www.epa.gov/research
technical BRIEF
BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS
Support for Environmental
Rapid Risk Assessment Database
Introduction
The U.S. Environmental Protection Agency's (EPA's)
Homeland Security Research Program (HSRP) was
established to conduct applied research and provide
technical support that would enable EPA to meet its
homeland security responsibilities. The HSRP builds
systems-based solutions by working with Agency
partners to plan, implement and deliver useful
science and technology products. HSRP's research
is conducted and science products are constructed
to address all hazards (i.e., all threats, intentional
and unintentional, that could could require an
emergency response) by filling gaps in scientific
information about chemical, biological and
radiological contamination.
U.S. EPA's Homeland Security Research
Program (HSRP) develops products based on
scientific research and technology evaluations.
Our products and expertise are widely used in
preventing, preparing for, and recovering from
public health and environmental emergencies
that arise from terrorist attacks or natural
disasters. Our research and products address
biological, radiological, or chemical
contaminants that could affect indoor areas,
outdoor areas, or water infrastructure. HSRP
provides these products, technical assistance,
and expertise to support EPA's roles and
responsibilities under the National Response
Framework, statutory requirements, and
Homeland Security Presidential Directives.
After an environmental contamination incident, the immediate threat must be identified and risk
must be assessed and managed. There is a need for improved information management
methodology so that data can be accessed rapidly to expedite risk-informed decision-making. In
response to this need, HSRP developed the Support for Environmental Rapid Risk Assessment
(SERRA) database to provide ready access to biothreat risk information. Specifically, the purpose
of the SERRA database is to make available the most relevant and reliable data for the
assessment of human health risk resulting from the release or sudden outbreak of a hazardous
agent. This comprehensive database was customized to meet EPA mission needs to plan for and
respond to a biothreat agent release, and to consolidate information from a variety of literature
resources. The SERRA database was further expanded to include exposure values for chemical
contaminants, information needed to perform human health risk assessments for exposures to
chemical agents.
While many databases offer information on biological agents, several features of the SERRA
database set it apart from others. One section of the SERRA database is the Knowledge Base of
non-classified data on threat agents, which is searchable and available for use by emergency
planners and responders, risk assessors, decision-makers, and on-scene coordinators 24/7. The
Knowledge Base contains mined data that has been peer-reviewed by subject matter experts. It
provides quick, direct access to specific and distilled information via bullet points organized by
topic. Expert commentary is also provided and knowledge gaps are identified. In addition to
capturing peer-reviewed published journal articles, the SERRA database repository also captures
grey literature (documents not published commercially or otherwise not widely accessible, such as
patents, white papers, and technical reports from scientific research groups or government
U.S. Environmental Protection Agency
Office of Research and Development, National Homeland Security Research Program
EPA/600-S-13/087
July 2013
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agencies). Clear data-quality indicators for each piece of literature are noted in the document
criteria report. Finally, the process of creating the SERRA database, including its original
development and its expansion, is a peer-reviewed and quality-assured process with continuing
updates to the seven biothreat agents.
The SERRA database is now comprised of three parts: the Knowledge Base (mined biological risk-
related information), the Literature Repository (electronic articles on biothreats, with a document
quality assessment), and, most recently, the Provisional Advisory Levels (risk-based exposure
levels for chemical contaminants).
Initial Database Development for Biothreat Agents
To develop the SERRA database, subject matter experts constructed a taxonomy of major fields of
knowledge (termed nodes) that are of key importance to a microbial risk assessment. For each
biothreat agent, the nodes include information on general topics such as synonyms, infection
symptoms, and form; dose-response; risk assessment techniques; fate and transport; and
sampling and detection. To populate the Knowledge Base, information was gathered from
published literature and federal archives. The approach was not to acquire all references on a topic
but rather to fill the SERRA database taxonomy with the most relevant information available. After
retrieving the cited references, the experts reviewed them and completed document criteria
reports, which identify the type of literature, original language, and type and quality of the data.
Information derived from these documents was incorporated into the Knowledge Base, the
information was categorized by node for each agent, and knowledge gaps and experts'
commentary were included. Information in the SERRA database can be accessed via the Browse
function, which allows users to view all information for an agent of interest, or via the Search
function for a more targeted query. Within the nodes, information is summarized and referenced,
and linked to the original documents. In addition, selected citations can be exported into EndNote®
(Thomson Reuters, Carlsbad, CA) software, which enables users to compile selected
bibliographies and reference lists.
The database was originally populated with information on the following seven biological agents:
Bacillus anthracis, Francisella tularensis, Yersinia pestis, Brucella suis, Burkholderia mallei,
Burkholderia pseudomallei, and H5N1 avian influenza. These microbes are the causative agents
for the diseases anthrax, tularemia or rabbit fever, plague, brucellosis, glanders, melioidosis, and
avian influenza or bird flu, respectively.
Updates to the SERRA Database
Characteristics of PAL Severity Levels
Effect thresholds
Tier Levels
PAL 3 - - -„
PAL 2
0) DAI -I
(/> rrtL '
f- - -| severe effects, lethality
impaired ability to escape
increased severity of irreversible
serious long-lasting effects
mild, transient, reversible effects,
including changes from baseline
biomakers of exposure
In 2012, the SERRA database was updated
to include health-based Provisional Advisory
Levels (PALs) for priority chemicals, chemical
warfare agents, and toxins. EPA homeland
security researchers have developed PALs to
identify and communicate emergency
reference levels for decision-making on re-
entry into buildings; use/reuse of drinking
water; use of infrastructure; and protection of
responders, following chemical
transportation/storage accidents, natural
disasters, or terrorist incidents. Prior to the development of PALs, a number of exposure limit
~2\
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reference values existed for some chemicals of concern. However, these are only developed for
exposures to air and are limited to either 1- or 8-hour durations. Consequently, these emergency
exposure guidelines do not address the exposure scenarios and durations needed to inform the full
range of potential recovery operations. PALs are threshold inhalation and oral exposure risk levels
applicable to exposures of the general public to priority threat chemicals. They are derived for 24-
hour, 30-day, 90-day, and 2-year exposure durations; as illustrated in the above figure, for each
exposure duration, three levels are developed to distinguish the degree of severity of toxic effects.
In the event of an intentional or unintentional release of hazardous chemicals, PALs will provide
emergency responders and managers with critical information to support site-specific decisions on
cleanup and re-entry.
The PAL development process incorporates extensive peer review and collaboration across EPA
and with other government agencies and national laboratories. The national laboratories include
Oak Ridge, Argonne, and Pacific Northwest. In addition, an external work group of scientists from
academia, state and federal agencies, and the private sector meets quarterly to evaluate and
approve developed PALs. The work group provides comprehensive review of the data used to
derive values. By engaging a community of stakeholders and partners, EPA researchers
developed PALs as scientifically sound advisories to help emergency planners and responders to
prepare for and respond to chemical releases.
The SERRA database contains PAL values for over 120 chemicals and degradation products of
concern. Chemicals and their associated PAL values can be accessed using the Search function;
via the chemical name, synonym, or CAS Registry Number® (American Chemical Society,
Washington, DC); or by selecting the chemical of interest from the drop-down list. PAL values and
technical information are displayed in table format for inhalational and oral exposures, with the
associated key references and technical support documents for each chemical. Although
previously limited in distribution to within the federal government, PAL chemicals and emergency
exposure levels are now available to a broader base of interested users via the SERRA database.
An additional update was completed in March 2013 to include current (post-2005) information for
Bacillus anthracis. The effort to keep the Bacillus anthracis related information current is ongoing,
with literature added as relevant documents are found. With continuing updates as information is
found via literature searches and other research and surveillance efforts, the SERRA database is
emerging as a one-stop repository of threat agent information for microbial and chemical risk
assessment.
Access to the SERRA Database
To register for access, go to https://serra.cbiac.org/serra/
For more information on the EPA's Homeland Security Research Program, visit our Web site at
www.epa.qov/nhsrc.
Technical Contact: Charlena Bowling (513) 569-7648, bowling.charlena@epa.gov
Communications Contact: Kathy Nickel (513) 569-7955, nickel.kathy@epa.gov
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