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INNOVATIVE RESEARCH FOR A SUSTAINABLE FUTURE
Strengthening the IRIS Process - 2011
What is IRIS?
IRIS, or EPA's Integrated Risk Information System,
provides information on potential human health risks
from long term exposure to over 540 chemicals present
in air, water, or on land. IRIS assessments are critical to
the agency's programs and regulations, as they provide a
scientific foundation for many of EPA's decisions. IRIS
assessments are also utilized by many local, state, and
international governments to assess health risks posed by
exposure to various environmental contaminants.
Background
In May 2009, EPA implemented a new IRIS process to
make it more responsive to the needs of the Agency and
its government partners. In part, the changes were in
response to a 2008 report by the Government
Accountability Office (GAO) that found that the IRIS
database was at serious risk of becoming obsolete
because EPA had not been able to routinely complete
timely, credible assessments or decrease its backlog of
ongoing assessments—a total of 4 were completed in
fiscal years 2006 and 2007. The aim of the new process
was to ensure the highest level of scientific quality,
integrity, transparency, and timeliness.
Changes to IRIS Process under Administrator Lisa P.
Jackson
The May 2009 revised process included the following
key features:
• EPA manages the IRIS program and has final
responsibility for the content of all IRIS assessments
• The assessment development time was shortened to
23 months—a reduction of more than half the
estimated time for an assessment to be developed
under the previous process
• The number of steps in the assessment development
process was reduced from 14 to 7
• Other federal agencies and White House offices
have the opportunity to provide scientific input at
two points in the assessment development process,
and their comments are made publicly available
• The assessment development process includes the
opportunity for public comment and relies on an
open, rigorous and independent external peer review
U.S. Environmental Protection Agency
Office of Research and Development
• A public listening session is offered for each
chemical assessment
• Changes in EPA's scientific judgments during the
process are clearly documented and explained
Further Changes to IRIS since May 2009:
• EPA's program and regional offices now have an
extended role in nominating and prioritizing
chemicals for assessment—ensuring the IRIS
program is focused on the highest Agency needs.
• IRIS program managers regularly meet with EPA
programs and regions to discuss individual IRIS
assessments and the IRIS process.
• EPA has created an IRIS logistics team to help
streamline the assessment development process
• EPA has developed the Health and Environmental
Research Online Database - or HERO - which
makes the scientific studies selected and used by the
Agency to develop assessments available to the
public.
• EPA has developed Memoranda of Understanding
with the California Environmental Protection
Agency's Office of Environmental Health Hazard
Assessment and the Agency for Toxic Substances
and Disease Registry, to cooperate in the
development of health assessments to encourage
data sharing and avoids duplication of effort.
Results of Improved IRIS since 2009
Since the new process was instituted in 2009, EPA has
completed 16 assessments, more than the number of
assessments that were completed in the previous four
years. The IRIS backlog has been significantly reduced
and the Agency has 70 assessments in the IRIS process
at various stages.
InFY 2010, EPA completed 10 IRIS assessments and
released nine for public comment and external peer
review, seven of which were major assessments. In FY
2011, EPA anticipates releasing 13 completed
assessments, including a number of major assessments
such as trichloroethylene, tetrachloroethylene, arsenic
and ethylene oxide. In addition, EPA has a number of
assessments that will be released for external peer
review, including PCBs and Libby amphibole asbestos.
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2011 National Academy of Sciences (NAS) Report on
EPA's IRIS Formaldehyde Assessment
In April, 2011, the NAS released its "Review of the
Environmental Protection Agency's Draft IRIS
Assessment of Formaldehyde." In addition to offering
comments about EPA's draft formaldehyde assessment,
the NAS included comments and recommendations to
improve IRIS documents. The NAS focused their
comments on the development of draft IRIS assessments
and did not recommend changes to the overall IRIS
process. EPA welcomes these recommendations and is
taking the following actions to implement them:
1. NAS recommended that EPA edit documents to
reduce the text volume and address redundancies
and inconsistencies.
In response, EPA is editing our assessment
documents to substantially reduce the volume of text
and eliminate redundancies and inconsistencies;
building on existing IRIS guidelines and process to
enhance the clarity and transparency of data
evaluation and the presentation of findings and
conclusions; consolidating related discussions to
eliminate redundancies; increasing the use of tables
and figures to improve communication of
information; and providing reference information on
the IRIS website for all studies considered.
2. NAS recommended that EPA include a fuller
discussion of methods and develop concise
statements of the criteria used to exclude, include
and advance studies for hazard evaluation and
derivation oftoxicity values.
In response, EPA is providing a fuller discussion of
the methods used in its assessments, along with
concise statements of the criteria used to exclude,
include, and focus on the highest quality studies for
hazard assessment and for derivation oftoxicity
values; working towards replacing text descriptions
of the studies with standardized evidence tables that
provide the methods and results of each study for all
health outcomes; and including text that will
accompany evidence tables to present the criteria
used to include or exclude studies.
3. NAS recommended that EPA provide a clearer
articulation of the rationale and criteria for
screening studies.
In response, EPA is enhancing the sequential
approach for progressively focusing on the most
pertinent information, including: searching the
literature, identifying the pertinent studies, and
evaluating study characteristics; evaluating the
overall weight of evidence for each health outcome;
identifying plausible approaches for developing
toxicity values; selecting the most pertinent data and
developing toxicity values for each health hazard;
and, portraying toxicity information graphically.
4. NAS recommended that EPA use uniform
approaches to thoroughly evaluate the strengths and
weaknesses of critical studies, summarize findings in
tables, and clearly articulate the rationale for the
studies used to calculate toxicity values.
In response, EPA is streamlining IRIS assessment
documents and more fully documenting the
approach for assembling and evaluating the range of
scientific data. As the NAS report indicated, EPA
has already made similar changes to how the
scientific evidence is presented on the criteria air
pollutants in its Integrated Science Assessments.
EPA is also implementing a more uniform approach
to the evaluation of the strengths and weaknesses of
critical studies to increase the clarity of the rationale
for selecting the studies used to calculate toxicity
values. Lastly, EPA is increasing the use of evidence
tables that summarize the factual details of pertinent
studies for each health hazard and developing
standardized language to describe study strengths
and limitations.
5. NAS recommended that EPA provide descriptions to
indicate various determinants of weight of evidence
to promote understanding of what elements were
emphasized in synthesizing the evidence.
In response, EPA is augmenting our current analysis
of data to indicate which criteria were most
influential in evaluating the weight of evidence.
In addition, EPA is working closely with the
Agency's Science Advisory Board to develop a
dedicated advisory committee that will exclusively
focus on the quality, transparency and scientific
rigor of IRIS assessments and guide EPA's response
to the NAS recommendations. A hallmark of the
new IRIS process is strengthened independent peer
review of the IRIS program.
EPA will also create a new peer consultation step
early in the development of major IRIS assessments
to enhance the input of the scientific community as
assessments are designed.
In making these changes, EPA's goal is to continually
improve its IRIS assessments without taking any
assessment backwards to earlier steps of the process.
Therefore, these recommendations will be implemented
in a tiered approach, making the most extensive changes
to documents that are in the earlier stages of the
assessment development process.
U.S. Environmental Protection Agency
Office of Research and Development
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