A FAVORITE WITH FARMERS
World annual spending on herbicide totals more than $14
billion, with more than $5 billion of that spent in the United
States alone, according to the EPA.
Thanks to the spread of herbicide-resistant crops,
herbicide use has been increasing rapidly, a factor
environmental and consumer groups find particularly
More than 2 billion lbs of herbicide were used globally in
2007, with one quarter of that total - 531 million lbs - used
in the United States in that timeframe, according to a report
issued in February by the EPA.
And of the more than two dozen top herbicides on the
market, glyphosate dominates all with more than 750 U.S.
products containing the chemical.
The top users are farmers. In 2007 alone, for instance, as
much as 185 million lbs of glyphosate was used by U.S. farmers,
double the amount used only six years earlier. The next most
popular herbicide - atrazine - has less than half the amount of
usage of glyphosate, according to EPA data.
Already more than 130 types of weeds have developed levels
of herbicide resistance in more than 40 U.S. states, more
resistant weeds than found in any other country. Experts
estimate glyphosate-resistant weeds have infested close to 11
million acres (4.5 million hectares), threatening U.S. farmers'
On March 18, a cross section of consumer and environmental
groups filed another in a series of lawsuits against the U.S.
Department of Agriculture for the agency's approval of more
Roundup Ready crops.
The latest suit, which targets Roundup Ready alfalfa,
involves a range of concerns, including "the cumulative impact
of increased herbicide load on the environment... and the
creation of Roundup Ready 'super weeds' that become immune to
the herbicide Roundup because of overuse." Yet more Roundup
Ready crops will "cause grave harm to neighboring crops, native
plants, microorganisms and biodiversity," the suit states.
Monsanto has acknowledged the spreading weed resistance
problems, which are particularly bad for U.S. cotton and
soybean growers. And last month Monsanto and Germany-based BASF
(BASFn.DE) announced a new collaboration to develop alternative
herbicide formulations using "dicamba" and to create
dicamba-tolerant soybeans, corn, cotton and canola.
The advent of new herbicides isn't assuaging critics
though. They worry that this may only make the problems with
weed resistance worse, because the new herbicides are being
used on top of glyphosate, not instead of it, putting even more
chemicals into the soil.
"That is going to spell big problems... even larger
problems with herbicide-resistant weeds," said Center for Food
Safety analyst Bill Freese. "It will just accelerate this toxic
spiral of increased pesticide use."
ASSESSING THE RISKS
Along with the problem of herbicide-resistant weeds,
health-related alarms have been raised by several scientists.
In January, well-known plant pathologist and retired Purdue
University professor Don Huber sent a letter to U.S.
Agriculture Secretary Tom Vilsack warning of tests that
indicated glyphosate could be contributing to spontaneous
abortions and infertility in pigs, cattle and other livestock.
Scientists in Argentina last year published a study saying
glyphosate caused malformations in frog and chick embryos.
Other scientists, both from private institutions and from
the federal government, have said research shows harmful
effects of glyphosate products on soil organisms, on plants,
and on certain animals. A 2008 lawsuit filed by the Center for
Biological Diversity said glyphosate was harmful to
California's red-legged frog and the EPA subsequently agreed it
was "likely to adversely affect" the frog.
The Institute of Science in Society has called for a global
ban on glyphosate, citing research showing the chemical has
"extreme toxicity," including indications it can cause birth
defects. It also submitted a report to EPA.
Another study being looked at by the EPA cited detectable
concentrations of glyphosate in the urine of farmers and their
children in two U.S. states. Higher levels were found in
farmers who did not wear protective clothing when they used
glyphosate or who otherwise improperly handled it. The EPA said
it will consider data from that study "more fully" as part of
its ongoing risk assessment.
The agency also said it is looking at a study partly
sponsored by the EPA and the National Institutes of Health
(NIH) that found some users of glyphosate were observed to have
a higher risk of multiple myeloma, a cancer affecting bone
marrow, than people who never used the chemical. The two-fold
increased risk was considered "non-significant" and EPA said
the findings were preliminary and based on a small number of
cases but it is still part of the review.
Monsanto has said repeatedly that glyphosate is safe and it
has said studies by Huber and other scientists are invalid.
The EPA also has discounted the validity of many of the
studies cited in biomedical literature and by opponents. But it
acknowledged there are areas that need more evaluation and has
said it wants more data on human health risk and risks to
certain endangered species.
"We look closely at every study to determine whether the
results are scientifically sound, regardless of the source,"
EPA officials said in a written statement.
The EPA is not doing its own studies, instead evaluating
information from others. Much of the data is coming from the
agricultural chemicals industry as part of a registration
review program that aims to examine each registered pesticide
every 15 years.
The agribusiness giants, including Monsanto, Syngenta, Dow
Chemical (DOW.N), and BASF, have formed a 19-member task force
to generate the data the EPA is seeking.
Another factor rankling opponents is that the EPA is using
a lower safety standard than they argue it should.
Though the Food Quality Protection Act requires the EPA to
use an extra tenfold (10X) safety factor to protect infants and
children from effects of the pesticide, the agency determined
there was adequate data available to show that the margin of
safety for glyphosate could be reduced to only a 1X factor.
The EPA's Office of Pesticide Programs is in charge of the
review and has three main options -- continued approval of
glyphosate with no changes; canceling the registration to ban
its use in the United States; or continue as an approved
product but with some modifications for its use.
The agency said it wants all the relevant data gathered by
the summer of 2012 and expects to have a final decision no
earlier than 2015.
Canada is likewise re-evaluating glyphosate and is
coordinating with the United States to "harmonize the
assessments," the EPA said.
Both supporters and detractors say it is uncertain what
the future holds for the world's favorite weedkiller.
Wellesley College professor and food expert Professor
Robert Paarlberg said critics are fueled more by dislike for
Monsanto than real evidence of harm.
"The critics would do well to spend more time talking to
farmers, who continue find glyphosate a safe and convenient way
to control weeds," Paarlberg said.
The science argues otherwise, according to Huber, who has
asked USDA to conduct in-depth research on glyphosate's
effects. Huber was heavily criticized by Monsanto after his
January letter to the USDA but he sent a second letter to
Vilsack on March 30, reiterating his concerns.
"We are experiencing a large number of problems in
production agriculture in the U.S. that appear to be
intensified and sometimes directly related to genetically
engineered crops, and/or the products they were engineered to
tolerate - especially those related to glyphosate," Huber
wrote. "A large reduction in glyphosate usage would be a
(Reporting by Carey Gillam. Edited by Martin Howell and