17 November 2002
made in Louisiana is important to farmers, but atrazine may be harming
the aquatic environment
Advocate staff writer
LIVONIA -- Like most farmers, Mark Engemann has to worry about weather,
insects, weeds, crop prices and labor costs in coaxing a field of
sugar cane or corn from the ground to make money.
he also worries about whether a herbicide that he sees as one of
his best tools -- atrazine -- may be taken from his hands and added
to his headaches.
science is questioning the safety of the herbicide, which has been
used for 44 years and is so pervasive in the environment that it
can be found in raindrops. The U.S. Environmental Protection Agency
has extended a regularly scheduled scientific review period to consider
research that could derail use in the United States of one of the
most commonly used weedkillers in the world.
we lose atrazine, we lose a good herbicide that is one of the most
cost-effective herbicides we can use in sugar cane," said Engemann
of El Dorado Plantation/Engemann Farms in southern Pointe Coupee
EPA is studying research that indicates there's a price for continued
use of atrazine.
done in 1998 and since have shown that atrazine is often found in
Louisiana at concentrations the EPA says are sufficient to harm
the aquatic environment.
research indicates atrazine and other pesticides may be suppressing
immunity in amphibians, allowing parasites and environmental factors
to cause deformities -- such as extra legs -- in frogs.
atrazine concentrations often exceed levels that cause some developing
male frogs to grow both male and female sex organs.
McLachlin, director of the Tulane-Xavier Bioenvironmental Research
Center, said the research suggests "the possibility that environmentally
relevant doses of atrazine can play hell with the sexual development
would be a big deal if I came to Tulane Medical School and was a
genetic male and had an ovary," he said.
Mark Engemann holds up a bag of the atrazine he uses in his fields
All of the atrazine made in the United States is made in St. Gabriel
by Syngenta. About 300 of the plant's workers are involved in the
production and packaging of the herbicide. Nationwide, more than
70 million pounds of it are used in 75 different crop-protection
at Syngenta's St. Gabriel plant have filed 10 lawsuits claiming
a link between atrazine and their prostate cancers. The Natural
Resources Defense Council, an environmental activist group, claims
Syngenta is hiding studies that show an increased risk of cancer
at the plant.
surveys have discovered 17 prostate cancer cases in Syngenta employees
or its contract workers since 1985.
which has an annual payroll of about $43.5 million in St. Gabriel,
denies allegations of a link between atrazine and cancer. It points
to an EPA review that said the elevated number of prostate cancer
cases probably is a result of higher-than-normal participation in
a prostate screening program for plant employees.
World Health Organization's International Agency for Research on
Cancer and an EPA advisory panel have both said atrazine is not
a likely cancer-causing agent, although at one time IARC did classify
it as a potential carcinogen.
also said it is concerned about atrazine levels found in drinking
water in 28 United States community water systems, including Iberville
Parish Water Works No. 3, which serves about 10,000 people.
in the early and mid-1990s showed elevated levels of atrazine in
that Iberville water supply, but Brian Berthelot, manager of the
Iberville Parish utilities department, said monthly tests show the
water meets federal standards.
said atrazine levels did spike earlier this year in water taken
from the Gulf Intracoastal Waterway, the water works' only water
source. That prompted the use of powdered, activated carbon to filter
atrazine out of the drinking water.
1998, state agencies monitored for atrazine in streams in the upper
Terrebonne Bay Basin, many of which feed into the Intracoastal Waterway.
One in five samples showed atrazine concentrations at or above the
level EPA says can harm the aquatic environment.
a result, Engemann and other farmers began applying their atrazine
more carefully. That seemed to help.
LSU Agricultural Center weed specialist Jim Griffin said part of
the drop might have been a result of several years of drought. Once
normal rainfall patterns resumed, atrazine started showing up in
higher concentrations in the Iberville Water Works No. 3 intake.
the Louisiana Department of Environmental Quality and the Louisiana
Department of Agriculture and Forestry monitored streams in the
upper Terrebonne Bay Basin in 1998, 19 percent of the samples had
atrazine levels exceeding 10 parts per billion. Sixteen of 220 samples,
or 7 percent, exceeded the 20 parts-per-billion level. Four samples
topped 100 parts per billion and the highest concentrations -- from
Bayou Maringouin and Bayou Tommy -- topped 200 parts per billion.
water quality standards currently allow up to 12 parts per billion
of atrazine in water.
Demcheck, a water quality specialist for the U.S. Geological Survey,
said some cornbelt states show water concentrations of atrazine
much higher than those found in Louisiana, but that the pesticide
still is pervasive in the Bayou State.
have a chronic atrazine problem," he said. "Almost any
time of the year, if we look, we can find it … except midwinter."
March, EPA released a draft scientific review of atrazine as part
of the reregistration required of all herbicides every five years.
The review says:
ecosystems are at risk from atrazine use, especially those in high-use
areas. This is based upon atrazine's toxicity to aquatic plants,
associated indirect effects on invertebrate fish populations …
and sensitive organisms lower on the food chain. ... Effects are
likely to be greatest where concentrations of atrazine in water
recurrently or consistently exceed 10-20 parts per billion."
of California-Berkeley researcher Tyrone Hayes published two
papers in scientific journals this year saying atrazine caused
developmental problems in frogs at .1 parts per billion, a level
one-thirtieth the existing drinking-water standard.
male frogs, both in the laboratory and in the field, had both male
and female reproductive tissue, Hayes said. Atrazine levels are
generally highest in the spring when tadpoles are becoming frogs.
is causing a disturbance in the natural ecology, even in doses that
we find in rainfall," Hayes said. His research, funded by the
National Science Foundation, was published in May in the Proceedings
of the National Academy of the Sciences, a distinguished peer-reviewed
said atrazine might be making frogs produce the enzyme aromatase,
which converts the male hormone testosterone into the female hormone
estrogen. The result: genetically male frogs which have both testes
director of the Tulane-Xavier Bioenvironmental Research Center and
a pioneer in research on chemicals that mimic or change hormones,
praises Hayes' research. He also said he wonders about the larger
effect on the population of 10 percent or 20 percent of male frogs
having a female gonad and being infertile.
professor and researcher Ann Cheek of Southeastern Louisiana University
has been trying to answer that question.
feminized some fish by exposing them to a substance that mimics
a hormone, then raised their offspring. The offspring "developed
normally and were able to make eggs and sperm, but genetically something
must be wrong because their embryos didn't hatch. I don't know what
appears that when you have transgendered effects, it may take several
generations before you see this decrease in production," Cheek
through an independent research group, funded research to review
Hayes' first lab results to see if they could duplicate it. They
could not, and the panel published a harsh critique of his study,
said Tim Pastoor, a toxicologist and Syngenta's head of global risk
Syngenta-sponsored scientists then went to South Africa to test
both atrazine-exposed and unexposed frogs of the same genus used
by Hayes in its natural habitat. They found no problems, Pastoor
took his research to the field and studied leopard frogs in parts
of the United States. He recently published his findings in the
journal Nature, saying he found similar sexual development problems
in the field that he found in his lab.
said Syngenta's panel is doing similar studies in the field now
and results will be published soon.
professor and researcher Joe Kiesecker of Penn State University
studied frogs in the field and looked for differences in those exposed
to herbicides like atrazine and those exposed to pesticides. He
concluded that the chemicals lowered the immune systems of the frogs,
allowing parasites to cause deformities such as growth of extra
rear legs. [more
on this study...]
said he thinks there may be more than one cause of frog deformities,
which were often documented before industrial chemicals were common
in the environment.
said "Kiesecker is a careful researcher … who has published
a fair amount of information on exposure to UVB (ultraviolet B light
rays)" and other factors that could be hampering amphibian
wants more information on the animals Kiesecker tested and on how
other factors, such as ultraviolet light, affect immune problems,
said his company has given EPA numerous studies that show atrazine
· Atrazine is used to control weeds in sugar cane and corn
fields across the state.
· It is made by Syngenta in St. Gabriel. Workers there are
paid $43.5 million annually in salary and benefits.
New research shows atrazine may be causing male tadpoles to develop
into frogs with male and female reproductive tissues.
In a 1998 survey, the state found atrazine concentrations of 10-20
parts per billion or higher in at least one in five samples taken
on the west bank of the Mississippi River.
A new scientific review of the herbicide atrazine should be complete
by January. It will determine if atrazine can continue to be used
and made here.
the mid-'90s, Syngenta sponsored a panel through an independent
group, and it has done a wide range of studies on alligators, turtles,
fish and other aquatic life.
overall health and reproductive capabilities of aquatic life and
environments have not been impaired," Pastoor said.
said atrazine is "the most-studied herbicide on the planet
and because of that we are real confident atrazine is going to be
Gabriel plant manager Bob Slaven said he also feels confident.
is a company that is dedicated to product stewardship … and
extremely sound environmental and safety programs," Slaven
interim reregistration decision was scheduled for August, but has
been delayed until January. A science advisory panel will then be
appointed by midyear to review the decision and make a final recommendation
in October, Pastoor said.
Lejuene and Butch Stegall of the Louisiana Department of Agriculture
worked on the 1998 special state study of atrazine. They said Syngenta's
research convinced them the herbicide does not pose a threat to
the state's environment.
Engemann and other farmers wait. Most are cautious about how and
when they use atrazine.
has been farming near Livonia and using atrazine since the 1980s.
For most of those years, he grew corn and soybeans, and used atrazine
on the corn.
1999, he switched from corn to sugar cane and uses atrazine to prepare
the fields. He also uses it after the cane has begun to sprout.
Some years he has used atrazine to treat the fields after harvest
to reduce weeds over the winter.
has always been a good, effective, fairly reasonably priced product,"
he and other farmers voluntarily cut on their use of atrazine when
LSU told them of the high readings.
didn't want to lose the chemical," he said.
with LSU, said most farmers in the area use one-fourth of what the
product label says they can use. They spray more selectively and
use tractors instead of airplanes to apply it, which makes the application
more accurate and reduces runoff.
said he might be able to afford more-expensive alternatives to atrazine,
but "for farmers who are struggling, atrazine has been the
most cost-effective," he said.
said he doesn't want farmers to have to give up any available herbicides
and that he thinks atrazine is safe if used properly.
like many farmers, Engemann said he is worried about mounting restrictions.
hope we don't get to the point we can't grow our own food here."