UNFTED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON D.C. 20460
October 29, 1992
OFFICE OF
THE ADMINISTRATOR
SCIENCE ADVISORY BOARD
EPA-SAB-IAQC-LTR-93-003
Honorable William K. Reilly
Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Subject: Science Ad /isory Board Review of the Risk Assessment
Forum's Draft Guidance Document on Assessing Health
Risks of Gasoline Vapors in Buildings
Dear Mr. Reilly:
On February 24-25, 1992, the Indoor Air Quality and Total Human
Exposure Committee (IAQTHEC) of the Science Advisory Board met to review the
Office of Research and Development's (ORD) proposed guidance on assessing
health risks of gasoline vapors in buildings (entitled: Regional Guidance on
Assessment of Health Risks Associated with Gasoline Vapors in Buildings).
According to the Risk Assessment Forum (RAF), this "...document is based on
discussions among EPA scientists and a few outside experts with the goal of
developing some limited guidance for situations where guidance does not currently
exist...." The RAF has developed this guidance for Agency-wide use, and plans on
distributing this guidance through the Agency's Risk Assessment Council.
However, before doing so, the Forum has requested that the SAB review its
interpretation of the underlying science upon which the guidance is based (i.e., is
the guidance scientifically defensible), and whether the recommendations represent
useful, practical guidance for Agency risk assessors.
Although the Committee believes that the draft document represents a good
start towards developing guidance to be used by Regional EPA risk assessors in
responding to public concerns, we believe the draft still needs significant
improvement. We are aware that the scientific basis for anything but general
advice in this case is extremely limited. As with many public health concerns,
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vague generic advice may be misleading and inappropriate for many specific
situations that arise.
The Committee has provided the Agency with a detailed discussion of their
concerns during the public meeting (for which a transcript has been made
available). The Committee has highlighted several of their concerns in this letter,
including some comments specific to this draft guidance document, as well as
comments which concern the preparation of such guidance documents in general.
Specifif- Comments:
a) The draft document gives both safety and health guidance. The title
should reflect that dual role.
b) The draft document addresses sampling but does not say who will do
it. Does EPA intend to send staff into the field? If not, a list of
commercial labs should be made available to the caller.
c) The draft document recommends that sensitive populations be "..taken
into account...", but does not say how. Use of different populations
can lead to inconsistent evaluations. More information on sensitive
populations is needed. It is important to define these groups
accurately and use them in determining overall population risk.
d) The removal of people from and/or ventilation of an area which has
significant sources of volatile organics is essential. Studies should be
done or guidelines provided concerning when one should make
measurements to determine the presence of gasoline and/or other
volatile organics.
e) Gasoline measurements should be taken in suspected source areas,
basement or garage, and in the locations where complaints are being
recorded from occupants. Fingerprint analysis of compounds is
essential from both places to ensure identification of the source
emissions.
f) If the building is located near an outdoor source, such as a gas
station or highway, the influence of background levels (based on air
transport from these sources) must be considered. Background
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measurements are essential to properly assess the sources of
exposure.
g) Information about plausible sources and interim methods of
remediation which provide more practical guidance to the homeowner
should be provided. In addition, the document should provide the
public with information on the general types of public agencies which
should be contacted for explosive versus less than explosive levels.
h) Most homeowners will not care to learn why occupational exposure
experience is not relevant to residential basements. Rather they will
want to eliminate the smell and the hazards.
General Comments:
We believe that there is also a need to provide easilv accessible information
to other public officials and the public who are also concerned about such
instances. Since local health department staff, e.g., local health officers,
sanitarians, and sanitary engineers, often have to (perhaps more often than EPA
regional staff) respond to such concerns, we recommend that EPA consider such
individuals as this guidance document is revised. Ultimately, EPA should consider
distributing the guidance to local health departments. We believe that it is not
only important that the various EPA regions give consistent advice, but that the
advice by EPA in a given region is consistent with that given by the local health
departments.
If the Agency chooses to request additional SAB review of guidance
documents such as this one in the future, we would suggest several generic
improvements in addition to the above comments. Clearly, one is a consistent
guidance document format with a standardized outline.
This particular document needs to be presented in a more polished form, so
that it can be reviewed for content and the appropriate use of the scientific
support for the recommendations and guideline steps that are included. We also
recommend that some mechanism be set up to document phone calls from citizens
and to detail the facts of specific incidents and the lessons they provide. By so
doing, regions can share information, providing a timely and informal mechanism
for assessors in the various regions to develop consistent advice. It would also be
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a mechanism for use by EPA Headquarters in determining the effectiveness of
these documents in establishing consistent advice across the Regions.
The Committee is not prepared to endorse this draft document as final EPA
guidance at this tune. If the Agency chooses to request SAB review of a revised
document in the future, we would are prepared to do so. We appreciate the
opportunity to review this draft document and look forward to your written
response.
Sincerely,
Dr. Raymond C. Loehr, Chair
Executive Committee
Science Advisory Board
Dr. Morton Lippmann, Chair
Indoor Air Quality and Total
Human Exposure Committee
Science Advisory Board
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U.S. Environmental Protection Agency
Science Advisory Board
Indoor Air Quality and Total Human Exposure Committee
Chairman
Dr. Morton Lippmann, Institute of Environmental Medicine, New York University
Medical Center, Tuxedo, NY
Vice C
Dr. Jan A. J. Stolwijk, School of Medicine, Department of Epidemiology and Public
Health, Yale University, New Haven, CT
Members
Dr. Joan Daisey, Indoor Environment Program, Lawrence Berkeley Laboratory,
Berkeley, CA
Dr. Timothy Larson, University of Washington, Seattle, WA
Dr. Victor G. Laties, University of Rochester Medical Center, Rochester, NY
Dr. Paul Lioy, Department of Environmental and Community Medicine, Robert Wood
Johnson School of Medicine, Piscataway, NJ
Dr. Jonathan M. Samet, New Mexico Tumor Registry, Albuquerque, NM
Dr. Jerome J. Wesolowski, Air and Industrial Hygiene Lab., California Department
of Health, Berkeley, CA
Dr. James E. Woods, Jr., College of Architecture and Urban Studies, Viginia Tech
Blacksburg, VA
Science Advisory Board Staff
Mr. A. Robert Flaak, Assistant Director, Science Advisory Board, U.S. EPA,
Washington, DC
Ms. Carolyn Osborne, Program Assistant, Science Advisory Board, U.S. EPA,
Washington, DC
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NOTICE
This report has been written as a part of the activities of the Science Advisory
Board, a public advisory group providing extramural scientific information and
advice to the Administrator and other officials of the Environmental Protection
Agency. The Board is structured to provide balanced, expert assessment of
scientific matters related to problems facing the Agency. This report has not been
reviewed for approval by the Agency and, hence, the contents of this report do not
necessarily represent the views and policies of the Environmental Protection
Agency, nor of other agencies in the Executive Branch of the Federal government,
nor does mention of trade names or commercial products constitute a
recommendation for use.
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