Chapter
I,
Page
1
of
5
Chapter
I.
Introduction
A.
Purpose
and
Organization
of
Document
The
purpose
of
this
document
is
to
provide
the
Scientific
Advisory
Panel
(
SAP)
with
an
overview
of
the
aquatic
and
terrestrial
Level
II
Refined
Risk
Assessment
(
RRA)
Models
(
Version
2.0),
a
key
product
of
EPA's
initiative
to
refine
the
ecological
risk
assessment
process.
These
refined
models,
which
will
be
presented
at
an
SAP
meeting
scheduled
for
March
30
­
April
2,
2004,
incorporate
probabilistic
tools
and
methods
that
provide
information
on
the
probability
or
likelihood
of
ecological
impact
and
on
the
magnitude
or
severity
of
the
effect
resulting
from
the
use
of
pesticides.

Organized
into
six
chapters,
this
document
begins
with
an
introductory
chapter
(
Chapter
1)
that
provides
background
information
for
the
SAP
meeting.
This
first
chapter
describes
the
purpose
and
organization
of
this
document,
the
goals
and
history
of
OPP's
initiative
to
refine
the
ecological
risk
assessment
process,
and
an
overview
of
the
proposed
conceptual
risk
assessment
process.
The
document
continues
with
Chapter
II,
which
describes
the
purpose
of
the
SAP
meeting,
presents
the
charge
to
the
Panel
by
listing
the
questions
the
Agency
would
like
the
SAP
to
address.
Chapters
III
and
IV
provide
an
overview
of
the
terrestrial
and
aquatic
Level
II
Refined
Risk
Assessment
Models
(
Version
2.0),
respectively,
focusing
on
those
changes
which
were
made
since
the
models
(
Version
1.0)
were
initially
presented
to
the
SAP
on
March
13
­
16,
2001.
Lastly,
the
document
ends
with
conclusions
(
Chapter
V),
a
bibliography
(
Chapter
VI),
and
appendices.

B.
History
and
Goals
of
Initiative
In
May
29
­
31,
1996,
the
Agency
presented
two
ecological
risk
assessment
case
studies
to
the
SAP
for
review
and
comment.
While
recognizing
and
generally
reaffirming
the
utility
of
EPA's
current
deterministic
assessment
process
(
risk
quotient
method),
the
SAP
offered
a
number
of
suggestions
for
improvement
(
FIFRA
Scientific
Advisory
Panel,
1996a
and
1996b).
Foremost
among
their
suggestions
was
a
recommendation
to
move
beyond
the
present
single
point
assessment
process
by
developing
the
tools
and
methodologies
necessary
to
conduct
a
probabilistic
assessment
of
effects.
Such
an
assessment
would
estimate
the
magnitude
and
probability
of
the
expected
impact
and
define
the
level
of
certainty
and
variation
involved
in
the
estimate.

The
recommendations
of
the
SAP
were
consistent
with
issues
that
risk
managers
within
EPA's
Office
of
Pesticide
Programs
(
OPP)
have
raised,
namely
questions
about
the
magnitude
of
the
risk
described
for
a
particular
pesticide,
the
probability
of
the
risk
occurring,
and
the
certainty
of
the
evaluation.

Following
the
recommendations
of
the
SAP
and
in
response
to
issues
raised
by
OPP
risk
managers,
the
Agency
began
an
initiative
to
refine
the
ecological
risk
assessment
process
for
Chapter
I,
Page
2
of
5
pesticides.
The
refined
process
focuses
on
evaluating
the
effects
of
pesticides
to
terrestrial
and
aquatic
species
within
the
context
of
FIFRA
(
Federal
Insecticide,
Fungicide,
and
Rodenticide
Act),
the
main
statutory
authority
for
regulating
pesticides
at
the
federal
level.

The
key
goals
and
objectives
of
EPA's
initiative
include
the
following:

°
Develop
a
conceptual
approach
to
refine
the
ecological
assessment
process;
°
Incorporate
probabilistic
tools
and
methods
to
provide
an
estimate
on
the
magnitude
and
probability
of
effects;
°
Address
the
broad
spectrum
of
responses
to
pesticide
exposure;
°
Reflect
more
realistic
actual
use
scenarios
and
field
conditions;
°
Build
upon
existing
data
requirements
for
registration;
°
Utilize,
wherever
possible,
existing
data
bases
and
create
new
ones
from
existing
data
sources
to
minimize
the
need
to
generate
additional
data;
and
°
Focus
additional
data
requirements
on
reducing
uncertainty
in
key
areas.

The
initiative
began
with
the
formation
of
The
Ecological
Committee
on
FIFRA
Risk
Assessment
Methods
(
ECOFRAM),
composed
of
experts
drawn
from
government
agencies,
academia,
contract
laboratories,
environmental
advocacy
groups,
and
industry.
This
Committee
was
tasked
with
identifying
and
developing
probabilistic
tools
and
methods
for
terrestrial
and
aquatic
assessments
under
the
FIFRA
regulatory
framework.
The
conclusions
and
recommendations
of
the
ECOFRAM
were
summarized
in
the
Draft
Aquatic
Workgroup
Report
and
the
Draft
Terrestrial
Workgroup
Report
(
ECOFRAM,
Terrestrial
Workgroup,
1999;
ECOFRAM,
Aquatic
Workgroup,
1999).

After
completion
of
the
ECOFRAM
draft
reports,
the
Agency
held
two
public
workshops
to
obtain
external
scientific
review
and
comment
on
the
reports
from
scientists
who
had
not
participated
in
the
developmental
process.
Participants
in
the
June
22
­
23
and
June
23
­
24,
1999
workshops
included
a
broad
representation
of
affiliations
and
represented
the
scientific
disciplines
necessary
to
conduct
a
thorough
review.
The
workshop
comments,
which
were
factored
into
the
decisions
regarding
the
implementation
of
the
ECOFRAM
recommendations,
may
be
accessed
through
the
home
page
for
this
initiative.

http://
www.
epa.
gov/
oppefed1/
ecorisk/
index.
htm
Once
the
reports
and
the
peer
review
workshops
were
completed,
the
Agency
formed
the
Refined
Risk
Assessment
Implementation
Team
(
Implementation
Team),
which
was
charged
with
developing
a
plan
to
incorporate
probabilistic
tools
and
methods
into
the
assessment
process.
After
evaluating
the
ECOFRAM
reports
and
workshop
comments,
the
Implementation
Team
developed
a
conceptual
approach
for
implementing
changes
to
the
current
deterministic
assessment
process,
using
the
reports
and
workshop
comments
as
a
starting
point.
This
approach,
which
was
evaluated
and
endorsed
by
the
SAP
in
2000
(
FIFRA
Scientific
Advisory
Panel,
2000),
is
based
on
a
four­
level
risk
assessment
scheme
(
U.
S.
Environmental
Protection
Agency,
2000a,
Chapter
I,
Page
3
of
5
2000b,
and
2000c)
and
is
described
in
Chapter
I.
C.
of
this
document.

After
proposing
the
four­
level
risk
assessment
scheme,
the
Implementation
Team
focused
on
developing
pilot
models
(
Version
1.0)
and
on
conducting
a
case
study
for
"
ChemX".
On
the
aquatic
side,
the
refined
risk
assessment
followed
the
approach
outlined
in
the
Agency's
four­
level
risk
assessment
scheme
for
Level
II.
On
the
terrestrial
side,
the
refined
assessment
went
beyond
the
Level
II
assessment
and
fell
somewhere
between
a
Level
II
and
III.
A
summary
of
the
case
studies
reviewed
by
the
SAP
is
presented
in
Appendices
A
and
B,
and
a
synopsis
of
the
major
SAP
comments
on
the
case
studies
is
presented
in
Chapters
III
and
IV.

Following
the
case
study
with
ChemX,
the
Agency
refined
the
models
based
on
the
SAP
comments
made
in
2001.
In
addition,
the
terrestrial
Level
II
model
was
also
refined
to
include
dermal
and
inhalation
exposure
based
on
recommendations
from
ECOFRAM.
These
routes
of
exposure
were
also
discussed
during
the
SAP
meeting
held
in
2000.
These
Level
II
models
(
Version
2.0),
which
are
presented
in
Chapters
III
and
IV,
are
the
subject
of
this
SAP
session.

C.
Overview
of
Proposed
Conceptual
Risk
Assessment
Process
This
section
provides
an
overview
of
the
Agency's
proposed
conceptual
risk
assessment
process.
Although
the
Agency
will
not
be
focusing
on
the
conceptual
risk
assessment
process
in
this
meeting,
a
summary
of
the
process
is
presented
in
this
section
to
help
the
Panel
understand
the
context
of
the
Level
II
models
within
the
conceptual
framework.

The
conceptual
risk
assessment
process
is
based
on
four
Levels
of
Refinement,
with
guidance
to
assist
risk
managers
in
determining
when
to
move
to
higher
levels.
Early
levels
provide
more
simplistic
assessments
and
use
more
conservative
assumptions,
while
higher
levels
include
probabilistic
tools
and
methods
and
provide
increasingly
realistic
biological
effects
and
exposure
scenarios.
Data
requirements,
in
addition
to
those
currently
in
place,
are
focused
at
each
level
on
those
parameters
for
which
there
is
the
least
confidence
and
where
uncertainty
can
only
be
reduced
by
the
collection
of
additional
data.

The
following
sections
(
C.
1
and
C.
2)
of
this
chapter
provide
an
overview
of
the
Levels
of
Refinement
and
a
discussion
of
the
guidance
that
is
being
developed
to
move
from
one
level
to
another.

1.
Levels
of
Refinement
The
conceptual
risk
assessment
process
for
both
aquatic
and
terrestrial
assessments
begins
with
Level
1,
in
which
effects
and
exposure
data
are
integrated
to
evaluate
the
potential
for
adverse
ecological
effects
to
non­
target
species.
Level
I
provides
a
conservative
screening
level
assessment
based
on
the
calculation
of
a
risk
quotient
in
which
a
point
estimate
of
exposure
is
divided
by
a
point
estimate
of
effects;
the
magnitude
and
probability
of
risk
are
not
evaluated
in
a
Level
I
assessment.
In
this
assessment,
the
estimated
environmental
concentration
(
EEC),
based
Chapter
I,
Page
4
of
5
on
maximum
application
rates
and/
or
rates
associated
with
other
label
options
such
as
typical
uses,
is
compared
to
an
effects
level,
such
as
an
acute
or
chronic
toxicity
value.

Once
the
risk
quotient
is
calculated,
it
is
compared
to
the
Agency's
Levels
of
Concern
(
LOCs).
These
LOCs
provide
the
Agency
with
criteria
to
analyze
potential
risk
to
non­
target
organisms
and
to
consider
the
need
for
regulatory
action.

The
next
level
of
assessment,
Level
II,
provides
an
initial
estimate
of
the
probability
and
magnitude
of
effects
in
vulnerable
areas.
Although
this
level
provides
point
estimates
for
some
parameters
where
little
or
no
data
are
available
for
generating
probability
distributions,
reasonable
hypothetical
distributions
of
exposure
and
effects
parameters
may
be
established
using
expert
judgment
and
available
published
data.
These
distributions
may
be
largely
generic
and
are
not
necessarily
species­
or
pesticide­
use
specific.
Examples
include
distributions
of
residues
on
avian
food
items
and
metabolism
of
pesticides
within
and
between
soil
and
water.
Through
sensitivity
analysis,
Level
II
assessments
will
identify
the
parameters
that
provide
the
greatest
contribution
to
the
variability
and
uncertainty
of
the
assessment's
conclusions.

Level
III
assessments
will
provide
more
refined
predictions
of
the
probability
and
magnitude
of
impacts.
They
will
focus
on
exposure
and
effects
parameters
that
contribute
the
most
to
the
risk
assessment
uncertainty
identified
in
the
sensitivity
analysis
of
the
Level
II
assessment.

Level
IV
assessments
will
provide
the
highest
level
of
refinement.
These
assessments
may
include
highly
specific
pesticide
use
scenarios
and
may
incorporate
additional
data
to
establish
the
spatial
and
temporal
pattern
of
exposure
for
species
of
concern.
Additionally,
data
may
be
required
to
reduce
the
uncertainty
associated
with
using
effects
data
generated
in
laboratories
for
test
species
other
than
the
focal
species
of
concern.
These
data
may
include
laboratory
testing
of
the
focal
species
themselves
and
effects
testing
conducted
under
actual
field
conditions
of
pesticide
use.

2.
Guidance
to
Move
Between
the
Levels
of
Refinement
The
Agency
believes
that
an
essential
component
of
this
risk
assessment
scheme
is
clear
and
publicly
available
guidance
regarding
the
types
of
information
that
need
to
be
considered
when
moving
to
a
higher
level
of
analysis.
The
guidance
that
is
being
developed
will
likely
consider
ecological
as
well
as
risk
management
factors.

On
the
ecological
side,
the
types
of
information
that
could
be
considered
in
developing
this
guidance
include
the
nature
of
the
toxic
effect,
the
likelihood
that
the
effect
will
occur
given
the
estimated
environmental
concentrations
of
the
pesticide
and
its
degradates,
the
uncertainty
surrounding
the
most
important
variables
affecting
the
predicted
risk,
and
the
number
and
types
of
organisms
potentially
affected.
From
a
risk
management
perspective,
examples
of
what
may
be
considered
include
the
availability
of
other
alternative
pesticides
and
their
effectiveness
for
the
Chapter
I,
Page
5
of
5
same
crop/
pest
combination,
ability
to
potentially
mitigate
the
risk,
and
the
data
needed
to
reduce
uncertainties
in
the
estimates
of
the
magnitude
and
likelihood
of
the
effects
given
the
additional
factors
required
to
reach
an
informed
risk/
benefit
decision.

Until
the
guidance
is
developed,
though,
the
Agency
will
make
the
decision
to
move
to
a
higher
level
of
refinement
on
a
case­
by­
case
basis,
considering
the
risk
assessment
uncertainties
and
risk
management
considerations
described
above.
