Document ID: EPA-HQ-OPP-2004-0005-0060
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-03-31T05:00Z

1
TERRESTRIAL
INVESTIGATION
MODEL
Version
X2.0
Scientific
Advisory
Panel
March
30,
2004
2
MODEL
MODIFICATIONS
1.
Modified
model
to
include
Generic
Species
2.
Modified
time
step
to
allow
inclusion
of
a
more
representativeBimodal
Feeding
Pattern
and
thus
exposure
estimates.

3.
Added
an
algorithm(
Markov
Chain)
to
address
serial
correlation
between
sequential
foraging
events
4.
Developed
a
New
Puddle
Model
that
attempts
to
more
closely
mimics
the
dynamics
of
puddles
on
agricultural
fields
Major
changes
in
response
to
the
SAP
review
of
Version
1
of
OPP's
Terrestrial
Investigation
Model
are:
3
MODEL
MODIFICATIONS
In
addition,
an
Inhalation
and
Dermal
Model
were
developed
and
incorporated
into
the
Model
as
previously
proposed
in
2000
at
the
SAP
Meeting
on
The
Agency's
Probabilistic
Modeling
Initative
The
uncertainty
associated
with
these
routes
of
exposure
is
high,

however,
it's
believed,
even
if
uncertain,
it's
preferable
to
making
the
incorrect
assumption
that
they
are
minimal
in
all
pesticide
use
scenarios.
4
MODEL
MODIFICATIONS
Version
2
of
the
Terrestrial
Investigation
Model
is
coded
in
the
computer
language
C
and
employs
Microsoft
Excel
as
the
input
platform.

The
Excel
spreadsheet
input
data
are
written
to
a
file
that
is
read
by
the
C
code
and
processed.
5
General
Model
Overview
The
revised
Terrestrial
Investigation
Model
can
be
Characterized
as:


Multi­
media
exposure/
effects
model
that
addresses
acute
mortality
in
generic
or
specific
species
over
a
user
defined
exposure
window.


The
Spatial
Scale
is
at
the
field
level,
such
that
the
field
and
surrounding
area
are
assumed
to
meet
habitat
requirements
for
each
species
considered.
6
General
Model
Overview
Comparison
to
Version
1
Yes(
puddle)

No
Soil
yes
No
Soil
Yes
No
Air
Yes
Yes(
dew
only)

Water
Yes
Yes(
food
only)

Vegetation
Degradation/
Dissipation
Yes
No
Air
Yes(
dew
&
dynamic
puddle)

Yes(
dew
&

static
puddle)

Water
Yes
Yes(
food
only)

Vegetation
Residues
on/
in
EXPOSURE
VERSION
II
VERSION
I
PARAMETER
7
General
Model
Overview
Comparison
to
Version
1(
cont.)
Yes
No
Correlated
Foraging
Events
Yes(
1
hr
steps)

Yes(
12
hr
steps)

Bi­
modal
Feeding
Pattern
Yes
No
Contaminated
Vegetation
Contact
Rates
Yes
No
Inhalation
Rates
Yes
Yes
Water
and
Food
Ingestion
Rates
Yes
Yes
Food
Habits
Behavior
Version
II
Version
I
Parameter
8
General
Model
Overview
Comparison
to
Version
1(
cont.)
Yes
No
Inhalation
Yes
No
Dermal
Yes
Yes
Oral
Routes
of
Exposure
Version
II
Version
I
Parameter
9
General
Model
Overview
Comparison
to
Version
1(
cont.)
Generic
or
Focal
Species
Focal
Species
Indicator
Species
Yes(
oral
dose
equivalents
used
to
account
for
difference)

No
Differential
Sensitivity
to
routes
of
exposure
(
oral,
dermal,
and
inhalation)
Yes
Yes
Individual
Tolerance
Yes
Yes
Species
Distribution
in
Sensitivity
EFFECTS
Version
II
Version
I
Parameter
10
Select:
Application
Method
Rate
Time
Crop
type
Input:

Site
Soil
Properties
Site
Meteorology
Data
Input
Chemical
Properties:

Media
specific
½
life
Henry's
Law
Constant
Koc,
Kow
ect.

Input
Inhalation
&
Dermal
Exposure
Parameters:

Spray
Height
&
Duration
Fraction
Inhaled
Crop
Mass,
Height,
Density
Specify
Species,
Feeding
times
&
Split
&
Input
Toxicological
Data:
Bird
LD50,
slope,
Rat
oral&

Inhal.
LD50,
Retention
Rate
Loop
Over
Days
Select
Individual
Bird
(
body
weight,
P­
factor,
FOF,
tolerance
Calculate
Transitional
Probabilities
Calculate
daily
metabolic
requirement
Select
AM/
PM
start
&

end
feeding
times;

AM/
PM
split
Calculate
days
food
Intake
fraction
of
total
required
Calculates
n
puddle
concentrations
and
durations
Selects
if
on/
off
field
Selects
hourly
feeding
fraction
Selects
time
dependent
pesticide
Con.
in
each
enviro.

media
Calculates
uptake
by
path
way
Compares
dose
to
tolerance
(
alive/
dead)

Pesticide
Body
Burden
reduced
by
hourly
elimination
rate
Model
Setup
Input
data
Loop
Over
Hours
If
Alive
Hourly
Loop
Daily
Loop