediate - effects.
Though some scientists believe that cells can repair damage
from small amounts of radiation, the prevailing scientific view is that
no amount of radiation may be considered "safe." Low-level expo-
sure to radiation can cause damage to cells' DNA. The harm can
remain invisible for decades. But once a cell is damaged, any of its
descendants can lose control of cell growth and division and cancer
appears.
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Chapter I -- Understanding Radon
Page?
ture can lead to the death of the cell or the formation of a cancerous
cell.
Radon Geology
An understanding of some fundamental principles of geology is
important to better understand, and communicate on, radon-related
health risks.
Unlike its ancestors, uranium and radium -which are in solid form
- radon is a gas, and therefore very mobile. The slightest fissure in
surrounding rock is enough to allow radon gas to be released from its
"prison" in the earth. It can percolate through the soil and move to the
surface with other soil gases (see Figure 3). From there it is free to
wander. The radon atoms may find their way through building cracks
and openings into areas where high radon concentrations can pose
increased lung cancer risks.
In the open air, most radon dilutes into insignificant concentra-
tions. But trapped and allowed to concentrate in a house or other
building, radon can become a serious public health threat.
Figure 3
How Soil Conditions Can Affect Radon
Pathways into Neighboring Houises
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Jill ' i!'
Page 8
R Guide to Radon
Within a single rock formation, however, the range of uranium
concentration - and therefore of radon - can vary widely. As a result,
geologists have difficulty predicting just which areas may have high
radon levels in the ground.
In combination, three factors determine the potential for high radon
levels in homes: 1) normal to high uranium concentrations, 2) soil
characteristics that allow gas movement to the surface, and 3) access
for uranium's decay products into homes.
Rock types that are most likely to cause indoor radon problems
include carbonaceous black shales, certain types of fluvial sandstones
arid fluyiaj sediments, phosphorites, chalk, certain types of glacial
deposits, bauxite, lignite, certain types of coal, many sheared or
faulted rocks, silica-rich volcanic rocks, and others.
.!'••" • ' • • . ; _,'", it'!;, ' ' .. I ;. •! "' ' "«! ' ' •" ' :;.; , .. j "! *;,,,:' 'f
How Radon Damages the Lung
Though we breathe radon into ourlungs, it tends to pass back out
harmlessly as we exhale. The threat stems from two of radon's decay
products, solid isotopes of polonium. Because they revert to solid
form, these radon decay products can be inhaled and can lodge in the
lungs. And since their half lives are no more than a few minutes, they
tend to "go off' before the lung can clear them. Radon has a relatively
short half-life of 3"8 days, meaning that by emitting radiation, half of its
atoms decay into another element in less than four days.
The harm can result when the polonium isotopes emit high-energy,
low-velocity particles called alpha radiation. These same alpha
particles constantly bombard the body from outside without harm
since most cannot penetrate the dead outer layer of the skin. But in
the lung, they can penetrate more sensitive and vulnerable lung tissue.
At equal concentrations of radioactivity, alpha particles, once
inhaled or ingested, are far more deadly cancer producers than beta
and gamma radiation. They move more slowly and deposit their
concentrated energy over a shorter distance. When alpha particles
collide with unshielded lung cells, they can sever strands of DNA's
double helix corkscrew, scrambling its genetic code. Cells are
efficient at repairing breaks in a single strand, simply copying the
other, according to David J. Brenner of Columbia University's Radiologi-
cal Research Laboratories. But damage from double-strand breaks,
he says, "may be permanent and may be transmitted to the cell's
daughters."
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Chapter 1 -- Understanding Radon Poge 9
The effects may not be seen for years, or even decades. But
ultimately the damage causes certain cells to lose control over cell
division and growth. This dysfunction - cell multiplication without
control - is the health risk associated with exposures to radon and its
"progeny" (its decay product), and radon has been identified as the
second leading cause of lung cancers, behind smoking.
UUher© is Radon?
The Pennsylvania woman looked confused. "How," she asked
after an hour-long speech about radon, "do they get the radon from
nuclear power plants into the ground and over into the houses?"
In fact, "they" don't. Radon occurs naturally almost everywhere.
Current estimates are that the average outdoor background level of
radon is 0.4 picocuries of radon per liter of air (pCi/L) and the average
U.S. home contains about 1.25 pCi/L. (Radon is measured in units
reflecting the amount of radiation, picocuries, in a fixed volume of air, a
liter.) But averages, as always, can be misleading. In "hot spots,"
home readings can - although rarely do — soar over 2,000 pCi/L. In
comparison, EPA recommends that homes testing at or above 4 pCi/L
should be mitigated. This recommended level for action is based on a
combined analysis of risk and technological feasibility (i.e., what
indoor levels might be technically and economically achievable).
Radon readings tend to range highest in areas with high concentra-
tions of uranium-bearing rocks, such as granites, but: there are plenty
of exceptions to that rule.
Radon problems have been identified in every state. The EPA
estimates that nearly 1 out of every 15 homes in the U.S. have radon
levels above the action level.
Since 1986, the agency has completed two surveys of radon in
residential dwellings. The "State/EPA Residential Radon Survey"
provides a measure of the distribution of radon "worst case" short-term
measurements among residences within each state and identifies "hot
spots" of radon concentration. The "National Residential Radon
Survey," estimates the annual average concentration in occupied
housing units throughout the U.S. Results of the two surveys are
described below.
State Survey. The "State/EPA Residential Radon Survey"
consisted of screening measurements taken in more than 60,000
randomly selected homes in 42 states (see Table 2).
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Page 10
fl Guide to Radon
Table 2
State/EPA Residential Radon Screening
Survey Cumulative Results
State
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Mexico
North Carolina
North Dakota
Ohio
Oklahoma
Pennsylvania
No. of
homes tested
1,180
1,127
1,507
1,535
1,885
1,443
1,451
1,534
523
1,266
1,450
1,914
1,381
2,009
879
1,314
839
1,126
1,659
1,989
919
960
1,859
833
2,027
1,562
1,885
1,290
1,596
1,734
1,637
2,389
percent
>4 pCi/L
6.4%
7.7%
6.5%
5.0%
2.4%
41.5%
18.5%
7.5%
0.4%
20.3%
19.2%
28.5%
71.0%
22.5%
17.1%
0.8%
29.9%
18.9%
22.7%
11.7%
45.4%
2.2%
17.0%
42.2%
53.5%
10.2%
21.8%
6.7%
60.7%
29.0%
3.3%
40.5%
percent
>20 pCi/L
0.3%
0.6%
0.1%
0.3%
0.1%
2.7%
0.9%
0.0%
0.0%
1.1%
0.8%
1.5%
7.5%
0.7%
1.5%
0.0%
1.9%
1.4%
1.3%
0.4%
1.4%
0.1%
0.7%
4.7%
1.9%
0.8%
0.8%
0.3%
4.3%
2.8%
0.0%
7.9%
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Chapter 7 -- Understanding Radon
Page 11
Table 2 (Confd)
State/EPA Residential Radon Screening
Survey Cumulative Results
State
Rhode Island
South Carolina
Tennessee
Texas .
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Total
No. of
homes tested
376
1,089
1,773
2,680
710
1,156
1,935
1,006
1,191
777
59,395
percent
>4 pCi/L
20.6%
3.7%
15.8%
3.6%
15.9%
13.9%
8.8%
15.7%
26.6%
26.2%
percent
>20 pCi/L
1.9%
0.3%
1.3%
0.2%
0.9%
1.2%
1.3%
0.8%
0.8%
1.8%
Source: U.S. Environmental Protection Agency, 1992.
Short-term tests of two to seven days were given in conditions
designed to give the highest radon concentration reading for the
structure. The results reflect tests conducted tinder closed-house
conditions during winter, and were done on the lowest livable level,
even if that part of the home was used infrequently.
Screening tests in some states indicate high proportions of homes
exceeding EPA's 4 pCi/L "action level" (see section, "The Federal
Role," in this chapter). In Minnesota and North Dakota, 45 and 61
percent, respectively, of the homes screened were found to have levels
above the 4 pCi/L guideline. The average level found in North Dakota
home tests was 7 pCi/L, almost double the EPA action level.
On the other hand, low levels are common in some states, too. In
Alabama, for instance, radon levels reached the "action level" in only 6
percent of homes tested. Even at that low rate, however, thousands of
Alabama households could potentially benefit from radon testing and
mitigation. Since the only way to know is to test, it is important that
all Alabama homes be tested. Despite the low readings for most
Alabama households, one recorded a reading of 180 pCi/L
Some critics have warned that these screening measurements
may overestimate the health risk and may be poor indicators of radon
health risks, since the tests were designed to show worst-case
-------
i|i|iiiii;«:i ni'i'" iinij "if1 •"
• : HP •, nil 'in!" .1111;. • .si!",,,1:"1'1
" I:
Poge T2
fl Guide to Radon
scenarios, not actual exposures. Also, radon can fluctuate widely over
a short period of time. Long-term tests representing annual average
radon concentrations provide better measures of potential health risks.
National Survey. EPA's "National Residential Radon Survey"
used year-long test devices to determine the annual average concen-
tration in occupied housing units throughout the U.S. to provide an
estimate of the frequency of those distributions.
Alpha track detectors (a type of long-term test) were used, and at
least one detector was placed on each level of the homes tested.
Based on the national survey, EPA estimates that:
• the annual average radon concentration in the U.S. housing stock
is1.25pCi/L;
• about 6 percent of U.S. homes have levels greater than 4 pCi/L;
• apartments or condominiums above the second floor seldom have
concentrations higher than EPA's action level; and
• single-family detached homes are four times more likely to require
mitigation than multi-family homes.
(See Chapter4 for discussion of EPA school survey.)
Map of Radon Zones
The U.S. Environmental Protection Agency, the U.S. Geological
Survey, and the Association of American State Geologists have
developed a map identifying areas of the U.S. that have the highest
potential elevated levels of indoor radon (see Figure 4). This map was
generated based on several types of information: indoor radon mea-
surements, geology, aerial radioactivity, soil parameters, and founda-
tion types.
Despite all the information, variations within regions, states, and
even neighborhoods unquestionably make radon levels hard to predict.
High radon measurements can be found in areas unlikely to have a
problem... and low readings can be found in areas thought likely to
have a serious problem.
The radon map serves as a tool for national, state, and local
organizations resource allocation strategies, and for organizations to
help implement radon-resistant building codes. It is not useful to
predict or anticipate concentrations in individual homes.
Each of the approximately 3,100 counties in the United States is
assigned to one of three zones:
• Zone 1 counties have a predicted average indoor screening level
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Chapter 1 - Understanding flodon
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Page 14
fl Guide to Radon
greater than 4 pCi/L;
• Zone 2 counties have a predicted screening level between 2 and
4 pCi/L; and
• Zone 3 counties have a predicted average screening level less
; than 2 pCi/L '' '
Copies of the map and supporting documentation are available
from state radon offices and EPA regionaToffices (see Chapters).
HOUJ Does Radon €nter Homes?
The major source of radon is beneath the home in soil or rock that
contains uranium, granite, shale, phosphate, and pitchblende. The
decaying radon particles in that soil or rock can enter a home or
building through cracks in the foundation floor and walls, drains,
sumps, joints, or other openings. Radon also can be transported into
homes and other buildings in water (see below). Occasionally, it also
is released from building materials like brick, clay or cement, although
this is rare and generally contributes little to radon in the environment.
Most of the indoor risks associated with radon are tied to exposures in
the air rather than to drinking water exposures.
Radon from the ground is generally diluted in outdoor air to low
levels that pose little threat! Within the closed structure of a home,
radon can accumulate to hazardous levels if there is a strong source
beneath it, and the soil and the house substructure conditions are
conducive to radon entering the home!
Indoor levels depend on the rate of entry and the rate at which it is
removed by ventilation. A home with little indoor and outdoor air
exchange is more likely to have higher radon levels than a home with
greater ventilation. Differences in type of foundation construction, as
well as local geologic and soil characteristics, can result in great
differences in radon levels for homes located in the same neighbor-
hood.
People living above the second floor generally need not be as
concerned about residential radon because radon dilutes as it moves
upward within a building. Under closed-house conditions, radon
readings in basements tend to be about double those on the first floor.
However, homes without basements may also have high levels.
Radon in Water. Radon in water generally poses a small risk
compared to radon in indoor air from soil. Groundwater that flows
through uranium-bearing rocks can absorb radon gas and then release
-------
Chapter I - Understanding Radon : Page 15
it into the air in the home through the shower, washing machine,
dishwasher, or faucet. According to EPA's Citizen's Guide to Radon,
"research suggests that swallowing water with high radon levels may
pose risks too ...," although much less than breathing air with high
levels of radon.
Radon in water accounts for approximately 5 percent of total
indoor air concentration in houses served by private wells. While
radon is usually not a problem with water from large community water
supplies, some private wells contain high levels of radon in water.
Homes which use well water and have been found to have a radon
problem in the air, should probably have the water tested.
Radon can be removed from water by using one of two methods:
aeration treatment or granular activated carbon (GAG) treatment.
Aeration treatment is considered the most efficient and economical
treatment for the removal of radon, according to EPA. It involves
spraying water or mixing it with air, and then venting the air from the
water before use. GAG treatment filters water through carbon. Radon
attaches to the carbon and leaves the water free of radon. In either
treatment, it is important to treat the water where it enters a home
(point-of-entry device) so that all the water will be treated. Point-of-use
devices, such as those installed on a tap or under the sink, will only
treat a small portion of the home's water and are not effective in
reducing radon in the home's water.
Who is at Risk?
Anyone who breathes is potentially at risk from radon. The risk
grows with the level and duration of exposure. The longer your expo-
sure and the higher the concentration, the greater the risk.
EPA currently estimates that between 7,000 and 30,000
annual lung cancer deaths in the U.S. are due to residential
radon exposure. This estimate reflects a number of changes in
EPA's approach to risk estimates resulting from new data and re-
search refinement including:
• results of a national survey of residential radon exposure;
• findings of the National Academy of Sciences on the
comparative dosimetry of radon in mines and homes; and
• quantitative analysis of the uncertainties associated with
the estimates of residential radon risk.
According to EPA, people who spend a lifetime in homes with a
-------
Page 16
fl Guide to fiadon
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Chapter ? -- Understanding Radon POQS 17
relatively high radon level of 20 pCi/L face the risk that 135 in 1,000
smokers, and 8 in 1,000 nonsmokers, may die of lung cancer. By
contrast, federal health regulatory programs routinely establish
one-in-a-million as a threshold level of concern.
Annual radon levels of 10 pCi/L or greater have been found in an
estimated 0.7 percent of homes based on EPA's "National Residential
Radon Survey," conducted in 1989.
But, as mentioned above, even at 4 picocuries pier liter— EPA's
guideline for action (discussed later)—radon exposures aren't "safe."
"Really, we've not found any level of radon you could call safe,"
says Margo Oge, former director of EPA's Office of Radiation and
Indoor Air Programs. "We have to go by the radon levels that can be
achieved in most homes using the technology we have available."
The EPA estimates that a lifetime exposure to 4 pCi/L will cause
lung cancer in 29 in 1,000 smokers and about 2 in 1,000 nonsmokers.
The National Academy of Sciences estimates the risk of lung cancer
from radon is 15 to 20 times higher for smokers than non-smokers
(see Table 3).
Notwithstanding EPA's caveats, many in EPA and Congress are
concerned that the four picocuries guideline unintentionally encour-
ages people to ignore the risks at or below that level.
When was the Threat Discovered?
Underground miners have been dying of lung cancers for centuries,
but it wasn't until the 1950s and 1960s that lung cancers and radon
were clearly linked.
In response, U.S. regulators set rules for reducing mine radon
levels by ventilation. In the 1970s health officials also turned to
cleaning up uranium mill tailings (waste materials from mining and
milling left after uranium has been extracted) that continued to emit
radon, including some that had been used as foundation materials for
homes.
But officials showed little interest or concern in naturally occurring
radon in homes until 1984, after nuclear plant worker Stanley Watras
set off radiation detection alarms, baffling the public health world.
At a Limerick, Pennsylvania, nuclear plant, Watras repeatedly
triggered radiation alarms as he entered the plant. Eventually, his
colleagues and employer learned that he was bringing radiation into
the plant. When Watras tested his home, he discovered the highest
-------
"If '?'••:,•'
Page 18
fl Guide to fiadon
residential radon level ever found until that time ~ 2,700 pCi/L.
"Trje Watras incident really changed the ball game," said Richard
Guimond, Assistant Surgeon General and former director of EPA's
Office of Radiation Programs. Homes built on mill tailings had regis-
tered up to 100 to 200 pCi/L, he recalls. "We thought the highest
naturally occurring radon in homes would be no more than one-tenth of
that."
The Watras incident prompted some nationwide sample testing of
homes for radon. Initially, concerns focused on a uranium-prone
geologic formation called the Reading Prong, stretching across
eastern Pennsylvania through northeastern New Jersey and part of
New York, and into Connecticut. But in 1986, as readings trickled in
from around the U.S., elevated levels turned up in all regions tested.
"Hot spot" clusters of homes, with readings of hundreds and even
thousands of picocuries per liter, were found in several states.
Since thai time, a number of epidemic-logical studies of under-
ground miners have shown an increase in lung cancer occurrences
with exposure to radon decay products. Radon has been classified as
a known human carcinogen based on this epidemiological data.
U.S. officials agree that radon isn't just a regional problem, but a
national one. Indeed, testing in Europe and elsewhere has demon-
strated that it is an international problem.
The Federal Role
A1988 health advisory issued by EPA and the Office of the U.S.
Surgeon General was concise and unequivocal in its statement to the
public:
"Indoor radon is a national health problem. Radon causes
thousands of deaths each year. IVIHIions of homes have
elevated radon levels. Homes should be tested for radon.
When elevated levels are confirmed, the problem should be
corrected."
EPA's role in addressing radon in air is nonregulatory and includes
research, technical and financial assistance to states, and information
arid guidance to the public, as set forth in the Indoor Radon Abatement
Act of 1988. The Act establishes a national long-term goal with
-------
Chapter 1 - Understanding Radon _ Page 19
respect to radon levels that "the air within buildings in the United
States should be as free of radon as the ambient air outside of build-
ings." Also, the Act requires EPA to:
• develop model construction standards and techniques for
controlling radon levels within new buildings.
• develop and implement activities designed to assist state radon
programs such as: training seminars for state and local officials
and publication of information materials concerning radon health
risks and methods of radon mitigation; and operation of a
voluntary proficiency program for rating the effectiveness of radon
mitigation devices and methods and effectiveness of private firms
and individuals offering radon-related architecture, design,
engineering, measurement, and mitigation services.
• provide appropriate information concerning technology and
methods of radon assessment and mitigation to professional
organizations representing private firms involved in building
design, engineering, and construction.
• provide grants to states to assist in the development and
implementation of programs for assessment and mitigation of
radon (with a non-federal match of 25 percent the first year, 40
percent the second year and 50 percent the third year).
• conduct a study, including a survey, to determine the extent of
radon contamination in schools and to compile a list of areas —
including schools - within the U.S. which have a high probability
of elevated levels of radon.
• make grants or cooperative agreements with institutions of higher
learning (orconsortia) to establish regional radon training centers.
The centers are to develop information and provicie training to
federal and state officials, professional and private firms, and the
public regarding the health risks posed by radon and demon-
strated methods of radon measurement and mitigation.
Figure 5 shows the level of radon awareness and percentage that have
tested their homes for radon. Compared to the nation as a whole,
levels of awareness and testing are higher in high raclon areas.
The Act requires that EPA revise A Citizens' Guide to Radon, first
published jointly in 1986 by EPA and the Department of Health and
Human Services, which it updated and republished in 1992. The
updated Guide recommends a radon testing procedure; presents
updated risk information; and outlines advances in mitigation mea-
-------
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Page 20
fl Guide to Radon
•I
sures. Also, as mandated in the Indoor Radon Abatement Act of
1988, the Guide presents the following information:
• a series of action levels and associated health risks clarifying that
the 4 pCi/L level is not necessarily a "safe" level of prolonged
exposure;
• radon health risks as they relate to particular population groups,
for instance smokers arid children; and
• short- and long-term measurement results and how they relate to
alternative action levels.
Two particularly significant changes from the 1986 guide are
reflected in the 1992 update:
Radon testing should take place in the lowest lived-in level (for
example, the basement if it is used frequently, otherwise the first floor)
of the home. The agency earlier had recommended screening tests in
the lowest livable level (even if the area was used infrequently), but
says that recent research suggests that because consumers will not
use long-term tests to follow-up on elevated screenintj results, a more
accurate short-term testing scenario in the home's living areas is the
!| ' , "" ' ' ! "
Figure 5
Awareness of Radon and Testing for Radon
80
National
High Radon Areas
Legend
B Claimed awareness • Knowledgeable
Tested awareness
Source: Conference of Radiation Control Program Directors, Radon
Risk Comunications and Results,Study, March 1993.
-------
Chopter 1 -- Understanding flodon Page 21
best alternative.
Streamlining testing protocol. The 1992 Citizens' Guide recom-
mends basing mitigation decisions on 1) two sequential short-term
tests; or 2) a short-term test followed by a long-term test (90 days to
one year) to confirm the short-term test's findings. The agency says
long-term tests are more representative of actual radon exposures, but
according to a 1990 analysis conducted for EPA only about 9 percent
of the public is willing to engage in a long-term test.
-------
Poge 22
fl Guide to Radon
Table 4
Estimated Lifetime Risk of Premature Death
Indoor Air Pollutants
Other
(Percent)
Radon (smokers)
20 years at 20 pCi/I
20 years at 4 pCi/L
Lifetime at 1.3 pCi/L
Radon (nonsmokers)
20 years at 20 pCi/L--
20 years at 4 pCi/L-
Lifetime at 1.3 pCi/L'
Passive smoking-^/
Volatile organic/
compounds
Asbestos
Radon from
domestic water **
100
\ 10 /
0.1
0.01
0.001
\
0.0001
/Cigarette smoking
/Automobile accidents
^Uranium mining
- Home accidents
"Jobs at chemical
plants
"Outdoor radon **
Benzene in
outdoor air
Chloroform in
domestic water
^Ethylene dibromide
in grains (banned)
* pd/L - picocuries per liter
** Average for smokers and nonsmokers
All risks are average for the whole population except where indicated.
Radon estimates presume a 10-fold difference between smoker and
nonsmoker risks due to synergism, but the exact ratio is not known. In
the unlikely event that there actually is no difference between the two
groups, the risk for the general population would be just below home
accidents for a lifetime at 1.3 pCi/L, somewhat above home accidents for
20 years at 4 pCi/L, and above the risk from auto accidents for 20 years
at 20 pd/L.
Source: "National Strategy for Indoor Radon," by Anthony V. Nero, Jr.,
Issues in Science, Fall 1992.
-------
Chapter 2
Testing and Reducing Exposure
Unlike smog or stratospheric ozone depletion, radon is a personal-
ized environmental threat, one that potentially affects people in
neighboring houses in far different ways. The threat comes not from
the vapors of the sky or the vastness of the atmosphere, but from in
one's own home.
Do-it-yourself radon tests are economical, easy to use, reliable,
and available, and most homeowners can — and should - measure the
levels in their homes. One home's low reading is not a substitute for a
reading in an adjacent or nearby home; differences in housing struc-
tures and underlying soil can produce widely varying levels in neighbor-
ing houses.
Given the relative ease and economy of testing and the
unpredictability of high concentrations, EPA and the U.S. Surgeon
General recommend that most homes be tested. Only testing, they
say, provides homeowners information about the exposures they
personally face.
According to Robert Sussman, former EPA Deputy Administrator,
only 9 percent of U.S. homes have been tested so far, and mitigation
has occurred in only about 300,000 (5 percent) out of the 6 million
homes estimated to have elevated radon levels.
Methods and Reliability of Tests
Measuring for radon is easy and generally quite reliable. For most
persons, use of a short-term test kit or measuring device over a period
of two to seven days is an effective way to begin understanding
potential individual radon risks. Short-term tests offer the quickest
way to test a home. If results are needed quickly, such as during real
estate transactions, a short-term test followed by a second short-term
test may be used to decide when to fix a home. However, because
radon levels in a home fluctuate widely overtime, long-term readings
over the course of several seasons provide the most reliable indication
of annual radon levels.
A variety of measurement methods are available for determining
radon concentrations. Results are reported either in "working levels"
(WL) of radon, or "picocuries per liter" (pCi/L) of radon gas (0.02 WL
-------
t: ,
Page 24
fl Guide to Radon
equals about 4 pCi/L in a typical home).
Passive Devices. Charcoal canisters, the most common type of
short-term device, and charcoal liquid scintillation devices are exposed
to air in a room. (EPA recommends testing in the lowest lived-in level
of the house, not necessarily trie lowest level of the house.) The kits
then are mailed, air-tight, to a laboratory, which measures them for
radioactivity. That allows determination of the level of radon to which a
device was exposed.
Another measuring device is the electret ion chamber. Installed in
the home for two to seven days or for three to 12 months (for short-
and long-term electret ion chambers, respectively), these devices
contain a charged electret (an electronically charged disk of Teflon®)
which gradually loses some of its charge when exposed to alpha
radiation from radon. Once exposed for the specified amount of time,
the device is resealed and sent to a laboratory for evaluation.
Long-term test kits exposed for three months to a year generally'
EPA's Measurement and Contractor
Proficiency Programs
EPA since 1986 has offered a voluntary program to evaluate
organizations that provide radon measurement services. Under the
Radon Measurement Proficiency Program, firms successfully
completing EPA's evaluation are listed in the National Proficiency
Reports as either primary providers, which can read/analyze the
device used in providing consumers with measurement services, or
secondary providers, which use a primary firm to read/analyze the
measurement device used in providing consumers with services.
Since January 1992, EPA has offered a program to assess for
individual proficiency in radon measurement. Once an individual
achieves listed status, he/she receives an identification card which
allows consumers to identify proficient radon measurement providers.
EPA's Radon Contractor Proficiency (RCP) Program requires
contractors to take training courses and pass an exam before being
listed in EPA's National RCP Report. RCP contractors carry a
current RCP photo identification card, and all RCP contractors are
required to follow EPA standards to meet minimum quality stan-
dards.
-------
Chapter 2 - Testing ond Reducing Exposure Page 25
are viewed as providing the most reliable and most representative
measurement of annual average radon levels in a home.
Alpha track kits, the most common long-term device, feature a
piece of special plastic in a filtered container. Alpha particles emitted
by radon gas "track" the plastic, leaving small tracks, or scars, which
are counted later by a laboratory as an indicator of radon concentra-
tion.
Active Devices. Active testing devices require power to function.
Continuous radon monitors, orworking level monitors, use electron
detectors to accumulate and store periodic radon or decay product
concentrations. They require operation by trained testers. Although
they generally give accurate measurements, continuous monitors cost
more to use than passive devices. (See discussion of real estate
transactions, Chapter 4.)
Testing Considerations. Several basic guidelines can be
followed for choosing a testing method.
• EPA-listed detectors, displaying the phrase "Meets EPA
requirements", should be used. State radon offices .(see
Chapter 5) can provide the names of EPA-listed detectors.
• The most accurate way to estimate the annual radon level in
a home is to test for a one-year period the area(s) where the
most time is spent. Alpha track detectors and electret ion
detectors are the most common long-term testing devices.
• The fastest way to find out if a home has a radon problem is to
use a short-term testing device for a period of a few days.
Charcoal test kits, liquid scintillation and electret ion detec-
tors are the most common passive short-term testing
devices. A continuous monitor, operated by a professional,
can also provide quick results.
• If hiring a professional to test is the desired option, EPA
recommends hiring a state-certified and/or EPA-listed
measurement company and requesting a radon tester
who also is EPA-listed.
Some state or local governments occasionally provide radon
detectors to homeowners at no charge or at a reduced cost. Private
non-profit groups and others also provide discounted radon kits and
services. Some hardware stores and mail-order firms; stock detectors.
Some testing services are listed in the telephone directory. Most
states also provide names of EPA-listed testing organizations.
-------
-'"„ liJ «' i ill!" • f11";,
Page 26
fl Guide to Radon
Testing Reliability Considerations
Short-term and long-term test results should be interpreted
differently. It may be helpful to think of short-term tests as providing
something of a snapshot of the radon situation in a particular home.
Radon levels in a home vary widely from room-to-roorn, day-to-day, and
season-to-season. While short-term devices cannot reliably assess
the magnitude of a problem, they can be used by homeowners to
make mitigation decisions: Longer-term radon measuring detectors
provide a better estimate of annual average radon concentrations in the
home. .
If short-term test results are elevated, the best way to determine
the annual radon level is bfmeasunng again over a one-year period.
At a minimum, EPA "recommends' that results be confirmed with a
second short-term test.
If long-term test results or the average of two short-term tests are
elevated (above 4 pCi/L), action should be taken to lower the radon
level in the home.
If short-term results are low, retesting could ensure that the first
test was not conducted at a time when radon levels happened to be
much lower than usual.
Additional Considerations. In addition to testing radon levels, a
homeowner concerned about radon exposures should also consider
these questions to determine radon risk:
Figure 6
House Foundation Types
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v.
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Basement
Source: U.S. Environmental Protection Agency, Consumer's Guide to
Radon Reduction, August 1992.
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Chapter 2 -- Testing and Reducing 6xposur®
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Page 28
fl Guide to Radon
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• Does anyone in the household smoke?
. Are there children in the family? _, . „, *rh*nc
. Does anyone spend unusually long periods in the home, perhaps
because of illness, age, occupation, or personal preference?
. Does anyone sleep or spend a significant amount of time in the
basement, where radon levels are higher than on other floors?
The more affirmative answers a homeowner has to these questions,
the sooner he or she should act to reduce the radon levels of the
house. ; , ".'
Short-term Actions. EPA considers the following reduction
strategies as only temporary or partial measures, but they can be
used in combination with others to reduce radon levels:
Sealing cracks and other openings in the foundation to limit the
flow of radon into the home (although sealing cracks alone has not
been shown to lower radon levels significantly or consistently).
House pressurization involves blowing air from upper floors or
outside into the lowest level of the house (typically the basement) to
prevent radon from entering the house. _
Natural ventilation reduces radon levels by mixing radon with
outside air; but it typically is only a temporary measure because of
substantially increased heating and cooling cqsts.
Afteaf recovery venfi/afor(HRVorair-to-air heat exchanger) can
increase ventilation. This increases heating and cooling costs, too,
but not as much as natural ventilation.
EPA does hot recommend that Individuals fix their own homes
because of the potential to worsen the problem. For example, an
exhaust fan in a basement window may draw more radon in from the
If a contractor is to be hired to fix a home, EPA recommends
selecting a state-certified contractor and/or one listed in EPA's Radon
Contractor Proficiency Program.
Long-term Actions. Several different methods are used to reduce
radon levels in homes over the long term. The method used depends
in part on the type of foundation in the house: basement, slab-on-
grSde, or crawl space (see Figure 6).
For houses with a basement or a slab-on-grade foundation, radon
levels usually can be reduced with orie of the following methods.
. Subslab suction (or subslab depressurization) is the most com-
mon method. Pipes are inserted through the floor slab or below the
-------
Chapter 2 •• Testing and Reducing exposure? Page 29
slab from outside the house into the crushed rock or soil underneath.
A fan connected to the pipes draws the radon from below the house
and releases it into the outdoor air.
• Drain tile suction can be used in houses where perforated drain
pipes have been installed to direct water away from the foundation, but
only when the tiles form a complete loop around the foundation.
• Sump hole suction can be used in houses with basements and
sump pumps. The sump can be capped so that it can continue to
drain water and also serve as the location for a radon suction pipe.
• Block wall suction can be used to remove radon from hollow
spaces in basement concrete block walls.
For houses with crawl spaces, the following methods can be used.
• Ventilating can be done passively (without a fan), or actively (with
a fan).
• Submembrane depressurization involves covering the earth floor
with a heavy plastic sheet and using a vent pipe and fan to draw the
radon from under the sheet.
According to EPA, such measures can reduce elevated levels of
radon to 4 pCi/L virtually all of the time and to 2 pCi/L more than 70
percent of the time. Table 5 lists estimated installation and operating
costs (in 1991 dollars) for various radon mitigation techniques.
-------
•• ; i;
.' . v ^v^i' Chapter 3
Disputing the Radon Risks
If you think you have never met an environmental issue
without controversy, and then along came radon ... think again.
The radon issue has its controversy, too, though the debate
tends to involve not whether high radon levels pose a public
health risk, but rather how much oi:a risk they pose, and under
what conditions.
Quantifying Latent Health Risks
Quantifying latent, or delayed, risks from low-level exposures is
notoriously imprecise. And in a field fraught with uncertainties, the
range of disagreement over radon's health risks is relatively small. For
many chemical hazards, risk estimates can range by 100-fold or more.
For dipxin, for instance, the range is more than 1,000-fold.
EPA concludes in its Citizen's Guide to Radon, "we know more
about radon risks than risks from most other cancer-causing sub-
stances ... because estimates of radon risks are based on studies of
cancer in humans (underground miners)." Although available animal
studies support the human data indicating health risks from radon
exposures; it is the availability and extent of the human data that
underlies the strength of the radon risk estimates. (For more detail
see Technical Support Document for the 1992 Citizen's Guide to
Radpn, EPA 400-R-92-11, May 1992.) A July 1993 article in Air &
Waste magazine notes that independent evaluations by the Interna-
tional Agency for Research on Cancer, the International Commission
on Radiological Protection, and the National Council on Radiation
Protection and Measurement have reached conclusions comparable to
EPA on trie significance of the indoor radon problem.
Sheldon Krimsky and Alonzo Plough - two Tufts University Center
for Environmental Management professors - agree. In Environmental
Hazards: Communicating Risks as a Social Process, they say, "Risk
assessments for radon exposure carry a greater certainty than those
for many other exposures, because extensive research has been done
oh the 'biological effects of radiation."
tet to date, epidemiologlcal studies of" residential radon exposure
have been inconclusive. Severalstudies"are currently underway, "but
those completed show little evidence of a correlation" between radon
-------
Chapter 3 - Disputing the Radon Risks Page31
exposure and the incidence of lung cancer, Leonard Cole writes in
Element of Risk, the Politics of Radon. Cole also notes that this may
be because "there is no relationship," or because of the design of the
studies, or because of insufficient numbers of cases to provide ad-
equate statistical power. Such studies are also difficult because
individuals' time spent at different places makes it difficult to determine
actual lifetime exposures. Many epidemiologists, according to Cole,
do not reject the possibility that linkage exists, but emphasize that the
matter is uncertain.
Radiation researcher Dr. Johnathan Samet of the University
of New Mexico Medical Center noted in the August 1993 issue
of the Journal of the American Medical Association that while
"ecological studies, which compare lung cancer occurrence in
areas having higher and lower radon concentrations, have not
provided consistent evidence of a hazard ... this investigative
method has well-known flaws and the failure to readily find such
descriptive evidence of a hazard of radon exposure should not be
used to dismiss the problem."
Dr. Samet also notes that although the miners studied were
exposed to higher radon concentrations than are typical indoors,
"increased lung cancer risk in miners has been demonstrated at
exposure levels approximately five times those sustained during
an average lifetime, and many homes in the United States have
concentrations of radon comparable to those found in underground
mines where workers have had excess lung cancer."
€stimating the Number
of Lung Cancer Deaths
There is controversy over the number of lung cancer cases ,
attributable each year to radon. EPA estimates that some 7,000
to 30,000 lung cancer deaths in the U.S. each year are attribut-
able to radon exposures.
The agency uses the risk projection model developed by the
National Academy of Sciences' Committee on Biological Effects
of Ionizing Radiation (BEIR). However, that group itself made no
estimate of the number of annual lung cancer deaths. The
National Council on Radiation Protection and Measurements
(NCRP) - a congressionally chartered, nongovernmental public
-------
Page 32
fl Guide to Radon
service organization charged with advising on radiation protection
measures - in 1984 estimated 9,000 deaths annually are attributable
to radon-induced lung cancers. It has not made a more recent
estimate of radon-induced lung cancer deaths. While less than EPA's
current estimate of some 14,000 lung cancer deaths annually because
of radon, that range of estimates is considered normal in health risk
assessments.
But whatever the actual number, even proponents of lower
radon risk estimates concede that radon risks are far higher than
those associated with most environmental health hazards regu-
lated by EPA. The agency calculates that lifetime exposure to the
average home radonlevel (about 1.3 pCi/L) will cause lung cancer in
about 1 in 1,000 nonsmbkers and 9 in 1,000 smokers (see Chapter 1,
TableS).
Radiation researchers Dr. Samet and Anthony V. Nero, Ph.D.,
a physicist at the University of California, Berkeley, write that,
"For average Americans living in houses with an average radon
concentration, the lifetime risk is projected to range ... far higher
than the estimated risk for most carcinogenic pollutants that are
reguiateci in outdoor air."
In a February 1987 staff report, "Unfinished Business: A
Comparative Assessment of Environmental Problems," based on
the staffs "professional judgment rather than on quantitative
methods," EPA concluded that indoor radon and worker expo-
Radon Risk: Individual Choice
Two interesting characteristics of radon set it apart from
other environmental health risks:
... individuals in most cases can easily test their own home
environment to establish the level of radon risk they face; and
... once finding that they face unacceptable risks, individu-
als in most cases can move effectively to reduce those radon
risks, and they usually can do so without incurring exorbitant
costs and without making changes in their own lifestyle.
If effect, radon is a risk that can be evaluated as it specifi-
cally applies to individuals. And it is one they can reduce on
their own if they choose.
-------
Chapter 3 - Disputing the Rodon Risks PQQ&53
sures to chemicals rank highest in terms of potential cancer risks.
That group of EPA professional civil servants cited agency data
indicating that radon-induced lung cancers greatly outnumbered annual
cancer cases caused by 20 different toxic air pollutants.
Their conclusions have been repeated in several EPA regional
office follow-ups, and the agency's Science Advisory Board in
September 1990, generally affirmed the 1987 "Unfinished
Business" report in "Reducing Risks: Setting Priorities and Strate-
gies for Environmental Protection."
Fretting over 'Routine' Risks?
Experts generally agree with the characterization of radon as an
important environmental problem and one that poses; risks larger than
most others EPA regulates. However, some contend that the risk of
even high radon concentrations may nonetheless be tolerable to many
people and that the public routinely copes with risks at this level in
their personal environments.
"The fact is that the estimated risks from radon - even at EPA's
remedial action guideline of 4 pCi/L - are no larger than the observable
risks that we routinely accept by living in homes or using our cars or
working at our jobs," Nero wrote in June 1989.* "In these places,
where we really spend our time, we encounter risks that have about a
1 percent - that's 1 in 100 - chance of eventually causing our deaths.
In contrast, the EPA, in regulating the extent to which industry or cars
pollute the atmosphere or water resources, rightly limits risks to much
lower levels, even as low as one in a million." (See Chapter 1, Table 4,
comparative risks.)
Former director of EPA Radiation and Indoor Air Programs, Margo
Oge, is not convinced by arguments that radon risks
parallel those "routinely accepted" by people. Oge says,
"We all take risks in our daily lives, but also we try to keep them under
control. If you go on a boat, you wear a life vest. On the stairs, you
hold to the banister, and buckle your seat belt while driving. People
living near nuclear power plants sometimes worry about radiation. But
have they checked to see if the natural radon in their homes isn't
posing far greater risk?"
Unpublished letter to the National Safety Council's Environmental
Health Center outlining Dr. Nero's views, June 1989.
-------
, i! ' lit, I'll
Poge 34
. . -
fl Guide to Radon
Target ULJorst Radon Homes First?
Some experts argue that public policy should target homes with
higher radon levels, 20 pCi/L or above (estimated at 50,000 to 100,000
U.S. homes) first, which EPA has not yet done.
On that point, Oge counters that the agency is working to
focus EPA, state and non-profit sector resources on those
geographic areas and populations (such as smokers) with the
greatest risks. Oge points to a wide range of activities including: a
42-state survey to identify radon "hot-spots"; state indoor radon grant
requirements that focus resources in highest risk areas; and collabora-
tive projects with American Lung Association, American Public Health
Association, Consumer Federation of America, and others which
target high risk geographic areas arid smokers.
Oge points out that EPA has funded research to improve the
agency's ability to target high-radon areas. Although EPA is
focusing resources on highest risk areas and populations, she
says the agency will not do that to the exclusion'of addressing
the problem for non-srnokers and in generally lower radon level areas,
because individual houses in areas with lower radon levels still fre-
quently have very elevated levels.
' • . , '" !. ,!H it ' I, I I » • " ' '" I Hi '•'"
Risks for Smokers vs. Nonsrnokers
Smoking combined with radon is an especially serious health risk.
In addition to increasing the overall chances of getting lung cancer,
cigarette smoking multiplies the risk produced by exposure to radon.
EPA points to some epidemiological evidence that shows a synergistic
relationship such that risk from exposure to both may exceed the risk
from either acting alone! The risks from radon are as great as 20
times higher for smokers, according to EPA (see Chapter 1, Table 3).
EPA's estimate of 14,000 annual lung cancer deaths in the U.S.
due to radon exposure includes both smokers and non-smokers:
Never smoked
Former smokers
Current smokers
Total
1,000
3,000
10.000
14,000
The 13,000 deaths in current and former smokers result from exposure
,;,; if;
-------
Chapter 3 -- Disputing the Rodon Risks Page35
to radon and tobacco smoke and would not have occurred without
exposure to radon.
Dispelling Popular Misconceptions
Reporters, public officials, and other community leaders can help
dispel what researchers say are the popular myths surrounding the
radon issue. For instance:
Some people believe that radon is isolated to relatively few
geographical "hot spots." In fact, naturally occurring radon is ubiqui-
tous, and elevated concentrations have been found throughout most of
the country.
Some people take false comfort in learning that neighboring
houses have had low radon readings. In fact, a low radon reading right
next door does not necessarily guarantee a low reading in one's own
home. On the other hand, the incidence of numerous high radon
readings in a community should heighten a homeowner's commitment
to individual testing.
Some people take a "Why test?" approach to radon. Consid-
ering that the costs of radon testing and mitigation compare with
the costs of fixing a leaky basement or getting rid of termites ~
other preventive measures -- a "Why not test?" attitude seems
more prudent.
And as with all health risks, still others adopt an "It can't
happen to me" approach to radon. But it can. Those people
might not think twice before wearing seat belts or installing a
banister down the basement steps. Why not take similar precau-
tions in reducing a risk which could lead to their developing lung
cancer down the road?
Is €Pfl Being Overly Cautious?
Some experts think EPA is being overly cautious in recommend-
ing possible mitigation of radon problems in millions of U.S. homes
which may not need their actual radon levels reduced. And some
environmental groups have suggested the agency is trying to shift
public concern away from obvious and intractable industrial sources.
Another issue is the presumption, from the standpoint of public
safety, that there is a level below which radiation exposures present no
risk to human health. The accepted approach with many carcinogens
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Page 36
fl Guide to Radon
!ii;;i:f I ,•' .;.
is to assume no threshold below which exposure will not lead to an
increased risk of cancer. The issue of whether a threshold exists for
radioactivity remains unresolved.
In the Indoor Radon Abatement Act of 1988, Congress established
a national goal of reducing indoor radon levels to that of outdoor radon
levels (afaoulO.4 pCi/L),though this is currently not feasible with
available technology.
... Or is the agency Leaving
people at Risk?
Just as EPA has radon critics who contend that the agency is
over-estimating risks, it likewise has critics who say it is doing
too little to protect against radon-induced lung cancers. In its
1987 publication Radon: The Citizen's Guide, for instance, the
Environmental Defense Fund says "cancer specialists believe that
there is no known safe level of exposure to radon or any other
cancer-causing agent. Rather, there is a dose/disease relation-
ship, wherein even the smallest exposure adds to the risk of
disease."
"The Environmental Defense Fund believes that the cancer
threat at 4 pCi/L is much too high, and that EPA is misleading
the public into believing that dangerously high levels of radon
exposure are safe. The EPA standard is not safe." (emphases in
original)
EPA's revised Citizen's Guide to Radon recommends that people
"consider" reducing levels between 2 and 4 pCi/L, although a level of 2
pCi/L is not always attainaBle with currently available technology.
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-------
Chapter 4
Other Radon and Indoor Rir Issues
Radon in Schools
Section 307 of the Indoor Radon Abatement Act of 1988 requires
EPA to conduct a study "for the purpose of determining the extent of
radon contamination in the nation's school buildings." The survey took
place during the 1990-1991 school year.
EPA conducted short-term screening tests in a total of 31,000
ground-contact rooms in 927 randomly selected public schools (out of
approximately 101,000 in the U.S.). Both short- and long-term tests
were conducted in all occupied rooms of 100 of those schools.
Short-term tests show that 2.7 percent of the school rooms have
radon measurements equal to or greater than EPA's action level
guideline of 4 pCi/L, and 19.3 percent have at least one ground contact
room with short-term levels equal to or greater than EPA's action
guideline. EPA recommends that all schools be tested for radon.
Many states also have been active in school radon testing. By the
end of 1992, approximately 30 percent of schools throughout the U.S.
had been tested.
Based on limited experience, EPA estimates that in schools
where elevated radon levels are discovered, diagnostic activities will
cost between $2,000 and $5,000 per school, and that mitigation will
cost between $3,000 and $30,000 per school, if needed. Schools with
complex foundation systems or a lack of gravel below the slab may
face higher mitigation costs.
In July 1993, EPA revised its guidelines for reducing radon in
schools based on continued school building research. The agency
says its research indicates that, in most cases, mitigation measures
that work in homes also work in schools.
Most school buildings studied had indoor ventilation problems.
EPA continues to evaluate radon reduction technology for overall
indoor air environment, including ventilation-based technologies.
Based on several years' studies, EPA's Office of Research and
Development has developed guidance for schools to incorporate
control measures into the design and construction of new schools and
other large buildings. The goal of the new designs is two-fold: to
prevent elevated radon in the completed buildings, and to provide this
protection at a fraction of the cost of retrofitting systems. A combina-
-------
•It;: 1 !!; , , I1
Page 38
fl Guide to Radon
<»!, I'll I. , li
tion of active subslab depressurization and operation of the heating,
ventilation, and air-conditioning system is being used to pressurize
buildings to achieve those goals.
Costs are difficult to estimate for HVAC control of radon because
HVAC systems in schools vary considerably. These systems also
require testing to determine correct operating techniques as well as
meeting health, comfort, and energy consumption guidelines.
EPA hf s eyajuated 34 schools and has mitigated or is mitigating
nine schools across the U.S. Additional mitigation research has been
conducted in another 49 schools.
Real €stat© Transactions
There are some significant differences between radon testing by
residents for their own use and testing for home sales. Legal, finan-
cial, and time elements make real estate radon testing more compli-
cated. The buyer does not have control over testing and there is a
potential for conflict of interest. Also, there may be differences in the
living patterns of the buyer arid seller that influence the appropriate
location for radon testing.
Based on a 1993 survey by the Conference of Radiation Control
Program Directors, EPA estimates that 9 million U.S. homes have
been tested, including 3 million during real estate transactions.
Approximately 16 percent of all real estate transactions include radon
testing, according to EPA.
The agency recommends that homeowners test their homes
before putting them on the market and, if necessary, reduce the radon
levels. The sellers also should save test results and all information
relating to steps taken to reduce high levels.
If long-term testing isn't possible, EPA suggests three options for
short-term testing: 1) a short-term passive test for at least 48 hours
followed by a second test for at least 48 hours; 2) two simultaneous
short-term passive tests for at least 48 hours (for options 1 and 2, a
decision should be based on the average of the two test results); and
3) testing the home with a continuous monitor for at least 48 hours.
Options 1 and 2 can be done by the homeowner; the third is generally
done by a professional.
Homebuyers should ask the seller for radon test results. If the
home has a radon reduction system, they should ask the seller for
information about the system.
-------
Chapter 4 -- Other flodon ond Indoor flir Issues PoQe59
Some active devices may have a number of features to prevent or
detect interference, such as: a frequent, periodic report of radon or
decay product levels to detect unusual swings; a motion detector to
determine whether the test device has been moved or testing condi-
tions have changed; a barometric pressure monitor to identify weather
conditions which may have affected the test; and a temperature record
to help assess whether doors and windows have been opened.
Windows can be taped shut to ensure closed house conditions.
Buyer and seller can negotiate provisions in the home sale
contract to clarify radon issues. A clause can specify the right of the
buyer to test for radon and a course of action based on test results. A
clause also can release the seller from claims regarding radon if proper
steps are followed.
Buyers should ask if radon-resistant construction features have
been built into any new home they are considering for purchase (see
discussion below). For custom-built homes, the buyer should discuss
radon-resistant features with the builder, including likely cost. Regard-
less of the type of home involved, the buyer should test shortly after
moving in to determine the average annual radon level.
Table 6 summarizes some proposed and enacted state laws and
realtor association recommendations regarding radon in real estate
transactions.
EPA guidelines for radon testing during real estate transactions
are outlined in EPA's Home Buyer's and Seller's Guide to Radon.
N©LU Construction
While the initial focus of EPA's radon program was on existing
homes, EPA is now also focusing on reducing risk in newly con-
structed homes. In 1989, EPA began developing a model standard for
building new homes that are radon resistant.
There are differing opinions about the viability of radon testing in
newly built homes. Some experts say there may not be a time during
construction for builders to achieve an accurate reading of the average
annual radon levels in a new home. Some believe that living habits in
a new home will alter levels, so a representative test result cannot be
achieved until after the home is occupied. Yet other experts believe
radon tests should be done in new homes before the sale is final.
New homes can be built with radon-resistant features that mini-
mize radon entry routes and allow for easier remediation of problems
-------
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-------
Chapter 4 -- Other Radon and Indoor flir Issues Page 41
Table 6 (Cont'd)
State Legislation and Realtor Association
Recommendations Regarding Radon
Realtor's Legislation
Association Regarding Legislation
Recommended Licensing or Regarding
State Procedure (1) Registration (2) Disclosure (3)
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
X
X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X
X X
X
X
X
Note: States not listed had no applicable legislation and no reported real estate
association activity.
(1) Generally recommended procedures and/or forms for disclosure of radon
information.
(2) Required licensing or registration of radon testing and mitigation profes-
sional.
(3) State laws regarding disclosure of radon information in a real estate
transaction.
Source: Proposed and Enacted Radon Legislation, August 1993, Environmental
Law Institute; Real Estate Legislation and De Facto Procedures Involving Radon,
Environmental Law Institute, April 1993.
that may occur later. These features cost less if installed during
construction than if added to an existing house, adding an estimated
$350 to $500 to the cost of a new home compared to $800 to $2,500
to retrofit an existing home (1991 dollars). A survey by the National
-------
Page 42
fl Guide to Radon
. Mill!
Association of Home Builders showed that 20.5 percent of homes built
in i&9i had some radon-resistant features.
Radpn-feslstant construction practices fall into three categories:
sealing radon entry routes,installing a soil "ventilation system, and
iising mechanical house ventilation systems to control radon levels
and entry.
Sealing entry routes is a basic element in radon mitigation and
includes many practices similar to those used for controlling moisture
and for energy conservation. Vapor barriers, caulks, and foams can
seal radon entry routes in foundation and floor areas.
Soil ventilation systems arei sometimes referred to as soil depres-
surization or sub-slab depressurization systems. They are used to
create a suction on the soil so that radon is removed as a soil gas
before it enters the house. Some of these systems use fans (active
systems) and some do not (passive systems).
Mechanical house ventilation systems may be designed to provide
extra outside air dilution or to maintain higher pressure inside the
building relative to outside, preventing radon from entering, although
less is known about such systems so far.
I? Adoption of EPA's model standards for making new homes radon
resistant is expected to achieve significant radon risk reduction, while
also increasing energy savings. EPA estimates that radon-resistant
features in new homes offer an average annual energy savings of about
$65 per house. These standards meet the requirements established
by Congress in the Indoor Radon Abatement Act of 1988.
The recommended techniques are intended to be technologically
feasible, easily implemented by builders, and cost-effective for home
builders arid buyers"' The model standard recommends that passive
radon control techniques be installed routinely in all new homes in
areas of highest ''radon['potential (see EPA's Radon Potential Map,
Chapter i).
EPA's model standard is supported by the National Association of
Home Builders, and the techniques are the same as those in the
American Society of Testing and Materials Standard Guide (E1465)
(see Figures 7 and 8).
Several states, including Washington and New Jersey, have
enacted legislation to codify the use of radon-resistant construction
techniques in new homes in high risk areas within the state.
-------
Chapter 4 -- Other flodon and Indoor flir Issues Page 43
Figure 7
Radon-Resistant Techniques for
New Home Construction: Passive System
1. Layer of gas permeable material, such as clean gravel, 4"
thick.
2. Continuous layer of polyethylene sheeting under entire
slab, overlapped at seams, to serve as a soil-gas-retarder.
3. Sealing and caulking of any openings through the slab and
foundation walls, such as drains, sumps, utility penetration,
and floor-wall joints to retard soil-gas entry.
4. Installation of 3"-4" PVC pipe that extends from the gas
permeable layer to the roof.
5. Roughed-in wiring for alter installation of fan and system-
failure warning device, if radon test shows elevated levels.
-------
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Page 44
fl Guide to Radon
Figure 8
Radon-Resistant Techniques for
New Home Construction: Active System
f Exhaust
Rafter
See Notes 1-5 in Figure 7.
6. System failure warning device.
7. Fan installed in stack
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"!:'1,.!, Iii.ilflili'^liiUl iiiiin''!'. :'i!!,"!i > it/,v; ': mif SB,,.,1 it v "; •« i'jt 'Ma- :iiiiilll'~ iiiiiliji :":. xi
-------
Chapter 4 -- Other Radon and Indoor flir Issues Page 45
Other Indoor flir Quality Issues
At the start of "the environmental decade" in 1970, the term
"environment" in America quickly became associated most strongly
with the country's great outdoors.
That's not surprising. The modern environmental movement was
launched as something of a "birds and bunnies" campaign - a term
used by some to affectionately characterize the notion of protecting
flora and fauna and by others to denigrate that same effort. The early
national attention on the highly visible plumes from billowing smoke
stacks, on garish effluents gushing from factory discharge pipes to the
nation's lakes, rivers, and streams, and on hazy vistas over national
parks and forests reinforced the movement's early emphasis on
protecting the outdoors.
But as the idea of environmental protection matured - and as
scientific data increasingly raised questions about potential public
health effects, particularly cancer - the term "environment" came to
mean much more than merely a focus on protecting and preserving
outdoor resources. Indeed, environmental issues since the late 1970s
have increasingly taken on a public health focus. Some critics
suggest, in fact, that an over-emphasis on health issues came at the
expense of welfare and resource issues.
That increased public health focus gradually has led to increased
awareness of indoor environmental pollutants. Formaldehyde emis-
sions from pressed wood products and indoor releases of volatile
organic compounds from a wide range of routine household products
like glues, paints, solvents, cleansers, and pesticide products are
significant concerns in homes, offices, hotels, and other buildings.
Similar concern has mounted on other indoor environmental assaults
like ozone from laser printers and copiers; second-hand tobacco
smoke; lead in painted surfaces and drinking water; and emissions
from combustion appliances. These issues have increasingly captured
media interest and public interest.
The increasing media interest in and public concern about such
issues was fueled, in part, by the recognition that efforts to increase
residential insulation - and therefore decrease air exchanges to the
outdoors - was actually contributing to higher indoor levels of poten-
tially harmful pollutants: Must energy conservation and increased
indoor air pollution go hand in hand?
Concerns about indoor pollution health effects grew because
-------
IK II II III
•I1*!!'1' ' ' j:
inr:iI '"i-!•• il ' 1
"I '
i in in
Page 46
fl Guide to Radon
indoor concentrations often can exceed those considered "safe"
outdoors and because of the nature of peoples' indoor exposures.
Ivjpst: people spend™morelmeIndoors than outside. Furthermore,
persons likely fb spend the most time indoors - the old, the young,
and the sick - are precisely those who may be at greatest risk of
adverse health effects from exposure to pollution.
Radon may be the besf example of such magnified effect because
it presents the highest risk of causing increased lung cancers of all the
pollutants over which EPA has authority. And yet it is also unique
among other indoor pollutants in homes, offices, and other buidlings
because it is naturally-occurring, not human induced.
Health Effects
Health effects from indoor air pollution, like those from outdoor air
pollution, can be acute or chronic. Acute effects are manifested
immediately after exposure (such as excessive exposure to carbon
monoxide), and are usually short-term and treatable. They can include
irritation of the eyes, nose and throat, headaches, dizziness, nausea,
and fatigue.
Figure 9
Suspected Causes of Building-Associated Illness
Other
Tobacco smoke
Hypersensitivity pneumonitis
Building fabrics
Humidity
Unknown
Outdoor air
Indoor air contaminants
Inadequate ventilation
' ' ^20 30 40 50
(Percent)
Source: E.J. Bardana, Jr., A. Montanaro and M.T. O'Hollaren,
"Building-Related Illness: A Review of Available Scientific Data,'
Clinical Reviews in Allergy, 1988, Table 4, p. 78.
-------
Chapter 4 -- Other floc/on ond Indoor flir Issues Page 47
Chronic effects which show up years or decades after exposure or
after long or repeated exposures include emphysema and other
respiratory diseases, heart disease, and cancer.
Key Indoor Air Terms
Sick Building Syndrome: Refers to a set of symptoms that
affect a number of building occupants during the time they spend in
the building and diminish or go away during periods when they leave
the building. It may be difficult to trace the symptoms to specific
pollutants or sources within the building.
Building-Associated Illness: Refers to a discrete, identifiable
disease or illness that can be traced to a specific pollutant or source
within a building (see Figure 9).
Chemical Sensitivity: Caused when some people develop health
problems characterized by dizziness, eye and throat irritation, chest
tightness, and nasal congestion whenever exposed to certain chemi-
cals. Such people may react to even trace amounts of chemicals to
which they have become "sensitized."
Environmental Tobacco Smoke (ETS): Is sidestream smoke
(smoke that comes from the burning end of a cigarette) and smoke
that is exhaled by smokers. Non-smokers' exposure to ETS is called
"passive smoking" or "second hand smoking."
lilhat Con B© Done flboul: It?
An interesting aspect of radon as with several other indoor air
pollutants is that it poses problems that people often can "do some-
thing about" once provided adequate information about potential risk
and how to manage or reduce it. Unlike widespread urban smog or
global climate change that must be addressed on broad societal
scales, individuals can act on their own to assess levels of risk and
reduce those that concern them.
That's important because it helps defeat feelings of despair and
frustration sometimes associated with environmental issues over which
individuals feel they have little direct control.
It's important also because controlling potential indoor risks often
can be done without imposing the "pain" of more radical life-style
changes routinely caused in work or commuting practices to solve
urban smog problems, for instance.
-------
* ,iih
Hi In,
Hi;,,::,, f ini
Page 48
fl Guide to
Radon
In the case of radon, as noted earlier, individual residents can
measure the likelihood that they and their families may be exposed to
levels posing a concern over a period of years and do so at relatively
small cost but high confidence. Once so informed they can make
decisions on what to do about those risks. Basic approaches to
reducing exposure include:
Source control - Eliminating individual sources or reducing their
emissions is usually the most effective way to improve indoor air.
Ventilation improvements - Increasing indoor/outdoor air
exchanges helps lower the concentrations of indoor air pollutants.
Depending on weather conditions and on the particular building
structure, merely opening windows and doors, turning on bathroom or
kitchen exhaust fans, and installing heat recovery ventilators (also
known as air-to-air exchanger) may lower pollution levels.
Air cleaners - Some air cleaners are very efficient at removing
particles but are not generally designed to/remove gaseous pollutants
such as radon. EPA "does riot recommend using air cleaners to
reduce radon and its decay products. The effectiveness of these
devices is uncertain because they only partially remove the radon
decay products and do not diminish the amount of radon entering the
home."
-------
Chapter 5
Sources for Further Information
Organizations
American Assoc. of Radon
Scientists and Technologists, Inc.
P.O. Box 70
Park Ridge, NJ 07656
(201)391-6445
American Lung Assoc. (ALA)
1726 M St., NW, # 902
Washington, DC 20036
(202) 785-3355
(202) 452-1805 (fax)
Contact: Leyla McCurdy
Mgr, Indoor Air Programs
American Medical Assoc.
515 North State St.
Chicago, IL 60610
(312)464-5957
Contact: Dr. Tom Houston
Director, Dept. of Preventive
Medicine
Association of State & Territorial
Health Officials
415 2nd St., NE, #200
Washington, DC 20002
(202) 546-5400
(202) 544-9349 (fax)
Contact: Lynn Bradley,
Project Manager
Conference of Radiation Control
Program Directors, Inc.
205 Capital Ave.
Frankfort, KY 40601
(502) 227-4543
(502) 227-7862 (fax)
Contact: Curt Hopkins
Consumer Federation of America
1424 16th St., NW, #604
Washington, DC 20036
(202)387-6121
(202) 265-7989 (fax)
Contact: Mary Ellen Fise,
Product Safety Director
Environmental Law Institute
1616 P St., NWa 2nd Floor
Washington, DC 20036
(202) 939-3800
(202) 328-5002 (fax)
Contact: Paul Locke,
Senior Attorney
International City/County Manage-
ment Association
777 N. Capital St., NE, #500
Washington, DC 20002
(202) 962-3593
(202) 962-3500 (fax)
Contact: Simon McNabb,
Program Manager
Medical College of Wisconsin
8701 Watertown Plank Rd.
Milwaukee, Wl 53226
(414) 778-4402
Contact: William Hendee, Ph.D.
Professor of Radiology & Bio-
physics
-------
Page 50
fl Guide to Radon
National Assoc. of City and
County Health "Officials
440 First St., NW, #500
Washington, DC 20001
(202)783-5550
(202) 783-1583 (fax)
Contact: Heidi Klein, M.S.,
Division Director
National Assoc. of Counties
440 First St., NW
Washington, DC 20001
'(262)393-6226
(202) 393-2630 (fax)
Contact: Lou Witt,
Radon Program Manager
National Assoc. of Home Builders
15th & M St., NW
Washington, b'C 20005
(202)822-0475
(202) 822-8873 (fax)
Contact: Saundra Harris,
Environmental Program Opera-
tions Manager
National Civic League
1445 Market St., #300
Denver, CO 80202-1728
(303) 571-4343
(303) 571-4404 (fax)
Contact: Monty Roulier,
Director of Civic Assistance
Programs
National Coalition of Hispanic
Health & Human Services Organi-
zations
1501 16th St., NW
Washington, DC 20036-1401
(202) 387-5000
(202) 265-8027 (fax)
Contact: Raphael Metzger,
Special Assistant to the Presi-
dent
National Conference of State
Legislatures
1560 Broadway, #700
Denver, CO 80202
(303) 830-2200
(303) 863-8003 (fax)
Contact: Barbara Foster,
Senior Policy Specialist
National Conference of States on
Building Codes & Standards
505 Huntmar Park Dr., #210
Herndon, VA 22070
(703)481-2024
(703) 481-3596 (fax)
National Safety Council's Environ-
mental Health Center
1019 19th Street, N.W., Ste. 401
Washington, DC 20036
(202) 293-2270
(202) 293-0032 (fax)
For general information:
(Radon Hotline (800) SOS-RADON
To speak with an information
specialist:
Radon Helpline (800) 55-RADON
Contact: Nyki Brandon Palermo,
Program Coordinator
-------
Chapter 5 — Sources for Further Information Page 51
University of New Mexico
New Mexico Tumor Registry
Medical Center
900 Camino de Salud, NE
Albuquerque, NM 87131-5306
(505) 277-5541
(505) 277-8572 (fax)
Contact: Jonathan Samet, M.D.,
Professor of Medicine
University of Lowell
Lowell, MA 08154
(508) 934-3287
(508) 441-0934 (fax)
Contact: Ken Skrable,
Department of Physics
-------
III iiininn n
Page
ft Guide to Radon
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Chopter 5 — Sources for Further Informotion
Page 53
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State
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Puerto Rico
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah John Hultqui
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
-------
Ill II
, -"I-
Page 54
fl Guide to Radon
€Pfl Regional Offices
Region 1
Connecticut
Maine
Massachusetts
New Hampshire
Rhode Island
Vermont
Reg ion 2
New Jersey
New York
John F. Kennedy Federal Building
One Congress Street
Boston, MA 02203
617/565-323-1
Jacob K. Javitz Federal Building
26 Federal Plaza
New York, NY 10278
212/264-2517
Region 3
Delaware 841 Chestnut Building
District of Columbia Philadelphia, PA 19107
Maryland 215/597-8320
'';_'r ''''Pennsylvania ' ' " '" ' "" '
• ' Virginia '
ii';l::;iWest"Viirgiri'ia
Region 4
Alabama
Florida
Qeprgia
Kentucky
Mississippi
'v^qriUi' Carolina
South Carolina
345 Courtland Street, N.E.
Atlanta, GA 30365
404/347-3907
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Chapter B - Sources for Further (nformofcion
Page 55
Region 5
Illinois
Indiana
Michigan
Minnesota
Ohio
Wisconsin
Region 6
Arkansas
New Mexico
Oklahoma
Texas
77 West Jackson Boulevard
Chicago, IL 60604
312/353-2205
First Interstate Bank Tower
Louisiana at Fountain Place
1445 Ross Ave, Ste 1200
Dallas, TX 75202-2733
214/655-7208
Region 7
Iowa
Kansas
Missouri
Nebraska
Region 8
Colorado
Montana
North Dakota
South Dakota
Utah
Wyoming
Region 9
Arizona
California
Hawaii
Nevada
Region 10
Alaska
Idaho
Oregon
Washington
726 Minnesota Avenue
Kansas City, KS 66101
913/551-7000
999 18th Street, Suite 500
Denver, CO 80202-2405
303/293-1440
75 Hawthorne Street
San Francisco, CA 94105
415/744-1048
1200 Sixth Avenue
Seattle, WA 98101
206/553-4166
-------
Jftlll , "i'l „ "illl'l ':, 'III! "Ik'; fin! ; '.il.
I I
Bit'1!
... Ill',,'I
Poge 56
fl Guide to Radon
Regional Training Centers
Eastern Regional Radon Training Center
Rutgers University
Bldg. 4087, Kilmer Campus
New Brunswick, NJ 08903
908/932-2582
Midwest Universities Radon Consortium
University of Minnesota
1985 Buford Avenue (240)
St. Paul, MN 55108-1101
;;.,' 614/624-6786 " "', "
Western Regional Radon Training Center
Colorado State University
Fort Collins, CO 80523
303/491-7742 or 800/462-7459
Southern Regional Radon Training Center
Harbert Engineering Center, Room 238
Auburn University, AL 36849-5337
205/844-6271 or 800/626-2703
"i. rjiwinnii iiir nil
11 i "iiii'i1:: , 'S.,|i;ir
!!!!! flail "''I ', >"'.' ' „>• .1 '' ' ... ,:!, '"''I:1'!''',- ' i " ": f f'"
-------
Chapter 5 - Sources for further Information Page 57
€Pfl Documents and Videos
These documents are available from the Radon Helpline (800) 55-
RADON or from EPA Radon Division at (202) 233-9370.
General Public Brochures:
1. Reducing Radon Risks
2. Citizens Guide to Radon
3. Home Buyer's and Seller's Guide
4. Consumer's Guide to Radon Reduction
5. Physicians Guide to Radon
6. American Lung Association Radon and Smoking
7. Radon in Schools (2nd edition)
8. El Raddn, Gula Para Su Proteccidn Y La De Su Familia
Public Service Advertising Materials:
1. Television 3/4 Kit
2. Radio Reel to Reel Kit
3. Magazine Slicks
4. Newspaper Print Ads
5. Yellow Transit Poster (21" x 22")
6. Yellow Transit Poster (14" x 28")
7. Lung X-Ray Transit Poster (14" x 28")
Video Tapes:
1. Radon: What Physicians Need to Know (20 min..),
American Medical Association
2. Radon: The Health Hazard in Your Home (10 min.),
American Lung Association
3. Radon Resistant New Homes: A Public Official's Guide, National
Conference of States on Building Codes & Standards
4. Radon Diagnostics in Schools, New York State EEnergy Office
5. Living Well America - Environment Update, American Medical
Television
6. Radon Does/? 't Have to be a Problem, National Association of
Home Builders
-------
Page 58
fl Guide to Radon
Supporting Materials:
1. Color Zone Map 11" x 8-1/2" w/fact sheet
Build Yourself a Healthy Home bookmark
Radon Resistant Techniques for New Homes Construc-
tion, Passive & Active Systems flyer
Radon Resistant New Construction in Homes, trifold
brochure
Learning About Radon - a part of Nature (for children)
Legislating Lower Health Risks brochure, National Conference of
State Legislators
?,
3.
5.
6.
Technical Documents:
Radon Resistant Cpjistruction Techniques for New
• Residehtial "Construction '" ""
Radon Reduction Techniques for Detached Houses
Indoor Radon & Radon Decay Product Measurement
Device Protocols
Radon Measurement in Schools ~ Revised Edition
Radon Measurement in Schools -' Self-Paced Training
Workbook
National Residential Radon Survey-Summary Report
Key Elements of a State Radon Program
Radon Prevention in the Design and Construction of
Schools and Other Large Buildings
1-
2.
3.
4.
5.
6.
7.
8.
Certification Program Development
10. Technical Support Document for the Citizen's Guide
11. Protocols for Radon and Radon Decay Product
Measurements in Homes
12. Radon Mitigation Standards
13. Model Standards & Techniques for Control of Radon in
New Residential Buildings
14. Deducing R"adbn"in 'ScfiobTs'-'A f earn Approach
15 State Legislative Report-- Radon: An Invisible Threat
16. State Radon Legislation Issues and Options
M. GAO Report: Action to Promote Radon Testing
18. EPA's Strategy to Reduce Risk of Radon, June 1993
19^ Architectural drawings - New Construction Blueprints,
18"x24" "
-------
Chapter 5 -- Sources for Further Information Poae 59
20. Architectural drawings - New Construction, 8 1/2" x 11"
21. Architectural drawings - New Construction, 81/2" x 11"
adhesive
-------
i"1 "",,'iB," . ..... lililZi;.1
• i 'iJB'ii ' ill1!,1!-!!!:,1
Page 60
fl Guide to Radon
'International Contacts
International Agency for
Research on Cancer
150, cours Albert Thomas
69382 Lyon Cedex 08 France
(33)7273-8508
Contact: Dr. Elisabeth Cardis,
Scientist, Office of the Director
Human Health Protection &
Dbsirrietry Department
Institute of Nuclear Protection &
Safety
Atomic Energy Commission
(CEA)
P,O. Box 6
92265 Fontenay-aux-Rbses
Fpntenay-aux-Roses CEDEX
France
(33)1-46547194
Contact: Dr. M. Tirmarche,
Senior Research Scientist
Radiation Protection Department
Federal Office for Radiation
Protection
117,Waldbwalle
0-1157 Berlin
Germany
(49)30-5022249
Contact: Dr. Sieglinde
Przyborowski
•I :
Institute for Radiation Protection
Federal Office for Radiation
Protection
1, Ingolstadter Landstrasse
8042 Nenherberg
Germany
(49)89-31603200
Contact: Dr. Werner Burkart,
Professor and Director
Federal Office of Public Health
P.O. Box 2644
3001 Berne
Switzerland
(+41)31-919603
Contact: Dr. Werner Zeller
• ill
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-------
flppendix fi
Radon Questions and Rnsuuers
What is radon?
Radon is a colorless and odorless radioactive gas that occurs
naturally in uranium-containing rocks and soils, underground water
supplies, and outdoor air at varying levels throughout the U.S.
What exactly is meant when people refer to radon's
"daughters"?
When radioactive materials decay, they "give birth" to new radionu-
clides. Radon is one offspring of uranium in soil and rocks produced in
a decay process that occurs over thousands of yeans. But radon is
not the last step in that decay. As radon itself decays, it gives rise to
its own "daughters" (also referred to as "progeny" or "decay products").
The radon decay products of greatest concern from the standpoint of
lung cancer are polonium-214 and -218, because they emit alpha
particles which can damage genetic materials (DMA) in the sensitive
lung cells.
Does radon pose health risks only in select geographical "hot
spots"?
That was once thought to be the case, based on high uranium
concentrations in former mining sites. In the mid-1980s, however, it
became clear that naturally occurring radon also posed significant
public health risks, and that those risks exist well beyond recognized
"hot spots" such as the Reading Prong in Pennsylvania, New Jersey,
and New York. The effect of this realization was to transform the radon
issue into a national problem, one requiring a coordinated national
approach.
Radon is identified as the second leading cause of lung cancer,
behind smoking. Are there other health effects identified with
radon exposures?
So far, an increased risk of developing lung cancer is the only
established health effect associated with exposures to elevated indoor
air radon levels. Generally fatal, lung cancer is the number one cause
of cancer deaths in the U.S.
-------
In
Page 62
fl Guide to Radon
Is the Federal Government recommending that all residences in
the United States test for radon, even where there are no signs of
high concentrations in a neighborhood?
Precisely because one cannot predict whether a particular resi-
dence in a neighborhood will have a high radon concentration, EPA
and the Surgeon General have recommended all dwellings below the
third floor should be tested for radon. Reliable and economical testing
procedures make sucnlesS a sound insurance policy for homeowners
wanting to manage their own potential cancer risks. Of course, the
need is greater when there is.a demonstrated presence of uranium
source rock.
Is a concentration of 4gicocuries per liter of air "safe"? Is 5
, p.c"^cijriesancfmore'corisiBereclunsafe?
It just isn't that simple. The concept of "safe" is relative, and some
individuals will feel comfortable with risks at a level that would make
others uhcornfqrtabje.there is no "aBsofuTery'safe level; there is
believed to be some level, of risk "associated with all levels of radon.
What distinguishes the radon fssueWornso many other environmental
health issues is that individuals can detect and control their own
cancer risks. There are proponents of both a higher and a lower radon
action level, but government public health experts recommend reduc-
ing radon levels as much as is practical. EPA believes most
homeowners will find it practical to reduce radon to less than four
picocuries per liter of air.
isit realistic for EPA's\risk assessments to assume exposufesat
radon concentrations over a 74-year life span?
EPA's risk estimates assume a person will be exposed to the
radon level found in the home for rougKly"70 years and that the indi-
vidual will spend 75 percent of his or her time in the home. Persons
should take those assumptions into consideration in assessing their
personal risks, keeping in mind that former or future residences may
have lower, comparable or higher radon levels than those found in the
current home.
Also, living with a high radon level, even for a shorter period of
time, can result in a significant level of increased risk, according to
EPA. " ' '
-------
fippendlx ft - flodon Questions ond flnsuueirs Page 63
Is EPA attempting to impose radon testing and removal costs on
the non-smoking population based on risk figures that apply
more accurately to smokers?
Smokers, former smokers, and nonsmokers can decrease their
lung cancer risk by decreasing their radon exposures. Stopping
smoking and discouraging smoking in homes will help reduce a
family's overall chance of contracting lung cancer. Because many
nonsmokers are more "risk-averse" than smokers overall, nonsmokers
frequently want to protect themselves against the incrementally
smaller increased risk of developing lung cancer.
Given thatEPA's own radon risk assessments are based on 74-
year exposures, why is the agency concerned about risk in
schools, where exposure durations certainly will be much
shorter?
EPA's concern results from several factors. No safe level of radon
exposure has been determined. Living with a high radon level, even for
a shorter period of time, can result in a significant level of increased
risk. Schools represent an involuntary risk that is additive to home-
based risk for the children. That is, any elevated exposure in school is
added to home exposure, contributing to greater cumulative exposure.
And, EPA takes a cautious approach for schools because children
have a longer future to accumulate risk overtime.
Test data from 927 schools screened nationwide? indicate that 19.3
percent of the nation's public schools have at least one ground-contact
room that screened greater than the action level; and 2.7 percent of
the schoolrooms exceed that concentration.
How do health risks posed by radon exposures compare with
other environmental health risks regulated by EPA?
Even at the lower end of various estimates of annual lung cancer
deaths in the U.S., radon exposures account for more deaths than
other environmental pollutants overseen by EPA.
Does the presence of neighboring houses with high radon mean
that a nearby house also will have high readings? Do low radon
concentrations throughout the neighborhood mean a house will
likely not have a problem?
Having a neighbor whose house tested below 4 pCi/L for radon is
-------
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page 64
fl Guide to Radon
rib guarantee that your house will test similarly. Differences in path-
Ways under the house and through the foundation make such assump-
tions inappropriate. On the other hand, a concentration of high radon
readings in the neighborhood should prompt homeowners to move
more expeditiously on testing their own homes. In that case too,
however, high readings in a neighboring home do not necessarily mean
a separate home also will test high.
What are the scientific bases for the lung cancer concerns which
the Environmental Protection Agency arid the Office of the
Surgeon Generalafflbliieio'radoriexposures?
Radon risk estimates are based on scientific studies of human
beings, miners exposed to different levels of radon in their underground
work. Because the risk estimates do not have to be extrapolated from
animal tests, scientists are considerably more certain of radon risk
estimates than of" estimates" based" solely oh animal studies. In the
case of radon, available animal tests support the human health data
which uniformly indicate iricreased incidences of lung cancer resulting
from radon exposures. As with all pollutants, there is some uncer-
tainty in estimating health risks associated with radon.
tyVfM'fl!,!!mli" I',' nr
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Arent radon testing kits Inaccuraie^'And don't they therefore
Most test kits, when used as directed, provide reliable indication of
radon concentrations over the time the kits are used. Test kits that
have successfully passed EPA's Radon Measurement Proficiency
Program are marked "Meets EPA Requirements." Longer-term tests
give more reliable measurements of annual radon exposure.
i:ii;l|TI,lit!
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Should I sell my house if it has a high radon concentration?
Should I refuse to buy a new house with a radon problem?
Would you sell your house because it doesn't currently have a
smoke alarm or because it needs new roofing? Would you refuse to
buy a new home based solely on those criteria? Again, the "beauty" of
the dilemma we face with radon is that the problem, if there is one for
a particular residence, is eminently fixable, and usually for fairly
reasonable costs.
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-------
fiaoendix fl •- Radon Questions and flnsmers Page 65
Why should I take the time fora long-term test rather than a
short-term test that provides results within a week?
The long-term radon test devices take into consideration
seasonal and even daily variations. Short-term tests cannot reflect
seasonal differences and other variations commonly associated
with indoor radon levels. When a short measurement is used, a
follow-up measurement (either a second short-term test, or
preferably a long-term test) is recommended as a prudent next
step. In real estate transactions where time considerations are
important, two short-term tests can be done simultaneously and
the results averaged.
Which radon testing device will give me the most reliable
results?
Most radon test kits are accurate and reliable for the purposes
for which they are marketed. However, long-term measurement
devices are able to measure across seasonal variations which
short-term devices cannot.
Is radon a problem in drinking water supplies, or only in
household air?
Radon can enter the home through well water and be released
into residences when faucets are turned on. In most cases, radon
entering the home through well water will be a small risk compared
to radon entering the home though soil. It generally contributes
about 5 percent of the total indoor air concentration in homes
served by radon-containing groundwater, according to EPA.
Radon in water poses a potential risk from both inhaling radon
when it gets in the air from the water, and ingesting radon from
drinking the water. Radon can be released into the air when water
is used for showering or other household uses. Research sug-
gests that swallowing water with high radon levels may pose a risk
too, although this risk is believed to be much lower than that from
breathing air with elevated radon levels.
-------
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flppendix B - Summary Table of Indoor flir Pollutants Poge 67
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Pollutant Sources
leaking
chimneys and
furnaces,
down-drafting
from wood
stoves and
fireplaces, gas
stoves, auto-
mobile exhaust
from attached
garages,
environmental
tobacco smoke
Nitrogen kerosene
Dioxide heaters,
unvented gas
stoves and
heaters,
environmental
tobacco
smoke
Respirable fireplaces,
Particles wood stoves,
kerosene
heaters,
environmental
tobacco
smoke
Organic household
Gases paints, paint
Health
Effects
•Impaired vision
and coordination
•Headaches
•Dizziness
•Confusion
•Nausea
•Can cause flu-like
Steps to
Reduce
heaters and furnaces
•Install and use exhaust fan
vented to outdoors over gas
stoves
•Open flues when gas
fireplaces are in use
•Choose properly-sized wood
symptoms that clear stoves that meet EPA
up after leaving home emissions standards
•Fatal at very high
concentrations
•Eye, nose, and
throat irritation
•Make certain that doors on
wood stoves fit tightly
•Have a trained professional
inspect, clean, and tune-up
central heating system
annually
•Do not idle car inside garage
•See steps under carbon
monoxide
•May cause impaired
lung function and
increased respiratory
infections in young
children
•Eye, nose, and
throat irritation
•Respiratory
infections
•Bronchitis
•Lung cancer
•Eye, nose, and
throat irritation
•Vent all furnaces to outdoors
•Keep doors to rest of
house open when using
unvented space heaters
•Choose properly-sized wood
stoves certified to meet EPA
emissions standards
•Make certain that doors on
all wood stoves fit tightly
•Have a trained professional
inspect, clean, and tune-up
central heating system
•Change filters on central
heating and cooling
systems according to
manufacturer's directions
•Use household products
according to manufacturer's
-------
flppendix B
Summary Table of Indoor flir Pollutants
Pollutant
Radon
Environ-
mental
Tobacco
Smoke
Biolog-
icals
Carbon
Mon-
oxide
Sources
earth and
rock beneath
home; well
water
smoking
cigarettes,
pipes, or
cigars
wet or moist
walls, carpets,
and furniture,
poorly-
maintained
humidifiers,
dehumidifiers,
and air
conditioners;
bedding;
household
pets
unvented
kerosene
and gas
heaters,
Health
Effects
•No immediate
symptoms
•Estimated to
cause 7,000 to
30,000 lung
cancer deaths
per year
•Eye, nose, and
throat irritation
•Headaches
•Bronchitis
•Pneumonia
•Increased risk of
respiratory and ear
infections in children
•Can cause lung cancer
•May contribute to
heart disease
•Eye, nose, and
throat irritation
•Shortness of breath
•Dizziness
•Lethargy
•Fever
•Digestive problems
•Asthma
•Humidifier fever
•Influenza
•Other infectious
diseases
•Fatigue
•Chest pain in
people with heart
disease
Steps to
Reduce
•Test your home for radon
•Seal cracks and other floor
openings in basement
•Install a sub-slab
ventilator or a heat
recovery ventilator
•Stop smoking and
discourage others
from smoking
•If you do smoke,
smokei outdoors
•Install and use fans
vented to outdoors in
kitchens and bathrooms
•Vent clothes dryers to
outdoors
•Clean cool mist and
ultrasonic humidifiers daily
and use only distilled water
in them
•Empty water trays in air
conditioners, refrigerators,
and dishumidiflers frequently
•Clean and dry, or remove,
water-damaged carpets
•Use basements as
living areas only if they
are leak-proof and have
adequate ventilation
•Keep gas appliances
properly adjusted
•Consider purchasing
vented gas space
-------
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appendix ft - Radon Questions and flnsmers Page 65
j . .i I
'' '"why should Itake Ithetime fora 'long-term test "rather than a""
short-term test that provides results within a week?
the long-term radon test devices take into consideration
seasonal and even daily variations. Short-term tests cannot reflect
sea_sonp''d]fterences"alid other variations commonly associated
with indoor radon levels. When a short measurement is used, a
follow-up measurement (either a second short-term test, or
preferably a long-term test) is recommended as a prudent next
step. In real estate transactions where time considerations are
important, two short-term tests can be done simultaneously and
the results averaged.
Which radon testing device will give me the most reliable
results?
Most radon test kits are accurate and reliable for the purposes
for which they are marketed." However, long-term measurement
devices are able to measure across seasonal variations which
short-term devices cannot.
Is radon a problem in drinking water supplies, or only in
household air?
Radon can enter the home through well water and be released
into residences when faucets are turned on. In most cases, radon
entering the home through well water will be a small risk compared
to ra|pn entering the Rome though soil. It generally contributes
about 5 percent of the total iridbor air concentration in homes
served by radon-containing groundwater, according to EPA.
Radon in water poses a potential risk from both inhaling radon
when it gets in the air from the water, and ingesting radon from
drinking the water. Radon can be released into the air when water
is used for showering or other household uses. Research sug-
gests that swallowing water with high radon levels may pose a risk
too, although this risk is believed to be much lower than that from
breathing air with elevated radon levels.
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-------
ffppencftx 8 - Summary Table oF Indoor flir Pollutants Page 69
Pollutant Sources
Health
Effects
Steps to
Reduce
Pesti-
cides
burning of
lead-based
paint, activities
involving lead
solder, friction
of lead paint
such as open-
ing and closing
windows which
are painted
with lead-
based paint
household
insecticides,
lawn and
•garden
insecticides
that are
tracked into
the house
in fetuses and
young children
•Decreased coordina-
tion and mental
abilities
•Damage to kidneys,
red blood cells, and
nervous system
•May increase high
blood pressure
•Eye, nose, and
throat irritation
•Damage to kidney
and central nervous
system
•Cancer
•Leave lead-based paint undis-
turbed; do not sand or burn off
•Cover lead-based paint with
wallpaper or other building
material
•Replace painted moldings or
woodwork, or remove them and
have them chemically treated
off-site
•Use well-ventilated areas for
hobby and house maintenance
activities
•Consider using "no lead"
solder
•If lead exposure is suspected,
consult your health department
about appropriate removal and
cleanup procedures; have your
blood lead levels tested
•Have your drinking
water tested for lead
•Use strictly according to
manufacturer's directions
•Mix or dilute outdoors
•Apply only in recommended
amounts
•Take plants or pets outside;
increase ventilation when using
inside
•Use non-chemical methods
of pest control where possible
•If you use a pest control
company, select it carefully
•Do not store unneeded pesti-
cides insidei home; dispose of
unwanted containers safely
•Store clothes with moth
repellent in separately vent-
ilated areas, if possible
•Keep indoor spaces clean and
well-ventilated in order to
eliminate or minimize use of air
fresheners
Source: U.S. EPA, 1988.
-------
Ill
111 Hill
111 I
ill1
Glossary
;'„;", ,"; ,.',,' „ '. ; ' !' ,"";; 1ll|ll ,,",,;,"1, I "„!,"",,' , '. . "1"™' ", '.',"!"'." T!,1,"
Active radon reduction system - Radon reduction which combines a
passive radon reduction system (see below) with a fan to more actively
draw radon from the soil and vents it to the atmosphere. Also includes
a system-failure warning device.
Acute or Immediate Effect - An effect that becomes apparent after a
one-time or brief exposure rather than being manifested only long after
exposure.
I
Alpha particles -An energized particle of two protons and two
neutrons that is ejected from a radioactive atom. High-energy low-
velocity particles more harmful than beta or gamma radiation.
Beta Radiation - A negatively charged subatomic particle (electron)
emitted from a nucleus during some types of radioactive decay.
Chronic pr"peia^d'En*ecr--'An'eflfecf,llsuch as cancer, which occurs
long after exposures.
,„''', ' " !' """ ' i'" ' i"M ! ','! I™'!" ,n' . in. i ! iiMI I ""i " '' "'.ii i .""" ''"IN" '!' n 'n' 'ii I " ''mm' • •
Curie - A unit quantity of a radioactive huclide equal to 3.7x1 Old
disintegrations per second.
Decay Product - As radioactive materials degrade they form decay
products, often referred to informally as "daughters" or "progeny." The
radon decay pfoducts of most concern from a public health standpoint
"'"'"
Gamma Radiation - Glimma''raysare trueTrays; of energy in contrast
tq alpha and beta radiation. The properties are similar to x-rays and
other electromagnetic waves. They are the most penetrating waves of
radiant nuclear energy but can be blocked by dense materials such as
lead. " '
,,;_,,;';,,,;,";' ' , ,;;;" ," ;;, ,„",„ i. ;;; w~; ",";,;; 'J • , ,,, , , ,,,
Half-Life r The time required for half the atoms of a radioactive
substance present at the beginning to disintegrate. For instance,
beginning with 100 units, there would be 50 units not disintegrated at
the end of the first half-life, 25 at the end.of the second, and so forth.
It oftens takes seven or more such decay periods before radioactivity
-------
Glossary Page 71
reaches relatively safe levels.
Indoor Radon Abatement Act - Passed in 1988 as Title III of the
Toxic Substances Control Act, this law establishes as a national goal -
- but not a requirement—that air within buildings "should be as free of
radon as the ambient air outside of buildings." The law mandates
development of model construction codes for controlling radon in new
buildings; directs EPA to help states establish a radon information
clearinghouse and provide states technical assistance; and authorizes
$10 million annually in grants to help states develop and initiate radon
assessment and mitigation programs. The law also directs EPA to
study radon contamination in schools, provide grants; to colleges to
establish radon training centers.
Latent or Delayed Effect - An effect that becomes apparent usually
long after exposure, as opposed to an immediate effect, which devel-
ops shortly after a one-time or short-term exposure.
Long-term radon test - Radon test conducted over a period of 90
days to 1 year.
Passive radon reduction system - Reducing/adon with barriers that
block out or reduce radon entry and stack effect reduction techniques
(see below) that reduce the rate of radon entry into a house, plus the
installation of a PVC pipe from beneath the slab to the roof. Works by
using natural pressure differentials.
Picocurie - A curie is a standard measurement for radioactivity,
specifically the rate of decay for a gram of radium - 37 billion decays
per second. A picocurie (pCi) is one-trillionth of a curie.
Polonium — A radioactive metallic element that occurs in pitchblende
and other uranium-containing ores.
Radium - A highly radioactive white shining element found in pitch-
blende, carnotite, and other uranium-containing minerals. It emits
alpha particles and gamma rays as it decays to form radon.
Radon - An odorless, tasteless, and invisible radioactive gas pro-
-------
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Poge 72
Ill I 111
fl Guide to Radon
duced by the gradual breakdown of uranium in native rocks and soils.
It is found in high concentrations in uranium, granite, shale, phos-
phate and pitchblende, but also is found in soils contaminated with
'''certain industrial wastes (those from uranium or phosphate mining)
and In underground wafer supplies. The radon decay products (also
called radon daughters or progeny) are particles that can be breathed
into the lung where they continue to release radiation as they further
decay. • ' ''
Reading Prong - A geographical area stretching throughout Pennsyl-
vania, New Jersey, and New York, known to have a high number of
tipmes with high radon concentrations.
""'RiM (Roentgen" Equivaient Man) ""-- the dose-equivalent unit used to
measure the amount of ionizing radiation to which the human body is
exposed.
Screening Measurement - The result of a short-term test designed
to give the highest radon concentration reading for a given structure.
Stack Effect Reduction Technique - Installed house features that
prevent or reduce the flow of warm conditioned air upward and out of
the building. If not reduced, stack effect can actually draw soil gas
containingI radon '"into the lower levels of the house.
Working Level - A working level, derived from safety and health
regulations covering mining, is a measurement of radon decay prod-
ucts rather than of radon itself. Roughly, one picocurie per liter of
radon gas is the same as 0.005 working levels. So one working level
(WL) is equal to about 200 picocuries of radon gas. The term gener-
ally is used less often than picocuries as a unit of measure.
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