When Margot McMillen was introduced to the Monsanto Co.'s Roundup Ready crops in the mid-1990s, she suspected the seeds, genetically engineered to be immune to powerful herbicides, were too good to be true.
The idea was you could spray a field with Roundup and you could kill everything on the field, and then your crop would come up and be resistant to the poison. Then you could have a harvest without worrying about the weeds, said McMillen, an organic farmer in Missouri who produces vegetables and meat for the restaurant trade.
The question of herbicide resistance was one raised by farmers from the beginning, according to McMillen. Constant use of glyphosate-based herbicides -- designed to kill bugs, weeds, and all plant life other than the crops genetically modified to resist it -- has led to the emergence of resistant weeds that can no longer be controlled by Roundup, the herbicide of choice for the past decade.
That's why McMillen, along with a host of consumer and environmental groups, is concerned now that the Dow AgroSciences unit of the Dow Chemical Co. is on the cusp of winning regulatory approval for corn that is genetically engineered to be resistant to 2,4-Dichlorophenoxyacetic acid, or 2,4-D, an old and robust herbicide that was an active ingredient in the Agent Orange defoliant used during the Vietnam War.
2,4-D Connected To Cancer, Impaired Reproductive Function
Continue Reading Below
Dow's new Enlist corn -- known by its critics as Agent Orange corn -- is close to being approved by the U.S. Department of Agriculture, which is accepting public comments on the issue until Friday. A coalition of more than 140 agricultural, consumer, environmental, and public-health groups sent USDA Secretary Tom Vilsack a letter this week urging him to reject the crop. In a petition signed by more than 365,000 people, the coalition argued the product could potentially have devastating environmental and public-health consequences by encouraging increased use of 2,4-D. Corn is the No. 1 crop grown in the U.S.
Although various scientific studies have connected 2,4-D to health problems -- including non-Hodgkin's lymphoma, endocrine dysfunction, and impaired reproductive function -- the U.S. Environmental Protection Agency continues to deny there is enough evidence to call 2,4-D a human carcinogen. This month, the agency rejected a petition from the Natural Resources Defense Council seeking the removal of 2,4-D from the market on health and safety grounds.
I've got workers who are generally young people who want to have a full life ahead of them. I worry about them, said McMillen, who is a member of the National Family Farm Coalition, one of many groups objecting to Enlist's potential approval.
Stronger Herbicides Will Lead To Further Resistance
The corn is the first in a new line of herbicide-tolerant crops awaiting regulatory approval. Dow is also developing soybeans and cotton immune to 2,4-D, while Monsanto is set to release soybeans, cotton, and corn resistant to dicamba, an older herbicide in the same family as 2,4-D.
Of the 20 genetically engineered crops awaiting USDA approval, 13 are intended to be resistant to one or more herbicides. While the companies producing these products argue it will benefit farmers by allowing them to easily produce larger harvests, scientists say it will simply lead to even more herbicide resistance, propagating a vicious cycle of even stronger herbicides and genetically modified crops designed to withstand them.
It's important to realize that for 20 years we've been promised that genetically modified organisms [GMOs] would do marvelous things. Now it's becoming clear that this is where the industry is heading, said Bill Freese, a science policy analyst for the nonprofit Center for Food Safety. No one is making the logical connection -- that these crops will lead to more resistance in turn.
Roundup Ready crops already account for about 90 percent of the soybeans and 70 percent of the corn and cotton produced in the U.S., according to the USDA. This resulted in an influx of glyphosate use that ultimately allowed weeds to develop resistance to the chemical. Dow said it will provide a way to control those glyphosate-resistant weeds with 2,4-D, something the company said should please farmers.
This is going to be a solution that we are looking forward to bringing to farmers, Joe Vertin, Dow's global business leader for Enlist, told Reuters.
Dow did not immediately respond to a request for comment on the issue.
EPA: No Proof Of Public-Health Risks
While most of the public-health problems associated with Agent Orange have been attributed to a different ingredient (called 2,4,5-T) as well as to dioxin contamination, a number of studies have also indicated that 2,4-D comes with considerable health risks, according to Gina Solomon, a senior scientist for the NRDC.
In the EPA denial, the Agency quotes its 1994 conclusion that 'the data are not sufficient to conclude that there is a cause and effect relationship between exposure to 2,4-D and non-Hodgkin's lymphoma,' Solomon wrote on the NRDC's official blog. Essentially, the Agency is saying that in the absence of animal studies showing a link to cancer, EPA will continue to ignore the multiple human studies which repeatedly show increased rates of this particular cancer in farmers and agricultural workers exposed to the chemical.
One of those studies was produced by Dow Chemical itself. An analysis of Dow employees exposed to 2,4-D between 1945 and 1994 found those workers had slightly higher rates of non-Hodgkins lymphoma, although the company determined the proportion was not large enough to be considered a significant risk. The company did report that employees exposed to 2,4-D had an increased risk for mortality due to amyotrophic lateral sclerosis (commonly known as Lou Gehrig's disease).
The likely increase of 2,4-D use is not just a concern for advocates of a healthy food supply. The chemical is known to drift easily, moving far away from the farm fields where it is applied and injuring crops on nontarget fields that are not engineered to resist its toxicity. Some contend the heavy use of herbicides also damages the livability of surrounding neighborhoods.
I don't know how many times I've walked out the door and smelled a strange chemical odor in the air. Sometimes I can't even tell where it's coming from, said George Naylor, an Iowa-based corn and soybean farmer who is also a member of the National Family Farm Coalition. The idea that we have to go down this road to feed the world is totally wrong; it's totally crazy.