Endocrine Disruptor Screening Program; Chemical Selection
Approach for Initial Round of Screening
[Federal Register: September 27, 2005 (Volume 70, Number 186)]
[Notices]
[Page 56449-56465]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27se05-53]
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ENVIRONMENTAL PROTECTION AGENCY
[OPPT-2004-0109 FRL-7716-9]
Endocrine Disruptor Screening Program; Chemical Selection
Approach for Initial Round of Screening
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice describes the approach EPA plans to use for
selecting the first group of chemicals to be screened in the Agency's
Endocrine Disruptor Screening Program (EDSP). The Food Quality
Protection Act of 1996 (FQPA) amended the Federal Food, Drug, and
Cosmetic Act (FFDCA) to direct EPA to develop a chemical screening
program using appropriate validated test systems and other
scientifically relevant information to determine whether certain
substances may have hormonal effects. In December 2002, EPA sought
comment on its approach for selecting the initial list of chemicals for
which testing will be required under the EDSP. Following review and
revision based on the public comments, EPA is now describing the
approach that it intends to use for selecting the chemicals for the
initial list. For this initial approach, as recommended by scientific
advisory committees, EPA will select 50 to 100 chemicals. The chemicals
will be selected based on their relatively high potential for human
exposure rather than using a combination of exposure- and effects-
related factors. The scope of this first group of chemicals to be
tested includes pesticide active ingredients and High Production Volume
(HPV) chemicals used as pesticide inerts. This will allow EPA to focus
its initial screening efforts on a smaller and more manageable universe
of chemicals that emphasizes the early attention to the pesticide
chemicals that Congress specifically mandated EPA to test for possible
endocrine effects. This notice does not identify the initial list of
chemicals, nor does it describe other aspects of the EDSP such as the
administrative procedures EPA will use to require testing, the
validated tests and battery that will be included in the EDSP, or the
timeframe for requiring the testing or receiving the data. The initial
chemical list and the details of the EDSP process that will apply to
the initial chemical list will be addressed in subsequent notices
published in the Federal Register.
FOR FURTHER INFORMATION CONTACT: For general information contact: Colby
Lintner, Regulatory Coordinator, Environmental Assistance Division
(7408M), Office of Pollution Prevention and Toxics, Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001; telephone number: (202) 554-1404; e-mail address:
TSCA-Hotline@epa.gov.
For technical information contact: Mary Belefski, Office of Science
Coordination and Policy (7201M), Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number:
(202) 564-8461; e-mail address: belefski.mary@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
This action is directed to the public in general. This action may,
however, be of interest if you produce, manufacture, use, consume, work
with, or import pesticide chemicals, substances that may have an effect
cumulative to an effect of a pesticide, or substances found in sources
of drinking water. To determine whether you or your business may be
affected by this action, you should carefully examine section 408(p) of
FFDCA, 21 U.S.C. 346a(p), and the Safe Drinking Water Act (SDWA), 42
[[Page 56450]]
U.S.C. 300j-17. Since other entities may also be interested, the Agency
has not attempted to describe all the specific entities that may be
affected by this action. If you have any questions regarding the
applicability of this action to a particular entity, consult the person
listed under FOR FURTHER INFORMATION CONTACT.
B. How Can I Get Copies of this Document and Other Related Information?
1. Docket. EPA has established an official public docket for this
action under docket identification (ID) number OPPT-2004-0109. The
official public docket consists of the documents specifically
referenced in this action, including EPA's response to comments
received and other information related to this action. In addition,
documents are also in docket ID number OPPT-2002-0066 for the proposed
approach. Although a part of the official docket, the public docket
does not include Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. The official
public docket is the collection of materials that is available for
public viewing at the EPA Docket Center, Rm. B102-Reading Room, EPA
West, 1301 Constitution Ave., NW., Washington, DC. The EPA Docket
Center is open from 8:30 a.m. to 4:30 p.m., Monday through Friday,
excluding legal holidays. The EPA Docket Center Reading Room telephone
number is (202) 566-1744 and the telephone number for the OPPT Docket,
which is located in EPA Docket Center, is (202) 566-0280.
2. Electronic access. You may access this Federal Register document
electronically through the EPA Internet under the ``Federal Register''
listings at http://www.epa.gov/fedrgstr/.
An electronic version of the public docket is available through
EPA's electronic public docket and comment system, EPA Dockets. You may
use EPA Dockets at http://www.epa.gov/edocket/ to view public comments,
to access the index listing of the contents of the official public
docket, and to access those documents in the public docket that are
available electronically. Although not all docket materials may be
available electronically, you may still access any of the publicly
available docket materials through the docket facility identified in
Unit I.B.1. Once in the system, select ``search,'' then key in the
appropriate docket ID number.
Certain types of information will not be placed in the EPA Dockets.
Information claimed as CBI and other information whose disclosure is
restricted by statute, which is not included in the official public
docket, will not be available for public viewing in EPA's electronic
public docket. EPA's policy is that copyrighted material will not be
placed in EPA's electronic public docket but will be available only in
printed, paper form in the official public docket. To the extent
feasible, publicly available docket materials will be made available in
EPA's electronic public docket. When a document is selected from the
index list in EPA Dockets, the system will identify whether the
document is available for viewing in EPA's electronic public docket.
Although not all docket materials may be available electronically, you
may still access any of the publicly available docket materials through
the docket facility identified in Unit I.B.1. EPA intends to work
towards providing electronic access to all of the publicly available
docket materials through EPA's electronic public docket.
II. Introduction
A. What Action is the Agency Taking?
Following review of public comments received in response to the
Federal Register notice of December 30, 2002 (67 FR 79611) (FRL-7286-
6), EPA is describing the approach it plans to use for selecting an
initial group of chemicals to be screened in the Agency's EDSP. This
notice does not identify the initial list of chemicals, nor does it
describe other aspects of the EDSP such as the administrative
procedures EPA will use to require testing, the validated tests and
battery that will be included in the EDSP, or the timeframe for
requiring the testing or receiving the data. The initial chemical list
and the details of the EDSP process that will apply to the initial
chemical list will be addressed in subsequent notices published in the
Federal Register.
EPA anticipates that it may modify its chemical selection approach
for subsequent screening based on experience gained from the results of
testing chemicals on the initial list, its needs to extend screening to
additional categories of chemicals (e.g., non-pesticide substances) and
additional pathways of exposure, and the availability of new priority-
setting tools (e.g., High Throughput Pre-Screening (HTPS) or
Quantitative Structure Activity Relationship (QSAR) models).
EPA developed its EDSP in response to the Congressional mandate in
section 408(p) of FFDCA to ``develop a screening program * * * to
determine whether certain substances may have an effect in humans that
is similar to an effect produced by a naturally occurring estrogen, or
such other endocrine effects as [EPA] may designate'' (21 U.S.C.
346a(p)). When carrying out the program, the statute requires EPA to
``provide for the testing of all pesticide chemicals.'' The statute
also provides EPA with discretionary authority to ``provide for the
testing of any other substance that may have an effect that is
cumulative to an effect of a pesticide chemical if the Administrator
determines that a substantial population may be exposed to such a
substance.'' In addition, section 1457 of SDWA provides EPA with
discretionary authority to provide for testing, under the FFDCA 408(p)
screening program, ``of any other substances that may be found in
sources of drinking water if the Administrator determines that a
substantial population may be exposed to such substance.''
The purpose of this notice is to describe the approach that EPA
plans to use to select this initial set of chemicals to undergo
screening. EPA will use an approach based in part on the compartment-
based priority-setting approach described in the Federal Register
notices of December 28, 1998 (63 FR 71542) (FRL-6052-9) and December
30, 2002. This approach focuses on human exposure-related factors
rather than using a combination of exposure- and effects-related
factors. However, in making selections for this exposure-based initial
list, EPA does not plan to select substances it considers to be a low
priority for early screening under the EDSP because they are
anticipated to have low potential to cause endocrine disruption (e.g.,
certain Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)
List 4 inerts, most polymers with number average molecular weight
greater than 1,000 daltons, strong mineral acids, and strong mineral
bases). Also, chemicals that are being used by EPA as ``positive
controls'' to validate the screening assays will be excluded from its
initial list.
Although EPA's general focus in this approach for the initial list
is on pesticide active ingredients and inerts with relatively greater
potential human exposure, EPA believes that the approach will also
identify chemicals with high potential for exposure of humans from non-
pesticide uses or chemicals with widespread environmental exposures to
other organisms. EPA does not intend to develop an ordinal ranking of
priorities of the chemicals within any list developed using this approach.
The Agency will use the approach set forth in this notice to select
the initial list of chemicals to test first under the
[[Page 56451]]
EDSP based primarily on exposure data. Therefore, this initial list of
chemicals should not be construed as a list of known or likely
endocrine disruptors nor characterized as such. Nothing in the approach
for selecting the initial list would provide a basis to infer that any
of the chemicals selected for the list interferes with or is suspected
to interfere with the endocrine systems of humans or other species.
In subsequent notices published in the Federal Register, EPA
intends to issue the draft initial list of chemicals resulting from the
implementation of this approach, and to describe the other aspects of
the EDSP, including the procedures it will use to require the testing
and the timeframe for the initial screening. EPA intends to provide
time for review and comment on the draft initial list prior to the
Agency's imposition of actual screening of the initial chemicals.
B. What is the Agency's Authority for Taking this Action?
Section 408(p) of FFDCA requires EPA ``to develop a screening
program to determine whether certain substances may have an effect in
humans that is similar to an effect produced by a naturally occurring
estrogen, or such other endocrine effect as [EPA] may designate.''
(FFDCA 21 U.S.C. 346a(p)). The statute generally requires EPA to
``provide for the testing of all pesticide chemicals.'' (FFDCA 21
U.S.C. 346a(p)(3)). However, EPA is authorized to exempt a chemical, by
order upon a determination that ``the substance is anticipated not to
produce any effect in humans similar to an effect produced by a
naturally occurring estrogen.'' (FFDCA 21 U.S.C. 346a(p)(4)).
``Pesticide chemical'' is defined as ``any substance that is a
pesticide within the meaning of the Federal Insecticide, Fungicide, and
Rodenticide Act, including all active and inert ingredients of such
pesticide.'' (FFDCA section 201(q)(1) (21 U.S.C. 231(q)(1))).
III. Background
A. EPA's Endocrine Disruptor Screening Program (EDSP)
EPA initially set forth the EDSP in the August 11,1998 Federal
Register notice (63 FR 42852) (FRL-6021-3) and solicited public comment
on the program in the December 28, 1998 Federal Register notice. The
program set forth in these notices was based on the recommendations of
the Endocrine Disruptor Screening and Testing Advisory Committee
(EDSTAC), which was chartered under the Federal Advisory Committee Act
(FACA), 5 U.S.C. App.2, section 9(c). The EDSTAC was comprised of
members representing the commercial chemical and pesticides industries,
Federal and State agencies, worker protection and labor organizations,
environmental and public health groups, and research scientists. EPA
charged EDSTAC to advise the Agency regarding:
1. Methods for chemical selection and setting priorities for screening.
2. A set of available, validated screening assays for early
application.
3. Ways to identify new and existing screening assays and
mechanisms for their validation.
4. Processes and criteria for deciding when additional tests beyond
screening would be needed and how to validate such tests.
5. Processes for communicating to the public about EDSTAC's
agreements, recommendations, and information developed during priority
setting, screening, and testing.
In response to this charge, EDSTAC recommended that EPA's program
address both potential human and ecological effects; examine effects on
estrogen, androgen, and thyroid hormone-related processes; and include
non-pesticide chemicals, contaminants, and mixtures in addition to
pesticides (Ref. 1). Based on these recommendations, EPA developed a
tiered approach for their program (referred to as the EDSP). The core
elements of EDSP are: Priority setting, Tier 1 screening, and Tier 2
testing. Tier 1 is envisioned as a battery of screening assays
(referred to as ``screening'') that would identify substances that have
the potential to interact with the estrogen, androgen, or thyroid
hormone systems. The purpose of Tier 2 testing (referred to as
``testing'') is to determine whether the substance could, in fact,
cause endocrine effects mediated by estrogen-, androgen-, or thyroid-
related processes, and to establish the relationship between doses of
an endocrine-active substance administered in the test and any effects
observed.
In addition, based on EDSTAC's recommendations, EPA proposed in the
December 28, 1998 Federal Register notice an approach to establish the
priority of chemicals for Tier 1 screening. The approach reflected the
concern that the quantity and quality of exposure and effects
information would be uneven across chemicals. EPA wanted to ensure that
data-rich and data-poor chemicals were not directly compared in the
priority-setting process because data-poor chemicals might tend to be
ranked low under such an approach. Thus, EPA proposed to develop
categories of information relating to the production, release,
exposure, and hazard of chemicals and to group the chemicals according
to the available data. This approach was termed a ``compartment-based
approach.'' The compartment-based approach was based on exposure- and
effects-related compartments even though it was recognized that effects
or toxicity data relevant to endocrine disruption would be extremely
limited for the majority of chemicals. To partly compensate for the
lack of relevant toxicity data, EPA proposed to conduct a HTPS study
addressing all chemicals with a production volume in excess of 10,000
pounds per year, excluding pesticide active ingredients. EPA developed
the Endocrine Disruptor Priority Setting Database (EDPSD) to assist in
assigning chemicals to compartments and setting priorities. More
information on the EDPSD is available at
http://www.epa.gov/scipoly/oscpendo/prioritysetting.
EPA currently is implementing its EDSP in three major parts. The
Agency is:
1. Developing and validating the screening level assays, selecting
the appropriate screening assays for the screening battery based on the
validation data, and developing and validating Tier 2 tests.
2. Finalizing the priority-setting chemical selection approach to
be applied to select an initial list of chemicals to go through screening.
3. Developing the procedures the Agency will use to require screening.
This notice deals only with finalizing the priority-setting
chemical selection approach to be applied to select an initial list of
chemicals to go through screening. As indicated, EPA intends to address
the other aspects of the EDSP in subsequent notices published in the
Federal Register.
B. Science Advisory Board/FIFRA Scientific Advisory Panel Review
EPA asked its Science Advisory Board (SAB) and the FIFRA Scientific
Advisory Panel (SAP), independent scientific review committees of non-
EPA scientists, to review jointly the Agency's proposed EDSP. The
Agency's charge to the SAB/SAP Subcommittee was broad and complex
consisting of 18 questions in four broad areas:
1. Scope of the program.
2. Priority setting.
3. HTPS.
4. Screening and testing.
The SAB/SAP Subcommittee met on March 30-April 1, 1999. Its report
was published the following July (Ref. 2). In general, the SAB/SAP
Subcommittee
[[Page 56452]]
agreed with the program that EPA had developed for conducting endocrine
disruptor screening. The following are recommendations from the SAB/SAP
Subcommittee with respect to the scope of the program and setting of
priorities for screening.
In the December 28, 1998 Federal Register notice, EPA explained
that it was considering 87,000 substances as potential candidates for
testing under EDSP. The SAP/SAB Subcommittee expressed some
reservations about the ambitious scope of the universe of chemicals
that EPA envisioned as potentially being included in the program. The
SAP/SAB Subcommittee felt that developing massive amounts of screening
data on a large universe of chemicals would not necessarily expedite
the development of the appropriate underpinning that the Agency needs
before it proceeds with the screening of the large universe of
chemicals that it anticipates will be included in EDSP. The SAB/SAP
Subcommittee also expressed concern that it did not see a provision for
mid-course correction or optimization of the program. Thus, the SAB/SAP
Subcommittee recommended that the EPA start by applying EDSP to 50 to
100 compounds and submit the data to independent review to consider
eliminating methods that do not work, and also evaluate how to optimize
the program.
The SAB/SAP Subcommittee also recommended against including
mixtures in the initial set of chemicals to be tested. The SAB/SAP
Subcommittee thought that the question of testing mixtures should be
deferred until single-compound methods had been successfully demonstrated.
The SAB/SAP Subcommittee also found that the compartment-based
approach to priority setting was supportable when ranking is based on
both effect and exposure data. It suggested that the greatest weight
should be given to chemicals for which there are data that indicate
actual human or environmental exposure and effects. Lower weight should
be given to chemicals for which the data are indicative of probable
exposure (in food or drinking water) or probable effects (from animal
studies). The lowest weight and priority should be given to chemicals
for which the data are indicative of possible exposure (based on
release or production volume) or possible effects (from in vitro or
HTPS assays). The SAB/SAP Subcommittee expressed concern that the lack
of effects data on the universe of chemicals currently in commercial
use would lead to a database that only identifies known problem
chemicals that are already well studied. To overcome this obstacle, the
SAB/SAP Subcommittee encouraged the development of new techniques
including QSAR and molecular modeling to help identify the bio-
available, potentially active compounds for further testing in EDSP.
The SAB/SAP Subcommittee supported the concept of nominations by
citizens, but recommended that the process needed further definition.
Finally, the SAB/SAP Subcommittee agreed with EPA's assessment that
the HTPS system, which EPA subjected to a demonstration project, was
not ready for use but that the concept was still valuable. The SAB/SAP
Subcommittee encouraged EPA to be open to other types of assays for
HTPS including receptor binding, gene chip and microarrays, and
computer modeling. The SAB/SAP Subcommittee also gave some guidance
regarding further development and employment of HTPS, including the
need for standardization and validation of any system to be used in
priority setting.
C. Public Comments on Priority Setting
In addition to comments provided by the SAB/SAP Subcommittee,
comments were also provided by the public on priority setting in
response to EPA's EDSP Proposed Statement of Policy notice published in
the December 28, 1998 Federal Register, at two public meetings held on
the Endocrine Disruptor Priority Setting Database (EDPSD), and from the
request for comment on the proposed approach in the December 30, 2002
Federal Register notice. The January 20, 1999 meeting was published in
the Federal Register of December 28, 1998 (63 FR 71568) (FRL-6052-8)
and the June 5-6, 2000 meeting was published in the Federal Register of
May 19, 2000 (65 FR 31900) (FRL-6559-9). All of these comments were
helpful to the Agency in developing the approach presented in this
notice for selecting the initial list of chemicals to be screened in EDSP.
IV. Summary of Comments Received on EPA's Proposed Approach to
Selecting the Initial Set of Chemicals
After reviewing all of the comments received, EPA has decided to
make some changes to the proposed approach. The priority-setting issues
raised in the most recent comments on the proposed approach are
addressed in the Comment Response Document for Endocrine Disruptor
Chemical Selection/Priority Setting (Ref. 3), which can be found in the
public docket. This unit addresses the major comments that caused EPA
to revise its proposed approach.
A. Use of Effects Data for Chemical Selection
In the proposed chemical selection approach in the December 30,
2002 Federal Register notice, EPA stated that, prior to publishing the
draft initial list of chemicals for screening, the Agency intended to
review the available effects information for those candidate chemicals
identified using the exposure-based approach, in order to identify any
chemical for which the effects information either clearly indicates an
endocrine-mediated effect/perturbation or clearly indicates low
potential to cause endocrine disruption. Such chemicals would then be
excluded from the initial list. Most commenters urged EPA to utilize
existing effects data to the greatest extent that is scientifically
justifiable, and emphasized that an exposure-based approach should only
be used, if at all, for the initial list.
Following review of the comments and further evaluation of the
proposed approach, EPA has decided for the initial list to limit its
review of effects data and primarily select chemical candidates based
on exposure. With two exceptions where EPA believes that it has
sufficient information of an appropriate quality, EPA generally
believes that it lacks sufficient information and experience to
determine whether a chemical should be designated as a ``potential
endocrine disruptor.'' As a general matter, EPA will therefore not
exclude chemicals from the initial list based on a finding of the
chemical's endocrine disruption potential.
Generally, with respect to using additional existing effects data,
given the current state of scientific understanding of endocrine system
effects and the types of testing currently available for most pesticide
chemicals, EPA has decided for this initial list that it would be
impractical to establish criteria for judging whether a chemical should
be designated as a ``potential endocrine disruptor'' and removed from
the initial group for screening. Although a relatively broad range of
toxicity data are available for pesticide active ingredients regulated
under FIFRA, in most cases EPA has not yet established how the
available data might be confidently used to predict the endocrine
disruption potentials of these chemicals. This may be due to the non-
specific nature of an effect or effects observed, questions related to
whether the mode of action in producing a given effect or effects is or
are endocrine system-mediated in whole or in part, or the lack of
relevant data to make a judgement altogether. When the draft
[[Page 56453]]
initial list is published, any company subject to a testing requirement
may request, during the comment period, a waiver (supported by
appropriate data) on the grounds that the chemical is an endocrine
disruptor and that EDSP screening is unnecessary.
EPA has identified two exceptions. First, chemicals that are being
used by EPA as ``positive controls'' to validate the screening assays
will be excluded from its initial list. Inclusion of these chemicals in
the initial list would be to require companies to generate duplicative
data unnecessarily. These chemicals were selected because they were
expected to elicit positive responses in the assays proposed to
identify estrogen-, androgen-, and/or thyroid-system disruptors.
Second, EPA does not plan to select substances it anticipates as having
low potential to cause endocrine disruption (e.g., certain FIFRA List 4
inerts, most polymers with number average molecular weight greater than
1,000 daltons, strong mineral acids, and strong mineral bases), and
considers these substances to be a low priority for early screening
under the EDSP. High molecular weight substances are unlikely to reach
molecular receptors or other target tissue; highly reactive chemicals
will destroy tissue at the point of entry leading to toxicity other
than through the endocrine system.
B. Appropriateness of the Proposed Data Sources
Many comments received on the appropriateness of the data sources
identified in the December 30, 2002 Federal Register notice questioned
the relevance and quality of the proposed data sources. Specific issues
raised in these comments included: The inability to analyze and fully
understand the data in some data sources because the raw data
underlying the summary data are not accessible; several databases are
very dated and may not be relevant to potential exposures today;
several databases may not be relevant to or extrapolated to the U.S.
population as a whole; some databases/data sources used biased sampling
rather than random or probability design; although the data do indicate
exposure, they do not fully characterize exposure in terms of time,
duration, and level of exposure; and that the EPA review of the
databases should comply with the Agency's policies provided in its
December 2002 information quality guidelines (Ref. 4).
In accordance with EPA's information quality guidelines, EPA has
reviewed the data sources described in this chemical selection approach
for the initial round of screening in the EDSP. Following review of the
proposed databases (Ref. 5), EPA made the determination to exclude the
Heidelberg College's Monitoring Data at this time because it has
limited public availability, at best, and because comparable data are
available from two other sources that are publicly available. For the
remainder of the data sources, EPA believes that the data sources are
appropriate and relevant for the intended application and that the
quality and transparency of the information is sufficient for the
intended use. The most current versions of the databases will be used
and evaluated when developing the initial list.
EPA acknowledges that many of the proposed data sources may be
limited in their usefulness for certain applications but believes,
nonetheless, that the data sources are of appropriate quality for their
intended use and purpose for a number of reasons. First, the most
current versions of the databases will be used and evaluated when
developing the initial list. In addition, the limitations of an
individual data set can be overcome, to some extent, by consideration
of multiple sets of data and multiple databases. EPA thinks that, when
considered collectively, the databases discussed in Units VI. and VII.
are not as vulnerable to criticism as a particular individual data set.
Finally, EPA generally determines the quality of data sources based on
the Agency's intended use of the data. For the initial list, EPA will
select 50 to 100 pesticide active ingredients and HPV chemicals used as
pesticide inerts to which the public may be more highly exposed. EPA
will use these data sources to help select just the first round of
chemicals to be screened and does not intend to use these sources to
create a definitive, scientifically rigorous list of chemicals with a
high potential for exposure, nor to develop quantitative exposure
estimates in this analysis. The chemicals identified under this
approach belong to the group of chemicals that are required to be
tested under FFDCA section 408(p)(3)(A)--pesticide chemicals. Because
Congress specifically required that these chemicals be tested, the
impact of EPA's assessments in this case is quite limited--merely
determining the timing of the testing, rather than whether the testing
is to be conducted. Consequently, EPA believes the proposed data
sources are of sufficient quality for their intended use.
C. Synchronization of the Endocrine Disruptor Screening Program's
Components
In response to comments and consistent with its intent to have the
initial list drafted and finalized when the screening assays are
available for testing, EPA plans on publishing the draft initial
chemical list well in advance of when an appropriate screening test
battery is ready for use. This interval is intended to allow adequate
time for EPA to solicit and consider public comments on the draft list
without delaying the initial round of testing.
V. EPA's Approach to Selecting the Initial Set of Chemicals to Undergo
Screening
On the basis of EPA's experience to date and comments received, EPA
is setting forth its approach for selecting the first group of
chemicals to be screened in the EDSP. Based on the SAB/SAP Subcommittee
recommendations and public comments, EPA will select and screen
approximately 50 to 100 chemicals drawn from pesticide active
ingredients and pesticide inerts with relatively large overall
production volumes considering both pesticide and non-pesticide uses
(HPV/Inert chemicals) to help the Agency further refine the EDSP. EPA
will list the chemicals alphabetically, or numerically by CAS number,
to avoid the appearance of a specific ranking of the chemicals selected
for initial screening.
As recommended by the SAP/SAB Subcommittee, the Agency intends to
conduct a review of the data received from the screening to evaluate
whether the program could be improved or optimized, and if so, how. In
addition to Agency scientists, the review of the initial list screening
results will be evaluated by an expert panel such as one under the SAP/
SAB Subcommittee. Evaluation of the screening results for the initial
50 to 100 chemicals will add substantially to our understanding of the
performance of the Tier I test battery. Thus, the evaluation may
identify methodological issues encountered when this larger set of
chemicals are tested by laboratories not involved in the assay
validation effort that may lead to further optimization of the assays
to improve performance. The evaluation may also identify interpretive
issues such as a determination that a specific assay may not be needed
because another assay in the screening battery adequately measures the
same effect. Other information from the review process
[[Page 56454]]
may help identify potential issues or areas for improvement, such as
whether there is sufficient laboratory capacity or problems with
correctly performing the tests, whether there are issues with the
industry's ability to test the identified chemicals, or whether there
are any procedural changes that would improve the overall program.
EPA will use an approach based in part on the compartment-based
priority-setting approach described in the December 28, 1998 Federal
Register notice that provided details about the EDSP and that the SAB/
SAP Subcommittee commented on in 1999. As explained in Unit IV.A., the
approach focuses primarily on exposure-related factors rather than
using a combination of exposure- and effects-related factors. Although
EPA will use many of the exposure data sets previously identified for
use in the EDPSD in this approach, EPA anticipates not directly using
the EDPSD itself at this time in light of the narrower scope and focus
of this initial list. EPA anticipates that it will modify its chemical
selection approach for subsequent screening lists based on experience
gained from the results of testing chemicals on the initial list, the
feasibility of incorporating different categories of chemicals (e.g.,
non-pesticide substances), and the availability of new priority-setting
tools (e.g., HTPS and QSAR models).
EPA will use several groups of data to identify pesticide active
ingredients to include on the initial list of chemicals for screening.
These data focus on human exposure by different pathways:
1. As a consequence of consuming food containing pesticide residues.
2. As a consequence of consuming drinking water containing
pesticide residues.
3. As a consequence of residential use of pesticide products.
4. Through occupational contact with pesticide-treated surfaces.
For each of the four pathways, EPA will use the most current data
available from each data source to identify active ingredients. To
ensure, to the extent possible, that all pesticide chemicals are
addressed using this approach based on comparable exposure potential,
EPA is most interested in identifying and selecting data sources which
provide occurrence/usage data on a broad range of pesticide chemicals
and across a wide geographical scope. Although the final selected data
sources do have limitations, EPA is confident that these data sources
can be used to identify pesticide active ingredients likely to be among
those having either potentially widespread or higher levels of human
exposure than would be expected for other active ingredients. EPA does
not plan to use these data sources to create a definitive,
scientifically rigorous list of pesticide chemicals to which the public
is the most highly exposed. Nor is EPA proposing to use these databases
to create quantitative exposure estimates in this analysis.
EPA is giving higher priority to chemicals likely to have human
exposure via multiple pathways, with the highest priority being given
to substances having potential exposure through all four pathways,
followed by those having potential exposure via three pathways, etc.
for inclusion on the list for initial screening. Details on EPA's
approach for selecting pesticide active ingredients are presented in
Unit VI.
EPA will use a similar approach to identify HPV/Inert chemicals to
be included in the initial list for screening in the screening battery.
However, EPA generally has more extensive information available to
assess potential exposure to pesticide active ingredients via food,
water, occupational, and residential exposure pathways than is
available to assess exposure to HPV/Inert chemicals. In addition, EPA
generally has more extensive information available on usage (including
both agricultural and residential) of active ingredients than is
available for HPV/Inert chemicals (including both pesticidal and non-
pesticidal uses of those same substances). For these reasons, the
specific pathways and data sources EPA has identified for selecting an
initial set of HPV/Inert chemicals for endocrine disruptor screening
differ somewhat from those for selecting pesticide active ingredients.
For HPV/Inert chemicals, EPA will focus on several indicators of
the potential for human exposure, including production volume, specific
pathways of exposure, and presence in human tissues. First, EPA will
use the most current databases available to identify chemicals that are
both pesticide inerts and HPV (defined as chemicals that are
manufactured or imported into the United States for all uses in amounts
equal to or greater than one million pounds per year) chemicals. This
first step will focus initial screening of pesticide inerts on
chemicals with higher potential human exposure on the basis of large
amounts produced or imported each year in the United States. Second,
EPA will review the most current existing data available for its use to
identify HPV/Inert chemicals that have been found to be present in:
Human biological samples, ecological tissues that have human food uses
(i.e., fish tissues), drinking water, and/or indoor air. Using this
approach, an HPV/Inert chemical appearing in monitoring data from one
or more of these media, would be a higher priority for testing than an
HPV/Inert chemical that does not appear in monitoring data from any of
the media. Details on EPA's priority-setting approach for selecting
HPV/Inert chemicals are presented in Unit VII.
While EPA's general focus in this approach is on pesticide active
ingredients and HPV/Inert chemicals with relatively greater potential
human exposure, this does not necessarily mean that the list developed
using this approach will not contain substances which also have
potentially high levels of environmental exposure to ecological
receptors. As explained in Units VI. and VII., EPA believes that the
approach to select an initial list of pesticide active ingredients and
HPV/Inert chemicals for screening, while focused on human exposure,
will also capture many chemicals to which other organisms have
potential for widespread environmental exposures. In addition, because
the screening battery will likely include assays involving different
species (e.g., amphibians and fish) whose results are relevant to both
humans and wildlife, EPA will capture information relevant to
ecological protection.
The approach is consistent with the proposed approach and many of
the comments received on the December 30, 2002 Federal Register notice.
For its approach EPA is:
1. Focusing chemical selection for this initial list on the subset
of chemicals for which testing is required (i.e., pesticide chemicals).
2. Using exposure data as the primary basis for chemical selection
rather than using HTPS, QSARs, or other hazard data in conjunction with
exposure data.
3. Excluding substances for the initial list anticipated to have
low potential to cause endocrine disruption (e.g., certain FIFRA List 4
inerts, most polymers with number average molecular weight greater than
1,000 daltons, strong mineral acids, and strong mineral bases).
4. Deferring consideration of nominations from the public.
5. Not including mixtures for the initial list.
6. Excluding chemicals that are no longer produced or used in the
United States.
7. Excluding ``positive control'' chemicals used for the validation
of the screening assays.
[[Page 56455]]
EPA will issue an additional Federal Register notice setting forth
the draft initial list of chemicals it proposes for screening. EPA
expects that low-priority designations will initially be made on a
case-by-case basis. Therefore, the Federal Register notice in which EPA
will publish for public comment the draft initial list of chemicals for
screening will clearly identify any chemical, which was identified
having priority for testing through the application of the exposure-
based criteria, but was excluded because it is considered to be a low
priority for one of the reasons listed in this unit. That Federal
Register notice will explain the rationale underlying any decisions
made for selection of chemicals in the draft initial list. The draft
initial list of chemicals is expected to be published to allow
sufficient time for review and comment prior to actual testing. After
considering comment on the draft list of chemicals, EPA will issue the
initial list of chemicals for which screening will be required.
VI. Approach for Selecting Pesticide Active Ingredients
As proposed, EPA will use several criteria to identify pesticide
active ingredients for the initial round of the screening. These
criteria would focus on human exposure by different pathways: As a
consequence of consuming food containing pesticide residues, drinking
water containing pesticide residues, and residential use of pesticide
products; and through occupational contact with pesticide-treated
surfaces. For each of the four pathways, EPA will review the most
current existing databases available to identify active ingredients
generally expected to be among those having either widespread or high
levels of human exposure.
While EPA's general focus is on pesticide active ingredients with
relatively greater potential human exposure, this focus does not
necessarily mean that the list of active ingredients will not contain
substances which also have potentially high levels of environmental
exposure to ecological receptors. Many of the pesticide active
ingredients having greater potential for human exposure will also have
greater potential for exposure to wildlife. For example, one pathway of
human exposure, drinking water, is also a pathway through which aquatic
life and many terrestrial species are exposed. Most of the databases
that EPA will consider in evaluating active ingredients for exposure
through drinking water contain monitoring data collected on raw surface
water (i.e., before the water enters a public water system). Thus,
these monitoring data show the levels of pesticide residues that fish,
amphibians, and other aquatic species will encounter. Similarly, when
data show higher and more widely distributed levels of pesticide
residues in food, EPA thinks that such residues generally tend to
reflect greater usage and/or persistence of the pesticide on crops and
thus, greater environmental loads. Accordingly, EPA believes that the
approach to evaluate pesticide active ingredients, while focused on
human exposure, will also capture many active ingredients with
widespread environmental exposures.
A. Food Pathway
Every person eats food and a significant portion of food contains
some amount of pesticide residues, although usually at very low levels.
Therefore, pesticide residues in food have the potential to cause
widespread human exposure. Pesticides have different use patterns and
have different physical and chemical properties that affect how they
move in the environment and how quickly they break down. As a result,
there are often significant differences among pesticides in the
proportion of food containing residues and in the levels of such
residues. People also consume different amounts of different foods. All
of these factors mean that people ingest greater quantities of some
pesticide active ingredients than others.
To evaluate the interplay of these different variables, EPA will
identify the pesticide active ingredients which are found most
frequently as residues on the top 20 foods that people consume. First,
EPA will use the most recent Continuing Survey of Food Intake by
Individuals (CSFII) to determine the mean amount of each raw
agricultural commodity consumed in the general population. The CSFII is
a database derived from a survey performed by the U.S. Department of
Agriculture (USDA) in 1994-1996 and supplemented with additional survey
responses collected in 1998. USDA collected food diary information from
over 20,000 individuals who were interviewed on 2 non-consecutive days,
generally spaced 3 to 10 days apart. After appropriate statistical
weighting, the survey, in the aggregate, is representative of the U.S.
population in terms of age, gender, major ethnic groups, and socio-
economic status. Moreover, sampling was representative of different
days of the week, seasons of the year, and parts of the country.
Extensive quality control procedures assured that the data collected in
the survey were accurate and reliable. More information on USDA's food
surveys and the CSFII (1994-1996) is available at
http://www.barc.usda.gov/bhnrc/foodsurvey.
Using standard, scientifically peer-reviewed recipes, EPA has
converted the reported food consumption for each CSFII survey
respondent into the constituent raw agricultural commodities. For
example, if a person reported eating six ounces of beef stew, EPA
estimated the amount of beef, carrot, potato, and each other raw
agricultural commodity used in making that quantity of beef stew. EPA
made similar conversions for each of the different finished foods
reported in the CSFII--from apple pie to yogurt. EPA then estimated the
total amount of each of the various raw agricultural commodities eaten
over the course of the day, for example summing the amount of apple
consumed from drinking cider and eating apple sauce. The results of
these recipe translations appears in the revised Food Commodity Intake
Database (FCID) (Ref. 6). Information on the FCID can be reviewed at
http://www.barc.usda.gov/bhnrc/foodsurvey/fcid.html.
This individual food consumption database provides the basis for
identifying the top 20 foods consumed, in terms of mean daily consumption
for the general population. Table 1 of this unit presents these raw
agricultural commodities.
Table 1.--Top Twenty Foods
------------------------------------------------------------------------
------------------------------------------------------------------------
Foods accounting for the largest quantity of food intake by individuals
(arranged alphabetically)
------------------------------------------------------------------------
1......................................... Apple
2......................................... Banana
3......................................... Beef
4......................................... Carrot
5......................................... Chicken
6......................................... Corn, field
7......................................... Corn, sweet
8......................................... Egg
9......................................... Grape
10........................................ Lettuce
11........................................ Milk
12........................................ Onion
13........................................ Orange
14........................................ Pork
15........................................ Potato
16........................................ Rice
17........................................ Soybean, oil
18........................................ Sugar
19........................................ Tomato
20........................................ Wheat
------------------------------------------------------------------------
Having identified the top 20 raw agricultural foods, EPA will
characterize the pesticide residue levels on these foods using
information collected by two Federal Agency monitoring programs, the
USDA Pesticide Data Program (PDP) and the Surveillance
[[Page 56456]]
Monitoring Program conducted by FDA's Center for Food Safety and
Applied Nutrition. PDP has been collecting pesticide residue data since
1991. PDP is designed to provide a nationally representative database
on the distribution of pesticide residues in food as close as possible
to the actual time of consumption as practical. Using analytical
methods that have been standardized and validated, and following strict
quality control procedures, USDA has focused on foods highly consumed
by children throughout the year. Over the years of operation, PDP has
collected data on over 290 different pesticides and 50 different
commodities. Additional information can be found at http://www.ams.usda.gov/
science/pdp/index.htm. The FDA Surveillance Monitoring
Program is designed primarily for enforcement of pesticide tolerances
on imported foods and domestic foods shipped in interstate commerce.
Domestic samples are collected as close as possible to the point that
the food enters the distribution system. FDA samples imported food at
the port of entry into the United States. Additional information on the
FDA program appears at http://www.cfsan.fda.gov/~dms/pesrpts.html.
Because of the differences in how samples are collected and
handled, EPA will rely on the PDP database when both sources cover the
same pesticides and commodities. The FDA Surveillance Monitoring
Program data covers different pesticides and commodities in different
years from the PDP monitoring (e.g., in 1999, FDA used analytical
methods capable of detecting 366 different active ingredients).
Therefore, in making its weight-of-the-evidence judgement, EPA will
consider the FDA information as a supplement to the information from
the PDP database.
EPA will review the two residue monitoring databases to identify
the pesticide active ingredients which appear on the largest proportion
of the samples, focusing on the 20 foods which make up the largest part
of the U.S. diet. EPA will then review all of the information to make a
judgment about whether the pesticide is likely to have relatively more
widespread or higher levels of human exposure by the food pathway than
other pesticides. This judgement involves consideration of such factors
as the number of foods on which the residue is detected, the quantity
of the diet represented by the food, and the overall number of
detections and the frequency of detection.
EPA recognizes that this approach would be more likely to give
higher priority to the pesticides which are the subject of routine
monitoring in either PDP or FDA's Surveillance Monitoring Program. Both
programs rely primarily on ``multi-residue methods'' that are capable
of detecting many different chemical substances using a single
analytical procedure. Active ingredients which require specialized
analytical methodology may not be looked for and thus would be unlikely
to be included for consideration in the food pathway. This limitation
particularly applies to newer pesticide active ingredients.
Notwithstanding these limitations, EPA believes the approach described
is a practicable approach for identifying pesticide active ingredients
with widespread or high levels of exposure.
B. Water Pathway
Portions of the general population may be exposed to pesticide
residues in sources of drinking water. Although monitoring data
indicate that most pesticide active ingredients are rarely detected,
analytical surveys in virtually every region of the country have
detected a number of active ingredients in ground and surface water
used as sources of drinking water. Monitoring also indicates that, even
when found in water, residue levels vary significantly both seasonally
and regionally for a single pesticide, as well as across pesticides.
Particularly for surface water, residues tend to occur in pulses that
can last days to weeks to months, depending on the type of water body
and the pesticide. Almost every person consumes some water every day,
either in prepared foods or beverages (e.g., coffee, tea, or
reconstituted juice) or simply by drinking water; therefore, water may
be a significant source of exposure.
To assess relative exposure to different pesticides in water, EPA
will examine a number of different databases that contain the results
of programs to monitor surface and ground water for the presence of
pesticide residues. The different media covered by these databases
include, finished drinking water, ambient water, finished ground water,
fish tissue, and sediment, all of which reflect the presence of a
substance in water sources. The presence of a substance in these media
establishes the potential for exposure via drinking water. All sources
of drinking water exposure will be considered of equal priority.
As with the residue data for the food pathway, EPA will compile the
information from the various databases concerning the detection of
different pesticides in water. After compiling the information, EPA
will examine the results to identify pesticides for which there appears
to be greater potential for widespread human exposure, based on factors
such as the number of samples and the geographic distribution of the
detections. The presence of a single or only a few detections of a
pesticide in a limited geographic area typically would not be a
sufficient basis for concluding that the pesticide should be identified
as potentially having either widespread or high levels of exposure by
the water pathway.
These databases, which contain data collected by Federal and State
agencies, academicians, pesticide companies, and others, are summarized
in this unit:
1. EPA Pesticides in Ground Water Database. The Pesticides in
Ground Water Database (PGWDB) was created to provide a more complete
picture of ground water monitoring for pesticides in the United States.
It is a collection of ground water monitoring studies conducted by
Federal, State, and local governments; the pesticide industry; and
private institutions between 1971-1991. The PGWDB compiles, in tabular
format, data from monitoring of untreated ground water and contains
data only from studies in which pesticides were included as analytes.
Some data limitations include: Age of the data; differences in the
design of studies; lack of historical pesticide use or hydrological
information; and lack of information on well use, sampling practices,
and laboratory procedures. Further details can be found in EPA
Pesticides in Ground Water Database, A Compilation of Monitoring
Studies: 1971-1991 National Summary (Ref. 7).
2. EPA Chemical-Specific Monitoring Data. Pesticide registrants
have conducted and submitted to the Agency targeted surface water and
ground water monitoring studies for approximately 50 pesticide active
ingredients. The Agency decides whether to require monitoring of
untreated or ambient surface or ground water for a pesticide based on
the environmental fate characteristics (persistence and mobility) of
the pesticide; the current or proposed use patterns for the pesticide;
and other information that would indicate potentially significant
levels of the pesticide that could be present in water. The design of
monitoring studies takes into consideration application rate, crops,
and the location of potentially more vulnerable use sites. These
studies are performed under Good Laboratory Practice regulations, and
contain internal quality assurance procedures. When submitted, the
monitoring data undergo primary and secondary review
[[Page 56457]]
by Agency scientists. In implementing its approach for selecting the
initial list of chemicals for screening, EPA will review these
chemical-specific monitoring data sources to determine if they contain
information for pesticide active ingredients without data from other
water monitoring data sources.
3. United States Geological Survey/EPA Reservoir Monitoring Study.
The United States Geological Survey (USGS)/EPA Reservoir Monitoring
Study was a pilot monitoring program initiated by the USGS and EPA to
provide information on pesticide concentrations in drinking water and
to assist in the implementation of FQPA. Drinking-water utilities that
withdrew water from reservoirs were sampled in 1999 and 2000. Water
samples were collected from raw water (at the intake point) and from
finished drinking water (at the tap prior to entering the distribution
system). At some sites, samples were also collected at the reservoir
outflow. Sampling frequencies were designed to measure long-term mean
and short-term peak concentrations of pesticides in drinking water. The
analytical methods used for analyzing the pesticides in the water
samples included 178 different pesticides and degradation products.
Additional information on the USGS/EPA Reservoir Monitoring Study can
be found in Pesticides in Select Water Supply Reservoirs and Finished
Drinking Water, 1990-2000: Summary of Results from a Pilot Monitoring
Program (Ref. 8).
4. Environmental Monitoring and Assessment Program. Environmental
Monitoring and Assessment Program (EMAP) is an EPA research initiative
designed to support the development of tools necessary to monitor and
assess the status and trends of national ecological resources. Research
is conducted on various ecosystems (e.g., estuaries, forests,
rangelands, and lakes). Sediment samples were collected in 18 states at
various times between 1990 and 1998. This data source provides
information about the contaminants present in sediment/soil that humans
and wildlife may contact. EMAP includes relevant data for over 170
chemicals and three separate data sets for estuary sediments. In
addition, six additional estuary data sets are now available that will
also be considered. Extensive field and laboratory quality assurance/
quality control (QA/QC) procedures were performed during the collection
and analysis of the samples. Further details can be found at
http://www.epa.gov/emap.
5. National Sediment Inventory. The Water Resources Development Act
(WRDA) of 1992 directed EPA, in consultation with the National Oceanic
and Atmospheric Administration (NOAA) and the U.S. Army Corps of
Engineers (USACE), to conduct a national survey of data regarding the
quality of sediments in the United States. To comply with the WRDA
mandate, EPA's Office of Science and Technology initiated the National
Sediment Inventory (NSI). The NSI is a database that documents the
composition of sediment in rivers, lakes, oceans, and estuaries. The
NSI tissue residues studies (primarily fish) help assess sediment
quality and can be used to assess potential exposure of humans to these
chemicals through the consumption of fish. Also, sediment chemistry
data are evaluated for theoretical bioaccumulation potential. The NSI
includes data collected by a variety of Federal, State, regional,
local, and other monitoring programs from 1980 through 1999. It
includes over 4.6 million analytical observations for over 50,000
monitoring stations across the country of sediment chemistry, tissue
residues, and sediment toxicity data. NSI's minimum data requirements
include monitoring program identification, sampling date, latitude and
longitude coordinates, and measured units. EPA retains additional data
such as QA/QC information, if available, but did not require that
information for a data set to be included in NSI. Additional
limitations of the compiled data include the mixture of data sets
derived using different sampling strategies, incomplete sampling
coverage, and the age and quality of the data. Because the data
analyzed in the NSI report were collected over a relatively long period
of time, conditions may have changed since the sediment was sampled.
Further details on the NSI database and the National Sediment Quality
Survey, which the NSI was developed to support, can be found at
http://www.epa.gov/waterscience/cs/nsidbase.html.
6. National Drinking Water Chemical Occurrence Database. EPA
developed the National Drinking Water Chemical Occurrence Database
(NCOD) to satisfy the statutory requirements set forth by Congress in
the 1996 amendments to SDWA to maintain a national drinking water
contaminant occurrence database using occurrence data for both
regulated and unregulated contaminants in public water systems. NCOD
provides a library of water sample analytical data (or ``samples
data'') that EPA is currently using and has used in the past for
analysis, rulemaking, and rule evaluation. The drinking water sample
data, collected at public water systems, are for both regulated and
unregulated contaminants. The data have been extensively checked for
data quality and analyzed for national representativeness.
Currently, NCOD provides links to the unregulated contaminant
monitoring data (UCMR), which are being collected and added to NCOD, as
well as to static data sets that have been used in published regulatory
analyses. These latter (static) data sets have been extensively
quality-checked, and their corresponding reports provide full
descriptions (meta data) of the data. Further details can be found at
http://www.epa.gov/safewater/data/ncod.html.
7. National Stream Quality Accounting Network Data. The National
Stream Quality Accounting Network (NASQAN), a monitoring and data
collection program conducted by the USGS, is designed to characterize
raw surface water and sediment in large sub-basins of rivers, determine
regional source areas for chemicals, and assess the effects of human
influences on observed concentrations and amounts of chemicals. Since
1995, NASQAN has focused on monitoring the water quality of four of the
nation's largest river systems: The Mississippi, the Columbia, the
Colorado, and the Rio Grande. A network of 40 stations monitors the
concentrations of a broad range of chemicals including pesticides,
major ions, and trace elements. NASQAN contains relevant data for over
70 chemicals. NASQAN samplers collect quality control samples to
evaluate the quality of sampling data. However, the data in NASQAN do
not characterize ambient water quality throughout the United States,
only for four river basins and sub-basins. Further details can be found
at http://water.usgs.gov/nasqan.
EPA will use the most current NASQAN data available. Following a
brief review of current NASQAN data, EPA determined that no sediment
data exists and only surface water data were available for pesticide
active ingredients. NASQAN data may be updated prior to selecting the
initial list of chemicals for screening and it is possible that
sediment data may be made available and used for pesticide active
ingredients for screening.
8. National Water Quality Assessment Program. Congress appropriated
funds in 1986 for the USGS to design and implement a program to address
questions related to status and long-term trends in raw surface and
ground water quality at national, regional, and local scales. The USGS
began a pilot program in seven project areas to develop and
[[Page 56458]]
refine a plan for the National Water Quality Assessment (NAWQA)
Program. In 1991, the USGS began full implementation of the program.
The NAWQA Program builds upon an existing base of water-quality studies
of the USGS, as well as those of other Federal, State, and local
agencies. The NAWQA Program was designed to study 60 of the Nation's
most important river basins and aquifer systems, which are referred to
as study units. A national map of these study units shows that they are
distributed throughout the Nation and cover a diversity of
hydrogeologic settings. More than two-thirds of the Nation's freshwater
use occurs within the study units and more than two-thirds of the
people served by public water-supply systems live within their
boundaries. The 60 study units have been divided into groups of 20
study units each, and their intensive data collection phases have been
staggered to allow efficient and effective use of resources. The first
20 studies began in 1991, the second group began in 1994, and the third
group began study in 1997. Due to funding constraints, only 14 of the
original first group of 20 study units began a second cycle of study in
the year 2000. The cycle is intended to continue into the future with a
total of 52 study units to provide both short-term information
necessary for today's water-resource management decisions, and the
long-term information needed for policy decisions. Further details can
be found at http://water.usgs.gov/nawqa.
9. USDA Pesticide Data Program Water Data. The Pesticide Data
Program (PDP) was designed by USDA in 1991 to collect data on pesticide
residues consumed in the United States. PDP samples are collected as
close as possible to the time of consumption, and are also designed to
provide better pesticide residue data for the foods most consumed by
children. PDP is a Federal-State partnership with program operations
carried out with the support of 10 States that collectively represent
50% of the U.S. population. Samples are collected using a statistically
reliable, random sampling protocol, and the number of samples collected
is apportioned according to State population or commodity production
figures. PDP has tested over 50 different commodities, including
drinking water, for more than 290 pesticides.
EPA recognizes that most of the monitoring databases just described
report results from samples of ambient or untreated water, rather than
treated drinking water prepared by a drinking water facility for its
customers. To the extent that treatment methodologies (such as
flocculation, softening, filtration, chlorination, sedimentation, etc.)
either remove or transform the pesticide residue in the source water,
residues found in the untreated water may not represent exposure of the
public consuming the finished water. EPA has considered the impacts of
various treatment methodologies on different classes of pesticides
found in untreated water and concluded that while conventional water
treatment processes (such as coagulation/flocculation, sedimentation,
and filtration) can reduce or remove some pesticides, there may be
little or no effect on the removal of other pesticides (Ref. 9). Thus,
the Agency regards the results of monitoring untreated or ambient water
as a plausible and appropriate indicator of potential human exposure.
Other factors affect the interpretation of water monitoring data.
These data sources represent compilations of data to support a variety
of regulatory and surveillance programs. Monitoring is most likely to
detect the presence of pesticide residues in water if it is conducted
in an area where the pesticide has been used, and samples are collected
at a time when residues are likely to occur. Moreover, the analysis
must employ methods sensitive enough to detect any residue. Often,
however, monitoring reports lack sufficient information to evaluate how
well the above conditions were met. Consequently, evaluation of water
monitoring data requires considerable judgment. See the discussion of
considerations affecting the evaluation of water monitoring data in
Estimating the Drinking Water Component of a Dietary Exposure
Assessment (Ref. 10) and the EPA Background Paper for the FIFRA
Scientific Advisory Panel Meeting on Monitoring Strategies for
Pesticides in Surface-Derived Drinking Water (Ref. 11).
The limitations of an individual data set can be overcome, to some
extent, by consideration of multiple sets of data and multiple
databases. EPA thinks that, when considered collectively, the databases
discussed in Unit VI.B. are not as vulnerable to criticism as a single
data set. Generally, all of these databases include studies with high
levels of quality control, and together they provide wide temporal and
spatial coverage for a large number of pesticides. Thus, the Agency
believes the databases in Unit VI.B. would provide a reliable basis for
drawing conclusions about the relative potential of different active
ingredients to leach into ground water or run off into surface water in
different parts of the country.
In light of these considerations, EPA will review the databases
described to identify those active ingredients which appear relatively
more frequently and/or in more geographical areas than other
pesticides. Because the scope of monitoring varies from pesticide to
pesticide, EPA will use a weight-of-the-evidence approach to assess the
frequency and geographic distribution of pesticide residues in water.
EPA's reliance on these databases would necessarily have some
limitations. For example, most monitoring looks only for the ``parent''
compound (i.e., the pesticide active ingredient), rather than for
environmental degradation products or compounds formed by chemical
reactions during the treatment of raw water sources in a drinking water
facility. Further, like food residue monitoring programs, monitoring
efforts rely on multi-residue methods that may not detect certain
compounds or classes of compounds. Notwithstanding these limitations,
EPA believes that the approach described is a practicable approach for
identifying pesticide active ingredients generally expected to be among
those having either widespread or high levels of human exposure.
C. Residential Use Pathway
Human exposure to pesticides may occur as the result of use of
pesticidal products in and around homes, schools, businesses, public
areas, golf courses, and similar sites. Such use patterns, collectively
referred to as ``residential use,'' include: Lawn and garden
treatments, insect repellants, termite and other indoor insect control,
fumigation products, products applied to pets for flea or tick control,
household sanitizers, and disinfectants, and many more.
EPA will use pesticide product labeling information as the primary
indicator of pesticides whose use involves potential human exposure by
this pathway. EPA will review its databases and identify those active
ingredients approved for residential use. Aside from products approved
only for limited exposure uses, such as rodenticides applied in tamper
resistant bait boxes, all currently registered residential use
pesticides will be identified as having higher priority with respect to
the residential use pathway. EPA may also consider the number of
residential uses for which each pesticide active ingredient is approved
in selecting the initial list of chemicals for screening.
The Agency recognizes that registration of a pesticide for
residential use does not necessarily mean that it
[[Page 56459]]
would be widely used or that its use would entail significant levels of
human exposure. EPA, however, generally lacks information to compare
the extent of application of different active ingredients for
residential uses. Moreover, EPA does not have a basis for
distinguishing among various residential use patterns on the basis of
those which consistently have potential for higher levels of human
exposure. Thus, EPA does not regard its basis for selecting priority
chemicals for this pathway as being as effective in setting priorities
among active ingredients as the criteria used for the other pathways.
Nonetheless, residential use pesticides involve potential exposures to
the general population, and the Agency believes it is appropriate to
consider giving priority to some of these products.
D. Occupational Exposure Pathways
Occupational exposure can occur either as a person mixes, loads, or
applies a pesticide product (i.e., during pesticide use), or as a
person, during some other occupational activity, comes in direct,
repeated contact with pesticide residues present on previously treated
surfaces (i.e., post-application exposure). Although numerically
smaller than the populations exposed to pesticides through food,
drinking water, and residential use, individuals receiving occupational
exposures generally experience significantly higher levels of exposure
than the larger groups encounter by the other pathways. Based on
available data and current agricultural practices, the number of
workers exposed through post-application is greater than the number of
workers exposed through mixing, loading, and applying pesticides. As a
result, EPA will focus on post-application exposures.
Many factors affect the post-application exposure of agricultural
workers, most notably the type of work activity and the level of
residue present on pesticide-treated surfaces. As will be discussed in
more detail in this unit, different activities involve differing levels
of contact with pesticide-treated surfaces and therefore can lead to
different levels of exposure. Exposure levels also depend on the amount
of residue available on a treated surface. This, in turn, depends on
the amount of pesticide initially applied, how quickly the material
degrades or is taken up by the plant, and how soon after application
the worker contacts the treated surface. Pesticides show a large range
of variation in application rates, application timing, and
environmental fate characteristics with the result that there are
significant differences in the levels of dislodgeable residues on
treated surfaces encountered by workers.
In identifying active ingredients for priority consideration by
this pathway, EPA will rank pesticides on the basis of their potential
for post-application exposure to agricultural workers. This group
includes farmers and farm workers who reenter pesticide-treated fields
and orchards to care for or harvest the crop. These agriculture
transfer coefficients developed by the Agricultural Reentry Task Force
(ARTF) clearly indicate that certain work activities in particular
crops lead to higher levels of exposure than other post-application
work activities (Ref. 12). For example, harvesting fruit in orchards or
pruning vines in a grape vineyard requires extensive contact with plant
foliage that is likely to contain pesticide residues. When the worker
touches the foliage, a certain amount of the residue transfers to the
worker's skin or clothing. The greater the contact is, the higher the
residue transferred, and the higher the ensuing exposure.
EPA will review the ARTF's transfer coefficient studies to identify
those work activities and crops which have the highest potential for
post-application exposure. The ARTF is a consortium of pesticide
companies that formed a joint venture to develop data for use in EPA
assessments of worker risk. The ARTF conducted a series of carefully
controlled studies that measured the amount of pesticide residue
present on workers' clothing after a specific period of time working in
a crop with known amounts of pesticide residue on the crop foliage. The
ARTF set of data is very extensive, covering over 100 different crops--
essentially all crops, including greenhouses and ornamental crops, in
which workers might come into contact with pesticide-treated leaf
surfaces. The studies permit the calculation of a standardized
``transfer coefficient'' for the crop and activity.\1\ Activities
having higher transfer coefficients should result in higher levels of
worker exposure, all other factors being equal.
---------------------------------------------------------------------------
\1\ The transfer coefficient is calculated by dividing the
amount of residue found on workers, expressed as milligrams (mg), by
the amount of dislodgeable residue found on the crop foliage,
expressed as mg per square centimeter (cm\2\), and dividing this
value by the length of time spent in the activity, expressed in
hours (hr). The resulting coefficient for each activity is expressed
as cm\2\/hr and quantitatively reflects the extent to which the
activity involves contact with pesticide-treated surfaces in a
manner that dislodges the residues present on the surface.
---------------------------------------------------------------------------
EPA will identify those work activities and specific crops and crop
categories (e.g., tree fruit crops) having approximately the dozen
highest transfer coefficients to identify the pesticides having the
highest levels of use on those crops. EPA will then identify specific
crops associated with the highest transfer coefficients to obtain
information from the data sources described in this unit. Specifically,
EPA will estimate the total number of acre treatments for each
pesticide on all of the top crops and then array the pesticides on the
basis of the highest totals.\2\ The Agency will obtain information
about the number of acre-treatments for each pesticide from a variety
of public and private data sources including USDA's National
Agriculture Statistics Service (NASS) and California's Department of
Pesticide Regulation (CDPR).
---------------------------------------------------------------------------
\2\ Acre-treatments are measured as the number of times an acre
of crop may have been treated with a pesticide. For example, if two
acres were each treated one time in a season, that would represent
two acre-treatments. If a single acre were treated two times in a
season, that would also represent two acre-treatments.
---------------------------------------------------------------------------
The USDA's NASS has, for more than 10 years, conducted annual
surveys of pesticide use in a large number of crops, surveying
thousands of agricultural producers in any given year. NASS conducts
their use survey every year for a set of row crops. NASS also surveys
pesticide usage on other crops, alternating every year between a group
of fruit and nut crops and a group of vegetable crops (i.e., selected
fruits/nuts were surveyed in 1997, 1999, 2001; selected vegetables were
surveyed in 1996, 1998, and 2000). NASS surveys States representing a
majority of national production for a crop and reports a number of
statistics for insecticide, fungicide, and herbicide use including:
Percent crop treated, application rate, numbers of applications,
acreage grown. Using these data, EPA can estimate the average acre-
treatments for the pesticides used on crops with the highest transfer
coefficients. More information on NASS pesticide use data can be found
at http://www.pestmanagement.info/nass.
The State of California has reported annually on all agricultural
pesticide usage in the State for almost 10 years. This data collection
effort is managed by CDPR, and includes an extensive array of treatment
information on crops including timing, location, area, and rate. These
data allow EPA to calculate average pounds of pesticides applied for
crops grown in California. In cases where crops with high transfer
coefficients are grown in California, but not reported by NASS, CDPR
data would be extremely useful. For those
[[Page 56460]]
crops reported by both CDPR and NASS, data from both sources would
serve to validate estimates. More information on CDPR pesticide usage
data can be found at http://www.cdpr.ca.gov/docs/pur/purmain.htm.
EPA's third major source of pesticide use information is
AgroTrak\TM\, a product of Doane Marketing Research, Inc. (referred to
here simply as Doane). Doane maintains a proprietary national database
of agricultural pesticide use summarizing data from surveys of
thousands of agricultural producers across a wide range of row and
specialty crops. Doane has conducted an annual survey for more than 15
years, and among the statistics they publish for a given crop/chemical
combination are acres grown, acres treated, and acre-treatments.
Although the database is proprietary, these data represent an important
source of data, and can be compared to NASS and CDPR data to fill data
gaps, or serve as another point of validation. Doane's survey can be
particularly useful because their national survey covers fruits and
vegetables producers every year. More information on Doane can be found
at http://www.doanemr.com/row-specialty-turf/index.html.
Basing its priorities for this pathway on the number of acre-
treatments of crops with worker activities having high transfer
coefficients should identify pesticides that have potential for
relatively higher worker exposure. The combined criteria of crops with
high transfer coefficients and pesticides used on such crops should
identify those active ingredients with potential for high worker
exposures. The use of the additional criterion of total acre-treatments
should identify pesticides with the widest use, and thus the potential
for exposures for the largest number of workers.
The criteria, however, would not account for any of the
characteristics specific to the use of a particular pesticide on a crop
that could decrease or increase the potential for exposure, such as
application rate, application timing, and environmental fate
characteristics. Consequently, the priority listing may not completely
reflect where the highest post-application exposures exist.
Nevertheless, EPA believes that the approach described is a
practicable approach for identifying those pesticide active ingredients
with the potential for either widespread or high levels of exposure to
post-application workers.
E. Integration of Pathway Priorities for Pesticide Active Ingredients
This unit addresses how EPA will integrate the information
developed on priorities through the analysis of the four exposure
pathways discussed Units VI.A. through VI.D. As its first step, the
Agency will apply the criteria for each pathway to produce four lists
of candidate chemicals for potential screening in the endocrine
disruptor screening battery. EPA expects that a number of pesticide
active ingredients will be identified for more than one pathway, and
that some chemicals will appear only on the list for a single pathway.
In choosing which active ingredients it will recommend for screening,
EPA will give higher priority to chemicals that appear on multiple
lists, with the substances appearing on four lists receiving the
highest priority, followed by the group of chemicals appearing on three
lists, followed by chemicals on only two lists. To the extent necessary
to establish priorities within these four groups, EPA will give greater
priority to chemicals which appear on the list for the food pathway
(which generally involves the most widespread exposure of the four
pathways), followed by the list for the occupational pathway (which
generally involves the highest per capita levels of exposure of the
different pathways).
EPA will review the candidate list to exclude the chemicals which
are being used as ``positive controls'' to validate the screening
assays. Also, in making selections for this exposure-based initial
list, EPA does not plan to select substances it anticipates as having
low potential to cause endocrine disruption (e.g., certain FIFRA List 4
inerts, most polymers with number average molecular weight greater than
1,000 daltons, strong mineral acids, and strong mineral bases), and
considers these substances to be a low priority for early screening
under the EDSP. EPA will also exclude any chemicals that are no longer
used or produced in the United States.
VII. Approach for Selecting High Production Volume Pesticide Inerts
EPA will use several sets of criteria for identifying High
Production Volume Pesticide Inerts (HPV/Inerts) that will be given
priority for screening in the screening battery. In general, the Agency
is using an approach for HPV/Inerts that is similar to that used for
pesticide active ingredients. EPA will focus on several indicators of
the potential for human exposure including production volume, specific
pathways of exposure, and presence in human biological samples. While
EPA's general focus is on HPV/Inerts with relatively greater potential
human exposure, this focus does not necessarily mean that the list of
chemicals produced will contain no substances which have potentially
high levels of environmental exposure to ecological receptors. Many of
the HPV/Inerts having greater potential for human exposure will also
have greater potential for exposure to wildlife. For example, the
databases to be reviewed for ecological biological monitoring data will
directly identify certain chemicals to which aquatic organisms have
been exposed (see Unit VII.B.). Similarly, several of the monitoring
databases that will be reviewed for the drinking water pathway contain
monitoring data collected on raw surface water (i.e., before the water
enters a public water system) (see Unit VII.C.). Thus, these surface
water monitoring data will show the levels of chemical to which fish,
amphibians, and other aquatic species are exposed. Accordingly, EPA
believes that the approach to evaluate HPV/Inerts, while focused on
human exposure, will also capture HPV/Inerts with potentially
widespread environmental exposures.
EPA generally has more extensive information available to assess
potential exposure to pesticide active ingredients via food, water,
occupational and residential exposure pathways than is available to
assess exposure to HPV/Inerts. In addition, EPA generally has more
extensive information available on usage (including both agricultural
and residential) of active ingredients than is available for HPV/Inerts
(including both pesticidal and non-pesticidal uses of those same
substances). For these reasons, the specific data sources and pathways
EPA has identified for selecting an initial set of HPV/Inerts for
endocrine disruptor screening differs somewhat from those for selecting
pesticide active ingredients.
First, EPA will review existing databases to identify chemicals
that are both pesticide inerts and HPV chemicals. HPV chemicals are
those chemicals manufactured or imported into the United States in
amounts equal to or greater than one million pounds per year. The HPV
chemicals are identified through information collected under the Toxic
Substances Control Act's (TSCA) Inventory Update Rule (IUR). IUR
provides for periodic updating of production volume and other
information pertaining to selected Inventory chemicals currently in
commerce. Second, EPA will review existing databases to identify HPV/
Inerts that are present in four types of environmental media or monitoring
[[Page 56461]]
data: Human biological samples, ecological tissues that have human food
uses (i.e., fish tissues), drinking water, and indoor air. Third, EPA
will prioritize these chemicals based on the number of monitoring data
types in which the chemicals have been detected. Thus, HPV/Inerts
appearing in four types of monitoring data would be given higher
priority than those appearing in only one type of monitoring data. To
the extent it becomes necessary to establish priorities within these
four types of monitoring data, EPA will give higher priority to those
HPV/Inerts that appear in human biological monitoring data, followed by
drinking water/indoor air monitoring data (weighted equally), followed
by ecological biological data relevant to human exposure.
A. High Production Volume/Inerts in Human Biological Monitoring Data
EPA will review the following data sources to determine which HPV/
Inerts have been detected in human biological samples and to identify
HPV/Inerts for which there appears to be widespread human exposure,
based on factors such as the number of samples and number of
detections. The presence of a single or only a few detections of a HPV/
Inert chemical typically would not be a sufficient basis for concluding
that the chemical should be identified as having significant exposure.
1. Third National Health and Nutrition Examination Survey. The
Third National Health and Nutrition Examination Survey (NHANES III) was
conducted between 1988 and 1994 on 33,994 people. The survey was
designed to obtain nationally representative information on the health
and nutritional status of the U.S. population through interviews and
direct physical examinations. Several studies (e.g., high blood
pressure, immunization status, nutritional blood measures, etc.) were
conducted under NHANES III. One study relevant to this priority-setting
exercise is the Priority Toxicant Reference Range Study, previously
referenced as Ashley et al (1994) (Ref. 13). This NHANES III article
contains relevant human biomonitoring data for over 40 volatile organic
compounds (VOCs). Standard QA/QC procedures such as sample duplicates
and blanks were used in the NHANES III Study. The study participants in
the special study are not statistically representative of the U.S.
population.
2. National Report on Human Exposure to Environmental Chemicals.
The National Report on Human Exposure for 2001 (Ref. 14) was a U.S.
Department of Health and Human Services (HHS), Centers for Disease
Control and Prevention (CDC) report that provided exposure information
about people participating in an ongoing national survey of the general
U.S. population--the NHANES. This report provides information on
concentrations of 27 environmental chemicals measured in blood and/or
urine in the U.S. population. The most current 2003 Report (Ref. 15)
presents exposure data for 116 chemicals (including the 27 chemicals
presented in the 2001 Report) during NHANES 1999 and 2000. VOCs are not
included in the 2003 Report. Chemicals and their metabolites were
measured in blood, urine, and blood serum samples from selected NHANES
participants. These chemicals include metals, organophosphate pesticide
metabolites, phthalate metabolites, and cotinine, a marker of exposure
to tobacco smoke. This report will be updated with additional
biomonitoring data for these same or different chemicals on an annual
basis.
3. National Human Adipose Tissue Survey. The EPA's Office of
Pollution Prevention and Toxics (OPPT) operated the National Human
Monitoring Program (NHMP) until the early 1990s. The NHMP's primary
activity was conducting a National Human Adipose Tissue Survey (NHATS),
which analyzed human adipose tissue specimens to monitor human exposure
to potentially toxic chemicals. A nationwide network of pathologists
and medical examiners from 47 standard metropolitan statistical areas
(SMSAs) collected tissue specimens from cadavers and surgical patients
that were then analyzed for certain chemicals. Throughout the 1970s and
early 1980s, the chemical residues of primary interest were
organochlorine pesticides and polychlorinated biphenyls (PCBs). In
1982, VOCs and semivolatile organic compounds (SVOCs) were included in
the survey. NHATS contains relevant human biomonitoring data for over
150 chemicals. Quality control samples, such as method and equipment
blank samples, control samples, and spike samples, were collected to
evaluate the quality of sampling data. Data are available for years
1970 through 1987 in 13 journal articles and reports (Refs. 16-29).
However, because a standard set of summarized data parameters has not
been published, the NHATS data were previously compiled into a database
by EPA, and this database was incorporated into the EDPSD (version 2).
(See http://www.epa.gov/scipoly/oscpendo/prioritysetting/database.htm)
In implementing its approach for selecting the initial list of
chemicals for screening, EPA will consider chemicals contained in the
database compiled for EDPSD and include those chemicals for which
geometric means were calculated for EDSP priority-setting purposes.
4. Total Exposure Assessment Methodology Study. The Total Exposure
Assessment Methodology (TEAM) Study was designed to develop methods to
measure individual total exposure (exposure through air, food, and
water) and resulting body burden of toxic and carcinogenic chemicals,
and to apply these methods within a probability-based sampling
framework to estimate the exposures and body burdens of urban
populations in several U.S. cities. The TEAM Study reports the results
of eight monitoring studies performed in five communities during
different seasons of the year. Breath, personal air, outdoor air, and
water samples were collected for 30 VOCs. (Refs. 30-32).
Established methods were used to collect and analyze TEAM Study
data. Quality control and quality assurance samples collected and
analyzed include reagent blanks, field blanks, duplicate samples, and
spiked samples. Data were reported for water using units of measure
different than those used for air and breath samples. Environmental and
biological data are generally lognormally distributed; thus, the data's
central tendency is generally best represented using a geometric mean.
Geometric means are provided for all compounds that were measured in
50% or more of the samples. For most of the compounds that were
measured in less than 50% of the samples, a minimum quantifiable limit
that can be used for ranking the data was provided.
B. High Production Volume/Inerts in Ecological Biological Monitoring
Data Relevant to Human Exposure
EPA will review the following data sources to determine which HPV/
Inerts have been detected in non-human tissues potentially relevant to
human ingestion exposure and to identify HPV/Inerts for which there
appears to be widespread human exposure, based on factors such as the
number of samples and number of detections. The presence of a single or
only a few detections of a HPV/Inert chemical typically would not be a
sufficient basis for concluding that the chemical should be identified
as having significant exposure.
1. National Sediment Inventory Fish Tissue Data (NSI Fish Tissue
Data). This database is described in Unit VI.B.5. In implementing its
approach for selecting the initial list of chemicals for screening, EPA
will consider fish species tissues for samples collected
[[Page 56462]]
after 1989 in NSI for EDSP priority-setting purposes.
2. National Fish Tissue Study. EPA is conducting a screening-level
study to estimate the national distribution of selected persistent,
bioaccumulative and toxic chemical residues in fish tissue from lakes
and reservoirs of the continental United States. This 4-year study,
which was initiated in 2000, will define the national background levels
for 265 chemicals in fish, establish a baseline to track the progress
of pollution control activities, and identify areas where contaminant
levels are high enough to warrant further investigation. The National
Fish Tissue Study is the first survey of fish tissue to be based on a
random sampling design. This sampling design will allow EPA to develop
national estimates of the mean levels of persistent, bioaccumulative,
and toxic chemicals in fish tissue. It will also provide data on the
largest set of persistent, bioaccumulative and toxic chemicals ever
studied in fish. More details can be found at
http://www.epa.gov/waterscience/fishstudy/results.htm.
3. National Water Quality Assessment Program Aquatic Animal Tissue
Data. This database, which also contains information on surface water
and ground water monitoring studies, is described in Unit VI.B.8. The
National Water Quality Assessment (NAWQA) has recently made aquatic
organism tissue data available for a variety of species and tissues.
EPA will consider NAWQA tissue data for all species and tissue types
for the ecological biological monitoring exposure pathway.
C. High Production Volume/Inerts in Drinking Water Monitoring Data
EPA will review the following data sources to determine which HPV/
Inerts have been detected in drinking water and in potential sources of
drinking water and identify HPV/Inerts for which there appears to be
widespread human exposure, based on factors such as the number of
samples and number of detections. The presence of a single or only a
few detections of a HPV/Inert chemical typically would not be a
sufficient basis for concluding that the chemical should be identified
as having significant exposure.
1. National Contaminant Occurrence Data Base (NCOD Database). This
database is described in Unit VI.B.6.
2. National Human Exposure Assessment Survey. EPA designed the
National Human Exposure Assessment Survey (NHEXAS) program to address
some of the limitations of single-chemical and single-media exposure
route studies. The purpose of NHEXAS is to evaluate comprehensive human
exposure to multiple chemicals from multiple routes on both a community
and regional scale, as well as its association with environmental
concentrations and personal activities. EPA completed Phase 1 field
sample collection and laboratory analyses of NHEXAS in 1998. EPA used
established methods to collect and analyze NHEXAS data. Quality control
and quality assurance samples collected and analyzed include reagent
blanks, field blanks, duplicate samples, and spiked samples. Samples
were split and analyzed in multiple laboratories; when appropriate
audit samples were available, they were also analyzed. Data are
reported for different media using different units of measure and
different measures of central tendency. For example, arsenic
concentrations are reported in micrograms per kilogram ([mu]g/Kg) for
beverages and food and in micrograms per liter ([mu]g/L) for water.
Sometimes the central tendency value is reported as an arithmetic mean,
sometimes as a median, and sometimes as a 90\th\ percentile. (Refs. 33-36).
3. Total Exposure Assessment Methodology Water Data (TEAM Water
Data). This study is described in Unit VII.A.4.
4. National Stream Quality Accounting Network (NASQAN) Data. This
database, which contains information on surface water monitoring
studies, is described in Unit VI.B.7.
5. National Water Quality Assessment Program (NAWQA). This
database, which contains information on surface water and ground water
monitoring studies, is described in Unit VI.B.8.
D. High Production Volume/Inerts in Indoor Air Monitoring Data
EPA will review the following data sources to determine which HPV/
Inerts have been detected in residential indoor air and to identify
HPV/Inerts for which there appears to be widespread human exposure,
based on factors such as the number of samples and number of
detections. The presence of a single or only a few detections of a HPV/
Inert typically would not be a sufficient basis for concluding that the
chemical should be identified as having significant exposure.
1. Office of Research and Development published literature. The
following eight EPA/Office of Research and Development (ORD)-authored
journal articles and reports provide indoor and personal air monitoring
data: Brown et al. (1994), Daisey et al. (1994), Kelly et al. (1994),
Immerman and Schaum. (1990), Samfield (1992), Shah et al. (1988),
Sheldon et al. (1992), and Shields et al. (1996) (Refs. 37-44). In
implementing its approach for selecting the initial list of chemicals
for screening, EPA will exclude the Kelly et al. (1994) article, as
this article only provides outdoor air data.
2. National Human Exposure Assessment Survey. The National Human
Exposure Assessment Survey (NHEXAS) Program was designed to evaluate
comprehensive human exposure via indoor and outdoor air to multiple
chemicals on a community and regional scale. Samples were collected of
both the indoor and outdoor air that people breathe. Preliminary
results of Phase I of NHEXAS were reported in 15 journal articles
published in 1999. Four of these 15 journal articles provided
information that is applicable to indoor air monitoring (Refs. 34-36,
44). In implementing its approach for selecting the initial list of
chemicals for screening, EPA will consider both NHEXAS indoor and/or
personal air samples for EDSP priority-setting purposes.
3. Total Exposure Assessment Methodology Study. The Total Exposure
Assessment Methodology (TEAM) Study is described in Unit VII.A.4. The
ORD literature (see Unit VII.D.1.) includes all of the indoor air data
collected in the TEAM Study; therefore, EPA will consider TEAM Study
data in implementing its approach for selecting the initial list of
chemicals along with the ORD data rather than as a separate source of
information.
E. Integration of Pathway Priorities for High Production Volume/Inerts
This unit addresses how EPA will integrate the information
developed on priorities through the analysis of the four types of
exposure monitoring data discussed in Units VII.A. through VII.D.
(human biological data, ecological biological data relevant to human
exposure, drinking water data, and indoor air data). As its first step,
the Agency will produce four lists of candidate chemicals, one for each
type of monitoring data, for potential screening in the endocrine
disruptor screening battery. EPA expects that a number of chemicals
will be identified in more than one type of monitoring data and that
some chemicals will appear only in a single type of monitoring data. In
choosing which HPV/Inerts to propose for the initial screening list,
EPA will give higher priority to chemicals that appear in multiple
types of monitoring data, with the HPV/Inerts appearing in four types
receiving the highest priority, three types the next highest priority,
etc. To the extent it becomes necessary to
[[Page 56463]]
establish priorities within these four types of monitoring data, EPA
will give greater priority to HPV/Inerts which appear in human
biological monitoring data, followed by drinking water/indoor air
monitoring data (weighted equally), followed by ecological biological
monitoring data relevant to human exposure. EPA will also exclude any
chemicals that are no longer produced or used in the United States.
EPA will review the candidate list to exclude the chemicals which
are being used as ``positive controls'' to validate the screening
assays. Also, in making selections for this exposure-based initial
list, EPA does not plan to select substances it anticipates as having
low potential to cause endocrine disruption (e.g., certain FIFRA List 4
inerts, most polymers with number average molecular weight greater than
1,000 daltons, strong mineral acids, and strong mineral bases), and
considers these substances to be a low priority for early screening
under the EDSP.
VIII. Integration of the Pesticide Active Ingredients and High
Production Volume/Inerts Lists
EPA will use similar but somewhat different sets of criteria for
identifying pesticide active ingredients and HPV/Inerts that should be
given priority consideration for inclusion in the initial round of
screening.
EPA will generate four lists of candidate pesticide active
ingredients (one for each exposure pathway) and four lists of candidate
HPV/Inerts (one for each type of exposure monitoring data). Because EPA
generally has more extensive exposure information for pesticide active
ingredients than for HPV/Inerts, the Agency does not think it would be
appropriate to integrate the eight lists. Instead, EPA will separately
select pesticide active ingredients and HPV/Inerts giving higher
priority to pesticide active ingredients and HPV/Inerts that appear in
multiple lists of exposure pathways and exposure monitoring data types,
respectively. Thus, the selected pesticide active ingredients may be
those that appear in three or more pathways whereas the selected HPV/
Inerts may be those that appear in one or more pathways. Finally, EPA
will review the lists for chemical class representation (e.g., as a tie
breaker). EPA's intent is to select a total of 50 to 100 chemicals to
initiate the screening program, but will not treat that overall target
as a rigid quota. In addition, EPA may sponsor Tier 1 screening of some
of the positive control chemicals used for validation of the assays,
and other chemicals, to provide data for comparison purposes and to
test the performance of the battery. This would be in addition to the
50 to 100 chemicals selected using the approach described in this notice.
IX. References
The following is a list of the documents that are specifically
referenced in this notice. These references are available in the docket
for this notice as described in Unit 1.B.1., under docket ID number
OPPT-2004-0109. In addition, some documents referenced are only
available in docket ID number OPPT-2002-0066, which is the docket used
for the proposed approach. These dockets are linked in EDOCKET, but to
simplify identifying the specific documents that can be found only in
docket ID number OPPT-2002-0066, those references include the
appropriate document ID number. (See Unit I.B.1. for information on how
to access these dockets).
1. EPA. Endocrine Disruptor Screening and Testing Advisory
Committee Final Report. August 1998. Available at: http://www.epa.gov/
scipoly/oscpendo/edspoverview/finalrpt.htm. Document ID number OPPT-
2002-0066-0003.
2. EPA, Science Advisory Board. Review of EPA's Proposed
Environmental Endocrine Disruptor Screening Program. July 1999. EPA-
SAB-EC-99-013. Available at: http://www.epa.gov/science1/pdf/ec13.pdf.
Document ID number OPPT-2002-0066-0002.
3. EPA. Comment Response Document for Endocrine Disruptor Chemical
Selection/Priority Setting. November 2004.
4. EPA. Guidelines for Ensuring and Maximizing the Quality,
Objectivity, Utility, and Integrity of Information Disseminated by the
Environmental Protection Agency. October 2002. EPA/260R-02-008.
Available at: http://www.epa.gov/quality/informationguidelines.
5. EPA. Compilation of Data Source Summaries Prepared for High
Production Volume (HPV) and Pesticide Inert Chemicals and Pesticide
Active Ingredients Data Sources. EPA Contract 68W02024, Task Order
#69. Eastern Research Group, Inc. June 2005.
6. USDA. Food Commodity Intake Database (FCID). July 2000.
Available at: http://www.barc.usda.gov/bhnrc/foodsurvey/fcid.html.
7. EPA. EPA Pesticides in Ground Water Database, A Compilation of
Monitoring Studies: 1971-1991 National Summary, EPA 734-12-92-001.
September 1992. Document ID number OPPT-2002-0066-0005.
8. USGS. Pesticides in Select Water Supply Reservoirs and Finished
Drinking Water, 1999-2000: Summary of Results from a Pilot Monitoring
Program. 2001. USGS Open File Report 01-456. Document ID number OPPT-
2002-0066-0006.
9. EPA. The Incorporation of Water Treatment Effects on Pesticide
Removal and Transformation in Food Quality Protection Act Drinking
Water Assessments. October 25, 2001. Available at: http://www.epa.gov/
pesticides/trac/science/water_treatment.pdf. Document ID number OPPT-
2002-0066-0007.
10. EPA. Estimating the Drinking Water Component of a Dietary
Exposure Assessment. Revised November 2, 1999. Available at:
http://www.epa.gov/fedrgstr/EPA-PEST/1999/November/Day-10/6044.pdf.
Document
ID number OPPT-2002-0066-0008.
11. EPA. EPA Background Paper for the FIFRA Scientific Advisory
Panel Meeting on Monitoring Strategies for Pesticides in Surface-
Derived Drinking Water. June 2000. Available at:
http://www.epa.gov/scipoly/sap/2000/june/drinkingwatersurvey.pdf.
Document ID number OPPT-2002-0066-0009.
12. EPA. Science Advisory Council on Exposure, Policy Number 003.1,
Agricultural Transfer Coefficients. Document ID number OPPT-2002-0066-0010.
13. Ashley, David L.; Bonin, Michael A.; Cardinall, Frederick L.;
McCraw, Joan M.; and Wootan, Joe V. Blood Concentrations of Volatile
Organic Compounds (VOCs) in a Nonoccupationally Exposed U.S. Population
and in Groups with Suspected Exposure. Clinical Chemistry (1994) 40:
1401-1404. Document ID number OPPT-2002-0066-0011.
14. HHS, CDC. National Report on Human Exposure to Environmental
Chemicals. March 2001. Document ID number OPPT-2002-0066-0012.
15. HHS, CDC. Second National Report on Human Exposure to
Environmental Chemicals. January 2003. Available at:
http://www.cdc.gov/exposurereport/2nd/pdf/secondner.pdf.
16. EPA. Chlorinated Dioxins and Furans in the General U.S.
Population: NHATS FY87 Results--Executive Summary. EPA-560/5-91-003.
May 1991. Document ID number OPPT-2002-0066-0013.
17. Cramer, Paul H.; Stanley, John S.; Bauer, Karin; Ayling, Randy
E.; Thornburg, Kelly R.; and Schwemberger, John. Brominated Dioxins and
Furans in Human Adipose Tissue: Final Report. EPA-560/5-90-005 (NTIS
PB91-103507). April 11,
[[Page 56464]]
1990. Document ID number OPPT-2002-0066-0014.
18. Cramer, Paul H.; Stanley, John S.; and Thornburg, Kelly R. Mass
Spectral Confirmation of Chlorinated and Brominated Diphenylethers in
Human Adipose Tissues: Final Report. EPA-560/5-90-012 (NTIS PB91-
159699). June 15, 1990. Document ID number OPPT-2002-0066-0015.
19. Mack, Gregory A. and Mohadjer, Leyla. Baseline Estimates and
Time Trends for Beta-benzene hexachloride, Hexachlorobenzene, and
Polychlorinated Biphenyls in Human Adipose Tissue 1970-1983. EPA-560/5-
85-025. September 30, 1985. Document ID number OPPT-2002-0066-0016.
20. Onstot, J.D.; Ayling, R.E.; and Stanley, J.S. Characterization
of HRGC/MS Unidentified Peaks from the Analysis of Human Adipose
Tissue: Volume I--Technical Approach. EPA-560/5-87-002A (NTIS PB88-
100367). May 1987. Document ID number OPPT-2002-0066-0017.
21. Onstot, J.D.; Ayling, R.E.; and Stanley, J.S. Characterization
of HRGC/MS Unidentified Peaks from the Analysis of Human Adipose
Tissue: Volume II--Appendices. EPA-560/5-87-002B (NTIS PB88-100375).
May 1987. Document ID number OPPT-2002-0066-0018.
22. Onstot, J.D. and Stanley, J.S. Identification of SARA Compounds
in Adipose Tissue. EPA-260/5-89-003 (NTIS PB90-132564). August 1989.
Document ID number OPPT-2002-0066-0019.
23. Orban, John E.; Stanley, John S.; Schwemberger, John G.; and
Remmers, Janet C. Dioxins and Dibenzofurans in Adipose Tissue of the
General US Population and Selected Subpopulations. American Journal of
Public Health. 1994 84: 439-445. Document ID number OPPT-2002-0066-0020.
24. EPA. Semivolatile Organic Compounds in the General U.S.
Population: NHATS FY86 Results--Volume I. EPA-747-R-94-001. July 1994.
Document ID number OPPT-2002-0066-0021.
25. Stanley, John S. Broad Scan Analysis of the FY82 National Human
Adipose Tissue Survey Specimens: Volume I--Executive Summary. EPA-560/
5-86-035 (NTIS PB87-177218). December 1986. Document ID number OPPT-
2002-0066-0022.
26. Stanley, John S. Broad Scan Analysis of the FY82 National Human
Adipose Tissue Survey Specimens: Volume II--Volatile Organic Compounds.
EPA-560/5-86-036 (NTIS PB87-177226). December 1986. Document ID number
OPPT-2002-0066-0023.
27. Stanley, John S. Broad Scan Analysis of Human Adipose Tissue:
Volume III--Semivolatile Organic Compounds: Final Report. EPA-560/5-86-
037 (NTIS PB87-180519). December 1986. Document ID number OPPT-2002-
0066-0024.
28. Stanley, John S. Broad Scan Analysis of Human Adipose Tissue:
Volume IV--Polychlorinated Dibenzo-p-Dioxins (PCDDs) and
Polychlorinated Dibenzofurans (PCDFs): Final Report. EPA-560/5-86-038
(NTIS PB87-177234). December 1986. Document ID number OPPT-2002-0066-0025.
29. Stanley, John S. and Stockton, Rodney A. Broad Scan Analysis of
the FY82 National Human Adipose Tissue Survey Specimens: Volume V--
Trace Elements. EPA-560/5-86-039 (NTIS PB87-180527). December 1986.
Document ID number OPPT-2002-0066-0026.
30. EPA. The Total Exposure Assessment Methodology (TEAM) Study:
Elizabeth and Bayonne, New Jersey, Devils Lake, North Dakota, and
Greensboro, North Carolina: Volume II. Part 2. EPA-600/6-87/002b (NTIS
PB88-100078). June 1987. Document ID number OPPT-2002-0066-0027.
31. EPA. The Total Exposure Assessment Methodology (TEAM) Study:
Selected Communities in Northern and Southern California: Volume III.
EPA-600/6-87/002c (NTIS PB88-100086). June 1987. Document ID number
OPPT-2002-0066-0028.
32. Wallace, Lance. Project Summary: The Total Exposure Assessment
Methodology (TEAM) Study. EPA/600/S6-87/002. September 1987. Document
ID number OPPT-2002-0066-0029.
33. Thomas, Kent W.; Pelizzari, Edo D.; and Berry, Maurice R.
Population-based dietary intakes and tap water concentrations for
selected elements in EPA Region V National Human Exposure Assessment
Survey (NHEXAS).Journal of Exposure and Environmental Epidemiology.
1999. 9: 402-413. Document ID number OPPT-2002-0066-0030.
34. Clayton, C.A.; Pellizzari, E.D.; Whitmore, R.W.; Perritt, R.L.;
and J.J. Quackenboss. National Human Exposure Assessment Survey
(NHEXAS): distributions and associations of lead, arsenic and volatile
organic compounds in EPA Region 5. Journal of Exposure and
Environmental Epidemiology. 1999. 9: 381-392. Document ID number OPPT-
2002-0066-0031.
35. O'Rourke, Mary Kay; Van de Water, Peter K.; Jin, Shan; Rogan,
Seumas P.; Weiss, Aaron D.; Gordon, Sydney M.; Moschandreas, Demetrios
M.; and Lebowitz, Michael D. Evaluations of primary metals from NHEXAS
Arizona: distributions and preliminary exposures. Journal of Exposure
Analysis and Environmental Epidemiology. 1999. 9: 435-445. Document ID
number OPPT-2002-0066-0032.
36. Robertson, Gary L.; Lebowitz, Michael D.; O'Rourke, Mary Kay;
Gordon, Sydney; and Moschandreas, Demetrios. The National Human
Exposure Assessment Survey (NHEXAS) study in Arizona--introduction and
preliminary results. Journal of Exposure Analysis and Environmental
Epidemiology. (1999) 9: 427-434. Document ID number OPPT-2002-0066-0033.
37. Brown, S.K.; Sim, M.R.; Abramson, M.J.; and Gray, C.N.
Concentrations of Volatile Organic Compounds in Indoor Air--A Review.
Indoor Air. 1994. 4: 123-134. Document ID number OPPT-2002-0066-0034.
38. Daisey, J.M.; Hodgson, A.T.; Fisk, W.J.; Mendell, M.J.; and
Brinke, J. Ten. Volatile Organic Compounds In Twelve California Office
Buildings: Classes, Concentrations and Sources. Atmospheric
Environment. 1994. 28: 3557-3562. Document ID number OPPT-2002-0066-0035.
39. Kelly, Thomas J.; Mukund, R.; Spicer, Chester W.; and Pollack,
Albert J. Concentrations and Transformations of Hazardous Air
Pollutants. Environmental Science and Technology. 1994. 28: 378A-387A.
Document ID number OPPT-2002-0066-0036.
40. Immerman, Frederick W. and Schaum, John L. Final Report of the
Nonoccupational Pesticide Exposure Study (NOPES). EPA/600/3-90/003
(NTIS PB90-152224). January 1990. Document ID number OPPT-2002-0066-0037.
41. Samfield, Max M. Indoor Air Quality Data Base for Organic
Compounds. EPA-600-R-92-025 (NTIS PB92-158468). February 1992. Document
ID number OPPT-2002-0066-0038.
42. Shah, Jitendra J. and Singh, Hanwant B. Distribution of
Volatile Organic Chemicals in Outdoor and Indoor Air. A National VOCs
Data Base. Environmental Science and Technology. 1988. 22: 1381-1388.
Document ID number OPPT-2002-0066-0039.
43. Sheldon, L.; Clayton, A.; Jones, B.; Keever, J.; Perritt, R.;
Smith, D.; Whitaker, D.; and Whitmore, R. Indoor Pollutant
Concentrations and Exposures: Final Report. California Air Resources
Board, Contract A833-156. January 1992. Document ID number OPPT-2002-
0066-0040.
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44. Shields, Helen C.; Fleischer, Daniel M.; and Weschler, Charles
J. Comparisons among VOCs Measured in Three Types of U.S. Commercial
Buildings with Different Occupant Densities. Indoor Air. 1996. 6: 2-17.
Document ID number OPPT-2002-0066-0041.
45. Gordon, Sydney M.; Callahan, Patrick J.; Nishioka, Marcia G.;
Brinkman, Marielle C.; O'Rourke, Mary Kay; Lebowitz, Michael D.; and
Moschandreas, Demetrios. Residential Environmental Measurements in the
National Human Exposure Assessment Survey (NHEXAS) Pilot Study in
Arizona: Preliminary Results for Pesticides and VOCs. Journal of
Exposure Analysis and Environmental Epidemiology. 1999. 9: 456-470.
Document ID number OPPT-2002-0066-0042.
X. Statutory and Executive Order Reviews
This notice describes the approach that EPA intends to use to
identify the first 50 to 100 chemicals to be screened under the EDSP.
It represents a statement of Agency policy in this respect, but does
not impose any requirements. As a policy statement related to a new
program and the potential for novel policy issues to arise during this
initial implementation of the statutory mandate in section 408(p) of
FFDCA, the Office of Management and Budget (OMB) has designated this
notice as ``significant'' under section 3(f) of Executive Order 12866,
entitled Regulatory Planning and Review (58 FR 51735, October 4, 1993).
The Agency therefore submitted this notice to OMB for review under this
Executive order, and any changes made in response to recommendations or
comments received from OMB during that review have been documented in
the public docket as required by the Executive order.
Since this notice is not a regulation and does not otherwise impose
any requirements, it does not qualify as an economically significant
action under section 3(f)(1) of Executive Order 12866. As such, this
action is not subject to Executive Order 13045, entitled Protection of
Children from Environmental Health Risks and Safety Risks (62 FR 19885,
April 23, 1997), or Executive Order 13211, entitled Actions Concerning
Regulations That Significantly Affect Energy Supply, Distribution, or
Use (66 FR 28355, May 22, 2001). Nor does this notice contain any
information collection requirements that require review and approval by
OMB pursuant to the Paperwork Reduction Act of 1995 (PRA) (44 U.S.C.
3501 et seq.).
Since this type of action does not require any proposal, no action
is needed under the Regulatory Flexibility Act (RFA) (5 U.S.C. 601 et
seq.), and since this action does not involve any technical standards,
section 12(d) of the National Technology Transfer and Advancement Act
of 1995 (NTTAA), Public Law 104-113, section 12(d) (15 U.S.C. 272
note), does not apply.
For the same reason, this action will not have substantial direct
effects on State or tribal governments, on the relationship between the
Federal Government and States or Indian tribes, or on the distribution
of power and responsibilities between the Federal Government and States
or Indian tribes. As a result, this action does not require any action
under Executive Order 13132, entitled Federalism (64 FR 43255, August
10, 1999), or under Executive Order 13175, entitled Consultation and
Coordination with Indian Tribal Governments (59 FR 22951, November 6,
2000). Nor does it impose any enforceable duty or contain any unfunded
mandate or otherwise require any action under Title II of the Unfunded
Mandates Reform Act of 1995 (UMRA) (Public Law 104-4).
Nor does this action require any special considerations under
Executive Order 12898, entitled Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations (59 FR 7629, February 16, 1994).
In addition, although not a final action that requires action under
the Congressional Review Act, 5 U.S.C. 801 et seq., which generally
provides that before a final action may take effect, the issuing Agency
must submit a report to each House of the Congress and the Comptroller
General of the United States, EPA has submitted a courtesy copy of this
notice to the U.S. Senate, the U.S. House of Representatives, and the
Comptroller General of the United States prior to its publication in
the Federal Register.
List of Subjects
Environmental protection, Chemicals, Endocrine disruptors,
Pesticides and pests.
Dated: August 8, 2005.
Susan B. Hazen,
Acting Assistant Administrator, Office of Prevention, Pesticides and
Toxic Substances.
[FR Doc. 05-19260 Filed 9-26-05; 8:45 am]
BILLING CODE 6560-50-S