United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-97/124 February 1998
Project Summary
Large Building Radon Manual
Charles S. Fowler, Ashley D. Williamson, Bobby E. Pyle and
Susan E. McDonough
Since 1992, the U.S. Environmental
Protection Agency (EPA) has worked
with the State of Florida to evaluate the
impact of heating, ventilation, and air
conditioning (HVAC) systems on radon
entry and mitigation in large buildings.
This manual summarizes information
on how building systems (especially
the HVAC system) influence radon en-
try and can be used to mitigate a radon
problem. Two chapters address the fun-
damentals of large building HVAC sys-
tems and the entry mechanisms for ra-
don in large buildings. Another chapter
reviews the different types of radon
measurements and how to plan a de-
ployment of instruments to obtain the
desired results. A proposed diagnostic
protocol for investigating a generic
large building, based on the investiga-
tions made in the State of Florida and
other places, is outlined. Another chap-
ter summarizes mitigation results re-
ported in previously cited papers and
reviews some of the factors to con-
sider in designing, installing, and evalu-
ating the effectiveness of a mitigation
system. The manual concludes with
some recommended building design
and operating practices for new-con-
struction large buildings.
This Project Summary was developed
by EPA's National Risk Management
Research Laboratory's Air Pollution
Prevention and Control Division, Re-
search Triangle Park, NC, to announce
key findings of the research project
that is fully documented in a separate
report of the same title (see Project
Report ordering information at back.)
Introduction
The U.S. EPA's Office of Research and
Development's (ORD's) Indoor Environ-
mental Management Branch (IEMB) has
been involved with the evaluation of com-
mercial and public building HVAC sys-
tems for a number of years. Since 1992,
they have worked with the State of Florida
to develop, validate, and provide guid-
ance for radon diagnostic procedures and
mitigation strategies applicable to a vari-
ety of buildings. This effort has produced
reports applicable to Florida buildings and
conditions. This manual summarizes find-
ings and reports of the work performed
with the State of Florida and integrates it
with other previous and current national
work.
The target audience includes architects,
engineers, building owners, operators, and
maintenance staff. It was developed to
assist such individuals to incorporate ra-
don mitigation practices into building de-
sign, construction, operation, and mainte-
nance. The evaluation of building ventila-
tion dynamics, building air system bal-
ance (including leakage rates of typical
residential, commercial, and public struc-
tures), and HVAC components and their
effect to dilute radon and indoor air pollu-
tion is an example of the type of informa-
tion this manual was written to communi-
cate. The ultimate benefit of disseminat-
ing such information to both the above
stated building professionals in the perfor-
mance of their specific jobs or tasks and
the public at large will be the improve-
ment of indoor air quality (IAQ) and re-
duction of adverse health effects of radon
and other indoor air contaminants.
Procedure
Many case studies of large buildings
and their ventilation patterns and prob-
lems have been made over the years,
especially in relatively recent times since
indoor contaminants have been connected
with phenomena such as "sick building
syndrome." Many of these studies have
been initiated by various federal agencies
with an interest in investigating or solving
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such problems. Some have had their
bases in efforts prompted by activities of
individual states, and a few have their
origins in the private or commercial sec-
tor. A listing of all such reports that have
sprung from these studies would be too
exhaustive for the purposes of this manual.
Therefore, only those that have a direct
link to radon contamination and a few that
are representative of IAQ issues in gen-
eral were reviewed. Radon research spon-
sored by the EPA, especially radon mea-
surement and mitigation in schools and
other large buildings, were discussed. A
few publications reporting on research con-
ducted by the National Institute of Stan-
dards and Technology (NIST) and the U.S.
Department of Energy (DOE) were also
reviewed. Finally, research sponsored by
state or private agencies, such as the
California Healthy Building Study, the
Florida Radon Research Program (FRRP),
and some private companies, were re-
viewed and abstracted.
Discussion
This manual brings together information
for a wide audience of building profes-
sionals on how building systems (espe-
cially the HVAC system) influence radon
entry and can be used to mitigate a radon
problem in large buildings. Because read-
ers may vary in knowledge of details of
building practices, familiarity with radon,
and involvement with correcting existing
or potential problems relating to them, not
everyone will want or need to read it cover
to cover in the order presented. The fun-
damentals of large building air handling
(AH) systems and the entry mechanisms
for radon in large buildings are presented
with descriptions of how HVAC system
operations affect ventilation and pressure
differentials which in turn affect indoor ra-
don concentrations. The different types of
radon measurements are reviewed for
building professionals who may not be
familiar with radon measurement technol-
ogy.
In addition to the fundamentals of build-
ing systems that may affect radon entry
and how to measure that effect, this
manual also addresses how to diagnose
the problem and offers some possible so-
lutions in existing buildings. A protocol is
given that starts with preliminary measure-
ments, information, preparations, and vis-
its that may be required, details, activities
of a diagnostic visit, and lists resulting
reports. Some mitigation options are sug-
gested that may be included in a mitiga-
tion plan. Examples are given from the
literature of mitigation strategies that have
been found to be successful in other large
building work. Some information on in-
stalling mitigation systems and making fol-
low-up measurements is also given.
Conclusions and
Recommendations
Exposure to elevated radon concentra-
tions is one of a number of IAQ issues
facing large building owners, managers,
and tenants. This document reviews the
fundamental systems and practices that
may exacerbate such problems. It also
presents an approach to examine, diag-
nose, and remedy the problems. Research
has identified several possible avenues to
reduce or eliminate radon from being an
indoor health concern and often to im-
prove other aspects of IAQ at the same
time. The very building systems that could
have been part of the problem can be
used to be part of a solution. An entire
section of the manual is devoted to giving
some recommended building design and
operating practices for new-construction
large buildings that can provide cost-ef-
fective assurance that radon should not
become a problem in the building or that
will enable a quick and reliable solution if
it does. The advantages of installing an
active soil depressurization system as the
foundation is being built, of ensuring that
the building's structural barrier is sound in
terms of resisting soil gas entry, and of
designing and installing an HVAC system
that will establish a pressure boundary to
resist radon entry are discussed.
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Charles S. Fowler, Ashley D. Williamson, Bobby E. Pyle and Susan E. McDonough
are with Southern Research Institute, Birmingham, AL 35255-5305.
Marc Y. Menetrez is the EPA Project Officer (see below).
The complete report, entitled "Large Building Radon Manual," (Order No. PB98-
123995; Cost: $25.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
Official Business
Penalty for Private Use $300
EPA/600/SR-97/124
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