[Federal Register: December 30, 2002 (Volume 67, Number 250)]
[Notices]
[Page 79611-79629]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30de02-85]
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ENVIRONMENTAL PROTECTION AGENCY
[OPPT-2002-0066; FRL-7286-6]
Endocrine Disruptor Screening Program, Proposed Chemical
Selection Approach for Initial Round of Screening; Request for Comment
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice.
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SUMMARY: This notice sets forth for public comment the approach EPA
plans to use for selecting the first group of chemicals to be screened
in the
[[Page 79612]]
Agency's Endocrine Disruptor Screening Program (EDSP). Following
consideration of comments on this draft approach, EPA will issue a
second Federal Register notice setting forth its approach for selecting
the first group of chemicals and the chemicals it proposes for this
initial list. Following comment on the draft list of specific
chemicals, EPA will issue the final list.
Because the list of chemicals produced using the proposed approach
will be a list of chemicals that the Agency, in its discretion, has
decided should be tested first, based primarily upon exposure
potential, it 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.
EPA anticipates that it will modify its chemical selection approach
for subsequent Tier 1 screening lists based on experience gained from
the results of testing of chemicals on the initial list, the
feasibility of incorporating different 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).
DATES: Comments, identified by docket ID number OPPT-2002-0066, must be
received on or before March 1, 2003.
ADDRESSES: Comments may be submitted electronically, by mail, or
through hand delivery/courier. Follow the detailed instructions as
provided in Unit I. of the SUPPLEMENTARY INFORMATION.
FOR FURTHER INFORMATION CONTACT: For general information contact:
Barbara Cunningham, Acting Director, 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: Greg Schweer, Exposure
Assessment Coordination and Policy Division (7203M), Office of Science
Coordination and Policy, Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington, DC 20460-0001; telephone number:
(202) 564-8469; e-mail address: schweer.greg@epa.gov.
SUPPLEMENTARY INFORMATION:
I. General Information
A. Does this Action Apply to Me?
This action is directed to the public in general, and may be of
particular interest to those persons who are or may be required to
conduct testing of chemical substances under the Toxic Substances
Control Act (TSCA), the Federal Food, Drug and Cosmetic Act (FFDCA),
the Safe Drinking Water Act (SDWA), or the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA). 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 technical 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-2002-0066. The
official public docket consists of the documents specifically
referenced in this action, any public comments received, and other
information related to this action. 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 submit or view public
comments, 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.
For public commenters, it is important to note that EPA's policy is
that public comments, whether submitted electronically or in paper,
will be made available for public viewing in EPA's electronic public
docket as EPA receives them and without change, unless the comment
contains copyrighted material, CBI, or other information whose
disclosure is restricted by statute. When EPA identifies a comment
containing copyrighted material, EPA will provide a reference to that
material in the version of the comment that is placed in EPA's
electronic public docket. The entire printed comment, including the
copyrighted material, will be available in the public docket.
Public comments submitted on computer disks that are mailed or
delivered to the docket will be transferred to EPA's electronic public
docket. Public comments that are mailed or delivered to the docket will
be scanned and placed in EPA's electronic public docket. Where
practical, physical objects will be photographed, and the photograph
will be placed in EPA's electronic public docket along with a brief
description written by the docket staff.
[[Page 79613]]
C. How and To Whom Do I Submit Comments?
You may submit comments electronically, by mail, or through hand
delivery/courier. To ensure proper receipt by EPA, identify the
appropriate docket ID number in the subject line on the first page of
your comment. Please ensure that your comments are submitted within the
specified comment period. Comments received after the close of the
comment period will be marked ``late.'' EPA is not required to consider
these late comments. If you wish to submit CBI or information that is
otherwise protected by statute, please follow the instructions in Unit
I.D. Do not use EPA Dockets or e-mail to submit CBI or information
protected by statute.
1. Electronically. If you submit an electronic comment as
prescribed in this Unit, EPA recommends that you include your name,
mailing address, and an e-mail address or other contact information in
the body of your comment. Also include this contact information on the
outside of any disk or CD ROM you submit, and in any cover letter
accompanying the disk or CD ROM. This ensures that you can be
identified as the submitter of the comment and allows EPA to contact
you in case EPA cannot read your comment due to technical difficulties
or needs further information on the substance of your comment. EPA's
policy is that EPA will not edit your comment, and any identifying or
contact information provided in the body of a comment will be included
as part of the comment that is placed in the official public docket,
and made available in EPA's electronic public docket. If EPA cannot
read your comment due to technical difficulties and cannot contact you
for clarification, EPA may not be able to consider your comment.
i. EPA Dockets. Your use of EPA's electronic public docket to
submit comments to EPA electronically is EPA's preferred method for
receiving comments. Go directly to EPA Dockets at http://www.epa.gov/edocket
, and follow the online instructions for submitting comments.
Once in the system, select ``search,'' and then key in docket ID number
OPPT-2002-0066. The system is an ``anonymous access'' system, which
means EPA will not know your identity, e-mail address, or other contact
information unless you provide it in the body of your comment.
ii. E-mail. Comments may be sent by e-mail to oppt.ncic@epa.gov,
Attention: Docket ID Number OPPT-2002-0066. In contrast to EPA's
electronic public docket, EPA's e-mail system is not an ``anonymous
access'' system. If you send an e-mail comment directly to the docket
without going through EPA's electronic public docket, EPA's e-mail
system automatically captures your e-mail address. E-mail addresses
that are automatically captured by EPA's e-mail system are included as
part of the comment that is placed in the official public docket, and
made available in EPA's electronic public docket.
iii. Disk or CD ROM. You may submit comments on a disk or CD ROM
that you mail to the mailing address identified in Unit I.C.2. These
electronic submissions will be accepted in WordPerfect or ASCII file
format. Avoid the use of special characters and any form of encryption.
2. By mail. Send your comments to: Document Control Office (7407M),
Office of Pollution Prevention and Toxics (OPPT), Environmental
Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460-
0001.
3. By hand delivery or courier. Deliver your comments to: OPPT
Document Control Office (DCO) in EPA East Building Rm. 6428, 1201
Constitution Ave., NW., Washington, DC. Attention: Docket ID Number
OPPT-2002-0066. The DCO is open from 8 a.m. to 4 p.m., Monday through
Friday, excluding legal holidays. The telephone number for the DCO is
(202) 564-8930.
D. How Should I Submit CBI To the Agency?
Do not submit information that you consider to be CBI
electronically through EPA's electronic public docket or by e-mail. You
may claim information that you submit to EPA as CBI by marking any part
or all of that information as CBI (if you submit CBI on disk or CD ROM,
mark the outside of the disk or CD ROM as CBI and then identify
electronically within the disk or CD ROM the specific information that
is CBI). Information so marked will not be disclosed except in
accordance with procedures set forth in 40 CFR part 2.
In addition to one complete version of the comment that includes
any information claimed as CBI, a copy of the comment that does not
contain the information claimed as CBI must be submitted for inclusion
in the public docket and EPA's electronic public docket. If you submit
the copy that does not contain CBI on disk or CD ROM, mark the outside
of the disk or CD ROM clearly that it does not contain CBI. Information
not marked as CBI will be included in the public docket and EPA's
electronic public docket without prior notice. If you have any
questions about CBI or the procedures for claiming CBI, please consult
the technical person listed under FOR FURTHER INFORMATION CONTACT.
E. What Should I Consider as I Prepare My Comments for EPA?
You may find the following suggestions helpful for preparing your
comments:
1. Explain your views as clearly as possible.
2. Describe any assumptions that you used.
3. Provide copies of any technical information and/or data you used
that support your views.
4. Provide specific examples to illustrate your concerns.
5. Offer alternative ways to improve the proposed approach.
6. Make sure to submit your comments by the deadline in this
notice.
7. To ensure proper receipt by EPA, be sure to identify the docket
ID number assigned to this action in the subject line on the first page
of your response. You may also provide the name, date, and Federal
Register citation.
II. Introduction
A. What Action is the Agency Taking?
In this notice, EPA is setting forth, and requesting public comment
on, the approach EPA plans to use for selecting an initial group of
chemicals to be screened in the Agency's EDSP. EPA anticipates that it
will modify its chemical selection approach for subsequent Tier 1
screening lists based on experience gained from the results of testing
of chemicals on the initial list, the feasibility of incorporating
different categories of chemicals (e.g., non-pesticide substances) and
additional pathways of exposure, and the availability of new priority-
setting tools (e.g., HTPS or QSAR models). EPA developed its EDSP in
response to a Congressional mandate in section 408(p) of FFDCA ``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 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
[[Page 79614]]
for testing, under the FFDCA section 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.''
EPA is following a tiered approach in implementing the requirements
of section 408(p) of FFDCA. The core elements of the tiered approach
are priority setting, Tier 1 screening, and Tier 2 testing. Tier 1 will
be comprised of a battery of screening assays to identify substances
that have potential to interact with the estrogen, androgen, or thyroid
hormone systems. The purpose of Tier 2 is to determine whether the
substance may cause endocrine-mediated effects via or involving
estrogen, androgen, or thyroid hormone systems, determine the
consequences to the organism of the activities observed in Tier 1, and
establish the relationship between doses of an endocrine-active
substance administered in the test and the effects observed. (Federal
Register issue of December 28, 1998 (63 FR 71542, FRL-6052-9, Docket
Control Number OPPTS-42208).
At the request of EPA, a joint subcommittee of the EPA Science
Advisory Board (SAB) and the FIFRA Scientific Advisory Panel (SAP)
reviewed a set of scientific issues related to the development of the
Agency's EDSP. One of the recommendations of the SAB/SAP Subcommittee
(Ref. 1) was that EPA should initiate the Tier 1 screening program with
a set of 50 to 100 chemicals and then convene a panel of independent
scientists to review the screening data for the purpose of evaluating
and optimizing the Tier 1 screening battery. EPA is proposing to adopt
this SAB/SAP recommendation to initially select and screen
approximately 50 to 100 chemicals to help the Agency further refine the
EDSP. The Agency intends to submit the data received from the screening
to an independent external panel of experts and request an evaluation
of whether the program could be improved or optimized, and if so, how.
EPA has stated its intention to consider a broad universe of
chemicals as potential candidates for testing under the EDSP including
pesticide chemicals, non-pesticide commercial chemicals, mixtures, and
environmental contaminants (63 FR 71542). However, for the first group
of chemicals to be tested, EPA is intending to focus only on pesticide
active ingredients and high production volume (HPV) chemicals with some
pesticidal inert uses (i.e., the chemicals that are specifically
mandated for testing under section 408(p) of FFDCA). The pesticide
inerts to be considered are those with relatively large overall
production volumes considering both pesticide and non-pesticide uses.
This approach will allow EPA to focus its initial endocrine screening
efforts on a smaller and more manageable universe of chemicals that
emphasizes early attention to the pesticide chemicals that Congress
specifically mandated EPA to test for possible endocrine effects.
The purpose of this notice is to describe the approach that EPA
plans to use to select this initial set of chemicals to undergo Tier 1
screening. EPA is proposing to use an approach based in part on the
compartment-based priority setting approach described in the December
28,1998, Federal Register notice (FRL-6052-9) in which EPA provided
details about, and requested comment on, its EDSP. The proposed
approach focuses on human exposure-related factors rather than using a
combination of exposure- and effects-related factors. The approach
would, however, exclude from the first group of chemicals to undergo
Tier 1 screening any chemical for which the available effects
information clearly shows an endocrine-mediated effect. Such chemicals
would be considered for proposed Tier 2 tests, mechanistic or special
studies, or hazard assessment. Similarly, the approach for this initial
list also would exclude substances that EPA anticipates 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).
Although EPA's general focus in this approach is on pesticide active
ingredients and inerts with relatively greater potential human
exposure, EPA believes that the proposed approach will also identify
chemicals with high potential for exposure of humans from non-pesticide
uses and/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 the
proposed approach.
Because the list of chemicals produced using the proposed approach
will be a list of chemicals that the Agency, in its discretion, has
decided should be tested first, based primarily upon exposure
potential, it 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.
EPA has decided to defer consideration of nominations from the
public until subsequent testing lists in order to keep this initial
effort administratively simpler and ensure that a set of test results
can be obtained in a relatively prompt timeline to aid the Agency in a
mid-course evaluation of the EDSP Tier 1 screening battery. In
addition, EPA has decided that the prudent approach would be to gain
experience with the Tier 1 screening battery on single chemicals before
the tests are used with mixtures. EPA also is proposing to exclude from
consideration for the initial Tier 1 screening list chemicals that are
no longer produced or used in the United States. The Agency thinks that
the added administrative complexity of determining who should be
responsible for testing such chemicals could unnecessarily delay EPA's
selection of an initial list for Tier 1 screening.
B. What is the Agency's Authority for Taking this Action?
In this notice, EPA is proposing an approach for selecting an
initial set of chemicals to go through endocrine disruptor screening.
EPA has a number of authorities at its disposal to require screening
and testing for endocrine disrupting effects. As explained previously,
FFDCA section 408(p) requires EPA ``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 effects as
[EPA] may designate.'' (21 U.S.C. 346a(p)). The statute requires EPA to
``provide for the testing of all pesticide chemicals.'' It defines
``pesticide chemical'' 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)). 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'' (21 U.S.C. 346a(p)(3)).
In addition, section 1457 of SDWA provides EPA with discretionary
authority to provide for testing, under the FFDCA section 408(p)
screening program, ``of any other substances that may be found in
sources of drinking water if the Administrator determines
[[Page 79615]]
that a substantial population may be exposed to such substance.'' (42
U.S.C. 300j-17). Several other Federal statutes also provide EPA with
authority to require testing of certain substances, including FIFRA and
TSCA. EPA may use any or all of these authorities to require testing of
substances to determine whether a substance may cause endocrine
effects.
III. Background
A. EPA's Endocrine Disruptor Screening Program
EPA initially set forth the EDSP in the Federal Register issue of
August 11, 1998 (63 FR 42852, FRL-6021-3, Docket Control Number OPPTS-
42206) and solicited public comment on the program in the December 28,
1998, Federal Register notice (FRL-6052-9). The program set forth in
these notices was based on the recommendations of the Endocrine
Disruptor Screening and Testing Advisory Committee (EDSTAC) which was a
committee chartered under the Federal Advisory Committee Act. The
Committee 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 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, and
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 EDSP
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. 2). Based on these recommendations, EPA developed a
tiered approach for the EDSP. The core elements of the proposed
approach are: Priority setting, Tier 1 screening, and Tier 2 testing.
Tier 1 is envisioned as a battery of screening assays that would
identify substances that have the potential to interact with the
estrogen, androgen, and thyroid hormone systems. The purpose of Tier 2
is to determine whether the substance could, in fact, cause endocrine
effects mediated by estrogen-, androgen-, and thyroid-related
processes, and establish the relationship between doses of an
endocrine-active substance administered in the test and any effects
observed (December 28, 1998, Federal Register notice (FRL-6052-9)).
In addition, based on EDSTAC's recommendations, EPA proposed in the
December 28, 1998, Federal Register notice (FRL-6052-9) 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, the approach
set forth in the December 28, 1998, Federal Register notice (FRL-6052-
9) was to set up categories of information relating to the production,
release, exposure and hazard of chemicals and to group the chemicals
according to what data were available. 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 on all non-pesticide active ingredient chemicals with
a production volume in excess of 10,000 pounds per year. HTPS
activities are discussed more fully in Unit IV.C. EPA developed the
Endocrine Disruptor Priority Setting Data Base (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 Tier 1 screening level assays,
selecting the appropriate screening assays for the Tier 1 battery based
on the validation data, and developing and validating Tier 2 tests.
2. Developing an approach for selecting an initial set of chemicals
to go through Tier 1 screening.
3. Developing the procedures the Agency will use to require
screening.
This notice deals only with the development of the approach that
EPA will use to select the initial set of chemicals for Tier 1
screening.
B. SAB/SAP Review
EPA asked the SAB and the SAP to review jointly the Agency's
proposed EDSP as described in the December 28, 1998 Federal Register
notice (FRL-6052-9). 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 Subcommittee met on March 30-April 1, 1999. Its report was
published the following July (Ref. 1). In general, the SAB/SAP
Subcommittee agreed with the program that EPA had developed for
conducting endocrine disruptor screening. The following are
recommendations from the Subcommittee with respect to the scope of the
program and setting of priorities for Tier 1 screening.
In the December 28, 1998, Federal Register notice (FRL-6052-9), EPA
explained that it was considering 87,000 substances as potential
candidates for testing under the 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 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 the EDSP.
The Subcommittee also expressed concern that it did not see a provision
for mid-course correction or optimization of the Program. Thus, the
Subcommittee recommended that the EPA implement the EDSP on 50 to 100
compounds and submit the data to independent review with an eye toward
eliminating methods that do not work and optimizing the program.
The Subcommittee also recommended against including mixtures in the
initial set of chemicals to be tested. The Subcommittee thought that
the question of testing mixtures should be deferred until accepted
single-compound methods had been successfully completed.
The Subcommittee also found that the compartment-based approach to
priority setting was supportable when ranking is
[[Page 79616]]
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 agents 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 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
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 the EDSP. The
Subcommittee supported the concept of nominations by citizens but
recommended that the process needed further definition.
Finally, the 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 Subcommittee
encouraged EPA to be open to other types of assays for HTPS including
receptor binding, gene chip and microassays, and computer modeling. The
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. Previous Public Comments on Priority Setting
In addition to comments provided by the SAB/SAP Subcommittee,
comments provided by the public on priority setting in response to
EPA's EDSP Proposed Statement of Policy in the December 28, 1998,
Federal Register notice (63 FR 71542, FRL-6052-9, Docket Control Number
OPPTS-42208) and at two public meetings on the Endocrine Disruptor
Priority Setting Data Base held on January 20, 1999 (Federal Register
issue of December 28, 1998 (63 FR 71568, FRL-6052-8, Docket Control
Number OPPTS-42207)) and June 5-6, 2000 (Federal Register issue of May
19, 2000 (65 FR 31900, FRL-6559-9, Docket Control Number OPPTS-42212))
have been helpful to the Agency in developing the approach presented in
this notice for selecting the first group of chemicals to be screened
in the EDSP.
IV. EPA's Approach to Selecting the Initial Set of Chemicals to Undergo
Tier 1 Screening
On the basis of EPA's experience to date and comments received from
the SAB/SAP Subcommittee and the public, EPA is setting forth its
approach for selecting the first group of chemicals to be screened in
the EDSP. Based on the SAB/SAP recommendations, EPA is proposing to
select and screen approximately 50 to 100 chemicals drawn from
pesticide active ingredients and HPV chemicals with some pesticidal
inert uses (HPV/Inert chemicals) to help the Agency further refine the
EDSP. As recommended by the SAP/SAB Subcommittee, the Agency intends to
submit the data received from the screening to an independent external
panel of experts and request an evaluation of whether the program could
be improved or optimized, and if so, how. EPA does not intend to
develop an ordinal ranking of priorities of the chemicals within this
initial list.
EPA is proposing to use an approach based in part on the
compartment-based priority setting approach described in the December
28, 1998, Federal Register notice (FRL-6052-9) that provided details
about the EDSP. That document proposed approach focuses on exposure-
related factors rather than using a combination of exposure- and
effects-related factors. The approach would, however, exclude from the
first group of chemicals to undergo Tier 1 screening any chemical for
which the available effects information clearly shows an endocrine-
mediated effect. Such chemicals would be considered for proposed Tier 2
tests, mechanistic or special studies, or hazard assessment. Similarly,
the approach for this initial list also would exclude substances that
EPA anticipates 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). Although EPA proposes to use in this approach
many of the exposure-data sets previously identified for use in the
EDPSD, EPA is not proposing to directly use 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 Tier 1 screening lists based on experience gained from the
results of testing of 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 is proposing to use several bodies of data to identify
pesticide active ingredients for screening in the first use of the Tier
1 battery. These data focus on human exposure by different pathways:
1. As a consequence of consumption of food containing pesticide
residues.
2. As a consequence of consumption of 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 has identified existing data that it
believes will help to identify active ingredients likely to be among
those having either relatively more widespread or higher levels of
human exposure than would be expected for other active ingredients. EPA
proposes to give higher priority for inclusion on the list for initial
screening to chemicals likely to have human exposure via multiple
pathways, with the highest priority being given to substances having
exposure through all four pathways, followed by those having exposure
via three pathways, etc. Details on EPA's proposed approach for
selecting pesticide active ingredients are presented in Unit V.
EPA is proposing to use a generally similar approach to identify
HPV/Inert chemicals to be included in the initial list for screening in
the Tier 1 battery. However, EPA generally has more extensive
information of known quality 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 data and approaches
EPA has identified for selecting an initial set of HPV/Inert chemicals
for endocrine disruptor screening differs somewhat from those proposed
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
review existing
[[Page 79617]]
databases 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 1 million
pounds per year) chemicals (HPV/Inert). This first step will focus
initial Tier 1 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
existing data to identify HPV/Inert chemicals that have been found to
be present in: Human tissue, 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 this priority setting approach for HPV/Inert
chemicals are presented in Unit VI.
While EPA's general focus in this approach is on pesticide active
ingredients and HPV/Inert chemicals with relatively greater potential
human exposure, this focus 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 V. and VI., EPA believes that the
approach proposed 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 with widespread
environmental exposures to other organisms.
This proposed approach for selecting the initial list of chemicals
to undergo Tier 1 screening differs from the more general EDSP priority
setting approach outlined in EPA's December 28, 1998, Federal Register
notice (FRL-6052-9) in several aspects: EPA would focus chemical
selection for this initial list on the subset of chemicals subject to a
statutory mandate for screening (i.e., pesticide chemicals); EPA would
use exposure data as the primary basis for chemical selection rather
than using HTPS, QSARs or other hazard data in conjunction with
exposure data; EPA would defer consideration of nominations from the
public; and EPA would not include mixtures in this initial list. The
reasons for these proposed changes are as follows:
A. Focusing on the Subset of Chemicals Subject to a Statutory Mandate
for Screening
For the initial Tier 1 screening list, EPA is proposing to focus
only on pesticide active ingredients and HPV chemicals with some
pesticidal inert uses (i.e., the chemicals that are specifically
mandated for testing under section 408(p) of FFDCA) as candidates. The
pesticide inerts to be considered are those with relatively large
overall production volumes considering both pesticide and non-pesticide
uses. This approach will allow EPA to focus its initial endocrine
screening efforts on a smaller and more manageable universe of
chemicals that emphasizes early attention to the pesticide chemicals
that Congress specifically mandated EPA to test for possible endocrine
effects.
B. Using Exposure Data as the Primary Basis for Chemical Selection
In response to the recommendations of EDSTAC, EPA had stated its
intention to incorporate effects information into an overall chemical
prioritization scheme in conjunction with exposure information for
identifying chemicals to undergo screening and testing for endocrine
disruption potential. However, in light of the limited availability of
data for many chemicals that would indicate their relative potential
for disrupting endocrine systems and the delays in identifying adequate
HTPS or QSAR approaches that are discussed in Units IV.C. and IV.D.,
the Agency is proposing to use a simpler and narrower approach based
primarily on exposure for this initial selection of a limited number of
chemicals for screening under the EDSP.
A relatively broad range of toxicity data generally are available
for pesticide active ingredients regulated under FIFRA, but in most
cases it has not yet been established how the available data might be
confidently used to predict the endocrine disruption potentials of
these chemicals. This may be due, for example, to the non-specific
nature of an effect or effects observed, questions related to whether
the mode of action of 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. A more limited set of toxicity data
generally is available for pesticide inert ingredients.
Nevertheless, for certain chemicals the available data may provide
a sufficiently clear indication of an endocrine-mediated effect or
perturbation to warrant exclusion from the first group of chemicals to
undergo Tier 1 testing. Such chemicals would be considered for proposed
Tier 2 tests, mechanistic or special studies, or hazard assessment.
Similarly, based on a review of the available information, there are
certain other substances which EPA anticipates 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). EPA
anticipates also excluding certain of these substances from the first
group of chemicals to undergo Tier 1 testing.
Therefore, except for purposes of exclusion (e.g., there are
sufficient data to determine that a chemical has endocrine-mediating
activity), effects data are not being considered in this approach for
identifying the initial group of chemicals for Tier 1 screening. This
does not necessarily mean, however, that toxicity data will not be used
in identifying subsequent groups of chemicals for Tier 1 screening.
Because the list of chemicals produced using the proposed approach
will be a list of chemicals that the Agency, in its discretion, has
decided should be tested first based primarily upon exposure potential,
it 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.
C. HTPS
Recognizing the limitations on existing hazard data, EPA proposed
in the December 28, 1998, Federal Register notice (FRL-6052-9) the use
of in vitro HTPS to assist in sorting and priority setting. The plan
was to use HTPS to pre-screen up to 15,000 chemicals that are produced
in quantities exceeding 10,000 pounds per year. HTPS data would define
one of the compartments in the EDPSD and provide a criterion for
identifying high priority chemicals. EPA sponsored a limited
demonstration of an HTPS system utilizing reporter gene assays for the
estrogen receptor (ER), androgen receptor (AR), and thyroid receptor
(TR). The reporter gene assays used in this demonstration project
employed a human cell line that naturally contains the receptor. A
reporter element was then introduced into these cells so that when a
substance binds to a receptor it would activate the genetic machinery
in the cell. This activation could be detected in a quantitative
manner. The SAB/SAP
[[Page 79618]]
Subcommittee agreed with EPA that the demonstration HTPS system did not
work well enough in its present form to serve as a tool for priority
setting (Ref. 1). The assays had too much variability and too low of a
response to be useful without modifications to boost their sensitivity.
EPA concluded that the HTPS approach still holds promise but that it
has potential for success only after substantial additional research.
EPA decided to defer its plans for using HTPS and to explore the
potential for using QSAR models to address the problem of inadequate
hazard data to prioritize chemicals. Nonetheless, the SAB/SAP
Subcommittee believed that HTPS is a promising tool for priority
setting and EPA agrees. EPA has issued a Request For Application (RFA)
under its Science to Achieve Results (STAR) research grants program to
solicit new approaches that may lead to the development of HTPS to
assist in the prioritization of chemicals for screening for endocrine
disrupting activity (http://es.epa.gov/ncer/rfa/current /2003high--
throughput.html). EPA is also following the work being conducted in
Japan on ER and AR transcriptional activation-based HTPS systems. EPA
will consider the applicability of new HTPS approaches to future
priority setting in the EDSP as those approaches are further developed
and refined.
D. QSAR Models
At the time EPA decided to suspend its efforts under the EDSP on
HTPS, it was aware of at least two QSAR models that were being
developed to predict the potential of a chemical to bind to cellular
ER. QSAR offers one important advantage over HTPS. It could provide
data on thousands of chemicals without testing them in the laboratory.
Such a tool could save millions of dollars in chemical testing costs,
but still, if valid, be able to predict whether a new molecule that had
never been synthesized or an untested existing chemical would be likely
to interact with the ER or AR. EPA designed a program to validate two
QSAR models within a defined chemical domain and activity range of
interest to EPA. The comparative molecular field analysis (CoMFA) model
developed by Federal Food and Drug Administration's (FDA) National
Center for Toxicological Research and the common reactivity pattern
(COREPA) model developed at the University of Bourgas were evaluated.
EPA asked each of the modeling teams to predict the relative ER binding
of 6,649 high production chemicals on the TSCA inventory. EPA selected
50 chemicals predicted to be positive by each model and approximately
200 chemicals selected from the 6,649 at random and tested almost all
in an ER binding assay. Thus, a total of nearly 300 chemicals were
tested to validate the models. Each model predicted about 300 of the
6,649 chemicals to be positive. There were 78 chemicals that were
predicted to be positive by both models (Ref. 3). A comparison of model
predictions with laboratory results did not meet EPA's expectations
because, although both models demonstrated relatively high specificity,
both models also demonstrated low sensitivity. EPA believes that the
performance problems associated with the models are likely due to the
chemical training set being significantly dissimilar in terms of
structures and binding potency ranges compared to the TSCA HPV
chemicals. EPA is continuing to encourage the development and
refinement of QSARs and beginning in Fiscal Year 2002 redirected $4
million to a computational toxicology initiative to integrate modern
computing and information technology, not limited to just QSARs, with
the technology of molecular biology and chemistry to improve EPA's
ability to prioritize chemicals for screening and testing, and its risk
assessments.
E. Deferring Consideration of Nominations From the Public
For the initial Tier 1 screening list, EPA proposes to focus on
pesticide active ingredients and HPV chemicals with some pesticidal
inert uses (i.e., the chemicals that are specifically mandated for
testing under section 408(p) of FFDCA) as candidates. EPA believes that
nominations from the public are important because they provide a
mechanism to identify chemicals which may result in high exposures in
local communities but which would not otherwise receive national
attention. However, EPA has decided to defer consideration of
nominations from the public until subsequent testing lists in order to
keep this initial effort administratively simpler and ensure that a set
of test results can be obtained in a relatively prompt timeline to aid
the Agency in a mid-course evaluation of the EDSP Tier 1 screening
battery.
F. Not Testing Mixtures
EPA has decided that the prudent approach would be to gain
experience with these tests on a variety of single chemicals before it
addresses mixtures. This judgement is consistent with advice from the
SAB/SAP Subcommittee (Ref. 1).
G. Excluding Chemicals that are no Longer Produced or Used in the
United States
EPA also is proposing to exclude from the initial Tier 1 screening
list any chemicals that are no longer produced or used in the United
States. The Agency thinks that such chemicals would not warrant high
priority for testing at this time. Although some of the databases that
EPA proposes to consider may report past detections of such chemicals,
the discontinuation of their use and manufacture means that exposure to
these substances is likely declining. Moreover, EPA anticipates that it
will have to resolve significant practical difficulties (such as
determining who EPA could require to conduct the testing) before it
attempts to require testing of these substances. This combination of
reasons leads the Agency to propose excluding discontinued chemicals
from the initial group of chemicals to undergo testing in the Tier 1
screening battery.
V. Approach for Selecting Pesticide Active Ingredients
EPA is proposing to use several sets of criteria for identifying
pesticide active ingredients to be given priority for screening in
EPA's initial application of the Tier 1 battery. These criteria would
focus on human exposure by different pathways: As a consequence of
consumption of food containing pesticide residues; as a consequence of
consumption of drinking water containing pesticide residues; as a
consequence of residential use of pesticide products; and through
occupational contact with pesticide-treated surfaces. For each of the
four pathways, EPA would review existing databases that can help the
Agency 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
[[Page 79619]]
for exposure through drinking water contain monitoring data collected
on raw surface water, i.e., before the water enters a Community Water
System. Thus, these monitoring data show the levels of pesticide
residues which 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 proposed to evaluate pesticide active
ingredients, while focused on human exposure, will also capture many
active ingredients with widespread environmental exposures.
A. The 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 of others.
To evaluate the interplay of these different variables, EPA
proposes to identify the pesticide active ingredients which are most
frequently found as residues on the top twenty foods that people
consume. First, EPA will examine 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
two 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 (`94-`96) is available
through http://www.barc.usda.gov/bhnrc/foodsurvey.
Using the CSFII information, EPA has converted the reported food
consumption for each survey respondent into the constituent raw
agricultural commodities. For example, if a person reported having
eaten 6 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. Then EPA 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. This individual food consumption database provides the
basis for identifying the top twenty foods consumed, in terms of mean
daily consumption for the general population. List 1 of this unit lists
these raw agricultural commodities.
List 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 foods, EPA would 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 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/
[sim]dms/pesrpts.html.
Because of the differences in how samples are collected and
handled, EPA would rely on the PDP database when both sources cover the
same pesticides and commodities. The FDA Surveillance data covers
different pesticides and commodities in different years from the PDP
monitoring. (For example, in 1999, FDA used analytical methods capable
of detecting 366 different active ingredients.) Therefore, in making
its weight-of-the-evidence judgment, EPA would consider the FDA
information as a supplement to the information from the PDP database.
EPA proposes to examine the PDP and FDA Surveillance databases to
identify the pesticide active ingredients which appear on the largest
proportion of the samples, focusing on the twenty foods which make up
the largest part of the U.S. diet. Generally, EPA would give higher
weight to pesticides that appear frequently on multiple foods. In
reviewing these data, EPA will take into account qualitatively any risk
mitigation measures implemented since residues levels were monitored.
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 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
[[Page 79620]]
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 that the
approach described is a practicable approach for identifying pesticide
active ingredients with widespread or high levels of exposure.
B. The Water Pathway
Significant portions of the general population may be exposed to
pesticide residues in 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.
Because 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, exposure to pesticides through the
drinking water pathway can be widespread and repeated. And, while such
exposure is usually neither as widespread nor of the same magnitude as
pesticide exposure through food, a significant portion of the
population in a particular region of the country can be exposed.
To assess relative exposure to different pesticides in water, EPA
would examine a number of different databases that contain the results
of programs to monitor surface and ground water for the presence of
pesticide residues. 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 (PGWDB). The 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 raw ground-
water\1\ and contains data only from studies in which pesticides were
included as analytes. Some of the 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. 4).
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 raw
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 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 by Agency scientists.
3. Heidelberg College's Monitoring Data. Heidelberg College's Water
Quality Laboratory (WQL) conducts research, monitoring and educational
programs that address the impacts of agricultural and urban land use on
the water resources of Ohio, the Midwest, and the Lake Erie and Great
Lakes ecosystems. The WQL began studying pesticides in 1981. These
studies now provide the longest and most detailed record of pesticide
residues in raw water available for any river system in the United
States. The WQL maintains a modern, highly automated water chemistry
laboratory with capabilities rarely found within academic research
settings. While much of the WQL's program is organized within the
context of a large-scale, long-term agricultural ecosystem study, the
lab also conducts research related to public drinking water supplies
(finished water), urban runoff, industrial and municipal pollution
sources and changing biological communities in Lake Erie. Further
details can be found on the web at: http://www.heidelberg.edu/WQL/index.html
.
4. U.S. Geological Survey (USGS)/EPA Reservoir Monitoring Study.
The USGS/EPA Reservoir Monitoring study was a pilot monitoring program
initiated by USGS and EPA to provide information on pesticide
concentrations in drinking water and to assist in the implementation of
the Food Quality Protection Act (FQPA) of 1996. 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. 5).
5. Environmental Monitoring and Assessment Program (EMAP). 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 which humans and wildlife may contact. EMAP includes
relevant data for over 170 chemicals and three separate data sets for
estuary sediments. Extensive field and laboratory QA/QC procedures were
performed during the collection and analysis of the samples. Further
details can be found on the web at: http://www.epa.gov/emap/.
6. National Sediment Inventory (NSI). 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
NSI. The NSI
[[Page 79621]]
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 this 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
and http://www.epa.gov/
waterscience/cs/draft/survey.html.
7. National Drinking Water Chemical Occurrence Database (NCOD).
NCOD is a repository of drinking water quality data, mandated by
Congress in the 1996 SDWA Amendments. NCOD contains national occurrence
data from public water systems and from ambient water from the USGS
National Water Information System. It includes information on regulated
and unregulated contaminants, containing physical, chemical, microbial,
and radiological information for both detects and non-detects. NCOD-
drinking water contains relevant data for over 120 chemicals, and
includes samples from both raw and finished water. Currently, NCOD-
drinking water contains occurrence only for those water systems that
have been reported by States to EPA's Safe Drinking Water Information
System. While data sets will be updated over time, they may reflect a
lag time of at least six months. Further details can be found on the
web at: http://www.epa.gov/safewater/data/ncodgateway.html.
8. National Stream Quality Accounting Network (NASQAN) Data.
NASQAN, a monitoring and data-collection program conducted by the USGS,
is designed to characterize raw surface water 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 (QC) 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 on the web at: http://water.usgs.gov/nasqan/.
9. The National Water Quality Assessment Program (NAWQA). 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 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 so as 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 on the web at: http://wwwga.usgs.gov/nawqa/main.nawqa.html.
EPA notes that most of the monitoring databases report results from
samples of ``raw,'' or untreated, water, rather than ``finished''
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 raw 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 raw water and
concluded that conventional water treatment processes (such as
coagulation/flocculation, sedimentation, and filtration) can have
little or no effect on the removal of certain pesticides (Ref. 6).
Thus, the Agency regards the results of monitoring raw or ambient water
as an appropriate indicator of potential human exposure.
Many other factors affect the interpretation of a set of water
monitoring data. 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
these factors were considered. 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. 7) and the EPA Background Paper for the FIFRA
Scientific Advisory Panel Meeting on Monitoring Strategies for
Pesticides in Surface-Derived Drinking Water (Ref. 8).
The limitations on 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 V.B. are not
[[Page 79622]]
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 V.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 proposes to review the
multiple databases 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 would 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 or 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. The 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 proposes to use pesticide product labeling information as the
primary indicator of pesticides whose use involves potential human
exposure by this pathway. EPA would 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 would be identified as having higher
priority with respect to the residential use pathway.
The Agency recognizes that registration of a pesticide for
residential use does not necessarily mean that it 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 which consistently have
potential for higher levels of human exposure. Thus, EPA does not
regard its proposed basis for selecting priority chemicals for this
pathway as being as effective in setting priorities among active
ingredients as the criteria proposed for the other pathways.
Nonetheless, residential use pesticides involve potential exposures to
the general population, the Agency believes it would be 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 proposes to 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 Unit V.D., 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 proposes to rank pesticides on the basis of their
potential for post-application exposure of agricultural workers. This
group includes farmers and farmworkers who reenter pesticide-treated
fields and orchards to care for or harvest the crop. A relatively
recent database developed by the Agricultural Reentry Task Force (ARTF)
clearly indicates that certain work activities in particular crops lead
to higher levels of exposure than other post-application work
activities (Ref. 9). 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.\2\ Activities
having
[[Page 79623]]
higher transfer coefficients should result in higher levels of worker
exposure, all other factors being equal.
EPA proposes to identify the crops having approximately the dozen
highest transfer coefficients and then to identify the pesticides
having the highest levels of use on those crops. Specifically, EPA
would estimate the total number of acre treatments for each pesticide
on all of the top crops and then rank the pesticides on the basis of
the highest totals.\3\ The Agency would 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, California's Department of Pesticide Regulation,
and Doane Marketing Research.
The USDA's National Agricultural Statistics Service (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 total 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 the California Department of Pesticide Regulation
(CDPR), and includes an extensive array of treatment information on
crops including timing, location, area, and rate. These data allow EPA
to calculate acre-treatments for pesticides on 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 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. 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 Marketing Research can be found at: http://www.doanemr.com/
.
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 proposed 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--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 would integrate the information
developed on priorities through the analysis of the four exposure
pathways discussed in Units V.A. through V.D. As its first step, the
Agency would apply the criteria proposed for each pathway to produce
four lists of candidate chemicals for potential screening in the
endocrine disruptor Tier 1 battery. EPA expects that a number of
pesticide active ingredients would 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 would recommend
for screening, EPA would give higher priority to chemicals that
appeared 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 would propose to 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). As a final step, EPA
would review the available effects information to identify any chemical
for which the information clearly indicates an endocrine-mediated
effect/perturbation. Such chemicals would be considered for proposed
Tier 2 tests, mechanistic or special studies, or hazard assessment.
During this step, EPA also would identify substances that EPA
anticipates would have low potential to cause endocrine disruption. EPA
would consider excluding substances in either category from the first
group of chemicals to undergo Tier 1 testing.
---------------------------------------------------------------------------
\1\ ``Raw'' water refers to a water source that has not been
treated in a drinking water facility. Water that has been treated is
referred to as ``finished'' water.
\2\ 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 (cm2), 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.
\3\ 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.
---------------------------------------------------------------------------
VI. Approach for Selecting Pesticide HPV/Pesticide Inert Chemicals
EPA is proposing to use several sets of criteria for identifying
HPV/Inert chemicals that should be given priority for screening in the
Tier 1 battery. In general, the Agency is proposing an approach for
HPV/Inert chemicals that is similar to that proposed 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 tissues. While EPA's
general focus is on HPV/Inert chemicals with relatively greater
potential human exposure, this focus
[[Page 79624]]
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/Inert
chemicals 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 VI.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
Community Water System (see Unit VI.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 proposed to evaluate pesticide HPV/Inert
chemicals, while focused on human exposure, will also capture HPV/Inert
chemicals with widespread environmental exposures.
EPA generally has more extensive information of known quality
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 inerts). For these reasons, the databases available
to evaluate potential human exposure of the two classes also differ.
First, EPA will review existing databases to identify chemicals
that are both pesticide inerts and HPV chemicals (HPV/Inert). 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 TSCA Inventory Update Rule (IUR). Organic chemicals that are
manufactured or imported into the United States in amounts equal to or
greater than 10,000 pounds per year are subject to reporting under TSCA
IUR every 4 years. Second, EPA will review existing data bases to
identify HPV/Inert chemicals that are present in human tissue, or
ecological tissues that have human food uses, or drinking water or
indoor air. Third, EPA will prioritize these chemicals based on the
number of data bases in which that the chemical was found. Thus, HPV/
Inert chemicals appearing in four types of monitoring data would be
given higher priority than those appearing in only one type of
monitoring data. EPA may also give higher priority to those HPV/Inert
chemicals that appear in human tissues than to those chemicals that
only appear in water, air, or ecological tissues.
As a final step, EPA would review the available effects information
to identify any chemical for which the information clearly indicates an
endocrine-mediated effect/perturbation. Such chemicals would be
considered for proposed Tier 2 tests, mechanistic or special studies,
or hazard assessment. During this step, EPA also would identify
substances that EPA anticipates would 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). EPA would consider excluding
substances in either category from the first group of chemicals to
undergo Tier 1 testing.
A. HPV/Inert Chemicals in Human Biological Monitoring Data
EPA proposes to review the following data sources to determine
which HPV/Inert chemicals have been detected in human biological
samples.
1. Third National Health and Nutrition Examination Survey (NHANES
III). 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 Ashley et al (1994) (Ref. 10). This NHANES
volatile organic compound (VOC) article contains relevant human
biomonitoring data for over 40 chemicals. Standard quality assurance/
quality control (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 (Ref. 11) is a Centers for
Disease Control and Prevention (CDC) report that provides 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. 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. It is anticipated that a second
report will be issued in late 2002 with human biomonitoring information
on an additional 75 chemicals.
3. National Human Adipose Tissue Survey (NHATS). The EPA's OPPT
operated the National Human Monitoring Program (NHMP) until the early
1990s. The NHMP's primary activity was conducting 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; however, a standard set of summarized data
parameters are not available. (Refs. 12-25).
4. Total Exposure Assessment Methodology Study (TEAM Study). The
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. 26-
28).
Established methods were used to collect and analyze TEAM Study
data.
[[Page 79625]]
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. HPV/Inert Chemicals in Ecological Biological Monitoring Data
Relevant to Human Exposure
EPA proposes to review the following data sources to determine
which HPV/Inert chemicals have been detected in non-human tissues
potentially relevant to human ingestion exposure.
1. National Sediment Inventory Fish Tissue Data (NSI Fish Tissue
Data). This database is described in Unit V.B.
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 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 survey 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
.
C. HPV/Inert Chemicals in Drinking Water Monitoring Data
EPA proposes to review the following data sources to determine
which HPV/Inert chemicals have been detected in drinking water and in
potential sources of drinking water.
1. National Drinking Water Chemical Occurrence Data Base (NCOD Data
Base). This database is described in Unit V.B.
2. National Human Exposure Assessment Survey (NHEXAS). EPA designed
the 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. 29-32).
3. Total Exposure Assessment Methodology Water Data (TEAM Water
Data). The TEAM Study is described in Unit VI.A.
4. National Stream Quality Accounting Network (NASQAN) Data. This
database, which contains information on surface water monitoring
studies, is described in Unit V.B.
5. The National Water Quality Assessment Program (NAWQA). This
database, which contains information on surface water and ground water
monitoring studies, is described in Unit V.B.
D. HPV/Inert Chemicals in Indoor Air Monitoring Data
EPA proposes to review the following data sources to determine
which HPV/Inert chemicals have been detected in residential indoor air.
1. Office of Research and Development Published Literature. The
following eight EPA/ORD-authored journal articles and reports provide
indoor 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.
33-40).
2. NHEXAS. The 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. 30-32,
41).
3. Total Exposure Assessment Methodology (TEAM). The TEAM Study is
described in Unit VI.A.
E. Integration of Pathway Priorities for HPV/Inert Chemicals
This unit addresses how EPA would integrate the information
developed on priorities through the analysis of the four types of
exposure monitoring data discussed in Units VI.A through VI.D (human
biological data, ecological biological data relevant to human exposure,
drinking water data, and indoor air data). As its first step, the
Agency would produce four lists of candidate chemicals, one for each
type of monitoring data, for potential screening in the endocrine
disruptor Tier 1 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/Inert chemicals it would recommend for screening,
EPA would give higher priority to chemicals that appeared 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 establish priorities within
these four types of monitoring data, EPA would propose to 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. As a final step, EPA would review the available effects
information to identify any chemical for which the information clearly
indicates an endocrine-mediated effect/perturbation. Such chemicals
would be considered for proposed Tier 2 tests, mechanistic or special
studies, or hazard assessment. During this step, EPA also would
identify substances that EPA anticipates would 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
[[Page 79626]]
bases). EPA would consider excluding substances in either category from
the first group of chemicals to undergo Tier 1 testing.
VII. Issues for Comment
In developing this proposed approach for selecting the first group
of chemicals to be screened in the Agency's EDSP, EPA discussed a
number of alternative approaches and identified a series of questions
to elicit information from the public that would help in the evaluation
of alternative approaches. In addition to the specific questions in
this unit, EPA invites comment on additional alternative approaches.
A. Overall Approach for Selecting the Initial Set of Chemicals to
Undergo Tier 1 Screening
1. Focusing on the subset of chemicals subject to a statutory
mandate for screening. EPA is intending to focus only on pesticide
active ingredients and HPV chemicals with some pesticidal inert uses
(i.e., the chemicals that are specifically mandated for testing under
section 408(p) of FFDCA) as candidates for the first group of chemicals
to be screened. The pesticide inerts to be considered are those with
relatively large overall production volumes considering both pesticide
and non-pesticide uses. This approach will allow EPA to focus its
initial endocrine screening efforts on a smaller and more manageable
universe of chemicals that emphasizes early attention to the pesticide
chemicals that Congress specifically mandated EPA to test for possible
endocrine effects. Please comment on this proposed decision.
2. Limited use of effects information. Because the amount and type
of toxicological data available to identify or characterize endocrine-
related human health or ecological effects is not considered by the
Agency to be adequate to support determinations of the endocrine
disruption potential of most pesticide chemicals, EPA has proposed an
approach that would use effects information only to exclude certain
chemicals from the first group of chemicals to undergo Tier 1
screening. The approach would exclude from the first group of chemicals
to undergo Tier 1 screening any chemical for which the available
effects information is determined by EPA to clearly shows an endocrine-
mediated effect. Such chemicals would be considered for proposed Tier 2
tests, mechanistic or special studies, or hazard assessment. Similarly,
the approach for this initial list also would exclude substances that
EPA anticipates 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). Please comment on this proposed decision and
comment on the types of studies/data which could be evaluated by the
Agency to aid in making exclusion decisions.
3. Focus on human exposure; no separate criteria pertaining to
exposure of ecological receptors. While EPA's general focus in this
approach is on pesticide active ingredients and HPV/Inerts with
relatively greater potential for human exposure, this focus does not
necessarily mean that the list developed using this approach will not
contain substances which have potentially high levels of environmental
exposure to ecological receptors. EPA believes that the proposed
approach, while focused on human exposure, will also identify many
chemicals with widespread environmental exposures to other organisms.
If EPA should consider such exposures separately, please identify
databases and criteria appropriate for setting priorities.
4. Deferring consideration of nominations from the public. For the
initial Tier 1 screening list, EPA proposes to focus on pesticide
active ingredients and HPV chemicals with some pesticidal inert uses.
EPA believes that nominations from the public are important because
they provide a mechanism to identify chemicals which may result in high
exposures in local communities but which would not otherwise receive
national attention. However, EPA has decided to defer consideration of
nominations from the public until subsequent testing lists are proposed
by EPA to keep this initial effort administratively simpler and ensure
that a set of test results can be obtained in a relatively prompt
timeline to aid the Agency in a mid-course evaluation of the EDSP Tier
1 screening battery. Please comment on this proposed decision.
5. Defer testing of mixtures. EPA believes that experience with the
Tier 1 tests on a variety of single chemicals needs to be attained
before the tests are used with mixtures. Therefore, EPA is proposing to
defer consideration of testing of mixtures until subsequent testing
lists are proposed by EPA. This judgement is consistent with advice
from the SAB/SAP Subcommittee. Please comment on this proposed
decision.
6. Excluding chemicals that are no longer produced or used in the
United States. EPA also is proposing to exclude from the initial Tier 1
screening list any chemicals that are no longer produced or used in the
United States. The Agency thinks that the added administrative
complexity of determining who should be responsible for testing such
chemicals could unnecessarily delay EPA's selection of an initial list
for Tier 1 screening. Please comment on this proposed decision.
7. Number of chemicals to be selected for the initial testing list.
The SAB/SAP Joint Subcommittee which reviewed EPA's proposed EDSP in
1999 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 to broaden this
effort. The Subcommittee also expressed concern that it did not see a
provision that would allow for mid-course correction or optimization of
the Program. Thus, the Subcommittee recommended that EPA should
initiate the Tier 1 testing program with a set of 50 to 100 chemicals
and then convene an external panel of independent scientists to review
the screening data for the purpose of evaluating whether the Tier 1
screening program could be improved or optimized, and if so, how. EPA
is proposing to adopt this SAB/SAP recommendation. Please comment on
this proposed decision.
8. Integration of lists generated by the pesticide active
ingredient approach and the pesticide inert approach. As discussed in
Unit IV, EPA is proposing to use similar but somewhat different sets of
criteria for identifying pesticide active ingredients and inerts that
should be given priority for screening in the Tier 1 battery. EPA
generally has more extensive information of known quality available to
assess usage and potential exposure to pesticide active ingredients
than is available to assess exposure to HPV/Inert chemicals. Thus, the
databases available to evaluate potential human exposure of the two
classes also differ. EPA has not yet decided on the method to use to
select the initial list of chemicals for screening from the separate
lists that will be generated by the proposed approaches for pesticide
active ingredients and HPV/Inert chemicals. Several alternative methods
are being considered including the following. After looking at the
separate lists, once they are generated, there may be natural break
points. For example, if the top category for pesticide active
ingredients (i.e., those chemicals which appear on lists for each of
the four pathways) yields 60 actives and the top category for HPV/Inert
chemicals (i.e., those chemicals which appear on lists for each of the
three pathways and in human biomonitoring samples) yields
[[Page 79627]]
30, the Agency may select these 90 chemicals. Another approach being
considered is a simple ratio approach. Because there are approximately
an equal number of pesticide actives as HPV/Inerts, one way to produce
a combined list would be to select approximately 50% of the chemicals
from the active list and 50% from the HPV/Inert chemicals list. Please
comment on these and other approaches that EPA could use to integrate
the lists.
B. Approach for Selecting Pesticide Active Ingredients
1. The Agency considered approaches that did not focus on the four
separate pathways of human exposure. Please comment on the following
issues.
i. The advantages and disadvantages of setting priorities based on
the overall extent of pesticide use, for example total pounds applied
or total acres treated.
ii. Should all four pathways be considered? If not, please comment
on which pathways should and should not be included.
2. Within separate pathways, EPA considered a variety of
alternative approaches. Please comment on the following issues.
i. Food pathway. Would ranking pesticides by the extent of use on
the top 20 crops be appropriate, given that it would be simpler and
more quantitative than the approach proposed in this Notice?
ii. Water pathway. With regards to the proposed databases, should
other databases be included, and should any be dropped?
iii. Residential use pathway. Should any additional criteria be
used to set priorities within the universe of active ingredients with
residential uses? For example, should EPA give higher or lower priority
to particular use patterns because they are consistently likely to lead
to greater or lesser levels of human exposure? Are there databases that
could provide information on the extent of residential use of
pesticides that would support setting priorities within this group?
iv. Occupational pathway. Are there criteria that would recognize
how the differences in rate and timing of application of a pesticide or
its environmental fate properties might affect levels of post-
application exposure? Also, please comment on whether EPA should employ
criteria to set priorities for active ingredients based on their levels
of exposure for mixers, loaders, and applicators. If EPA should
consider such exposure in setting priorities for the occupational
pathway, please identify databases and criteria appropriate for setting
priorities. Also, please comment on whether EPA should consider
criteria for the occupational pathway that employs data from reports on
the incidence of adverse effects among workers, such as data collected
by the California's Pesticide Illness Surveillance Program (PISP) (see,
for example, the PISP report for 2000, http://www.cdpr.ca.gov/docs/dprdocs/pisp/2000pisp.htm
) or the National Institute of Occupational
Safety and Health's Sentinel Event Notification System for Occupational
Risk (see http://www.cdc.gov/niosh/pestsurv/default.html).
3. EPA's proposed approach to setting its overall priority for
pesticide active ingredients that combines the analysis for each of the
four pathways generally gives each pathway equal weight. Alternative
approaches are also possible. Please comment on the following issues.
i. Should a different approach be used to integrate the information
from the four different pathways, for example by assigning different
weights to the pathways?
ii. Should there be any limit on the number of active ingredients
included on the list for a single pathway?
iii. Should any factors other than the pathway lists and the
hazard-based considerations be included in the integrative step?
iv. Should EPA attempt to explicitly consider magnitude of the
environmental concentrations of chemicals in this approach and, if so,
how?
C. Approach for Selecting Pesticide HPVolume/Pesticide Inert Chemicals
1. EPA's proposed approach for setting screening priorities for
pesticide inert ingredients that are also HPV chemicals uses four types
of monitoring data. These are human biomonitoring data, ecological
biomonitoring data relevant to human exposure, water monitoring data
and indoor air monitoring data. Please comment on the following issues.
i. Should the selection of priority HPV/Inert chemicals be based
upon all four types of monitoring data? If not, please comment on which
type of monitoring data should and should not be included.
ii. Should other types of exposure information be used instead of
or in addition to monitoring data?
2. Within the four separate types of monitoring data, EPA
identified and selected sources of monitoring data for use in priority
setting for HPV/Inert chemicals. Please comment on the following
issues.
i. The appropriateness of the data sources identified in this
proposed approach.
ii. For human biological monitoring data, are there additional
sources of data that EPA should consider?
iii. For ecological biological monitoring data relevant to human
exposure, are there additional sources of data that EPA should
consider?
iv. For water monitoring data, are there additional sources of data
that EPA should consider?
v. For indoor air monitoring data, are there additional sources of
data that EPA should consider?
3. EPA's proposed approach to setting its priorities for HPV/Inert
chemicals combines the analysis for each of the four types of
monitoring data and generally gives each type of monitoring data equal
weight. However, if necessary to establish priorities within these four
types of monitoring data, higher weight would be assigned to human
biomonitoring data than to the other three types of monitoring data.
Alternative approaches are also possible. Please comment on the
following issues.
i. Should a different approach be used to integrate the information
from the four different types of monitoring data, for example by
assigning different weights initially to all types of monitoring data?
ii. Should there be any limit on the number of HPV/Inert chemicals
included on the list for a single type of monitoring data?
iii. Should any factors other than the lists of HPV/Inert chemicals
found in the four types of monitoring data and the hazard-based
considerations be included in the integrative step?
VIII. References
The Agency's actions are supported by the references listed in this
unit and cited in this notice. These references are available in the
public record for this notice under docket ID number OPPT-2002-0066.
(See Unit I.B. for information on how to access this docket).
1. 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.
2. EPA. Endocrine Disruptor Screening and Testing Advisory
Committee Final Report. August 1998. Available at: http://www.epa.gov/scipoly/oscpendo/history/finalrpt.htm
.
3. EPA. Evaluation of SAR Predictions of Estrogen Receptor Binding
Affinity. EPA Contract No. 68-W-01-023, Work
[[Page 79628]]
Assignment No. 2-3, Battelle Memorial Institute. August 1, 2002.
4. EPA. EPA Pesticides in Ground Water Database, A Compilation of
Monitoring Studies: 1971-1991 National Summary, EPA 734-12-92-001.
September 1992.
5. 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.
6. EPA. The Incorporation of Water Treatment Effects on Pesticide
Removal and Transformation in Food Quality Protection Act Drinking
Water Assessments. November 21, 2001. Available at: http://www.epa.gov/pesticides/trac/science/#drinking
.
7. EPA. Estimating the Drinking Water Component of a Dietary
Exposure Assessment. Revised November 2, 1999. Available at: http://www.epa.gov/pesticides/trac/science/#drinking
.
8. EPA. EPA Background Paper for the FIFRA Scientific Advisory
Panel Meeting on Monitoring Strategies for Pesticides in Surface-
Derived Drinking Water. June 2002. Available at: http://www.epa.gov/scipoly/sap/2000/june/drinkingwatersurvey.pdf
.
9. EPA. Science Advisory Council on Exposure, Policy Number 003.1,
Agricultural Transfer Coefficients.
10. 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.
11. CDC. National Report on Human Exposure to Environmental
Chemicals. March 2001. http://www.cdc.gov/nceh/dls/report/reportsummary.htm
.
12. EPA. Chlorinated Dioxins and Furans in the General U.S.
Population: NHATS FY87 Results--Executive Summary. EPA-560/5-91-003.
May 1991.
13. 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, 1990.
14. 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.
15. 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.
16. 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.
17. 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.
18. Onstot, J.D. and Stanley, J.S. Identification of SARA Compounds
in Adipose Tissue. EPA-260/5-89-003 (NTIS PB90-132564). August 1989.
19. 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.
20. EPA. Semivolatile Organic Compounds in the General U.S.
Population: NHATS FY86 Results--Volume I. EPA-747-R-94-001. July 1994.
21. 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.
22. 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.
23. 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.
24. 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.
25. 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.
26. 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.
27. EPA. The Total Exposure Assessment Methodology (TEAM) Study:
Selected Communities in Northern and Southern California: Volume III.
EPA-600/6-87/002c (NTIS PB88-00086). June 1987.
28. Wallace, Lance. Project Summary: The Total Exposure Assessment
Methodology (TEAM) Study. EPA/600/S6-87/002. September 1987.
29. 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 Analysis and Environmental
Epidemiology. (1999) 9: 402-413.
30. 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 Analysis and
Environmental Epidemiology. (1999) 9: 381-392.
31. 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.
32. 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.
33. 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: 123-124.
34. 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.
35. 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.
[[Page 79629]]
36. 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.
37. Samfield, Max M. Indoor Air Quality Data Base for Organic
Compounds. EPA-600-R-92-025 (NTIS PB92-158468). February 1992.
38. 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.
39. 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.
40. 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.
41. Gordon, Sydney M.; Callahan, Patrick J.; Nishioka, Marcia G.;
Brinkman, Marielle C.; O'Rourke, Mary Kay; Lebowitz, Michael D.; and
Moschandreas, Demetrios J. 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: 546-470.
IX. Statutory and Executive Order Reviews
This notice is not subject to review by the Office of Management
and Budget (OMB) under Executive Order 12866, entitled Regulatory
Planning and Review (58 FR 51735, October 4, 1993). Nevertheless, OMB
participated in an interagency review of this notice and any comments
or suggestions received during that review, have been addressed.
Since this notice does not impose any requirements, and instead
seeks comments and suggestions for the Agency to consider in developing
its approach for selecting the first group of chemicals to be screened
in the Agency's EDSP, the various other review requirements that apply
when an agency imposes requirements do not apply to this notice. As a
part of your comments on this document, however, you may include any
comments or information that would facilitate the Agency's
consideration of approaches for selecting the first group of chemicals
to be screened in the Agency's EDSP, including but not limited to
potential impacts on small entities covered by the Regulatory
Flexibility Act (RFA) (5 U.S.C. 601 et seq.), the availability of
voluntary consensus standards pursuant to 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), and potential paperwork
burden and costs, as well as any suggested methods for minimizing
respondent burden, including through the use of automated collection
techniques, related to the collection of this information as described
by the Paperwork Reduction Act (PRA) (44 U.S.C. 3501 et seq.). The
Agency will consider such comments during the development of the
approach and will take appropriate steps to address any applicable
requirements.
List of Subjects
Environmental protection, Chemicals, Endocrine disruptors,
Pesticides and pests.
Dated: December 23, 2002.
Stephen L. Johnson,
Assistant Administrator for Prevention, Pesticides and Toxic
Substances.
[FR Doc. 02-32853 Filed 12-24-02; 11:49 am]
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