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A comment to Ann Veneman about pharm corn in Texas (Sunday, Aug. 15, 2004 -- CropChoice news) -- Comments by Neil J. Carman, Ph.D. of the Sierra Club to APHIS regarding Prodigene's application to grow pharmaceutical corn in Texas. SC comments to DOCKETS No. 04-044-1 and DOCKET No. 04-August 10, 2004 The Honorable Ann Veneman APHIS DOCKET # 04-044-1 and DOCKET # 04-041-1
Regulatory Analysis and Development, PPD
APHIS, Station 3C71
4700 River Road - Unit 118
Riverdale, MD 20737-1238 Via email: regulations@aphis.usda.gov Re: Comments #3 to Dockets No. 04-044-1 and No. 04-041-1 on APHIS' draft
Environmental Assessments and Prodigene's permits to grow up to 725 acres of
pharmaceutical corn in Frio County, Texas Dear Secretary Veneman: I am writing on behalf of The Sierra Club, America's largest grassroots
conservation organization with over 750,000 members. Comments are submitted
to Dockets No. 04-044-1 [aprotinin] and No. 04-041-1 [trypsinogen] regarding
Prodigene, Inc.'s two pending permit applications to grow up to 725 acres of
biopharmaceutical corn in Frio County, Texas and APHIS' two Environmental
Assessments (EA). Sierra Club has been calling for more intelligent
regulation of transgenic organisms in the outdoor environment for many
years, and requesting environmental impact statements (EIS) as part of this
process, but APHIS chose to conduct scaled-back EA's rather than
comprehensive EIS's, perhaps to minimize public input, corn farmers'
outrage, and scientific critique. In the comments below, the term "pharm" is
used in place of pharmaceutical. Sierra Club already sent comments #1, #2a
and #2b previously. The Sierra Club recommends denial of the two permits that Prodigene is
seeking to authorize it to grow up to 725 acres of pharm corn in Texas. The
reasons for permit denial include the following: APHIS has not conducted
adequate scientific reviews of the pharm corn field trials, failed to allow
sufficient time for public comments, failed to allow local Frio County,
Texas residents an opportunity to attend public meetings to speak their
mind, failed to allow Texas' affected corn farmers and consumers an
opportunity to attend and speak at public meetings, and the Prodigene
permits are so seriously flawed that denial is the most appropriate
response. If APHIS decides to modify the permits, then an additional public
notice and comment period of sixty-days should be allowed on the
alterations. The Sierra Club vigorously protests the brief comment period since it's
unacceptable to allow only a thirty-day public comment period rather than
sixty-days when such a significant action is pending to authorize the first
large scale planting of a commercial pharmaceutical corn crop in the US.
Frio County residents, concerned corn farmers and Sierra Club members, who
need to share their concerns with USDA, have not been properly informed
about Prodigene's pharmaceutical corn crop in their back yard. At this time,
USDA has not held any local public meetings to present information about
Prodigene's project in Frio County. Even if the Frio County pharm trial site
is secret, local residents have a right-to-know about these crops and how
they may be impacted. At this point, USDA and Prodigene appear to have done
an effective job of keeping Frio County residents in the dark. #1 Prodigene has requested two pharm corn permits for an undisclosed site and
unknown amount of field trial acreage somewhere in Frio County, Texas, just
southwest of San Antonio. Frio County covers 1,133 square miles and 725,120
acres. APHIS only mentions in the EA that all of Prodigene's proposed field
tests called "the cumulative acreage planted" in Frio County for 2004-2005
will not exceed one-thousandth of the Frio County's area. So Prodigene's
field trial acreage could be as much as 725 acres, implying tens of
thousands of corn plants and increasing the probability for genetic escape
by cross-pollination and seed dispersal. Prodigene's field trials would make
it by far the largest pharm crop field trials in the US where acreage is
known. Certainly the magnitude of gene escape by pollen and seed increases
with the acreage size. Cross-pollination with local corn fields is a major
concern since Frio County had 4,000 acres of corn planted in 2001. Frio County is generally considered in South-Central Texas being relatively
close to Central Texas counties where organic, conventional and non-pharm
biotech corn crops are grown. The South-Central Texas region is periodically
subjected to hurricanes, tornadoes and severe weather systems carrying high
winds blowing through the region including Frio County. If such high winds
of 30-60 mph occur during the time that the Prodigene pharm corn is
producing pollen, a weather event could potentially transport a plume of
pharm corn pollen leading to a long-distance dispersal event by spreading it
all over the Central Texas region and beyond where tens of thousands of
acres of other corn varieties are grown each year, thereby resulting in a
low but predictable degree of pharm DNA contamination. Currently some 120+
Texas counties are growing commercial corn crops out of 254 counties
statewide, or nearly 50% of Texas counties have some corn acreage planted. Does the USDA or Prodigene, Inc. have any plans to offer a specific pharm
corn DNA test or to pay for such an independent pharm corn DNA test for the
Texas farmers who want to find out if their corn crops have any pharm DNA
contamination? It's important for USDA's credibility on the Prodigene-Frio
County experiment to offer or find a way to pay for such a specific pharm
corn DNA test. The USDA's proposed one mile buffer zone is grossly inadequate to prevent
widespread transgenic corn contamination occurring from Prodigene's pharm
corn pollen over an exceptionally large area of Central Texas, well beyond
Prodigene's Frio County crop site and even beyond the one mile buffer zone.
In the Federal Register notice, USDA is proposing to authorize two permits
for Prodigene's pharm corn crop with a one mile buffer as a purely
theoretical safety zone where no other commercial corn crop will be grown in
Frio County, Texas. The USDA obviously believes that most of the scientific
evidence from studies of corn pollen dispersal supports a one mile buffer
zone as protective enough to ensure against cross pollination from the pharm
corn pollen crop reaching downwind neighboring corn fields beyond one mile. Clearly, USDA believes a theory that long-distance dispersal from
Prodigene's pharm corn pollen to be so rare an event as to cause no concern
for Texas' organic corn farmers, conventional corn farmers, and non-pharm
biotech farmers. The Sierra Club asserts that the USDA is technically wrong
by using flawed science to authorize a one mile buffer zone, and we maintain
that the one mile distance is grossly inadequate to prevent pharmaceutical
corn contamination, particularly since corn pollen is capable of
long-distance dispersal over much greater distances than a one mile limit. #2 USDA is using a flawed scientific evaluation to propose approving the Prodigene,
Inc. permits. The Sierra Club hopes that USDA will seriously consider the
following scientific information in its decision-making process. A 1999 paper by Emberlin, Adams-Groom and Tidmarsh presents challenging
information and a comprehensive analysis of why many previous dispersal
studies are flawed and why there is a high probability for so-called "rare"
long-distance dispersal of corn pollen for hundreds of miles from
Prodigene's originating corn field. The research paper commissioned by the
UK Soil Association, "A Report on the Dispersal of Maize Pollen," January
1999, was compiled by three scientists, Dr. Jean Emberlin, Beverley
Adams-Groom BSc and Julie Tidmarsh BSc, of the National Pollen Research
Unit, University College, Worcester WR2 6 AJ, United Kingdom. A copy of the
Soil Association report is being mailed and emailed to the Docket
separately. A brief summary of the report's most important points is being
presented here as part of the Sierra Club's comments (sent as email #1 from
Sierra Club to both DOCKETS). In addition, a second report by Dr. Rob Treu and Professor Jean Emberlin was
published January 2000 and titled "Pollen dispersal in the crops Maize (Zea
mays), Oil seed rape (Brassica napus ssp olerifera), Potatoes (Solanum
tuberosum), Sugar beet (Beta vulgaris ssp vulgaris) and Wheat (Triticum
aestivum)." Treu and Emberlin collected and studied evidence from
publications. Their report was commissioned for the UK Soil Association from
the National Pollen Research Unit, University College Worcester, UK. The
report was sent as emails #2a and #2b from Sierra Club to both DOCKETS. Treu and Emberlin state in the 2000 report's summary addressing pollen
dispersal and the potential for hybridization with wild or cultivated
relatives of Oil seed rape, sugar beet, maize, wheat and potato: "None of
the crops considered in this report has pollen that can be completely
contained. The use of appropriate vegetation or other barriers, and/or the
use of border rows on the source and receptor crops can reduce dispersal
from the fields and transport into other areas. However it is likely that in
certain weather conditions medium to long range transport of some pollen
will occur." Obviously corn is not considered as an isolated species as a
candidate to pose a threat for long-distance pollen dispersal and transgenic
contamination. Treu and Emberlin further emphasize: "Maize presents a medium to high level
risk for cross pollination with other maize crops as the pollen can spread
on the airflow. ... The percentage of cross breeding with other maize crops
in the vicinity will depend on factors such as separation distance, local
barriers to pollen movement, such as woods and hedges, local climate and
topography." Although Treu and Emberlin's report is written more for the
corn crop grown in the UK, I maintain that their obvious concerns are
directly applicable to Prodigene's pending pharm corn permit applications
for Frio County, Texas, but USDA has apparently neglected to take into
consideration this type of scientific information in preference to a desire
to rubberstamp the pharm corn permits. Treu and Emberlin cite the work of Tauber (1965, 1967) in creating his
scheme to explain pollen load in the air and its potential travel distance
downwind, which utilizes three basic components. #3 Gravity is Tauber's first component with pollen having only a short
horizontal spread. Tauber proposed that applying the gravity component for
anemophilous plants like corn means that most of the pollen is deposited
very close to the parent plant and onto leaves of adjacent plant as well as
the soil. Tauber's second component is called "local pollen." "Local pollen" means
that this component is dispersed downwind like a diffusion cloud with a
centerline of concentration remaining parallel to the ground. The "local
pollen" plume again has a steep gradient in concentrations with distance
downwind. But Tauber's third component, termed "the regional pollen," is the one
creating the most concern for predicted long-distance dispersal of
Prodigene's pharm corn pollen over a large area of Central Texas. As Treu
and Emberlin eloquently point out and which USDA needs to carefully consider
in this matter, "regional pollen" grains are those caught by upward air
movements and are transported above the height of vegetation and the local
air current conditions created by surface features. "Regional
pollen"--including Prodigene's pharm corn pollen--may travel considerable
distances downwind in Central Texas and even further distances to outlying
regions of Texas. The 1999 report by Emberlin et al. reviews available evidence from published
sources and also communications from named authorities about corn pollen
dispersal. Emberlin et al. present a wealth of background information on the
characteristics of corn pollen, including morphology and duration of
viability, together with pollen quantities produced and the salient features
of pollination. Dr. Emberlin's 1999 Soil Association paper also discusses relevant data from
empirical studies, dispersion theory models and airborne particle deposition
theory to provide estimates for pollen deposition rates and concentrations
of pollen remaining airborne downwind from a source field. The authors
honestly concede, however, that it's not possible to provide accurate
assessments for practical crop field use, which is applicable in this case
to Prodigene's pharm corn crops and the USDA's pending review, because most
empirical corn pollen dispersal work has been done within a narrow range of
weather conditions and many studies suffer from the constraints of pollen
monitoring only close to the source and of errors in pollen sampling. For example, the corn pollen dispersal evidence from previous work can be
used as a basis for making only generalized estimates of percentages of the
pollen concentrations remaining airborne downwind in low-to-moderate wind
speeds compared with concentrations at 1 meter from the source. Based on
such limited studies, these downwind corn pollen concentrations are
approximately 2.0% at 60 meters, 1.1% at 200 meters and between 0.75% and
0.5% at 500 meters. The implications of these concentrations for potential cross pollination are
considered, but it's emphasized by the two reports of Emberlin et al. and
Treu and Emberlin that the data should be used only as rough guidelines and
not for the USDA prescribing an absolute regulatory limit established for
Prodigene's pharm crop permit safety conditions. In addition, it should be
especially noted for USDA's Prodigene review that pollen dispersal gradients
would be altered by factors such as climatic conditions and local
topography, #4 and the Sierra Club's concern here is that USDA has not adequately
considered all reasonably possible climatic conditions occurring in Frio
County and the Central Texas region during a typical growing season. Transport on the airflow patterns jetting over longer distances than merely
the one mile safety/buffer zone proposed by USDA for Prodigene is likely to
occur under a range of weather situations, including uplift and horizontal
movement in convection cells, turbulent conditions, and uplift and transport
in frontal weather storms. Since corn pollen grains typically remain viable
for about 24-hours in the normal weather conditions representative of those
occurring in the Central Texas/Frio County area during a typical growing
season, pollination could occur at receptive corn field sites quite remote
from the Prodigene source (e.g. 180 km or 108 miles, a distance well beyond
Frio County borders extending into over thirty nearby counties of Comal,
Guadalupe, Hays, Travis, Caldwell, Bastrop, Atascosa, Wilson, Gonzalez,
Karnes, Lavaca, De Witt, Goliad, Victoria, Bee, Live Oak, McMullen, La
Salle, Dimmit, Zavala, Duval, Jim Wells, Webb, Maverick, Uvalde, Bandera,
Real, Kerr, Kinney, Gillespie, Kendall, Edwards, and Blanco Counties; square
mileage is 36,644 for the 108 mile radius - Note that a number of these
nearby thirty counties are growing thousands of acres of commercial corn
crops). Corn pollen dispersal away from the fields of the Prodigene pharm crop can
also take place by transport on bees and other pollinating insects likely to
occur in Frio County. Emberlin et al. cite evidence (Bateman, 1947a;
Percival, 1955; Vaissiere and Vinson, 1994) that corn pollen is typically
collected by area bees in notable amounts, and we expect this bee activity
to occur in the Frio County area of the Prodigene pharm corn fields, that is
unless the USDA can manage to control the bee populations and keep them away
from the Prodigene pharm corn. Crop fields of fertile corn tassels would
likely be closely observed by local wild and commercial bee populations and
the bees would begin to collect the pharm corn pollen in significant
quantities when it becomes available, especially since Prodigene is not
proposing to cover the tassels so as to prevent bees from harvesting the
pollen. Once collected by bee populations, the pollen is transported several
miles from the crop plot in suitable weather conditions. But Bateman (1947a) suggests that bees are more likely to visit the tassels
to collect pollen and less likely to visit the silks where there is no
pollen. With the tassels and silks separated on corn plants since corn is
diclinous, cross pollination by bees may be less plausible than by other
mechanisms. Of course, the pharm pollen collected by bees can become a
constituent of honey, which will present difficulties of organic beekeepers
whose bees are foraging in Frio County. Has USDA surveyed how many organic beekeepers, if any, are present in Frio
County (or the adjoining counties closest to the Prodigene site) and how
close they are to the Prodigene pharm corn sites? The Sierra Club requests
that the USDA check with the Texas Department of Agriculture, the Texas
Department of Health, Texas Organic Farming organizations, Texas Organic
Beekeeper organizations, and the Frio County Extension Agent, including
Extension Agents in adjacent counties closest to the Prodigene site, to
inquire if there are known local organic beekeepers. #5 Prodigene, Inc.'s Pharm Corn Pollen Production in Frio County, Texas:
Implications for Probable Long Range Dispersal Airflow Currents for
Statewide Transgenic Contamination in Texas. In certain weather conditions airborne particles, including pollen grains
such as we would expect even from Prodigene's pharm corn fields, can travel
long distances on the airflow. Long-distance dispersal of corn pollen needs
to be seriously considered by the USDA within the constraint of its
viability time (in the region of 24-hours under normal weather conditions,
Purseglove, 1972; however, Emberlin et al. cite corn pollen with a duration
of viability from 3 hours up to 8 days depending on conditions). Reports by
Treu and Emberlin (2000) and Emberlin et al. (1999) both explore the weather
conditions that corn pollen can travel for long distances within its
viability period, given the right conditions for doing so. Palynology research has shown, for example, that typical corn pollen is
relatively large and heavy averaging approximately 100 microns in size
(larger than most wind-pollinated grass species and species in other
angiosperm families), and which is also an expected characteristic of
Prodigene's pharm corn pollen. Corn pollen does vary in size and can range
from 90-125 microns. Empirical work on corn pollen dispersal has indicated relatively steep
declines in pollen concentrations with distance away from the source and
limited upward spread of the plume. However, what's extremely relevant to
the USDA's consideration of Prodigene's pharm corn proposal is that Emberlin
et al. point out a serious experimental flaw, among the several flaws they
discovered, in these corn pollen studies where the researchers investigated
pollen dispersal only to limited heights of about 4.6 meters above ground in
the downwind direction and to short distances of approximately 500 meters
maximum downwind away from the source. As USDA recognizes, there is no
invisible atmospheric barrier to prevent Prodigene's pharm corn pollen from
being transported to heights above 4.6 meters above ground or carrying
downwind for more than 500 meters. Furthermore, Emberlin et al. also reveal another major problem with these
flawed experimental pollen studies since they have been conducted in a
narrow, selective range of weather conditions. In this regard, they note
that no research has been performed specifically on the movement of corn
pollen in convection currents, or on movement aloft in turbulent conditions
or during the passage of weather fronts. Studies done on the dispersal of
other pollen types has demonstrated that long range transport does take
place including pollen from low level sources. But USDA has failed to
comprehensively evaluate this obvious concern with Prodigene's pharm corn
plans for Frio County fields or else Prodigene's proposal would have already
been rejected as unsound for the economic impacts it will have on
contaminating significant non-pharm corn acreage. Vertical transport of lightweight corn pollen particles high above the corn
fields takes place by several mechanisms and would be expected to take place
in Frio County at the Prodigene pharm corn site, since USDA and Prodigene
can not control the local weather patterns. Texas is well known to have
particularly warm-to-hot summer days when vertical transport weather
patterns routinely develop at the same time that Prodigene's pharm corn is
producing #6 viable pollen, with an average-sized corn plant capable of producing between
14-50 million pollen grains (Miller, 1985) over 2-14 days and more typically
5-8 days (Purseglove, 1972). During warm-to-hot Texas summer days with
characteristic low wind speeds, local convective currents driven by the
heating of the ground by the sun lead to mixing through the boundary layer.
This activity has a marked diurnal influence with particles being dispersed
laterally through convection cells during the day, and later descending when
the convection subsides (Oke, 1978). As long as there is a positive
convective air movement, the net result will be to keep pollen up in the
atmosphere. Settling out of pollen usually occurs during cooling in the
evening when the majority of pollen grains will return to the surface. Of
course, Texas' hottest summer days are in July and August when Prodigene's
pharm corn is most likely to be flowering and releasing its pollen in the
air. Nights in July and August in Texas tend not to cool off as they might
in a northern state with night time temperatures often staying in the 80s. According to the lucid analysis by Emberlin et al., most anemophilous (wind
pollinated) pollen will be liberated during day time hours in dry, warm
weather, which will be predominant in the Texas summers as around
Prodigene's Frio County sites. What USDA must be made aware of is that Texas
summer days like this frequently have thermals rising turbulently that will
have a positive effect in bringing pollen grains up into the higher strata,
as Emberlin et al. explain; in this respect Prodigene could not have picked
a worse location for a high probability to cause widespread transgenic
contamination across a large portion of Texas. The upper limit for convective ascent is marked by the thermal inversion,
often shown by the presence of cumulus clouds. Convective cells are
typically 1-3 km in diameter, reaching some 1,000-2,000 meters in height and
last about 20 to 30 minutes each, during which time they can move downwind.
The individual cells may form composite cells reaching 5-10 km across and
last for several hours. Upward velocity of cell tops reaches 0.5-1.5 meters
per second and horizontal expansion of 0.5-1.0 meters per second (Hardy and
Ottersten, 1968). Therefore, as a consequence, a measurable portion of Prodigene's pharm corn
pollen grains will have reached the inversion layer when the bubble
collapses. The pollen may then be transported horizontally considerable
distances depending on weather conditions. During the evening and night
time, the convection building process will cease and the pollen will tend to
fall towards the ground but this may be impeded by low level inversions. The
usual length of time available for pollen to travel as it's kept aloft by
convection is a maximum of one day. This would be equivalent to a distance
of about 50 - 180 km or 30 - 108 miles, although it is well known that much
longer transports do occasionally take place (Faegri & Iversen, 1989) when
suitable meteorological conditions occur. Another important point is that on cooler, cloudy days with less solar
heating and higher wind speeds, pollen can be dispersed vertically by
turbulence generated either by instability in the lapse rate or by rough
surfaces such as uneven topography; although Frio County has large flat
areas, unfortunately, USDA has kept the Prodigene pharm corn site
confidential, yet Sierra Club maintains that relevant topographical
information should be made public to allow for a more thorough evaluation of
the site. Biological particles introduced into the boundary layer have been #7 observed in detectable concentrations to distances of several hundred
kilometers downwind (e.g. Hjelmroos, 1991), and so we expect that similar
observations can occur with Prodigene's corn pollen grains over large areas
of Central Texas' corn growing region. Penetrative transport to great
atmospheric heights can also take place through updrafts generated by deep
intense convective storms. In such storms, large masses of air, originally
lying near the surface, are transported in a few tens of minutes to heights
typically of the order of 8 to 12 km. At such heights, in the middle
latitudes, winds are often very strong, in the range 25 to 50 meters per
second, so that pollen can travel great distances in a matter of hours
(Mandrioli et al., 1984). Why has USDA ignored this information? Researchers Hirst and Hurst (1967) sampled the ambient air for pollen and
spores over the north seas and observed pollen and fungal spores at heights
between 500m and 1500m. Their results include a case in which a pollen cloud
generated over Britain was later found traveling as a pollen concentration
cloud over the North Sea. Hirst and Hurst (1967) concluded that "...it seems
safe to assume that distant transport is both frequent and extensive and
probably important in temperate latitudes over the summer." Pollen released
during one day was found the following day 300-400 km off the coast.
Transport took place over the sea where dispersal conditions could be
different from those over land depending on the weather. For example, pollen
transport over land could be enhanced by increased convection but conversely
the concentrations could be depleted by more deposition due to turbulence.
Another researcher, Tyldesley (1973), likewise found appreciable quantities
of arboreal pollen (up to 30 grains per cubic meter) in the air in the
basically treeless Shetland Isles, which lie some 250-380 km (150-228 miles)
away from the nearest forests, in connection with favorable meteorological
conditions, i.e. cyclonic storms. In Central Texas centering around Frio
County, a radius distance of 150-228 miles consists of a huge region where
Prodigene's pharm corn pollen could be transported. The number of Texas
counties encompassed by a radius of 150-228 miles is dozens, certainly more
than the 30+ counties touched by the 108 mile radius. A recent study of pollen in rain in Northwest India identified pine tree
pollen, which is also from a wind-pollinated species with 100 micron average
pollen size similar to corn's average pollen size. The researchers concluded
that long-distance dispersal of pollen could allow the grains to travel 600
km or 360 miles by finding pine pollen at that distance downwind from the
closest pine trees (Singh et al., 1993). Due to the large size of both pine
and corn pollen, the report by Singh et al. provides additional evidence
that Prodigene's pharm corn pollen will probably be dispersed toward far
greater distances than USDA believes is possible in Central Texas. Emberlin et al. explain that a frontal storm can lift air masses several
kilometers up in the air in a very short time and thus place pollen grains,
such as Prodigene's, far above the day and night cycle (Faegri & Iversen,
1989). Once pollen has arrived in the upper atmosphere (such as over Frio
County, Texas), it can travel for many hundreds of miles on the airflow
with a high wind speed usually in the range of 25-50 meters/second (15-30
mph) until finally being deposited or it may be captured by water drops and
return to the surface in precipitation (Mandrioli et al., 1984). In general,
long range pollen transport occurs most efficiently in dry conditions with
limited mixing depth and moderate to high wind speeds. We see lots of summer
days in #8 Texas with these kinds of hot, dry conditions where long range pollen
transport from Prodigene's pharm corn fields will predictably transpire. Pollen grains can also be re-suspended from surfaces in gusts of wind and
re-deposited at other locations. For example, Erdtman (1938) described
finding Zea pollen in the air in Sweden during midwinter (Faegri & Iversen,
1989). Erdtman (1943) also cites finding atmospheric pollen at all points
across the Atlantic ocean with a mid ocean figure of 0.7 grain per 100m3
compared to 18 grains per 100m3 on the Swedish mainland. If re-suspension
took place within the time of corn pollen viability, it could extend the
effective transport distance. USDA needs to recognize the potential for
Prodigene's pharm corn pollen re-suspension and subsequent dispersal as
another challenge to this unsound proposal. The available evidence reveals why it's reasonable to assume that corn
pollen, including from Prodigene's pharm corn fields, can remain viable and
capable of effective fertilization for at least 24 hours in most weather
conditions prevailing in Frio County, Texas. This means that with mean
horizontal wind speeds of only 2 meters per second, that can occur routinely
on Texas summer days with convection currents that could keep the pollen
grains aloft, Prodigene's pharm corn pollen could travel downwind 1.0 km
(0.6 miles) in 4.16 minutes, 7.2 km (4.3 miles) in an hour (potentially
172.8 km in a day, or 103.7 miles). Applying higher wind speeds of 10 meters per second, which occurs in Central
Texas, some pharm pollen grains would travel greater downwind distances
before descending by dry or wet deposition than in slower wind speeds. Winds
of 10 meters per second would give rise to turbulent conditions in the
boundary layer keeping some Prodigene pharm corn pollen airborne for longer
than in non-turbulent air flows. If the Prodigene pharm corn pollen remained airborne, it could travel 36 km
(22 miles) in an hour and nearly 864 km (518.4 miles) in 24 hours. The key
question for USDA and Prodigene is how much of Texas' corn growing regions
would be covered by a radius of 518 miles from Frio County? The area enclosed by 518.4 miles is 844,269 square miles and encompasses the
whole core of Central Texas extending well across the State of Louisiana to
the East, well into the State of Arkansas to the Northeast, nearly to El
Paso in the West, deep into Mexico to the South close to where native maize
populations are growing, past the Oklahoma State border to the north, and
even well into the Texas Panhandle to the Northwest. Is the USDA proposing
to allow Prodigene to contaminate a significant portion of non-pharm corn
growing in Texas? The wild maize populations in Mexico? If USDA grants additional comment time, further comments may be submitted.
In conclusion, the USDA needs to step back from its Environmental
Assessments of Prodigene's pharm corn and reassess the phenomenal potential
for regional corn contamination from the Prodigene pharm corn field trials. Sincerely yours, NEIL J. CARMAN, Ph.D. Reference List | |
