^ COMPARATIVE ANALYSIS OF ACUTE AVIAN RISK
FROM
GRANULAR PESTICIDES
Office of Pesticide Programs
U. S. Environmental Protection Agency
Washington, D.C.
March, 1992
-------
AVIAN GRANULAR PROJECT TEAM
Environmental Fate and Effects Division
Douglas Urban
Mark Roberts
Ingrid Sunzenauer
Dennis McLane
Jeffrey Bigler
Benefits and Economic Analysis Division
Ellis D. Thomas
David Brassard
John Faulkner
Y. S. Ng
Special Review and Reregistration Division
Margaret Rice
Office of Research and Development
Michael Troyer
Office of General Council
Steven Wolfson
Office of Policy, Planning, and Evaluation
Roger Holtorf
Suzanne Giannini
Acknowledgements
Richard Bennett and Anne Fairbrother of EPA's Environmental
Research Laboratory in Corvallis, Oregon, provided useful
comments and suggestions on the Analysis. Jeanne Richards and
James Roelofs of the Policy and Special Projects Staff, Office of
Pesticide Programs lent skillful editorial assistance to the
project.
-------
EXECUTIVE SUMMARY
Purpose of the Analysis
The Comparative Analysis of Acute Avian Risk from Granular
Pesticides describes the Environmental Protection Agency's (EPA
or the Agency) Office of Pesticide Programs' approach for
screening granular formulation pesticides to identify those that
may pose acute lethal risk to birds.
EPA's concern about the particular risk to birds posed by
some granular pesticides is based on the high toxicity and the
distinct exposure that the granules present to birds. Birds
ingest pesticide granules while foraging for food items and in
some cases only a few of the tiny granules are sufficient to kill
a bird.
In publishing this analysis, EPA is notifying the public and
pesticide registrants that it is concerned about the risk that
some granular pesticides pose to birds and is encouraging users
and registrants to initiate risk-reduction measures.
Methodology
EPA first identified the active ingredients (AIs) found in
granular formulation products, then analyzed the acute toxicity
of those AIs to birds. EPA reviewed laboratory acute oral
toxicity studies measuring LD50s (milligrams of AI per kilogram
of bird body weight that will kill 50% of a test population) for
representative species of waterfowl, upland game birds, and
songbirds, when songbird data were available. Active ingredients
with LD50s exceeding 500 mg/kg were eliminated from further
analysis.
For the remaining compounds, the Agency considered exposure
based on the use pattern of the chemical and the amount of
toxicant readily available to birds. Additional chemicals were
eliminated because' their use did not result in exposure to birds.
Considering both toxicity and exposure, the 14 pesticides
identified in the Analysis as posing potentially high risk to
birds are: aldicarb, bendiocarb, carbofuran, chlorpyrifos,
diazinon, disulfoton, ethoprop, ethyl parathion, fenamiphos,
fonofos, isofenphos, methomyl, phorate, and terbufos.
The analysis uses a "risk index" to compare the relative
risks to three test species of birds for 14 chemicals on 21 crops
and use sites. The risk index is a ratio or quotient of the
exposed toxicant to the inherent toxicity of the chemical. Many
factors are involved in calculating the amount of toxicant
available to birds. These include the application rate, the
-------
method of application, the percent of active ingredient in the
product applied and the efficiency of incorporating the granules
into the soil.
In the analysis the ratio or risk index is expressed as the
number of LD50s per square foot, although any unit area could be
used. The higher the number of LDsos per square foot, the
greater the potential relative risk to birds.
EPA uses a weight-of-evidence approach to characterize
ecological risk. This approach considers not only the risk
index, but also confirmatory field effects data in the form of
field studies and bird kill incident reports. The analysis
reviews available field studies and bird kill incident reports,
but does not evaluate field data in detail.
Limitations of the Analysis
It is important to clarify the limitations of the screening
methodology used in this analysis. The analysis is not intended
to propose regulatory action, only to identify those granular
pesticides that may pose high acute lethal risk to birds and may
require more in-depth risk assessments.
An ecological risk assessment to support regulatory action
could include additional ecological considerations such as: the
number of acres treated as well as the location and climate of
specific crop-growing areas; the abundance of bird species in
these areas; and the timing of pesticide applications and
pesticide persistence in relation to bird life cycles. Chronic
risks, such as reproductive impairment, and risks to other non-
target organisms could also be included.
Conclusion
The Analysis concludes that the use of the 14 granular
pesticides may result in concentrations of granules in the
environment and available to birds at levels that could be
lethally toxic. Birds are expected to be present during and
after granular pesticide applications and can and do ingest
granules remaining both on and below the soil- surface. The
Agency is also concerned about the widespread use of these
chemicals over a variety of ecological zones resulting in
exposure and risk to many species and large numbers of birds.
EPA encourages registrants of the 14 pesticides to consider
risk reduction measures that will lessen the amount of toxicant
available to birds and other vulnerable wildlife and to assess
the need for data to support these measures or to further
characterize risk.
-------
CONTENTS
Page
IINTRODUCTION
A. Purpose 1
B. Background 1
C. Scope 2
II. HAZARD AND EXPOSURE ASSESSMENT FOR
GRANULAR PESTICIDES
A. Approach 3
B. Hazard: Acute Avian Toxicity 4
C. Environmental Exposure 7
1. Presence of Birds in Treated
Fields 7
2. Bird Foraging Behavior 8
3. Quantity and Likelihood of
Granular Consumption 9
a. Quantity 9
b. Likelihood of Consumption 9
4. Amount of Toxicant Available
to Wildlife 10
a. Number of Granules Available 10
b. Application Methods 11
c. Incorporation Efficiency 12
D.
Calculation of Amount of' Toxicant Available
13
-------
Page
III. ECOLOGICAL RISK CHARACTERIZATION
A. Calculation of the Risk Index 17
B. Confirmatory Data 21
1. Field Studies 21
2. Bird Kill Incidents 22
3. Field Evidence for Avian Mortality
from 14 Granular Pesticides 25
C. Weight-of-Evidence 25
D. Ecological Considerations 31
E. Extent of the Risk 3 2
F. Assumptions and Conditions Used in
Evaluating Acute Avian Risk 3 6
IV. UNCERTAINTY IN ACUTE AVIAN RISK ASSESSMENT
A. Strengths and Weaknesses of the Data 38
B. Sources of Uncertainty 38
C. Refining Avian Risk Assessment 40
V. SUMMARY AND CONCLUSION
VI. RISK REDUCTION
A. Reducing the Risk Index 42
B. Granule Modification 42
C. Other Risk Reduction Measures 43
D. Public Participation 43
VII. REFERENCES
44
-------
APPENDICES
Page
Appendix 1: Pesticides with Granular Formulations
not Included in the Analysis
48
Appendix 2
Median Granular Weight and Estimated
Number of Granules per Square Foot
51
Appendix 3
Acre Treatments with Granular
Formulations of 14 Chemicals
52
Appendix 4:
Appendix 5:
Appendix 6:
Appendix 7:
Appendix 8:
Application Data Used for Calculations
Calculations Used in Determining Risk
Indices
Exposed Toxicant in mg/ft2 for Granular
Formulations on 21 Common Use Sites
Calculated Red-Winged Blackbird LD50s/ft2
for Granular Formulations on 21 Common
Use Sites
Calculated Bobwhite Quail LD50/ft2 for
Granular Formulations on 21 Common
Use Sites
53
59
61
62
63
Appendix 9:
Calculated Mallard Duck LDsos/ft for
Granular Formulations on 21 Common
Use Sites
64
Appendix 10: Field Evidence for Certain Granular
Pesticides
65
Appendix 11: Risk Use Summary
70
-------
1
2
3
4
5
6
7
8
9
TABLES
LDS0 Values of Active Ingredients for
Mallard Duck, Bobwhite Quail, and
Red-winged Blackbirds
Range of Exposed Active Ingredient per
Square Foot for 14 Granular Pesticides
Summary of Risk Indices for Three
Avian Species
Ranges of LD50/ft2 Values for Representative
Species on Corn
Site Specific Examples from the Songbird Risk
Index for Corn, Peanuts and Turf/Lawn
Weight-of-Evidence Summary for Granular Use on
Corn
Weight-of-Evidence Summary for Granular Use on
Peanuts
Weight-of-Evidence Summary for Granular Use on
Turf
Risk-Use Summary for Corn
Risk-Use Summary for Peanuts
Risk-Use Summary for Turf
-------
I. INTRODUCTION
A. Purpose
This document describes the Environmental Protection
Agency's (EPA or the Agency) Office of Pesticide Programs'
approach for screening granular formulation pesticides to
identify those that may pose acute lethal risks to birds. The
document also describes other factors that the Agency considers
in avian risk assessment, such as field data and extent of risk.
For the purposes of this analysis, these other factors have not
been as thoroughly developed as the initial screening process.
By publishing this document, EPA is notifying the public and
the registrants that it is concerned about the risks that
granular pesticides can pose to birds and that it encourages
users and registrants to initiate risk-reduction measures.
B. Background
Agency concern about the particular risk to birds posed by
some granular pesticides is based on the high acute toxicity and
the distinct exposure that the granules present to birds. Birds
ingest granules while foraging for food items and for some
pesticides only a few of the granules are sufficient to kill a
bird.
Granular formulation pesticides were developed in the 1960s
in order to reduce worker exposure during pesticide applications.
However, subsequent data received by the Agency indicated that
granular pesticides might pose risk to birds and other wildlife.
The Special Review of carbofuran, initiated in 1985, found that
the granular form of that pesticide posed significant risk to
birds (U.S. EPA, 1989).
As a result of the carbofuran Special Review, both Congress
and registrants requested that EPA address the avian risk from
granular pesticides in a comprehensive manner, rather than
reviewing the avian risk granular pesticides one-by-one.
To compare the potential risk of various granular pesticides EPA
has used a "risk index," which takes into account both the
quantity of pesticide available to birds after application on a
field, and its inherent toxicity. EPA has also reviewed field
studies and bird kill reports where available.
In May 1991, EPA reached an agreement with the
registrants of granular carbofuran to phase-out all major uses by
1994.
-------
2
The risk index methodology described in this analysis has
previously been available for both public and scientific review.
EPA first presented the risk index in the Carbofuran Technical
Support Document (U.S. EPA, 1989) for the carbofuran Position
Document 2/3, which was issued for public comment through the
Federal Register (54 FR 3744), January 25, 1989. In addition, as
part of the carbofuran Special Review Process, EPA presented the
risk index to the FIFRA Scientific Advisory Panel (SAP) for peer
review. The SAP supported the risk index as an acceptable
initial approach to characterize avian risk (FIFRA Scientific
Advisory Panel, 1989). Ecological risk assessment is an evolving
field. EPA sponsors research and works with industry and other
agencies in a continuing effort to refine the Agency's ecological
risk assessment methodologies.
C. Scope
EPA has the responsibility under FIFRA for ensuring that
pesticide uses pose no unreasonable risks to human health or the
environment. In addition, FIFRA requires EPA to consider
pesticide benefits in any regulatory decisions. Therefore, any
final regulatory action would take into account not only risks,
but also the economic, social, and environmental benefits of a
pesticide's use.
The current analysis does not consider the benefits of
granular pesticide use, nor is it intended to propose any
regulatory action. It is intended only to compare the potential
acute lethal risk to birds posed by the granular formulations of
a number of highly toxic pesticides on certain use sites. EPA
recognizes the potential risk to birds and other non-target
wildlife from non-granular formulations of highly toxic
pesticides and will address those risks in future assessments.
EPA focuses on the risk index in this analysis as an initial
screen for comparing the acute lethal risk to birds posed by
different granular pesticides, and for identifying those
pesticide which pose the highest risk and thus warrant closer
examination. It is important to clarify the limitations of this
approach, because this analysis is not intended to fully
characterize the risks of these pesticides or to serve as the
sole basis for regulatory actions.
A complete ecological risk assessment of any of these
pesticides, that could be used to support regulatory action,
would require a more comprehensive assessment of available field
data, and might include evaluation of other information including
chronic avian risk and risk to other non-target organisms. In
addition, a complete ecological risk assessment of these
pesticides could take into account the extent, location and
ecological sensitivity of the areas treated.
-------
3
The value of the analysis presented in this document is that
it identifies those granular pesticides presenting the highest
acute avian risk. Despite its limited scope, the analysis
presents important information about a group of granular
pesticides, based on sound data and a peer-review methodology.
EPA wishes to provide this information to the general public as
well as to the registrants and users of these granular
pesticides.
II. HAZARD2 AND EXPOSURE CHARACTERIZATION FOR GRANULAR
PESTICIDES
A. Approach
EPA first identified the active ingredients (AIs) found in
granular formulation products (NPIRS, 1990). This search yielded
a list of over 2 00 compounds with at least one granular product.
From this list, EPA then deleted those compounds not registered
for outdoor use, not having a toxic mode of action (such as
pheromones and repellents) or not applied in granular form (such
as water dispersible granules and dry flowables).
EPA analyzed the remaining 99 AIs in terms of acute toxicity
to birds by reviewing laboratory acute oral toxicity studies
measuring LD50s (milligrams of AI per kilogram of bird body
weight that will kill 50% of a test population) for
representative species of waterfowl, upland game birds, and
songbirds, when songbird data were available. That review
indicated that many of the granular pesticides were not highly
toxic to birds. Those pesticides with avian LD50s > 500 mg/kg
were eliminated from the current analysis, since the Agency
generally considers chemicals with LD50s between 500 and 2000 to
be only slightly toxic to birds and those over 2000 to be
practically non-toxic to birds.
The Agency then considered exposure. An initial exposure
screening eliminated compounds that, though highly toxic to
birds, are used in a manner resulting in limited exposure (and
thus limited risk) to birds. Generally, these compounds have
specialized or very specific uses, such as containerized nursery
stock or feed-through fly-control products for livestock.
Finally, the Agency considered potential exposure for the
remaining compounds based on the amount of toxicant available to
The terms "hazard" and "ecological effect" are used
synonymously in this analysis. Avian mortality is the only
adverse effect being considered.
-------
4
avian species on the soil surface per unit area. The cutoff for
evaluating comparative risk was made at 1 LDS0 per square foot.
The 14 chemicals exceeding the above-mentioned criteria for
both toxicity and exposure were subjected to further analysis.
The 14 are: aldicarb, bendiocarb, carbofuran, chlorpyrifos,
diazinon, disulfotop, ethoprop, fenamiphos, fonofos, isofenphos,
methomyl, parathion , phorate, and terbufos.
Appendix 1 lists the 85 pesticides that were eliminated,
their mode of action, and the reason for exclusion from the
current analysis.
Chemicals not included in the current analysis will be
reevaluated as additional avian toxicity and exposure data become
available and/or if the chemical's use patterns change.
B. Hazard: Acute Avian Toxicity
EPA ranked the remaining 14 pesticides, all of which are
carbamate or organophosphate insecticides, in order of their
acute toxicity to representative avian species (Table 1).
The values given in Table 1 are the result of toxicity tests
typically performed on adult birds. Table 1 does not reflect the
variation in sensitivity among species, nor the most sensitive
sub-groups within a species. Greater sensitivity may be found in
juveniles of a species due to the immaturity of their detoxifying
systems, protective barriers, or excretory processes. Kendall et
al. (1989) reported such an increase in sensitivity in juvenile
starlings.
EPA selected 1 LDS0 per square foot as the cutoff level of
concern because field study data submitted to the Agency thus far
indicate that pesticide applications resulting in environmental
concentrations of at least 1 LD50 per square foot have resulted
in avian mortality. In some cases, avian mortality has been
documented at less than 1 LDS0 per square foot. A full
discussion of the Agency's rationale for using the LDS0/ft2
calculation and its limitations can be found in Sections II and
III.
4
In September, 1991, EPA reached agreement with the
registrants of ethyl parathion to voluntarily withdraw all uses
of that chemical except alfalfa, barley, corn, canola, cotton,
sorghum, sunflower, and wheat. No granular parathion products
remain registered. However, existing stocks in the hands of
users may be used through July, 1992.
-------
Table 1.
LDSu Values of Active Ingredients for Mallard Duck
and Red-winaed Blackbirds
Bobwhite Quail.
Mallard Duck
(Anseriformes)
Bobwhite Quail
(Galliformes)
Red-winged Blackbirds
(Passeriformes)
Pesticide
(mg/kg)
CI(,) Ref.(b) Pesticide
LD,
'50
(mg/kg)
CI
(s)
LDso
Ref.(b) Pesticide (mg/kg)
CI(,)Ref.,b)
Carbofuran
0.40
0.32-0.50
15
Fenamiphos
1.00
0.70-1.30
14
Carbofuran
0.42
none
24
Phorate
0.62
0.37-1.03
15
Aldicarb
2.00
1.40-2.90
14
Phorate
1.00
0
.56-1.80
23
E. Parathion
1.44
1.16-1.80
15
Ethoprop
4. 21(d)
3.03-5.83
15
Aldicarb
1.78
1.78
6.90(O
none
21
Ethoprop
12.6
10.6-15.0
15
Disulfoton
12.0
7.00-19.0
14
Isofenphos
none
2
Methomyl
15.9
11.4-22.0
15
Terbufos
15.0
12.0-19.0
14
Bendiocarb
none
2
Fonofos
16.9
13.4-21.3
15
Methomyl
15. 0
10.0-22.3
15
Fonofos
10. 0
5.
62-17.8
24
Isofenphos
32.0
22.0-46.0
31
Bendiocarb
19.0
12.0-32.0
34
Methomyl
10.0
5.
62-17.8
21
Chlorpyrifos
75.6
35.4-161.0
15
Chlorpyrifos
32.0
24.0-43.0
14
Chlorpyrifos
13.3
none
24
(a) CI = 95% confidence interval
(b) Numbers in Ref. columns correspond to the references cited in Section VII of this document.
(c) No data available for technical grade terbufos. LD50 value extrapolated from test using formulated (15G)
product.
(d) LD50 value given is for ring-necked pheasant.
(e) LD50 value was estimated by the binomial method from toxicity data in Ref. 2. Value extrapolated from tests using
formulated product.
-------
6
Since relatively few species, usually mallard duck and
bobwhite quail, are used in standard toxicity testing, it is
likely that the species most sensitive to each pesticide has not
been tested. Balcomb et al. (1984) illustrate the differences in
sensitivity that can occur even between similar species. In that
study, one hundred percent of the red-winged blackbirds died with
10 granules of Counter 15G (terbufos) whereas only 40 percent of
the house sparrows died after receiving the same dose. Because
of this variation in sensitivity, it is unlikely that this
analysis will show the worst case risk for all pesticides.
Table 1 is a useful indication of relative hazard for the
standard test species based on the acute LD50 toxicity data
currently available. The LD50 values would vary if additional
data were generated for different species and different age
groups.
Using formulated products, Balcomb et al. (1984) conducted
toxicity tests with 13 of the 14 granulars listed in Table 1.
(Balcomb did not assess the toxicity of methomyl.) The objective
of Balcomb's study was to determine the toxicity of graduated
doses (1, 5, 10, 20, and 40 granules) of commonly used granular
products to house sparrows and red-winged black birds. When
birds in each test group were fed only one granule, at least 2 0%
mortality resulted from 5 of the 13 pesticides. When birds were
fed 5 granules, mortality resulted from 7 of the 13; and when
they were fed 10 granules, mortality resulted from 12 of the 13.
Mortality did not occur in the group receiving isofenphos until
20 granules were administered.
Balcomb et al. (1984) noted further that ingestion of
granules exposes birds to discrete doses of these generally quick
acting pesticides. The manner of exposure (ingestion of
granules) is comparable to that in LD50 toxicity testing. Thus,
the LD50 value is an appropriate toxicity parameter to assess
avian hazard for granular pesticides. Hudson et al. (1984) also
specifically noted the direct applicability of LD50 data in
assessing hazards associated with granular materials.
The acute risk of granulars to birds comes from the
relatively high concentration of Al purposefully placed in/on the
granule. The concentration is "high" in relation to the amount
of toxicant necessary to kill a bird. In some cases, only one
granule conveys a lethal dose. (See Appendix 2.)
The immediate concern from highly toxic granulars is acute
mortality. Although EPA recognizes their potential impact,
chronic effects, such as reproductive impairment, have not been
considered in the current analysis. In future risk assessments,
EPA will consider available data on chronic effects.
-------
7
A laboratory dose that is considered to be sublethal may
actually result in mortality of birds in the field, since the
organism's ability to feed, escape from predators, seek shelter
from adverse climatic conditions, and care for young could be
impaired. In the case of waterfowl, to cite one example, a
sublethal dose can result in mortality when the affected bird
loses motor coordination and, unable to swim or hold its head out
of the water, drowns.
C. Environmental Exposure
The amount of toxicant a bird is likely to ingest, inhale,
or absorb can not be quantified as it can be for human exposure.
Due to differences among bird species, the variety of bird
feeding, mating, and migration behavior and other factors, a
definitive avian exposure model is not currently available.
Environmental exposure has two components: the numbers,
types, distribution, life cycle and behavior the organisms that
may come into contact with a pesticide; and the amount or
concentration of a pesticide in the environment and available to
these non-target organisms. As the following sections show,
birds are present in fields treated with granular pesticides,
granules are available to birds in the fields, and birds can and
do ingest available granules.
Since the amount of pesticide actually ingested by birds
cannot be quantified, EPA has assumed that the amount of toxicant
available to birds per unit area provides an indication of the
actual amount of granular pesticide that birds could ingest. It
is important to note that the Agency is not attempting to
estimate the actual number of birds that would receive a lethal
dose, nor the probability of a given bird consuming a lethal
dose. Estimates of that sort would depend on the number of acres
treated, the species and numbers of birds present in a given area
and many factors of bird behavior, that have not yet been
adequately documented.
1. Presence of Birds in Treated Fields
Many different bird species are expected to be present or
fly into fields during and after granular pesticide treatments.
In the spring, birds are seen feeding in fields during planting,
often following planting equipment. Being opportunistic, birds
are attracted to soil invertebrates, seeds, or crop remains which
are brought to the tilled surface by the planter.
Seed-eating birds forage for grit, an abrasive material that
acts as an essential digestive aid by grinding food in the bird's
gizzard. Insect-eating birds have a lesser need for the grinding
-------
8
action of grit, but may ingest it incidentally. Birds foraging
for seeds or grit (e.g., quail, doves, blackbirds, sparrows) or
for insects and earthworms (e.g., robins, woodcock, killdeer) may
be unable to avoid ingesting granular pesticides and food items
containing pesticide residues.
Bent (1963) has documented the prodigious quantities of food
that birds can consume. He found 7500 seeds in the stomach of a
mourning dove and reported that a bobwhite quail consumed 1000
grasshoppers and over 500 other insects in a single day.
In addition to the resident bird population, many species of
migratory birds will be on their northerly migrations in the
spring and may land in fields to feed. In many cases, they will
be ending an extensive migration period and require large amounts
of food to replenish fat reserves in preparation for breeding.
Birds are expected to be present in fields later in the
season when some granular pesticides are applied, as well.
Resident populations rearing young will be attracted to maturing
crops producing fruits and seeds.
Whenever granular pesticides are'applied, secondary exposure
to hawks, eagles, other predators, and scavengers may occur from
ingestion of prey such as mice, small birds, mammals, amphibians,
and fish containing pesticide residues. Secondary exposure and
other indirect effects have not been considered in this screening
analysis. Both would be important considerations in in-depth
ecological risk assessments.
2. Bird Foraging Behavior
Data are not currently available to determine to what extent
ingestion of pesticide granules is incidental, accidental,
selected for, avoided or some combination of these possibilities.
Birds may inadvertently ingest granules along with other
material, may mistake the granules for seeds, grit, or other food
items, or may actively select or avoid the granules. With
accidental or incidental exposure, ingestion is assumed to be
proportional to availability. If birds actively select for
pesticide granules, the toxicity of each granule would be of
greatest concern. Hill (1986) stated that if the ingestion of
granules "is selective, then extreme caution must be exercised
wherever the granular formulations are used". If granule
ingestion is a function of active selection or avoidance by
birds, risk would be less dependent on chemical availability on
soil surface and more dependent on the toxicity of each granule.
The reasons for ingestion may differ between species and
geographical region. It is possible that granule ingestion is
both accidental and selective, with some species ingesting
-------
9
pesticide granules accidentally or incidentally and others
actively selecting or avoiding the granules for whatever reason.
In this analysis, the ingestion of pesticide granules is
assumed to be primarily a random process, where pesticide
ingestion will increase as the availability of granules
increases. If granule ingestion can be demonstrated to be a
selective process, either actively avoided or intentional and
repeated, risk estimates could change.
3. Quantity and Likelihood of Granular Consumption
a. Quantity
In food consumption studies, Shellenberger (1971, as cited
in Kenaga, 1974) determined that northern bobwhite quail consumed
up to 4.9 grams of untreated granules per bird per week. Based
on these data and the median granule weights provided by Hill and
Camardese (1984), EPA estimates that northern bobwhite quail
could theoretically consume a quantity of grit equivalent in
weight to approximately 1300 (aldi'carb 15G) or over 10,000
(chlorpyrifos 15G) granules per day. It is not expected that
pesticide granules would be the sole source of grit or grit-like'
material available under actual use conditions. Also, the
composition of the pesticide carrier (base material such as
silica, clay, and corn cob) may influence the rate as well as the
quantity of granules consumed.
Best and Gionfriddo (1991) have pointed out that the amounts
and types of grit consumed by birds are determined not only by
availability, but also by other factors such as dietary
preference and stage in the reproductive cycle. These factors
differ among seasons and geographic locations, so" that data
presented in one study may not be representative of other species
in other locations.
b. Likelihood of Consumption
Birds are known to consume granular pesticides because
carcass analysis has revealed pesticide granules in the digestive
systems of dead birds and residues of the pesticides in the
birds' tissue (Flickenger, 1980 and FMC Corporation, 1983).
Balcomb (1980) has noted that the ingestion of pesticide granules
is plausible because the size of these granules approximates the
size of grit normally consumed by birds. Factors such as color
and shape, as well as size may affect the likelihood of a bird to
pick up and ingest a granule.
In ongoing research designed to better characterize grit use
by cornfield birds, Best and Gionfriddo (1991) found that grit
-------
10
consumption patterns differed among species. The percentage of
gizzards containing grit in birds of a given species ranged from
15-100%, and the median amounts of grit found in birds' gizzards
ranged from 0-69 particles. Most grit found in gizzards was
intermediate between having sharp, irregular surfaces and having
smooth, rounded surfaces. Grit ranged in size from 0.1-6.0 mm
and grit size increased linearly with the log(10) of body mass.
Best and Gionfriddo contend that overlap in the characteristics
of grit used by birds and the characteristics of granular
insecticides could be used to evaluate the likelihood that birds
will pick up insecticide granules as a source of grit. This
would not, however, account for accidental ingestion of pesticide
granules, nor would it account for pesticide exposure via routes
other than oral ingestion.
4. Amount of Toxicant Available to Wildlife
a. Number of Granules Available
The number of granules on the soil surface will vary
depending on the formulation (percent of active ingredient of the
particular product used), carrier (size and weight of the
granule), application rate, application method, efficiency of
incorporation, and application accuracy (O'Brian, 1987). The
Agency does not presently have data to determine the range of
variation for all of these factors.
Appendix 2 gives the granular weight of one formulation of
each chemical considered in this analysis and, based on that
weight, provides an estimate of the average number of exposed
granules per square foot for each formulation considered. The
estimates range from 14,451 granules of ethoprop 10G weighing
0.051smg each to 295 granules of aldicarb 15G weighing 0.536 mg
each.
Appendix 2 shows that for the given formulations the range
of the number of granules constituting a songbird median lethal
dose (LDS0) is 1-72. Twelve of the fourteen require less than 30
granules to transmit a median lethal dose, and six of the 14
require less than 10 granules. In considering the extremes of
the number of granules necessary to convey a songbird median
lethal dose, the Agency calculates, in Appendix 2, that only one
granule of carbofuran would be sufficient, whereas, 72 granules
of chlorpyrifos would be necessary. These numbers were derived
using a songbird body weight of 0.052 kg (Dunning, 1984) and the
toxicity values from Table 1.
Appendix 2 is provided for reference only. All
calculations in this Analysis are based on mg of AI per unit area
rather than number of granules.
-------
11
Since the number of granules constituting a median lethal
dose for songbirds falls within the range of 1-72 for all 14
pesticides, it is reasonable to assume that birds are capable of
consuming enough granules to equal a lethal dose of the pesticide
formulations examined and that multiple lethal doses are readily
available to birds in the relatively small area of one square
foot.
Those pesticide formulations where a few granules constitute
a lethal dose might be considered the most hazardous, since the
likelihood of a bird consuming at least a few granules is greater
than the likelihood of its consuming a large number of granules.
Birds may ingest granules remaining on or just below the
soil surface after a pesticide application. These granules may
be consumed while a bird is foraging for seed, grit or insects on
the surface or probing below the surface of the soil.
Furthermore, subsurface granules may also have exposure potential
via routes other than direct ingestion (e.g., dermal exposure via
contaminated water after irrigation or rainfall). Data are not
available to estimate the amount of pesticide ingested by birds
probing below the soil surface. Therefore, for this analysis, the
Agency has considered only the amount of pesticide on the surface
of the soil after a granular pesticide application, recognizing
that this is an underestimate of the actual amount available to
some avian species.
b. Application Methods
Methods and timing of applications vary with the specific
product, the crop, and reason for treatment. Though some
application-incorporation regimes are more effective than others
at reducing granular exposure, exposed granules can result from
all granular application methods including band, in-furrow,
drill, shanked-in, broadcast, side-dress and aerial broadcast.
Preferred application methods also vary with crop and
location. With corn, for example, the majority of granular
applications are in-furrow and banded. Relatively few acres of
corn receive ground broadcast and aerial applications.
Band application deposits pesticide granules over the
planted seed or to the side of emerged plants. It is a common
method of granular application and results in highly variable
distribution of granules. The granules are applied as a band to
the soil surface and are usually incorporated with devices such
as a chain or spring tine. Incomplete incorporation of the
granules generally results.
Granules are also applied in-furrow. The granules are
dropped into the seed furrow along with the seeds and usually
-------
12
covered with soil, although some granules will remain exposed.
Drill and shanked-in methods also deposit the pesticide granules
in the seed furrow leaving some granules exposed.
Other types of ground application include broadcast and
side-dress. Broadcast applications are made by distributing
granules over a broad surface area. The granules are typically
disked in prior to planting. Side-dressing is the application of
granules to one or both sides of the row during or after
cultivation. The granules generally are covered with soil by
cultivation disks.
Granules also may be applied post planting by aerial
broadcast. These granules are not incorporated, resulting in
high exposure to birds. Birds can be exposed to granules on the
field surface and lodged in the plants.
Additionally, granules are left on the soil surface when (1)
machinery is being loaded, (2) planter shoes are lifted out of
the furrows to permit turning, (3) planter shoes rise out of the
soils of irregularly contoured fields, and (4) machinery is worn
or is not operating correctly. However, these additional
considerations have not been factored in to the current exposure
calculations.
c. Incorporation Efficiency
Several researchers have confirmed that band and in-furrow
applications, following label directions and using conventional
commercial application equipment, result in exposed granules on
the soil surface (Beskid and Fink, 1981; Whitehead, 1975; and
Balcomb, 1984). The limited available data describing
incorporation efficiency of band application indicates that 6 to
4 0 percent of the granules remain on the surface, with an average
value of approximately 15 percent (Erbach and Tollefson, 1983).
This wide range of variability indicates that more research on
incorporation efficiency would be useful. Data on in-furrow
application show that about one percent of the granules remain on
the soil surface (Hummel, 1983).
-------
13
Based on these studies and basic producer pesticide label
statements regarding incorporation of granules, EPA assumed
either 0, 85, or 99% incorporation efficiency (100, 15, or 1%
granules available, respectively) for the following application
and incorporation methods:
Method: Incorporation efficiency:
Banded, cover with specified
amount of soil 99%
In-furrow, drill, or
shanked-in 99%
Side-dress, banded, mix or lightly
incorporate with soil 85%
Broadcast, mix or lightly
incorporate with soil. 85%
Side-dress, banded,
unincorporated. 0%
Broadcast, aerial broadcast,
unincorporated. 0%
Because of differences and ambiguity in the language of the
many labels surveyed, the estimates given above are
generalizations of several application methods and incorporation
regimes. In reviews of specific chemicals, EPA would use more
specific data, if available, to determine incorporation
efficiency.
D. Calculation of Amount of Toxicant Available
To provide a basis for comparison, EPA evaluated the amount
of toxicant available on the soil surface for common registered
use sites of the 14 granulars of concern. For the purpose of
this analysis, common use sites are defined as those for which
three or more of the 14 granular pesticides are registered. Four
of the 21 sites identified, corn, sorghum, soybeans, and cotton,
-------
14
are considered "major" use s^.tes, i.e., representing at least $1
billion annually in revenue.
EPA estimated the amount of toxicant remaining on the soil
surface and available to avian species using information from
basic producer labels current as of June, 1990 (U.S. EPA, 1990b).
For the purposes of this analysis, basic producers are defined as
the initial applicants for federal registration. Using only
basic producer labels enabled the Agency to survey a
representative sample of use sites and application rates while
reducing the likelihood of including obscure use sites and the
extremely high or low rates sometimes found on formulator's
labels.
The following label information was considered in
calculating the amount of toxicant and number of granules
available per square foot: highest application rate (ounces per
1000 foot of row or pounds AI per acre), method of application,
crop row spacing, band width, and whether incorporation was
indicated. Label statements regarding application methods and
incorporation of granules were used to estimate the incorporation
efficiency. Where more than one rate and application scenario
were given on the basic producer label, the Agency used the
highest application rate and method resulting in maximum exposed
granules on the soil surface. Label information selected for use
in this analysis is presented in Appendix 4.
EPA calculated the estimated environmental concentration of
toxicant available in milligrams of AI per square foot using the
formulae given in Appendix 5 for each pesticide registered on the
21 use sites. As can be seen from Appendix 4, application rates
can be expressed in two ways: (1) as ounces per 1000 foot of row
(row treatment); and (2) as pounds per acre (broadcast
treatment). Labels with application rates expressed as ounces
per 1000 foot of row usually indicate band, side-dress, or
in-furrow application methods. With all of these application
methods, the granules are concentrated in a specified band width.
For this analysis the Agency selected use sites that
represent the majority of the use of the granular insecticides of
concern. The 21 sites analyzed represent about. 85% of the use of
these insecticides, with corn alone accounting for approximately
60-70% of granular use. Estimates of acres treated with granular
insecticides are given in Appendix 3.
-------
15
The calculations in Appendix 5 take into consideration the
fact that the concentration of granules, and the mg of AI, per
unit of treated area is higher for band and side-dress
applications than would result from an equivalent amount of
pesticide broadcast. The treated row calculation does not factor
in the area between rows that is not treated, since birds focus
their foraging activity on the disturbed and/or treated area.
The concentration of granules in row treatment applications is of
concern because many avian species follow directly behind
planting equipment foraging for food items brought to the
freshly-tilled surface.
This analysis uses one square foot as the unit for
calculating toxicant availability, although any constant unit
area could be used. DeWitt (1966) suggested this unit for
calculating environmental exposure when he related quantities of
toxic pesticides ingested by birds to quantities of toxic
pesticide deposited per square foot using several laboratory and
field studies. Felthousen (U.S. EPA, 1977a) proposed Agency risk
criteria for granular pesticides related to the amount of toxic
pesticide per square foot available to an animal. Current Agency
ecological risk assessment procedures use a similar approach for
determining the amount of toxicant available (U.S. EPA 1986a and
1989) .
Appendix 6 gives the results of the calculations of amount
of toxicant available on selected use sites. Table 2, below,
summarizes those results by showing the sites with the highest
and lowest amount of exposed active ingredient, as well as the.
number of sites surveyed for each chemical.
Table 2 is intended only as a summary to give a general idea
of the range of the amounts of AI available on various sites.
The reader is referred to Appendix 6 for comparisons of the
amount of each AI available on any given use site.
Only sites appearing on basic producer labels were
evaluated for this analysis. Therefore, not all sites showing
usage in Appendix 3 have corresponding values in Appendices 6-9.
-------
16
Table 2. Range of Exposed Active Ingredient per Square Foot for
Fourteen Granular Pesticides
Pesticide
Active Ingredient (mg/ft )
.(c)
Aldicarb
Bendiocarb
Carbofuran
Chlorpyrifos
Diazinon
Disulfoton
Ethoprop
Fenamiphos
Fonofos
Isofenphos
Methomyl
Parathionv
Phorate
Terbufos
.
High(a)
r (a)
Low
(b)
n
62.7
(citrus)
1.3
(sw. potatoes)
10
31.2
(turf)
31.2
(turf)
1
53 . 3
(peanuts)
3.4
(cotton)
9
127.6
(peanuts)
1.6
(onions)
14
76.3
(beans)
6.3
(cole crops)
14
198.4
(potatoes)
51.0
(tobacco)
12
312.0
(lawns)
7.6
(cabbage)
11
208.0
(turf)
11.7
(cabbage)
6
45.4
(peanuts)
1.7
(onions)
17
21.8
(lawns)
15.5
(corn)
3
10.4
(corn)
6.9
(cabbage, vegs)
7
15.6
(corn)
6.2
(onions)
11
196.2
(potatoes)
7.5
(peanuts)
9
12.2
(sorghum,
8.5
(corn)
3
sugar beets)
(a) Figures taken from Appendix 6.
(b) Number of sites analyzed.
(c) EPA reached agreement with the registrants of carbofuran in
May, 1991, to phase-out all major uses of the granular
formulations of that chemical by 1994.
(d) Per agreement between EPA and the registrants of ethyl
parathion in September, 1991, no granular products remain
registered. However, end users may apply existing stocks
through July, 1992.
Mote: Table 2 and subsequent tables contain values for parathion
and carbofuran for comparative purposes only. All major uses of
granular carbofuran and all uses of granular ethyl parathion are
being phased out.
-------
17
III. ECOLOGICAL RISK CHARACTERIZATION
A. Calculation of the Risk Index
The Agency currently uses the quotient method to express
ecological risk. The quotient method compares a toxicological
level of concern for a given species with the estimated
environmental concentration of a chemical:
Estimated Environmental Concentration (EEC^ = Risk Quotient
Toxicological Level of Concern
In general, risk quotients greater than one represent a high
risk, i.e., a strong likelihood that the ecotoxicological effect
of concern will occur. Conversely, quotients considerably less
than one indicate a likelihood that the effect of concern will
not occur. In situations where quotients equal or approach one,
the Agency usually requires field testing to confirm or refute
the assumption of risk.
This general concept can be applied to generate an index for
acute avian risk with mortality as the ecotoxicological effect of
concern. The acute avian risk from a pesticide use has two
components: the acute toxicity of a pesticide and the amount of
toxicant available to the organism. The risk from a pesticide
will vary, depending on both factors. This analysis looks at
acute avian risk as a quotient of the amount of toxicant readily
available on the treated soil surface within a square foot (a
rough indicator of exposure) to the acute avian toxicity
(expressed as an LDS0) . Equation (1), below, is a general
statement of the relationship of exposure to hazard. Equation
(2) more specifically defines how that relationship has been
applied in the current analysis.
(l)
Risk = Exposure = EEC
Hazard Acute Toxicity
(2) Exposed Toxicant (mg ai/ft2)
LD50 (mg ai/kg) x Bird Weight (kg)
No. of LD50s
per
Square Foot
-------
18
Thus, one way to express potential acute risk is in terms of
the number of LD50s per square foot. The higher the number of
LDsos per square foot, the greater the relative acute risk to
birds. Calculations using the above equations were conducted for
each representative species on the 21 common use sites. Average
bird body weights used were 1.082 kg for mallard duck, 0.178 kg
for bobwhite quail and 0.052 kg for red-winged blackbirds. In
the two cases where ring-necked pheasant values were substituted
for quail, a body weight of 1.135 kg was used (Dunning, 1984).
The results are presented in Appendices 7, 8, and 9 as risk
indices and may be used to compare the relative risk, expressed
as the number of LD50s per square foot, of the granular
pesticides across the 21 use sites for each of the three test
species. The "high" and "low" columns in Table 3 give the
highest and lowest single values from any of the three acute
avian risk indices.
The risk indices are intended to be used as rough indicators
of comparative risk, and cannot be used to predict how many birds
will actually die, or the probability of a bird receiving a
lethal dose. Site-specific considerations such as the
attractiveness of the treated fields, the species distribution,
the density of birds in the area, as well as the number of acres
treated would affect the number of birds actually exposed.
Furthermore, the index does not provide a definitive value
for the amount of pesticide that will be available to birds. The
actual amount of pesticide available will vary depending on
application method, configuration and calibration of equipment,
and field conditions.
g
See Footnote 6
-------
19
Table 3. Summary of Risk Indices for Three Avian Species
Pesticide Avian LDS0s/ft2
High(a) Lowcb) n
-------
20
Table 4. Ranges of LD50/ft2 Values for Representative Species on
Corn
Songbird(a) Gamebird(a) Waterfowl(a)
Carbofuran
1168
20-39
47-74
Chlorpyrifos
30
3-5
0.1-0.6
Diazinon
22-68
3-5
2-7
Ethoprop
47
2-3
0.6-0.9
Fonofos
22-70
8-11
0.9-1.4
Isofenphos
56
8-13
0.3-0.6
Methomyl
11-36
0.4-1
0.4-0.8
Parathion
127
10-22
8-12
Phorate
91-292
4-12
8-21
Terbufos
78
2-4
0.5-1
(a) LD50/ft2 values were calculated from Table 1 and Appendix 6.
Note: Ranges could not be calculated for LD50 values lacking
confidence intervals in Table 1.
Table 5 compares only the songbird risk index values for the
chemicals used on 3 sites, corn, peanuts, and turf. Table 5 and
the examples that follow focus on songbird index values because
songbirds are more likely to be found on all sites than gamebirds
or waterfowl and songbirds, generally, are the most sensitive
species for which data is available.
As seen in Table 5, the songbird risk index for several
chemical-site combinations is greater than 1000. Other chemicals
used on the same sites have index values less than 100.
Differences of this magnitude lead the risk assessor to look more
closely at the specific conditions of use on a site, including
whether or not the chemicals are substitutes for one another for
control of the same pests.
-------
21
Table 5. Site Specific Examples from the Songbird Risk Index for
Corn. Peanuts and Turf/Lawn
Pesticide Songbird LD50s/ft2(a)
Corn Peanuts Turf/Lawn
Aldicarb
—
303
—
Bendiocarb
—
—
87
Carbofuran
1168
2441
—
Chlorpyrifos
30
184
16
Diazinon
60
—
436
Disulfoton
—
750
—
Ethoprop
47
303
1425
Fenamiphos
—
129
2247
Fonofos
39
87
80
Isofenphos
56
—
73
Methomyl
20
—
—
Parathion
127
—
—
Phorate
164
144
—
Terbufos
78
—
—
(a) Songbird risk index values from Appendix 7
B. Confirmatory Data
Data relating to the actual use of these granular pesticides
have also been reviewed. These data consist of field studies and
documented bird kill incident reports, and are used to confirm
the potential risk indicated by the LD50 per square foot
calculation (i.e., the risk index). For the purpose of this
screening analysis, the field effects data have not been as
thoroughly evaluated as they would be for a complete risk
assessment.
1. Field Studies
The Agency can require field testing to support the
registration of pesticide products if the use of the pesticide is
likely to result in adverse effects on wildlife exposed to the
pesticide. The Agency's decision to require field testing takes
into account: the physical and chemical properties of the
compound; the environmental fate of the pesticide; estimated
-------
22
exposure including the amount of the pesticide available to
wildlife and the variety of wildlife present; available
laboratory toxicity data and field incident reports.
Although both bird mortality and population effects are end
points of concern, most of the field studies reviewed for this
analysis addressed only acute effects, such as direct poisoning
and death. The studies indicate that adverse effects, usually
mortality, occur in the field. They were not designed to
quantify the magnitude, frequency, or duration of the adverse
effects.
The data gathered rely upon methods such as carcass
searching, residue analysis of dead or moribund wildlife and
their food sources, brain and/or blood acetylcholinesterase
measurements, and behavioral observations. EPA has published a
Guidance Document for Conducting Terrestrial Field Studies (U.S.
EPA, 1988a) to aid registrants in designing and conducting field
studies. Some of the circumstances limiting the utility of
current field study data are: inadequate carcass searches; delay
in initiating searches; limited search areas; and inappropriate
site selection.
Field testing is generally required only on a few sites
representative of the use pattern of a chemical, since testing on
all registered sites is not usually economically feasible. Avian
or other non-target species mortality on these representative
sites indicates a likelihood of mortality on other sites, given
similar application rates, incorporation, and environmental
conditions, especially for at-planting applications. Similarly,
kill incidents reported on any site attributable to a specific
pesticide, indicate the potential for mortalities on other
similar sites.
In a continuing effort to ensure that EPA field testing
procedures evolve with the science of wildlife toxicology and
produce increasingly sensitive data, EPA has,joined with
industry, environmental groups, representatives from academia,
and other government agencies in the Avian Effects Dialogue Group
to improve field test design (The Conservation Foundation, 1989).
2. Bird Kill Incidents
There is continual mortality of animals in the wild
attributable to many causes. Yet, relatively few carcasses are
found by humans. When birds are,poisoned, they tend to go into
brush or cover and are unlikely to be noticed by human observers.
Investigators may not find poisoned birds because predators or
scavengers have carried the dead or debilitated birds away from
the treatment site (Bunyan, et. al., 1981). Even when dead birds
-------
23
are found, the observer may not attribute the deaths to a
pesticide application.
Field evidence (U. S. EPA, 1990d) indicates that some
pesticides can produce lethal effects for many months after they
are applied or spilled. Thus, a farmer or other observer not
familiar with the history of a use site may not attribute bird or
other wildlife mortality to a pesticide application. Even if a
person suspects that wildlife may have been poisoned^ the
individual may not know where to report the incident , may not
believe that it is important to report it, or may believe that
there is some liability associated with reporting.
Wildlife literature confirms the difficulty in detecting
carcasses. In studies conducted in Texas and Alabama, Rosene and
Lay (1963) found that predators and scavengers quickly consume
dead or dying quail and the remains are difficult to see in the
field. The results indicated that finding a few dead animals
suggests that considerable mortality has occurred and that
failure to find carcasses is poor evidence that no mortality has
occurred.
In a later study to assess the effectiveness of field
searching, Stutzenbaker et al. (1983) found that relatively few
of the carcasses that had been purposely placed in both exposed
and covered wetland habitat locations were found. Only 12% of
the exposed carcasses and none of the covered ones were
recovered. They also found that carcasses disappeared rapidly
from cover vegetation and from predator traveled corridors. The
authors concluded that "results clearly demonstrate that lack of
carcasses recovered during intensive searching does not rule out
extensive waterfowl mortality" and that casual searches would
almost invariably result in negative findings (i.e., no
carcasses).
Detection of carcasses is especially difficult when
searching for small birds. Many smaller birds do not form large
conspicuous flocks, and smaller carcasses are more readily
scavenged than larger ones.' Therefore, it is unlikely that
carcasses of small birds such as sparrows will be detected. The
difficulty in detecting bird carcasses is increased by the
cryptic plumage of many of these species. Their coloration,
Bird kill incidents can be reported to the regional
offices of the U. S. Fish and Wildlife Service or state wildlife
agencies. Whether or not incidents are investigated depends on
availability of specially trained USFWS or state staff and
resources. For statistical purposes only, incidents can be
reported to the National Pesticide Telecommunication Network at
1-800-858-7378.
-------
24
including streaked and mottled patterns, often blends with soil,
crop stubble, and vegetation along field edges.
Public observation is important in the rate of bird kill
reporting. The reporting of bird kills on golf courses resulting
from diazinon poisoning, for example, reflects, to some extent,
the regular presence of the public in an open area with good
visibility, and the relatively large size of the birds (i. e.,
waterfowl) frequenting golf courses. Nonetheless, debilitated
birds may select heavy cover along the golf course edge and still
avoid detection. In contrast, most agricultural sites lack
public visitation all together, and visibility rapidly diminishes
with crop growth.
Many times carcasses are found in such poor condition that
pesticide residue analysis is impossible, thus eliminating the
possibility of positive identification of the pesticide involved.
Residue analysis from avian tissue is very difficult with
organophosphates and carbamates under the best of circumstances
as many do not lea^e tissue residues of either the parent form or
metabolites. Crop or gizzard contents may be analyzed for
residues but a time delay could result in non-detectable
concentrations.
EPA currently lacks a systematic and reliable mechanism for
monitoring and reporting of bird kills. Currently, the Agency
relies heavily on the incident monitoring efforts of the states.
There is considerable variability among states' reporting
programs. Due to limited funding, only a few states have
personnel trained and equipped to respond to kill reports and to
conduct the thorough investigation necessary to determine the
pesticide and application rate used and whether label directions
were followed. Also, there is no formal mechanism for states to
report incidents to EPA, and very few states do so on a regular
basis.
U.S. Fish and Wildlife Service (Lamson, 1989) has noted that
the number of reported poisoning incidents would be greater if
more effort were expended. Stone and Gradoni (198 6) provide a
similar overview of factors contributing to the under reporting
of wildlife incidents. Currently, EPA is working with U.S. Fish
and Wildlife Service to improve interagency communication and
dissemination of field kill information.
The crop is an enlargement at the distal end of the
bird's esophagus.
-------
25
3. Field Evidence for Avian Mortality from 14 Granular
Pesticides
Appendix 10 summarizes the status of field study
requirements generated through the reregistration process and
data-call-in notices issued under FIFRA section (3)(c)(2)(B) for
the 14 granular pesticides of concern. Some open literature
studies have also been tabulated (U. S. EPA, 1990d).
Appendix 10 also enumerates documented bird kill incident
reports for the granulars of concern (U.S. EPA, 1990d).
Generally, only those incidents in which the pesticide was
clinically diagnosed as the cause of mortality or was strongly
implicated were counted. In most cases this involved site
inspection and environmental and/or bird carcass analysis to
determine the level of residue and cause of death.
Incidents not tabulated in the total number of kill
incidents reported in Appendix 10 were those: (1) involving
possible misapplication, (2) involving formulations other than
granular, (3) in which the formulation was not identified, and
(4) in which the currently available supporting documentation was
incomplete. Similarly, incidents that occurred in foreign
countries are mentioned, but have not been counted for the
purpose of this analysis because the information was often
incomplete and the incidents often occurred on sites and/or with
application methods not registered in the U.S. Although these
incidents have not been counted in the total for the summary in
Appendix 10, they do provide additional useful information.
It should be noted that the numbers of kill incidents
reported in Appendix 10 reflect the fact that the 14 pesticides
under consideration are in various stages of the regulatory
process. EPA has found, for example, that following initiation
and public announcement of proposed regulatory action on diazinon
and carbofuran, many additional incidents were reported to the
Agency.
C. Weight-of-Evidence
EPA currently uses the weight-of-evidence approach for
characterizing ecological risk. A weight-of-evidence
determination involves consideration of the quality and adequacy
of the data, as well as the frequency and magnitude of the
observed or estimated effect, if that information is available.
The current analysis is not intended to provide definitive
weight-of-evidence determinations for the chemicals of concern,
since all of the field effects data has not been thoroughly
evaluated.
-------
26
The weight-of-evidence data considered in this analysis are
based only on the granular formulations, and thus do not provide
a complete picture of avian risk. Kill incident reports
involving liquid or unidentified formulations are indicated in
Appendix 10 and would be included in risk assessments of other
formulations.
The weight-of-evidence approach allows flexibility for EPA
to make appropriate judgments on a case-by-case basis, giving
consideration to all relevant information, both quantitative and
qualitative. In addition to acute avian risk from granular
formulations, weight-of-evidence determinations for in-depth
reviews of individual chemicals might also include chronic, as
well as acute risks, both to birds and other non-target organisms
and environmental media from both granular and non-granular
formulations.
The data considered for this granular weight-of-evidence are
the risk index, expressed as the number of LD50s per square foot,
and confirmatory field effects data in the form of field studies
and bird kill incident reports from actual pesticide use.
Confirmatory field data exist for seven of the granular
pesticides in the analysis. Field studies are in various stages
of completion for the other seven.
Tables 6, 7, and 8 on the following pages show the weight-
of-evidence summary for the 14 granulars on three specific use
sites: corn, peanuts, and turf. For the purpose of this analysis
only, EPA first listed the pesticides in each of these three
tables in order of decreasing songbird LDsos per square foot,
since songbirds are generally the most sensitive of the species
tested. EPA then revised the order, giving the most "weight" to
chemicals having documented avian mortality either from a field
study or kill incident report. Weight-of-evidence determinations
to support regulatory actions would involve more thorough
evaluation of available field data.
Kill incidents listed in Tables 6, 7, and 8 may have been
reported on sites other than corn, peanuts and turf/lawn. Kill
incidents reported on one site may be indicative of avian risk on
other sites under similar usage conditions.
Some of the kill incidents in Tables 7, and 8 involve
species that are endangered or threatened. For this analysis,
no special consideration was given to these incidents in the
weight-of-evidence determination; nor has any special weight been
Although not all species and sites have been evaluated,
the U. S. Fish and Wildlife Service has rendered "jeopardy"
opinions for endangered species on at least some use sites of all
14 chemicals.
-------
27
given to kill incidents involving birds of prey (raptors) that
would indicate secondary poisonings and food-web implications.
However, both of these factors would be considered in in-depth
reviews.
Tables 6, 7, and 8 are based on consideration of information
on file with the Agency as of May, 1990. As pending studies are
completed and additional kill incident reports documented, the
weight-of-evidence could change. Risk reduction through label
modification will also affect the risk index component of the
weight-of-evidence. See Section VI for a discussion of risk
reduction. It should be noted that many but not all pesticides
listed in Tables 6, 7, and 8 are substitutes for one another.
-------
28
Table 6: Weiaht-of-Evidence Summary for Granular Use on Corn
Pesticide Songbird Confirmatory Data
LD50s/ft Fid. Stds. Kill Inct. Rpts.
-------
29
Table 7: Weiaht-of-Evidence Summary for Granular Use on Peanuts
Pesticide Songbird Confirmatory Data
LD50s/ft Fid. Stds. Kill Inct. Rpts.(c)
Carbofuran
2441
C
Disulfoton
750
C
Aldicarb
303
C
Phorate
144
C
Chlorpyrifos
184
I
Fenamiphos
129
R
Ethoprop
87
I
Fonofos
87
I
G(b)
G (b)
Key to Field Studies:
C= study completed for granular formulation,
avian mortality reported
I=study in progress
R=study under review
Key to Bird Kill Incident Reports:
G=mortality attributed to granular formulation
Notes: (a) Songbird risk index values from Appendix 7.
(b) Bird kills also reported from liquid and/or
unidentified formulation (see Appendix 10 and
Ref. 44).
(c) Kill incidents listed may have been reported on
sites other than peanuts. Kill incidents reported on
one site may be indicative of avian risk on other
sites under similar usage conditions.
-------
Table 8: Weiqht-of-Evidence Summary for Granular Use on Turf and
Lawns
Pesticide
Songbird
Confirmatory Data
Fid. Stds. Kill Inct. Rpts
LD50s/ft
(c)
Diazinon
Isofenphos
Fenamiphos
Ethoprop
Bendiocarb
Fonofos
Chlorpyrifos
436
73
R
P
R
I
I
I
I
2247
1425
87
80
16
Key to Field Studies:
I=study in progress
P=decision on study requirement pending
R= study under review
Key to Bird Kill Incident Reports:
G=mortality attributed to granular formulation
Notes: (a) Songbird risk index values from Appendix 7.
(b) Bird kills also reported from liquid and/or
unidentified formulation (see Appendix 10 and
Ref. 44).
(c) Kill incidents listed may have been reported on
sites other than turf and lawns. Kill incidents
reported on one site may be indicative of avian risk
on other sites under similar usage conditions.
-------
31
Currently, field studies and incident reports are useful to
the Agency to confirm risk predicted by the risk index and to
further characterize actual effects on wildlife in the field.
The field studies thus far submitted to the Agency have shown
avian mortality, although the studies were not designed to
characterize the magnitude, frequency, and duration of this or
other adverse ecological effects.
The growing body of field test data available to the Agency
indicate that concentrations of pesticides in the environment of
at least 1 LD50/ft have resulted in avian mortality, although
mortality has been reported at concentrations less than 1
LD50/ft . EPA recognizes that some avian mortality may be an
inevitable consequence of agricultural activity. However, the
Agency has not yet articulated "negligible risk" criteria for
avian effects. In practice the Agency uses 1 LDS0/ft as a level
of concern, i.e., a screen to identify the need for more in-depth
risk assessment. The Agency's regulatory activities thus far
have been directed toward those chemic|ls with relatively high
risk index values (well above 1 LDS0/ft ) and substantial
confirmatory evidence.
D. Ecological Considerations
Both pesticide-induced bird mortality and population effects
are impacts of concern to EPA. However, a recent Agency decision
has established that there is no need to demonstrate population
effects before taking regulatory action. In the Diazinon Remand
Decision, Administrator William K. Reilly states, "the Agency's
concern for wildlife is not limited to long-term adverse effects
on populations. Absent some countervailing benefit of continued
use, as a matter of policy an unnecessary risk of regularly
repeated bird kills will not be tolerated" (U.S. EPA, 1990a).
It would be extremely difficult, time consuming, and
expensive to show whether or not pesticide use resulting in bird
kills or diminished reproductive rates would also significantly
affect the sustainability of bird populations. More importantly,
by the time such effects were proven, it might be too late to
mitigate them. The current analysis deals only with gross
mortality to individual birds, recognizing these mortalities as
an indicator of potentially larger ecological problems.
Naturally occurring populations of birds do not exist in
isolation. The well-being of one population is dependent upon
other populations which serve as a food source for that
population or act in governing that population through predation
or competition. Ideally, avian risk assessments should evaluate
direct effects on a variety of species, as well as indirect
effects to those species. Indirect effects might include food-
-------
32
web or ecosystem perturbations. These perturbations could
include disruptions in the forage/prey and competition/predation
relationships of a particular population with other species.
Many ecological considerations influence the potential
population effects of individual bird mortalities. Some bird
populations, for example, can withstand repeated and high
mortality without being significantly diminished. However, once
a threshold is passed the population can drop very rapidly and
without warning. Even populations having exhibited resilience in
the past might not be expected to rebound from future stress if
some subtle environmental circumstances were to bring those
populations below the threshold.
Furthermore, mortality that fails to have any direct effect
on population levels may still significantly reduce genetic
diversity. This, in turn, could reduce the species ability to
adjust to future environmental changes.
It is unlikely that the effects of specific pesticide uses
on wildlife populations can be measured directly, because of the
many species and other complex variables involved. Modeling may
be feasible for aiding in the prediction of how pesticide use may
affect specific population parameters under certain circumstances
and to determine which aspects of a particular species' life
history may be most sensitive to pesticide exposure. This highly
specific information gained from the use of current models
appears to have only limited value in the pesticide regulatory
process.
E. Extent of the Risk
Because it is only a screening exercise, the current
analysis has been limited to consideration of acute avian risk on
a unit area basis, the risk to individual birds. No attempt has
been made to quantify the risk or to identify the bird
populations at risk.
In prioritizing chemicals for further review, the Agency may
take the extent of use (the number of acre treatments) into
consideration. Chemical-site combinations with high risk index
values, confirmatory field evidence and large numbers of acre
treatments are likely candidates for regulatory attention. Corn,
cotton, turf/lawn, sorghum, and peanuts are the five biggest uses
of the granular pesticides considered in this analysis (Appendix
3) •
Tables 9, 10, and 11, below, provide a summary of the
estimated number of acre treatments with the granular
formulations of the chemicals registered on corn, peanuts, and
turf/lawns, the songbird risk index values, and kill incidents
-------
33
associated with these and similar sites. Bird kills documented
on one site may be indicative of avian risk on other similar
sites, under comparable use conditions.
Appendix 11 gives the calculated songbird risk index value,
the number of acre treatments, and the kill incidents associated
with each pesticide-site combination considered in the analysis.
While acreage may be a factor in prioritizing regulatory
activities, it is important to note that risk is not necessarily
proportional to the number of acre treatments. For example, a
pesticide application to a relatively small site in an
ecologically sensitive area could have a proportionately greater
impact than the same pesticide used over a large area of less
sensitive habitat.
Table 9: Risk-Use Summary for Granular Use on Corn
Pesticide Songbird Acre
LD50s/ft Ca) Treatments(
(x 1000)
Carbofuran
1168
(K)
3920
Chlorpyrifos
30
4500
Diazinon
60
(K) *
10
Ethoprop
47
20
Fonofos
39
2700
Isofenphos
56
(K) *
R
Methomyl
20
12
Parathion
127
R
Phorate
164
(K)
2300
Terbufos
78
(K)
9100
Total corn acre
treatments:
22/562/000
R=registered, but no use reported
(a) From Appendix 7
(b) U.S. EPA estimates; Appendix 3
(K) Confirmed bird kill (field study or incident report) on corn
(K)* Kill incident reported on other crop
-------
34
Table 10: Risk-Use Summary for Granular Use on Peanuts
Pesticide Songbird Acre
LD50s/ft (a) Treatmentsc 5
(x 1000)
Aldicarb 303 (K)* 673
Carbofuran 2441 (K)* 20
Chlorpyrifos 184 130
Disulfoton 750 (K) 50
Ethoprop 87 4 0
Fenamiphos 129 25
Fonofos 87 30
Phorate 144 (K)* 80
Total peanut acre treatments: 1,048,000
(a) From Appendix 7
(b) U.S. EPA estimates; Appendix 3
(K) Confirmed bird kill (field study or incident report) on
peanuts
(K)* Kill incident reported on other crop
-------
35
Table 11: Risk-Use Summary for Granular Use on Turf/Lawns
Pesticide Songbird Acre
LD50s/ft (a) Treatments* 5
(x 1000)
Bendiocarb 87 40
Diazinon 436 (K) 540
Ethoprop 1425 48
Fenamiphos 2247 R
Fonofos 80 R
Isofenphos 73 (K) 240
Chlorpyrifos 16 415
Total turf and lawn acre treatments: 1,283/000
R=registered, but no use reported
(a) From Appendix 7
(b) U.S. EPA estimates; Appendix 3
(K) Confirmed bird kill (field study or incident report) on turf
or lawns
A more in-depth ecological risk assessment could include a
discussion of the extent of the risk—how widespread is the
problem, specifically, how many and what species of birds are
likely to be adversely affected and the ecological consequences
of the observed or estimated adverse effect.
Currently, ecological consequences are difficult to assess
due to the lack of scientific knowledge in some areas. For
example, more methods are currently available to assess impacts
on terrestrial species at the individual organism level than to
assess population, community or ecosystem level effects.
When the data are available, other factors that the Agency
may consider in evaluating the extent of the risk to avian
species in site-specific decisions are:
• the areal extent, location, climate, and topographic
features of specific crop-growing areas;
• the abundance and richness of bird species in these areas;
-------
36
• the reproductive potential and resilience of local
bird populations;
• the timing of pesticide applications in relation to bird
breeding and migration cycles;
• the likelihood of secondary poisonings; and
• the proximity, extent and quality of available habitat.
F. Assumptions and Conditions Used in Evaluating Acute
Avian Risk
In conducting this comparative analysis, the Agency has
presented the scientific basis and rationale along with a
discussion of the assumptions, uncertainties and limitations
inherent in the available data. The assumptions and
uncertainties associated with the present analysis are discussed
in the appropriate sections of this analysis and are summarized
below.
The data for this analysis were obtained from EPA files, and
published literature. Several assumptions concerning the
toxicity and exposure components of the risk index used in the
calculations and data analysis are:
1. The risk index was calculated using the most toxic
(lowest) LDS0 values for each test species (mallard duck,
bobwhite quail, and red-winged blackbird) from studies
judged scientifically sound. Ring-necked pheasant values
were substituted where quail data were unavailable.
2. The average bird body weights used were 1.082 kg for
mallard duck, 0.17 8 kg for bobwhite quail, and 0.052 kg
for red-winged blackbirds. In the two cases where ring-
necked pheasant values were substituted for quail, a body
weight of 1.13 5 kg was used. Dunning (1984) based the
average mallard weight on 5,847 individuals ranging from
0.720-1.580 kg. The average bobwhite quail weight was
based on 847 individuals with no range given. Average red-
winged blackbird weight was' based on 539 individuals
ranging from 0.029-0.0611 kg. Average ring-necked pheasant
weight was based on 7,137 individuals.
3. Where more than one use rate and application scenario was
provided in the Granular Analysis — Summary of Basic
Producer Labels (U.S. EPA,1990b), the highest application
rate and method providing maximum toxicant available on the
soil surface were used.
-------
37
4. Only application information from basic producer labels
was considered. These provided the Agency with a
manageable sample and reduced the likelihood of
including unrepresentative application rates.
5. Granule incorporation in the soil was assumed to be
either 0, 85, or 99% based on the application method and
label statements (Erbach and Tollefson, 1983; and Hummel,
1983) .
Several additional assumptions and/or conditions relating to the
risk determination and comparison of risk index values should be
stated:
6. The higher the number of LD50s per square foot, the greater
the potential risk to birds, although the relationship of
these factors may not be linear.
7. Granule ingestion is primarily accidental (random) rather
than selective or intentional.
8. For in-furrow, banded, and side-dress applications, LD50
per square foot calculations were based upon the treated
row, since it is the most disturbed area in the field and
the focus of bird foraging activity.
9. Birds can consume enough granules to equal the laboratory
LD50 value for the 14 pesticides in this analysis.
10. The number of LDsos per square foot (risk indices) were
calculated for each of the three representative avian
species using the toxicity values in Table 1.
11. The comparative risk analysis was conducted for 21 common
use sites for which three or more of the 14 granular
pesticides were registered. Comparison of risk indices are
entirely dependent on these 21 use sites and 14 pesticides.
12. A weight-of-evidence approach, LDsos per square foot and
confirmatory field data, was used to determine overall
relative risk of these granular formulations. The quantity
and quality of confirmatory data varies among chemicals.
13. Although some worst-case assumptions have been used in this
analysis, the risk index values in this analysis do not
represent a worst-case scenario for avian risk for the
following reasons:
-------
38
-calculations do not take into consideration spillage
at end-rows, from loading, or from worn machinery;
-calculations do not include toxicant available just below
the soil surface to probing bird species;
-LD50 values are derived from toxicity tests using only
adult birds, and a very limited number of test species,
not fully representative of the age and species
variability in the wild;
-only exposure by oral ingestion (represented by the LD50
value), was considered in this analysis. Exposure via
other routes may occur, thus increasing the possibility of
adverse effects.
IV. UNCERTAINTY IN ACUTE AVIAN RISK ASSESSMENT
A. Strengths and Weaknesses of the Data
Like all Agency risk assessments, the current comparative
analysis of acute avian risk contains uncertainties. Unlike many
human risk assessments, however, the endpoint of concern, in this
case avian mortality, is known to occur as a direct effect from
the use of pesticides. In most human risk situations, the Agency
calculates a risk, but it is generally not known if and to what
extent the adverse effect actually occurs in the human
population, and to what extent the occurrence of any adverse
effect can be attributed to pesticide exposure.
The acute avian risk indices used in this analysis are
relative indices of risk based on the relationship between
potential exposure and hazard. The risk indices are not intended
to predict the probability that a pesticide will cause mortality
of individual birds. Given the many complex factors contributing
to uncertainty and the lack of information on the inter-
relationships of these factors, the uncertainty associated with
the calculation of the risk indices has not been quantified. The
following discussion is intended to give a qualitative
description of uncertainty.
B. Sources of Uncertainty
One of tjie primary sources of uncertainty in this analysis
is the role of bird behavioral responses to granules and how
these behaviors affect exposure. Although birds are known to
ingest pesticide granules, the mechanisms of bird attraction,
avoidance, and/or selection are not yet completely understood.
Birds may also be exposed to granular pesticides through
routes other than direct oral ingestion of granules; for example,
-------
39
by drinking contaminated water after heavy rainfall. Still other
potential routes of exposure include dermal, ocular, inhalation,
and percutaneous absorption. Consideration of additive exposures
would result in higher risks than have been predicted in this
analysis.
The persistence of a pesticide in the environment may affect
the cumulative exposure of birds to that pesticide, although none
of the granular pesticides identified in this analysis are as
persistent as earlier generation organochlorine compounds.
Furthermore, the limited data now available suggest that even
relatively short-lived chemicals, such as carbofuran, can cause
considerable mortality.
Factors affecting the persistence of the granules, per se,
and the rate of release of various chemicals from their carriers
are not well known. These factors include size of granule, type
of carrier, i.e., clay, sand, corncob, or silica, and the
environmental conditions attendant to the granular pesticide's
use.
The temporal component of exposure, i.e., the length of time
that pesticides and birds occur together in the same place, has
not been fully developed in this analysis but may be a
consideration in future analyses.
Relative to the toxicity component of the avian risk
calculations, uncertainty is associated with extrapolating LD50s
from one species to another and from one sub-population to
another.
The relationship between the risk index values and the
actual lethal risk to wild birds, i.e., the predictive value of
the risk index, is uncertain. This analysis assumes that as the
risk index increases, the potential risk to birds increases.
However, the form of that relationship is unknown. It is
unlikely that there is a linear relationship, i.e., that a 30%
reduction in the risk index would translate to a 3 0% reduction in
risk in the field. Furthermore, the Agency recognizes that the
risk index is a continuum and that ranges of values probably
represent comparable risk. For example, for practical purposes,
there is little difference between index values of 58 and 79.
A final question involves the role of pesticides in the
overall decline of some bird populations. Many factors
contribute to declining populations, including loss and
fragmentation of habitat, degradation of habitat from chemical
and other stressors, climate change, and environmental
pollutants. The additive role of stress from pesticides in this
decline may never be precisely defined.
-------
40
C. Refining Avian Risk Assessment
The goal of the Agency is to use the best available methods
for assessing and comparing the risks posed by pesticides.
Agency scientists and the SAP support the use of the risk index
as an initial approach to characterize avian risk. EPA's Office
of Research and Development current research plan includes
components to determine the reliability of the quotient method
(risk index) for predicting chemical risk to avian species (U.S.
EPA, 1991). Certain categories of additional information would
be useful to EPA and could aid in refining the Agency's approach
to avian risk assessment.
Given the uncertainty over the role of behavioral responses
to granules, some additional data could help clarify the
mechanisms of granular ingestion. Is ingestion random or
selective? Is preference/avoidance species specific? Could
granules be designed or formulated to repel birds or to pass
through bird's digestive systems without toxic effect?
Data to quantify the effectiveness of various methods of
soil incorporation would be useful to assess risk reduction. The
LD50/ft index is based on surface availability of granules, but
it has not been conclusively demonstrated that shallow
incorporation methods mitigate the risk, since many birds forage
below the soil surface.
Finally, EPA supports the recommendation of the Avian
Effects Dialogue Group (Conservation Foundation, 1989) that a
coordinated incident monitoring and investigation program,
including a national data base be implemented. Such a program
would provide additional data for risk assessments, a means of
evaluating risk reduction measures, and would be useful in
determining the relative risks associated with alternative
compounds used on the same crops and pests.
V. SUMMARY AND CONCLUSIONS
Direct ingestion of granular pesticides poses a distinct,
although not the only, risk to birds from pesticides. Birds are
expected to be present during and after granular pesticide
applications and can and do ingest granules remaining both on and
below the soil surface.
EPA screened 99 granular compounds for both toxicity and
exposure to identify those posing potentially high risk to avian
species. The 14 pesticides identified, all carbamate or
organophosphate insecticides, were subjected to further analysis
including comparisons of potential acute avian risk across use
-------
41
sites based on the risk index (the number of LDsos per square
foot) and by considering confirmatory field effects data from
field studies and kill incident reports.
The Agency has concluded that the labelled use of these 14
granular pesticides can result in concentrations of granules in
the environment, available to birds at levels that can be
lethally toxic to these organisms. Relatively higher values in
the risk index with confirmatory data in the form of field study
mortalities and/or bird kill incident reports for some of these
14 heighten the Agency's concern. Also of concern to the Agency
is the widespread use of many of these chemicals over millions of
acres and a variety of ecological zones resulting in exposure and
risk to many species and large numbers of birds.
Registrants are encouraged to consider risk reduction
measures on these 14 pesticides and to assess the need for data
to further characterize risk and to support any proposed risk
reduction measures. Since it is not EPA policy to delay its
regulatory processes to allow registrants additional time in
which to conduct research to support their risk mitigation
proposals, any such proposals would be most useful if submitted
prior to the Agency's further consideration-of what regulatory
action, if any, is appropriate.
EPA recognizes the need to provide industry and the public
with clear standards for ecological risk assessment and
management that can be applied in an equitable fashion. The many
uncertainties associated with ecological risk assessment make
this goal particularly challenging. The current analysis raises
many issues that the Agency will continue to address in future
eco-risk projects. These include: developing negligible risk
criteria for ecological risk concerns; better characterizing the
behavioral, spatial, and temporal components of environmental
exposure; relating effects on individual organisms to higher
organizational levels (i.e., communities and ecosystems); and
continuing to develop risk management strategies that take into
account increasingly complex risk trade-offs.
VI. RISK REDUCTION
As an adjunct to its regulatory responsibility, EPA promotes
source reduction (lessening toxic inputs to the environment) as
the most immediate option for reducing ecological risk from
granular pesticides.
The Agency believes that risk reduction may be possible for
some of the granular pesticides in this analysis. Risk reduction
can take several forms: label amendments that result in lower
risk index (LD50/ft ) values; label amendments and other measures
that do not affect the risk index but that nonetheless may reduce
-------
42
risk; and modifications to the granule that limit exposure. Each
is discussed below.
A. Reductions in the Risk Index
Little can be done to reduce the inherent toxicity of a
pesticide. However, exposure, which takes into account various
factors influencing the amount of toxicant available to birds and
other non-target organisms, can be reduced. Registrants should
consider modifying labels to require better soil incorporation
and lower application rates.
EPA recognizes that the labels on which the calculations in
this document are based represent a "snapshot" in the regulatory
process. The registrants of some of the listed chemicals have
already amended their labels to reduce exposure in response to
regulatory actions. Others have not. Efficacy considerations
will also limit the amount of risk reduction that is feasible for
each chemical. Therefore, EPA has not established a target level
for risk reduction.
B. Granule Modification
It is important to note that label modification is not the
only approach to reducing avian risk from granular pesticides.
Modifications to the granule itself that discourage ingestion or
otherwise limit exposure are also worthy of investigation.
Modifications of this stgrt would not be reflected as changes in
the risk index (LD50s/ft ) but could nonetheless represent genuine
risk reduction.
C. Other Risk Reduction Measures
Registrants are urged to consider other innovative
approaches to lessen the amount and availability of these
toxicants in the environment of birds and other non-target-
wildlife. These might include-but should not be limited to
decreasing the number of pesticide applications per year,
prohibiting pesticide use in ecological sensitive areas, and fine
tuning product labels to permit reduced application rates under
certain conditions such as late planting and low pest pressure.
Some risk reduction proposals, while reducing risk index
values, may not result in "real" risk reduction in the field.
The ultimate test of the effectiveness of any risk reduction
measures will be actual field data indicating low risk to
wildlife and environmental media. The Agency's acceptance of
-------
43
label amendments or other risk reduction proposals does not
necessarily imply that risk has been reduced to an acceptable
level.
D. Public Participation
In light of the risk posed to birds and other wildlife, the
Agency urges homeowners, farmers, and other potential pesticide
users to first consider whether alternatives to chemical use may
be feasible. These alternatives might include cultural practices
such as crop rotation, lawn aeration, and use of native and
varied ground cover, as well as integrated pest management
techniques, such as scouting to determine pest infestation levels
rather than applying chemicals prophylactically.
Good stewardship of both urban and agricultural ecological
resources demands that if pesticides are used, they be used
judiciously. When pesticides are necessary, label directions and
cautions should be observed, granule spills should be avoided or
cleaned up quickly, granules should be incorporated as indicated,
and application equipment should be in good condition and
properly calibrated. If domestic or wild species are hurt or
killed as a result of pesticide use, the incident should be
reported to a regional office of the U.S. Fish and Wildlife
Service, a state wildlife ^gency, or to the National Pesticide
Telecommunication Network.
12 The National Pesticide Telecommunication Network can be
reached at 1-800-858-7378.
-------
44
VII. REFERENCES
1. Balcomb, R. 1980. Granular pesticides: Restricted
classification based on the hazard to avian wildlife.
Presentation to U.S. EPA Scientific Advisory Panel,
March 5. Ecological Effects Branch, Hazard Evaluation
Division, Office of Pesticide Programs.
2. Balcomb, R., R. Sevens, and C. Bowen III. 1984. Toxicity
of 16 granular insecticides to wild-caught songbirds.
Bull. Environs. Contam. Toxicol. 33:302-307.
3. Bent, A.C. 1963. Life Histories of North American
Gallinaceous Birds. Dover Publications, Inc.
New York.
4. Beskid, J.C. and R. Fink. 1981 Final Report: Simulated
field study—bobwhite quail: Project No. 13 0-131A-D.
(Unpublished study received May 21, 1981 under 241-
257; prepared by Wildlife International Ltd., submitted
by American Cyanamid Co., Princeton, N.J.; CDL:
245263); MRID No. 74623.
5. Best, L.B. and J.P. Gionfriddo, 1991. Characterization
of grit use by cornfield birds. Wilson Bulletin,
103:68-82.
6. Bunyan, P.J., M.J. Van Den Heuvel, P.I. Stanley, and E.N.
Wright. 1981. An intensive field trial and a multi-
site surveillance exercise on the use of aldicarb to
investigate methods for the assessment of possible
environmental hazards presented by new pesticides.
Agro Ecosystems 7:239-262.
7. The Conservation Foundation. 1989. Pesticides and Birds—
Improving Impact Assessment. Report of the Avian
Effects Dialogue Group. Washington, D.C. 68 pp.
8. DeWitt, J.B. 1966. Methodology for determining toxicity of
pesticides to wild vertebrates. J. Applied Ecol. 3
(suppl.):275-278.
9. Dunning, J. 1984. Bodyweights of 686 species of North
American birds. Western Bird' Banding Assoc. Monogr.
No. 1.
10. Erbach, D. and J. Tollefson. 1983. Granular insecticide
application for corn rootworm control. Trans. ASAE-
1983. Amer. Soc. Agric. Eng. 0001-2351/83/2603-0696.
-------
11
12
13
14
15
16
17
18
19
20,
21,
45
FIFRA Scientific Advisory Panel. 1989. A set of scientific
issues being considered by the Agency in connection
with the Special Review of carbofuran. Report dated
2/23/89 in response to public review 2/15/89,
Arlington, VA.
Flickenger, E., K.A. King, W.F. Stout, and M.M. Mohn. 1980.
Wildlife hazards from Furadan 3G applications to rice
in Texas. J. Wildl. Manage. 44:190-197.
FMC Corporation. 1983. Effects of Furadan formulation 10G
and 15G on avian populations associated with corn
fields. Final Report. Opp Accession No. 251053.
Hill, E.F. and M.B. Camardese. 1984. Toxicity of anti-
cholinesterase insecticides to birds: Technical grade
versus granular formulations. Ecotoxicol. Environs.
Safety 8:551-563.
Hudson, R.H., R.K. Tucker and M.A. Haegele. 1984. Handbook
of toxicity of pesticides to wildlife (2nd ed.). U.S.
Fish and Wildlife Service Resource Publication 153.
90p.
Hummel, J.W. 1983. Incorporation of granular soil
insecticides by corn planters. Trans. ASAE-1983.
Amer. Soc. Agric. Eng. Paper No. 83-1017/83-7008.
Kenaga, E.E. 1974. Evaluation of the safety of
chlorpyrifos to birds in areas treated for insect
control. Residue Reviews 50:1-41.
Kendall, R.J., L.W. Brewer, T.E. Lacher Jr., T.E. Whitten.
1989. The use of starling nest boxes for field
reproductive studies. The Institute of Wildlife
Toxicology, Huxley College of Environmental Studies,
Western Washington University, Bellingham, WA 98225.
(presently at Clemson University, Clemson, SC 29631)
Lamson, S.R. 1989. Letter to EPA concerning Document
Control Number OPP 30000/48A (28 March 1989). U.S.
Fish and Wildlife Service, Washington, D.C. 4 pp. with
attachment.
NPIRS. 1990. National Pesticide Information Retrieval
System. Purdue University, Lafayette, IN.
O'Brien, K. 1987. Application accuracy. Agrichemical Age
31(16):10-16.
-------
22
23
24
2 5
26
27
28
29
30
31
32
33
34
46
Rosene, Jr., W. and D.W. Lay. 1963. Disappearance and
visibility of quail remains. J. Wildl. Manage.
27:139-142.
Schafer, E.W. 1972. The acute oral toxicity of 369
pesticidal, pharmaceutical and other chemicals to
wild birds. Toxicol, and Applied Pharmacology,
21:315-330.
Schafer, E.W., Jr. and R.R. Brunton. 1979. Indicator bird
species for toxicity determinations: Is the technique
usable in test method development. pp.157-168 in Vert.
Pest. Control and Manage., Am. Soc. Test and Materials,
J.R. Beck, ed. ASTM STP 680, Philadelphia, PA.
Shellenberger, T.E. 1971. Toxicity and acceptance studies
of granular DURSBAN formulations with bobwhite quail.
Study No. 2. Dow Chemical Company. Midland, MI. (As
cited in Kenaga 1974).
Smith, G.J. 1987. Pesticide use and toxicology in relation
to wildlife: Organophosphorus and carbamate compounds.
U.S. Department of the Interior, Fish and Wildlife
Service. Resource Publication 170.
Stone, W.B. and P.B. Gradoni. 198 6. Poisoning of birds by
cholinesterase inhibitor pesticides. Wildl. Rehab.
5:12-28.
Stutzenbaker, C.D., K. Brown, and D. Lopries. 1983.
Special report: An assessment of the accuracy of
documenting waterfowl die-offs in a Texas coastal
marsh. U.S* Fish and Wildlife Service, Fed. Aid. Proj.
Rep. W 106R, Texas PWD. pp.88-95.
U.S. Department of Commerce. 1987. Census of Agriculture,
vol. 1, part 51, U.S. Summary and Data.
U.S. EPA. 1977a. Memorandum, dated 9 September 1977,
to Environmental Safety Section, OPP, U.S. EPA:
Classification of granulated formulations, from
R. Felthousen.
U.S.
EPA.
1977b.
MRID No. 096659
U.S.
EPA.
1978.
MRID No. 071980
U.S.
EPA.
1979a.
MRID No. 099080
U.S.
EPA.
1979b.
MRID No. 121635
-------
35
36
37
38
39
40
41
42
43
44
45
46
47
U.S. EPA. 1986a. Hazard Evaluation Division Standard
Evaluation Procedure—Ecological Risk Assessment.
Office of Pesticide Programs, Washington, D.C.
EPA 540/9-85-001. 96 pp.
U.S. EPA. 1986b. EEB Review #47 dated 14 February 1986
U.S. EPA. 1987. MRID No. 40660705 (Note: LD50 value has
been recalculated since original review)
U.S. EPA. 1988a. Guidance Document for Conducting
Terrestrial Field Studies. Prepared by E. Fite,
L. Turner, N. Cook, and C. Stunkard. Ecological
Effects Branch, Hazard Evaluation Division, Office
of Pesticide Programs. EPA 540/09-88-109.
September 1988.
U.S. EPA. 1988b. MRID No. 40895301
U.S. EPA. 1989. Technical
Review of Carbofuran.
U.S. EPA. 1990a. Diazinon
Reilly, Administrator.
Support Document for the Special
January 1989.
Remand Decision. William K.
July 12, 1990.
U.S. EPA. 1990b. Granular analysis—Summary of basic
producer labels. (Unpublished document prepared
by the Biological and Economic Analysis Division,
Office of Pesticide Programs.)
U.S. EPA. 1990c. Memorandum to the Public Docket dated
8 May, 1990, from Richard Dumas, Economic Analysis
Branch, Biological and Economic Analysis Division,
Office of Pesticide Programs.
U.S. EPA. 1990d. Summary of Field Evidence for Certain
Granular Pesticides. (Unpublished document prepared by
the Environmental Fate and Effects Division, Office of
Pesticide Programs.)
U.S. EPA. 1991. Ecological Risk Assessment Research
Program FY92-FY96 (Draft). Office of Research and
Development.
Whitehead, P. 1975. Memorandum dated 1 December 1975 to
Dr. D. Hocking, Chief, Wildlife Management Service:
Report of waterfowl kills by granular carbofuran,
with attachments and analytical reports.
-------
48
APPENDIX 1: PESTICIDES WITH GRANULAR FORMULATIONS NOT INCLUDED
IN THE ANALYSIS }
Key: F=fungicide l=limited exposure to birds
H=herbicide 2=not highly toxic to birds
I=insecticide 3=no avian toxicity data available
M=molluscicide
Common Name
Action
Reason
Acephate
I
l(b)
Alachlor
H
2
Atrazine
H
2
Avermectin
I
2
Bacillus thuringiensis
I
2
Benfluralin
H
2
Bensulide
H
3(c>
Bromacil
H
'2..
Butralin
H
2
Butylate
H
2(d)
Calcium cyanamide
H,F
3
Carbaryl
I
2
Chloramben
H
2
Chloroneb
F
2
Chlorothalonil
F
2
Cyanazine
H
2
Cycloate
H
2
Cyromazine
I
2
2,4-D
H
2
DCPA
H
2
DDVP
I
1
Dicamba
H
2
Dichlobenil
H
2
Diflubenzuron
I
2
Dimethoate
I
1
Diphenamid
H
2
Diuron
H
2
DSMA
H
2
Endothall
H
2(e)
EPTC
H
2
Ethion
I
2
Fenthion
I
1
Fenvalerate
I
2
Ferrous ammonium
sulfate
H
3
Ferrous sulfate
heptahydrate
H
3
Ferrous sulfate
monohydrate
H
3
-------
49
Common Name Action Reason
Heptachlor
I
Iprodione
F
2
Malathion
I
2
MCPA
H
2
MCPP
H
2
Mefluidide
H
2
Mercuric chloride
F
1
Mercurous chloride
F
1
Metalaxyl
F
2
Metaldehyde
M
2
1(g)
Methiocarb
I / M
Methoxychlor
I
2
Methyl Parathion
I
1
Metolachlor
H
2
Mexacarbate
11M
1
Molinate
H
2
2
Monuron
H
Napropamide
H
2
Niclosamide
M
3Cd)
Nicotinic acid
H
Norflurazon
H
2
Oxadiazon
H
2 .
lCO
Oxamy1
I
Oxyfluorfen
H
2
PCNB
F
2
Pebulate
H
2
Pendimethalin
H
2
Permethrin
I
3
Phenyl mercuric acetate
F
3
Pirimophos-ethyl
I
1
Propachlor
H
2 .
1(J)
Propoxur
I
Siduron
H
2
Simazine
H
2
Sodium chlorate
H
Sodium fluosilicate
I
Tebuthiuron
H
2
Tefluthrin
I
2
Temephos
I
1
Terrazole
F
2
Tetrachlorvinphos
I
2
Thiobencarb
H
2
Thiophanate-methyl
F
2
Thiram
F
2
Triadimefon
F
2
Triallate
H
2
-------
50
Common Name
Action
Reason
Trichlorfon
Trifluralin
Trimethacarb
I
H
I
1
2
2
Notes
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
(i)
(j)
Compiled Feb.-March 1990, based on National Pesticide
Information Retrieval System run dated Jan. 26, 1990
(Ref. 20).
Only two granular products (239-2453 and 239-2472) registered
for use on ornamentals.
Avian LC50 > 10,000 ppm.
List D
Avian LCS0 > 10,000 ppm.
One remaining registration (13283-04) for fire ant control in
transformer boxes.
Acts as bird repellent-aversion agent.
Avian LC50 > 4,000.
Only two granular products (904-417 and 904-415) for
greenhouses and containerized nursery stock.
One registered product (538-59) would exceed level of
concern, but is not marketed.
-------
APPENDIX 2. MEDIAN GRANULE WEIGHT AND ESTIMATED NUMBER OF GRANULES PER SQUARE FOOT
Granule Wt.("
Range of
No. of
No. of Granules/
Pesticide
Formulation
Granule Ut.w
Exposed Granules""'
a Al)
(mg)
(mg)
(/ft2)
Ethoprop
10G
0.051
-------
APPENDIX 3. ACRE TREATMENTS WITH GRANULAR FORMULATIONS OF 14 CHEMICALS ON SELECTED SITES
(X 1,000)
SITE
AID
BEN
CAR
CHL
DIA
DIS
ETH
FEN
FON
ISO
MET
PAR
PHO
TER
SUB-
TOTAL
Beans
25
s
20
1
2
8
n
60
108
Cole Crops
20
s
1
3
2
6
S
s
26
Citrus
212
10
s
6
228
Corn
3920
4500
10
30
20
2700
n
12
n
2300
9100
22592
Cotton
3195
100
100
70
s
125
3590
lettuce
s
s
s
8
0
Onions
s
s
n
n
n
0
Peanuts
673
20
130
s
50
40
25
30
2
80
1050
Potatoes
416
5
50
70
5
s
s
300
846
Sorghum
72
870
40
20
n
s
21
150
1173
Soybeans
225
40
90
5
s
40
20
7
30
457
Sugar Beets
170
75
50
s
1
10
s
n
40
220
566
Sugarcane
n
s
20
n
8
28
Sweet Potatoes
18
s
n
40
n
58
Tobacco
29
10
s
10
50
10
s
109
Tomatoes
s
5
s
s
s
5
Turf/Lawns
40
415
540
48
n
n
240
1283
Subtotal
5035
40
5025
5265
555
292
292
153
2767
240
12
9
2964
9470
32119
s * Data indicate some use of the chemical; however, data are not available that specifically indicates granular usage, although the
granular formualtion is registered for this site. The usage of the granular formulation is probably small (< 10,000 acre treatments).
n « No data are available that indicate any usage of the chemical of any formulation on this site; however, the granular formulation of the
chemical is registered for this site.
blank = The granular formulation is not registerered for this site.
SOURCE: U.S. EPA estimates
-------
53
APPENDIX 4. APPLICATION DATA USED FOR THE CALCULATIONS IN THE
ANALYSIS
A. OUNCES PER 1000 FT OF ROW
• BAND(b>
PESTICIDE
CROP OR SITE
OZ/IOOO
FT(a) (FT)
% AI
% INC.Cc)
aldicarb
beans
22.5
0. 50
10
85
cotton
18. 0
0.33
10
85
peanuts
33 . 0
0. 50
10
85
potatoes
21.0
0.33
10
85
sweet potatoes
45
1.0
10
99
sorghum
11
0. 10
10
99
soybeans
33
0 . 50
10
85
sugarbeets
33
0.33
10
85
sugarcane
55.5
0.83
10
99
carbofuran
corn
36.0
0 . 60
10
85
cotton
12 . 0
0. 10
10
99
peanuts
22.0
1. 17
10
0
sorghum
8.0
0. 60
15
85
soybeans
16.0
0. 60
15
85
sugarbeets
13 . 0
0. 50
10
85
chlorpyrifos
broccoli
9.20
0.33
15
85
brussel sprout
9 . 20
0.33
15
85
cabbage
9.20
0.33
15
85
cauliflower
9.20
0.33
15
85
onions
3.7
0. 10
15
99
peanuts
15.0
0. 50
15
0
sorghum
12 . 0
0. 50
15
85
soybeans
8.0
0.33
15
85
sugarbeets
9.0
0.42
15
85
diazinon
sugarbeets
9.4
0.42
14 . 3
85
-------
cj
0
0
0
0
0
0
0
0
0
0
85
0
85
85
85
85
85
85
85
85
85
85
85
85
85
99
0
85
85
85
85
54
PER 1000 FT OF ROW (CONTINUED)
BAND(b)
WIDTH
CROP OR SITE QZ/1000 FT(a)(FT) % AI
beans
90
0 . 50
2
broccoli
7.4
0 . 50
15
brussel sprout
7.4
0 . 50
15
cabbage
11.3
0 . 50
15
cauliflower
7.4
0 . 50
15
cotton
12 . 0
0 . 50
10
lettuce
12 . 0
0.50
10
peanuts
22 . 0
0 . 50
10
potatoes
35.0
0.50
10
soybeans
12 . 0
0 . 50
10
tobacco
60. 0
0 . 50
10
tomatoes
120. 0
0 . 50
2
beans
22.4
1. 00
15
cabbage
22.4
1.25
10
corn
12 . 0
0 . 50
10
peanuts
44 . 8
1. 00
10
sweet potatoes
51.2
1. 00
10
soybeans
33 . 6
1. 00
10
sugarcane
88 . 0
1. 00
10
tobacco
153 . 6
1. 50
10
brussel sprout
18 . 4
1.00
15
cabbage
18.4
1. 00
15
cotton
18.0
0. 50
15
peanuts
18.7
1.00
15
corn
16.0
0 . 50
15
onions
6.0
0 . 10
10
peanuts
12.0
1.50
20
sorghum
6 . 0
0 . 60
20
sugarbeets
10.5
0 . 60
10
sugarcane
110. 2
1. 17
10
corn
o
•
00
0 .33
15
-------
55
A. OUNCES PER 1000 FT OF ROW (CONTINUED)
PESTICIDE
phorate
terbufos
(a)
BAND
WIDTH
(b)
CROP OR SITE QZ/1000 FT (FT)
beans
corn
cotton
peanuts
potatoes
sorghum
soybeans
corn
sorghum
sugarbeets
14 ,
12,
24,
22 ,
34 ,
12 ,
18,
8.0
8.0
8.0
0,
0 ,
0 .
1,
0 ,
0 ,
0 ,
50
60
25
25
50
60
60
0 . 60
0 .42
0 . 42
% AI
10
10
10
10
10
10
10
15
15
15
% INC.
85
85
85
85
0
85
85
85
85
85
Cc)
(a) From basic producer label
(b) From basic producer label or Agency estimate
(c) Agency estimate based on Refs. 10 and 16
-------
56
B. BROADCAST APPLICATIONS
PESTICIDE
CROP OR SITE
LB / ACRE
-------
57
B. BROADCAST APPLICATIONS (CONTINUED)
PESTICIDE
isofenphos
methomyl
parathion
CROP OR SITE
LB/ACRE
(a)
AI
INC.
(b)
phorate
lawns
283.1
0.74
0
turf
130. 0
1. 5
0
broccoli
60. 0
1. 5
0
cabbage
60. 0
1.5
0
corn
20.0
5
0
cotton
44.5
1.5
0
lettuce
60. 0
1. 5
0
sugarbeets
60. 0
1.5
0
tomatoes
60. 0
1.5
0
beans
50. 0
10
85
broccoli
250
2
85
brussel sprout
250
2
85
cabbage
250
2
85
cauliflower
250
2
85
corn
15. 0
10
0
lettuce
250
2
85
onions
40.0
10
85
potatoes
60.0
10
85
sugarbeets
50.0
10
85
tomatoes
60.0
10
85
sugarbeets
10. 0
15
0
(a) From basic producer label
(b) Agency estimate based on Refs. 10 and 16
-------
58
C. BROADCAST-BANDED APPLICATION
CROP OR SITE LB/A % AI
BAND ROW
WIDTH SPACE %
riN^ TIN) INC,
aldicarb
diazinon
fenamiphos
phorate
citrus
beans
sugarcane
citrus
sugarcane
67 . 0
14 . 0
28 . 0
67 . 0
39 . 0
15
14 . 3
14 . 3
15
10
60
6
12
120
10
240
22
60
240
60
85
0
85
85
85
-------
59
APPENDIX 5. Calculations Used in Determining Risk Indices for
14 Granular Pesticides
Part 1
Method of determining the number of LDsos per square foot for products
with application rates expressed in ounces per 1000 foot of row,
usually band, side-dress, or in-furrow applications.
a) Product per Square Foot
Productloz per 1000 Ft of Row) x 28349 mq/oz = Product(mg)/Ft2
1000 Ft x Band Width (Ft)
b) Toxicant per Square Foot
Product (mg)/Ft2 x
Percent
Active Active
Ingredient = Ingredient(mg)/Ft
Active Percent Exposed
Ingredient(mg)/Ft x Unincorporated = Active
Ingredient(mg)/Ft
c) LDsos per Square Foot
Exposed
Active Ingredient fmqWFt = LD50s/Ft
LDS0 x Bird
(mg/kg) Weight (kg)
-------
60
Part 2
Method of determining LD50s per square foot for products with
application rates expressed in pounds per acre, usually aerial
or ground broadcast.
a) Active Ingredient fmg)/Ft2
Percent
Pounds Active Active
Product/Acre* x Ingredient x 453,590 mg/lbs = Ingredient(ma)
43,560 Ft'/Acre FtT
b) LD50s per Square Foot
Exposed
Active Ingredient fmgW Ft = LD50/Ft
LD50 x Bird
(mg/kg) Weight (kg)
-------
APPENDIX 6. EXPOSED TOXICANT IN mg/ft2 FOR GRANULAR FORMULATIONS ON 21 COMMON USE SITES
Beans
ALD
BEN
CAR
CHL
DIA
DIS
ETH
FEN
FON
ISO
MET
PAR
PHO
TER
19.1
76.3
102.1
14.3
6.8
7.8
11.9
Broccoli
17.8
6.3
62.9
3.4
9.4
7.8
Brussel Sprouts
17.8
6.3
62.9
11.7
3.4
7.8
Cabbaae
17.8
6.3
96.1
7.6
11.7
3.4
9.4
7.8
Cauliflower
17.8
6.3
62.9
3.4
7.8
Citrus
62.7
10.5
31.4
Corn
25.5
21.1
6.3
10.2
20.4
15.5
10.4
15.6
8.5
8.5
Cotton
23.2
3.4
68.0
23.0
6.9
40.8
Lawns
11.3
45.3
312.0
42.3
21.8
Lettuce
6.3
68.0
9.4
7.8
Onions
1.6
6.3
1.7
6.2
Peanuts
28.1
53.3
127.6
124.7
19.1
11.9
45.4
7.5
Potatoes
27.1
6.3
198.4
18.7
6.8
9.4
196.2
Sorahum
3.1
8.5
15.3
B.5
8.5
12.2
Soybeans
28.1
17.0
15.5
68.0
14.3
12.8
Suctar Beets
42.5
11.1
13.7
13.6
7.4
9.4
7.8
15.6
12.2
Sucrarcane
1.9
31.2
37.4
40.1
36.5
Sweet Potatoes
1.3
3.2
31.2
21.8
6.8
Tobacco
4.7
51.0
43.5
3.1
Tomatoes
6.3
136.1
3.4
9.4
9.4
Turf
31.2
312
208
41.6
20.3
ALD = aldicarb BEN = bendiocarb CAR = carbofuran CHL = chlorpyrifos
DIA = diazinon DIS = disulfoton ETH = ethoprop FEN = fenamiphos
FON = fonofos ISO = isofenphos MET = methomyl PAR = ethyl parathion
PHO = phorate TER = terbufos
-------
APPENDIX 7. CALCULATED RED-WINGED BLACKBIRD LDS0/FTZ FOR GRANULAR FORMULATIONS ON 21 COMMON USE SITES
Beans
ALD
BEN
CAR
CHL
DIA
DIS
ETH
FEN
FON
ISO
MET
PAR
PHO
TER
207
734
613
65
13
63
229
Broccoli
26
60
378
7
18
63
Brussel SDrouts
26
60
378
127
7
63
Cabbaae
26
60
578
35
127
7
18
63
Cauliflower
26
60
378
7
63
Citrus
678
15
339
Corn
1168
30
60
47
39
56
20
127
164
78
Cotton
251
156
409
248
13
785
Lawns
16
436
1425
81
78
Lettuce
60
409
18
63
Onions
2
60
3
51
Peanuts
303
2441
184 „
750
87
129
87
144
Potatoes
292
60
1193
86
13
76
3773
Sorahum
34
389
22
16
164
111
Soybeans
303
779
22
409
65
245
Suaar Beets
459
506
20
131
14
18
63
300
111
Suaarcane
20
300
171
77
702
Sweet Potatoes
U
5
300
99
13
Tobacco
7
307
199
6
Tomatoes
60
818
7
18
76
Turf
87
1425
2247
80
73
ALD = aldicarb BEN = bendiocarb CAR = carbofuran CHL = chlorpyrifos
DIA = diazinon DIS = disulfoton ETH = ethoprop FEN = fenamiphos
FON = fonofos ISO = isofenphos MET = methomyl PAR = ethyl parathion
PHO = phorate TER = terbufos
-------
APPENDIX 8. CALCULATED BOBWHITE QUAIL LDjq/FT2 FOR GRANULAR FORMULATIONS ON 21 COMMON USE SITES
Beans
ALD
BEN
CAR
CHL
DIA
DIS
ETH
FEN
FON
ISO
MET
PAR
PHO
TER
54
43
4B
3
3
7
10
Broccoli
3
4
29
2
« 1
7
Brussel SDrouts
3
4
29
66
2
7
Cabbaae
3
4
45
2
66
2
< 1
7
Cauliflower
3
4
29
2
7
Citrus
176
2
176
Corn
28
4
4
2
10
10
< 1
15
7
3
Cotton
65
4
32
129
< 1
33
Lawns
2
25
65
20
14
Lettuce
4
32
< 1
7
Onions
< 1
4
< 1
6
Peanuts
79
59
22
58
4
67
21
6
Potatoes
76
4
93
4
3
9
157
Sorahum
9
9
3
4
7
5
Sovbeans
79
19
3
32
3
10
Suaar Beets
119
12
2
8
3
< 1
7
13
5
Suaarcane
5
18
8
19
29
Sweet Potatoes
4
< 1
18
5
3
Tobacco
< 1
24
9
1
Tomatoes
4
64
2
< 1
9
Turf
9
65
1169
19
13
ALD
DIA
FON
PHO
aldicarb
diazinon
fonofos
phorate
BEN = bendiocarb
DIS = disulfoton
ISO = isofenphos
TER = terbufos
CAR = carbofuran
ETH = ethoprop
MET = methomyI
CHL = chlorpyrifos
FEN = fenaxniphos
PAR = ethyl parathion
-------
APPENDIX 9. CALCULATED MALLARD DUCK LD5Q/FT2 FOR GRANULAR FORMULATIONS ON 21 COMMON USE SITES
Beans
ALD
BEN
CAR CHL
DIA
DIS
ETH
FEN
FON
ISO
MET
PAR
PHO
TER
5
50
14
1
< 1
5
18
Broccoli
< 1
4
9
< 1
< 1
5
Brussel SDrouts
< \
<,
9
6
< 1
5
Cabbaae
* 1
4
14
< 1
6
< 1
< 1
5
Cauliflower
* 1
4
9
< 1
5
Citrus
17
< 1
17
Corn
59
< 1
4
< 1
1
< 1
< 1
10
13
< 1
Cotton
6
8
10
13
< 1
61
Lawns
< 1
29
23
2
< 1
Lettuce
4
10
< 1
5
Onions
< 1
4
< 1
4
Peanuts
8
123
2
18
1
7
2
11
Potatoes
7
4
28
1
< 1
6
292
Sorahum
< 1
20
< 1
< 1
13
< 1
Soybeans
8
39
< 1
10
1
19
Sucrar Beets
12
26
< 1
9
< 1
< 1
5
23
< ^
Suaarcane
< 1
20
3
2
54
Sweet Potatoes
< 1
< 1
20
2
< 1
Tobacco
< 1
7
3
< 1
Tomatoes
4
19
< 1
< 1
6
Turf
9
23
114
2
« 1
ALD
DIA
FON
PHO
aldicarb
diazinon
fonofos
phorate
BEN = bendiocarb
DIS = disulfotori
ISO = isofenphos
TER = terbufos
CAR = carbofuran
ETH = ethoprop
MET = roethomyl
CHL = chlorpyrifos
FEN = fenamiphos
PAR = ethyl parathion
-------
APPENDIX 10. FIELD EVIDENCE FOR CERTAIN GRANULAR PESTICIDES (REF. 44)
Field Studies Bird Kill Incident Reports
Number of Number of Kill
Pesticide Field Studies Comments Incident Rpts. Comments
Aldicarb
1*
-Screening study, conducted in
citrus, cotton, and potatoes
resulted in mortality to birds
mammals, and other taxa.
-Study demonstrated that aldicarb
poses acute hazard.
-Additional field data are not
required at this time.
-Incidents that were reported
occurred in Europe or were
considered a misuse.
Bendiocarb ongoing -Screening study is being conducted
for-granular and liquid application
to golf courses. Due in 1993.
Carbofuran
5* -Field studies were conducted for
granular application to corn. All
of the studies resulted in bird
mortality, regardless of application
rate and commonly practiced techniques
for soil incorporation. Mammals
were also found.
-Mortality from direct and secondary
exposure occurred.
-In one study, carbofuran application
resulted in avian mortality through-
out the 60-day search period.
1* -Study was conducted for granular
application to pineseed orchards
using specialized equipment.
Despite 99.1-100% soil incorpora-
tion, avian nortality occurred.
31
-Incidents reported
include waterfowl, game-
birds, and songbirds. The
incidents occurred in corn,
peppers, potatoes, rice, and
other crops. Incidents involved
1 to more than 200 birds.
-Mortality from secondary
exposure has also occurred
and involved eagles, red-tailed
and red-shouldered hawks, and
other birds of prey (Ref. 44).
-Incidents have also been
reported in which the
formulation was not identi-
fied and for the liquid
formulation.
•Despite deficiencies such as flawed field searches, the study demonstrated that the pesticide poses
a hazard to the non-target speciea indicated.
-------
Field Studies
Bird Kill Incident Reports
Pesticide
Number of
Field Studies
Comments
Number of Kill
Incident Rpts.
Comments
Carbofuran
(cont *d)
1*
-Study was conducted for granular
application to rice. Avian
mortality resulted.
Chlorpyrifos
ongoing
-Field study due in 1994.
-Incidents that have been
reported were for the liquid
formulation.
-Incidents reported
include waterfowl, a robin,
blue jays and brown-
headed cowbirds. Incidents
have occurred on turf and
and involved 1-200 birds
being killed or poisoned.
-Incidents have also been
reported in which the formu-
lation was not identified and
for the liquid formulation.
Diazinon - -Study was conducted in 1986 for 11
granular application to home and
commercial lawns, but was too
flawed to draw any conclusions.
-Studies have also been conducted
for liquid application to golf
courses and have indicated a
hazard to birds.
ongoing -Screening studies have been
conducted for liquid application
to apples and granular applicat-
ion to carrots and corn. Studies
were received in June, 1990, and
are under review.
ongoing -Screening studies are being
conducted for granular and
liquid application to turf in
office parks. These studies are
being conducted voluntarily by
the registrant and focus on the
effect of diazinon to songbirds.
*Despite deficiencies such as flawed field searches, the study demonstrated that the pesticide poses
a hazard to the non-target species indicated.
-------
Field Studies
Bird Kill Incident Reports
Pesticide
Number of
Field Studies
Comments
Number of
Kill Incidents
Comments
Disulfoton
1*
-Screening study was conducted for
granular application to potatoes
and resulted in mortality to birds,
mammals, and other taxa.
Ethoprop - -Screening study conducted in 1984 0
was unacceptable and could not be
upgraded, although the registrant
submitted additional information.
ongoing -Protocols are being reviewed for
screening study for granular and
liquid application to potatoes,
tobacco, and turf. Due date
is pending.
Fenamiphos under -Screening study conducted
review for granular application
to golf courses, citrus,
and tobacco submitted in
1991.
Fonofos
ongoing
-Field study due 1994.
Isofenphos pending -Decision regarding field
testing is pending.
-The incident occurred on a home
lawn in 1987 and involved 2 robins.
-Incidents in which the
formulation was not identified
were also reported.
~Despite deficiencies such as flawed field searches, the study demonstrated that the pesticide poses
a hazard to the non-target species indicated.
-------
Field Studies
Bird Kill Incident Reports
Pesticide
Number of
Field Studies
Comments
Number of Kill
Incident Rpts.
Comments
Methomyl
ongoing -Screening study will be
conducted with the 5% granular.
Sites being considered include
corn and sorghum. Due in 1993.
Parathion
-Field studies have not been
required because the data based on
the bird kill incidents resulting
from liquid and unknown formulations
collectively demonstrate that ethyl
parathion repeatedly kills large
numbers of birds living or feeding
in treated areas.
-Incidents that were reported
for granular products occurred
in New Zealand. The dead
birds recovered included a
Harrier hawk, suggesting the
potential for secondary poisoning.
-Incidents have been reported
for the liquid formulation.
-Incidents in which the
formulation was not identified
were also reported.
Phorate
1*
-Screening study was conducted in
corn and resulted in mortality to
birds and mammals.
-Incidents reported include
waterfowl, gamebirds and
others. The incidents
occurred on winter wheat,
barley and sugar beets. They in-
volved 1- > 2000 birds per incident.
•Despite deficiencies such as flawed field searches, the study demonstrated that the pesticide poses
a hazard to the non-target species indicated.
-------
Field Studies
Bird Kill Incident Reports
Pesticide
Number of
Field Studies
Comments
Number of Kill
Incident Rpts.
Comments
Phorate
(cont *d)
-Additional field data are not
required at this time.
-Mortality from secondary
exposure has also occurred
and involved eagles, hawks
and owls.
-Phorate was sufficiently
toxic 6 months after applica-
tion to kill approximately
100 waterfowl and 7 bald
eagles.
Terbufos
2*
ongoing
-Screening studies were conducted
in corn and resulted in mortality
to birds, mammals, and other taxa.
-Additional field testing is being
conducted in corn. Preliminary
results include mortality to birds,
mammals, and other taxa. In addition,
possible reproductive impairment in
starlings was noted. Final report
is due in 1992.
^Despite deficiencies such as flawed field searches, the study demonstrated that the pesticide poses
a hazard to the non-target species indicated.
-------
70
APPENDIX 11. RISK USE SUMMARY
CHEMICAL SITE ACRE TREATMENTS(a) LD50/FT2(b)
(X 1000)
Carbofuran (K)
Corn
3920
1168
Phorate
Potatoes
300
3773
Aldicarb (K)
Cotton
3195
251
Terbufos (K)
Corn
9100
78
Phorate (K)
Corn
2300
164
Carbofuran
Sorghum
870
389
Diazinon (K)
Turf/Lawns
540
436
Aldicarb
Peanuts
673
303
Aldicarb (K)
Citrus
212
678
Chiorpyr if os
Corn
4500
30
Aldicarb
Potatoes
416
.292
Fonofos
Corn
2700
39
Phorate
Cotton
125
785
Aldicarb
Sugar Beet
170
459
Ethoprop
Turf/Lawns
48
1425
Aldicarb
Soybeans
225
303
Disulfoton
Potatoes
50
1193
'Carbofuran
Peanuts
20
2441
Disulfoton
Cotton
100
409
Carbofuran
Sugar Beet
75
506
Disulfoton (K)
Peanuts
50
750
Carbofuran
Soybeans
40
779
Terbufos
Sugar Beet
220
111
Chlorpyrifos
Peanuts
130
184
Isofenphos (K)
Turf/Lawns
240
78
Fenamiphos
Cotton .
70
248
Terbufos
Sorghum
150
111
Carbofuran
Cotton
100
156
Phorate
Beans
60
229
Disulfoton
Beans
20
613
Phorate (K)
Sugar Beet
40
300
Phorate
Peanuts
80
144
Ethoprop
Tobacco
50
199
Phorate
Soybeans
30
245
Chlorpyrifos
Turf/Lawns
415
16
Ethoprop
Potatoes
70
86
Phorate
Sugarcane
8
702
Aldicarb
Beans
25
207
Disulfoton
Tomatoes
5
818
Ethoprop
Sweet Potatoes
40
99
-------
71
CHEMICAL SITE ACRE TREATMENTS*3' LD50/FT2
------- |