Document ID: EPA-HQ-OPP-2006-0689-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-01-24T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

     WASHINGTON, D.C. 20460

                        OFFICE OF PREVENTION,                           
                                                                        
      

                        PESTICIDES AND TOXIC  

                       			          				  SUBSTANCES  

JUN 20 2006

MEMORANDUM

SUBJECT	Environmental Risk Assessment for Monsanto’s MON89034 x
MON88017 Bacillus thuringiensis Corn EUP (MRID: NA; DP Barcode:
DP324864)

TO			Mike Mendelsohn, Senior Regulatory Action Leader

			Microbial Pesticides Branch

			Biopesticides and Pollution Prevention Division, 7511P

FROM	Tessa Milofsky, M.S.	Agronomist				signed

			Microbial Pesticides Branch

			Biopesticides and Pollution Prevention Division, 7511P

PEER REVIEW         Zigfridas Vaituzis, Ph.D. Microbiologist			signed

	Microbial Pesticides Branch

		Biopesticides and Pollution Prevention Division, 7511P

CONCLUSION

At present, the Agency is aware of no identified significant adverse
effects of the Cry1A.105, Cry2Ab2, and Cry3Bb1 proteins on the abundance
of non-target beneficial organisms in any population in the field,
whether they are pest parasites, pest predators, or pollinators. The
Agency anticipates that, for the duration of this limited acreage
experimental crop-destruct program, no hazard will result to the
environment.

For the purposes of this EUP, the registrant’s request to bridge to
ecotoxicity data submitted in support of registered microbially-derived
Cry proteins is acceptable. However, a Section 3 registration will
require submission and review of additional non-target data.

BACKGROUND

Monsanto is applying for an Experimental Use Permit (EUP) to allow
further evaluation of transgenic corn [Zea mays] plant lines which
express the Cry1A.105, Cry2Ab, and Cry3Bb1 insecticidal proteins derived
from Bacillus thuringiensis. All corn plants that will be evaluated
under this EUP were derived from corn transformation event numbers 89034
and 88017 and express the Cry1A.105, Cry2Ab2, and Cry3Bb1 proteins. The
program will be carried out during the 2006-2007 and 2007-2008 cropping
seasons in 29 states and Puerto Rico on a total of 2797 acres in
2006-2007 and 6480 acres in 2007-2008, respectively (see EUP Program
Review for further details).

ENVIRONMENTAL EFFECTS

	

A.  Non-target species effects 

	

In lieu of ecotoxicity testing for this limited duration and limited
acreage EUP, the applicant has requested to bridge to non-target effects
data submitted in support of Bt PIPs that were reviewed previously by
EPA, including Cry2Ab2 cotton, Cry2Ab2 corn, and Cry3Bb1 corn. Although
Cry1A.105 is considered a new active ingredient, it is a chimeric
protein with overall amino acid sequence identity to the Cry1Ac, Cry1Ab
and Cry1F proteins of 93.6, 90.0 and 76.7%, respectively. Given the
76.6% or greater sequence similarity between the individual proteins and
those which comprise Cry1A.105, data submitted in support of the
independent proteins may be used to support the chimeric protein at the
EUP stage. Extrapolating from previous studies on Bt proteins, which
tend to be very species specific in their activity, no significant or
irreversible interactions with non-target organisms are anticipated for
the proposed limited duration and limited acreage EUP. Further, the
nature of the contained EUP program and the expression of the active
ingredients within the corn plant will limit exposure to non-target
species. However, additional data will be required to support a Section
3 registration of MON89034 x MON88017.

	1. Risk Characterization for Terrestrial Animals

	a. Avian

Data submitted in support of the Cry1Ab corn, Cry1Ac cotton, Cry2Ab2
cotton, Cry2Ab2 corn, and Cry3Bb1 corn and registrations show that the
consumption of corn or cotton seed containing Bt Cry protein has no
measurable deleterious effects on the representative avian species
bobwhite quail. This finding suggests that the proposed limited
time/acreage EUP is not likely to have any measurable effects on avian
wildlife.

	b. Mammalian Wildlife

Many different Cry proteins have been evaluated in mammalian toxicology
tests over the last 40 years. No adverse effects have been observed in
mammals following oral exposure to any of these Cry proteins. Data
submitted to EPA in support of other Cry protein registrations indicate
that there is no significant toxicity to rodents from acute oral testing
at the maximum hazard dose. In light of the above toxicology
information, risk to mammalian wildlife from the proposed limited
time/acreage EUP is expected to be minimal to nonexistent.

	

	c. Non-target Plants

Since the active ingredient in this product is an insect toxin (Bt
endotoxin) that has never shown any toxicity to plants, non-target plant
study requirement has been waived for this product.

	d. Non-target Beneficial Organisms

		1. Honey Bees

Data submitted in support of the Cry1Ab corn, Cry1Ac cotton, Cry2Ab2
cotton and Cry3Bb1 corn registrations show that no deleterious effects
resulted from feeding pollen, collected from Bt expressing corn plants,
or microbe produced Cry toxin to honey bee adults and larvae. These
findings suggest that no discernible detrimental effects to honey bees
should result from the proposed limited time/acreage EUP. 

		2. Lady Beetle:  

Data submitted in support of the Cry1Ab corn, Cry1Ac cotton, Cry2Ab2
cotton and Cry3Bb1 corn registrations show that no deleterious effects
resulted from feeding pollen, collected from Bt expressing corn plants,
or microbe produced Cry toxin to lady beetles. These findings suggest
that no discernible detrimental effects to lady beetles should result
from the proposed limited time/acreage EUP. 

		3. Carabid

Data submitted in support of the Cry3Bb1 Bt corn registration shows that
no deleterious effects resulted from feeding purified microbe produced
Cry toxin to the Carabid beetle, Poecilus chalcites. Lepidopteran active
Cry1Ab, Cry1Ac, and Cry2Ab2 proteins have no effect on coleopteran
species. These findings suggest that no discernible detrimental effects
to carabid beetles should result from the proposed limited time/acreage
EUP. 

. 

		4. Orius

Data submitted in support of the Cry3Bb1 Bt corn registration shows that
no deleterious effects resulted from feeding microbe produced Cry toxin
to insidious flower bug, Orius insidiosus. These findings suggest that
no discernible detrimental effects to predaceous bugs should result from
the proposed limited time/acreage EUP. 

		5. Earthworm:

Data submitted in support of Cry2Ab2 cotton, Cry3Bb1 corn and other
previous Bt corn and cotton registrations show that consumption of
purified Bt Cry protein has no measurable deleterious effects on
earthworms, a representative beneficial soil invertebrate species.
Consequently, the proposed limited time/acreage EUP is not likely to
have any measurable effects on beneficial soil invertebrates.

		6. Collembola: 

Data submitted in support of Cry1Ab corn, Cry1Ac cotton, Cry2Ab2 cotton,
Cry3Bb1 corn and other previous Bt corn and cotton registrations show
that consumption of purified Bt Cry protein has no measurable
deleterious effects on collembola (Folsomia candida), a representative
beneficial soil insect species. Consequently, the proposed limited
time/acreage EUP is not likely to have any measurable population effects
on beneficial soil insects. 

		7. Green Lacewing 

Data submitted in support of the Cry1Ab, Cry1Ac, Cry2Ab2, Cry3Bb1 and Bt
corn registrations show that consumption of Cry protein by the green
lacewing larvae at field exposure rates has no measurable detrimental
effects on these species. 

		8. Parasitic Wasp

Data submitted in support of the Cry1Ab, Cry1Ac, Cry1F, Cry2Ab2 and
Cry3Bb1 Bt registrations show that consumption of protein by the
parasitic wasps has no measurable detrimental effects on these species.

		9. Field Abundance

Field insect abundance studies show no consistent pattern of differences
in abundance of predatory insects in all currently registered Cry
protein plots, compared to control plots throughout the growing season.
These findings suggest that the proposed limited time/acreage EUP is not
likely to have measurable effects on non-target insects.

	2. Risk Characterization for Aquatic Animals

	  a. Fish

Data submitted in support of the Cry1Ab, Cry2Ab2 cotton, Cry2Ab2 corn
and Cry3Bb1 Bt corn registrations show that consumption of protein by
catfish and/or rainbow trout has no measurable detrimental effects on
these species. A data waiver request was accepted for Cry1F corn.

The requirement for a static renewal toxicity study is usually waived
since fish are not generally exposed to Cry protein expressed in Bt
corn. If exposure to Bt toxins via corn plant material (e.g. pollen or
leaf material) does take place, the exposure will be of short duration
and small quantity and is not expected to have any detectable effect on
freshwater fish. Farmed fish may be exposed to Cry protein in fish feed.
However, Cry protein activity is generally destroyed during typical fish
food manufacturing processes and consequently, exposure of farmed fish
to active Bt Cry proteins is not expected.

	  b. Aquatic Invertebrates

Data submitted in support of the Cry1Ab corn, Cry1F cotton, Cry2Ab2,
Cry3Bb1 corn, and registrations shows that consumption of these Cry
proteins has no measurable deleterious effects on Daphnia magna. These
data suggest that the expected environmental concentration of corn
pollen from the proposed limited time/acreage EUP is not likely to have
any measurable population effects on aquatic invertebrates.

  

	  c. Estuarine and Marine Animals

Estuarine and shrimp studies are not required for this product because
of very low potential for exposure.      

B. Outcrossing and Weediness

EPA has reviewed the potential for gene capture and expression of the
Cry endotoxin in corn by wild or weedy relatives of corn in the United
States, its possessions or territories. The Agency has determined that
there is no significant risk of gene capture and expression of any Bt
endotoxin by wild or weedy relatives of corn in the U.S., its
possessions or territories.

Pollen transfer to non-Bt corn plants may be mitigated by one or more of
the following containment measures: 1) Test plants will be destroyed
prior to anthesis; 2) Tassels will be kept bagged prior to anthesis
until pollen shed is complete or until tassels are removed from the
plant; 3) Test plants will be detasseled prior to the onset of anthesis;
4) Test plants may be located within 660 feet of open-pollinating
conventional corn that is not part of this research, provided that the
period of pollen shed for the test plants does not overlap with the
presence of sexually receptive silks of the conventional plants; 5) Test
plants may be located within 660 feet of conventional corn in a breeding
nursery, provided the ear shoots of the conventional plants are covered
for the period of time during which the silks of the conventional plants
are viable. The EUP trials will be conducted under a crop-destruct
program; therefore, any foliage containing foreign proteins will be
harvested and/or destroyed.

C. Environmental fate

Numerous studies, when performed under realistic environmental
conditions, have shown that the Bt proteins produced in Bt crops are
rapidly degraded in soil. These findings were confirmed in a FIFRA
Scientific Advisory Panel Report (December 8, 1999) that concluded
“bioaccumulation is not expected to occur with transgenic proteins
because biodegredation mechanisms for proteins are ubiquitous.”  As a
component of EPA’s regulatory data requirements, the degradation of Bt
protein in plant tissue is evaluated for each Bt crop that is approved
by EPA. In addition, EPA scientists have carried out independent studies
that evaluated the degradation of Bt proteins (Cry1Ac cotton, Cry1Ab
corn, and Cry3A potato) in soil. In all of these studies, the amount of
Bt protein, added as Bt plant material to the soil, was higher than
conservative upper estimates of how much plant tissue and Bt protein
might enter the soil from cultivation of Bt crops.

All of these studies demonstrated that the Bt proteins expressed in Bt
plants are rapidly degraded at rates similar to microbial Bt products.
These findings support evidence that, when assessed under realistic
environmental conditions, Cry proteins expressed in Bt plants readily
degrade. 

D. Endangered species considerations

Based on previously submitted Cry protein toxicity and exposure data,
EPA does not expect that exposure to MON89034 x MON88017 EUP plots will
result in a "may effect" situation for endangered mammals, birds,
plants, aquatic, and most insect species. Test plots must not be located
within ¼ mile of the habitats of endangered/threatened lepidoptera or
coleoptera species that could be affected by exposure to the toxin.

Of particular concern is the endangered Karner blue butterfly (Lycaeides
melissa samuelis) with populations in Illinois, Indiana, Michigan,
Minnesota, New Hampshire, New York, and Wisconsin. Because of the
potential for Bt Cry protein containing pollen to affect Lepidoptera
adversely, the test plots must not be near habitats of the Karner blue
butterfly and may not be planted in the following counties where the
Karner blue butterfly is known to exist in scattered populations:
Illinois - Lake; Indiana - LaPorte and Lake; Michigan - Allegan, Lake,
Monroe, Montcalm, Muskegon, Newaygo and Oceana; Minnesota - Anoka and
Winona; New Hampshire - Merrimack; New York - Albany, Saratoga,
Schenectady and Warren; Wisconsin  - Adams, Barron, Burnett, Chippewa,
Clark, Dunn, Eau Claire, Green Lake, Jackson, Juneau, Kenosha,
Marquette, Menominee, Monroe, Oconto, Outagamie, Polk, Portage, Sauk,
Shawano, St. Croix, Waupaca, Waushara, Wood. Although it is unlikely
that sufficient Cry protein expressing pollen would accumulate on the
wild lupine (Lupinus perennis) that constitutes the butterfly’s sole
food source, this precaution is needed in the lack of adequate data from
the field indicating the precise proximity of wild lupine to proposed
experimental plots.

Also of concern are the following beetles which are found in the states
and counties listed below: 1) American burying beetle in Arkansas
(Franklin, Logan, and Sebastian counties), Georgia (Lamar county),
Kansas (Doniphan, Douglas, Montgomery, Pottawatomie, Riley and Saline
countries), Kentucky (Henderson, Jefferson and Trigg counties), Missouri
(Bollinger, Boone, Franklin, Howard, Jefferson, Mississippi, Newton, St.
Louis and Wayne counties), South Dakota (Brookings, Haakon and Union
counties), Texas (Lamar and Red River counties); 2) the delta green
ground beetle in California (Solano county), and 3) the valley
elderberry longhorn beetle in California (Butte, Colusa, Dorado, Fresno,
Glenn, Madera, Mariposa, Merced, Placer, Sacramento, San Joaquin,
Solano, Stanislaus, Sutter, Tehama, Yolo and Yuba counties). In Michigan
(Emmet and Montmorency counties), do not dispose of Cry
protein-containing plant litter into or near the aquatic habitat of
Hungerford’s crawling water beetle. 

In addition, because there are no sexually compatible wild or weedy
relatives of maize (Zea mays) in the United States, the Cry protein
endotoxin gene cannot escape into plants on which endangered or
threatened species feed on in these areas.  

E. HAZARD ASSESSMENT

At present, the Agency is aware of no identified significant adverse
effects of any Cry proteins included in MON89034 x MON88017 on the
abundance of non-target beneficial organisms in any population in the
field, whether they are pest parasites, pest predators, or pollinators.
Provided that experimental use sites are not located within ¼ mile of
endangered coleoptera or lepidoptera habitat, the Agency anticipates
that, for the duration of this limited acreage experimental
crop-destruct program, no hazard will result to the environment.

 PAGE   

 PAGE   3