GMOs and Pesticides—What Concerns Scientists

Genetically engi­neered crops have been with us now for some 20 years, and it is becom­ing appar­ent that the real­ity of GMOs has fallen far short of busi­ness model expec­ta­tions. A report issued in 2009 by the Union of Concerned Scientists enti­tled Failure to Yield: Evaluating the Performance of Genetically Engineered Crops found that GM tech­nol­ogy has not increased yields at all through its entire his­tory, despite the mil­lions that have been spent on GM devel­op­ment, much of it from gov­ern­ment funding.

The pub­lic is becom­ing increas­ingly con­cerned about GMOs, as sci­en­tific evi­dence is argu­ing against the safety of pub­lic con­sump­tion and the wide­spread grow­ing of GMO crops. Of great­est con­cern, how­ever, is new research regard­ing pes­ti­cides devel­oped strictly for GMOs, which may prove to be the tip­ping point for the entire technology.

Pesticide Resistance

One trait that has been suc­cess­fully bred into GMO crops is resis­tance to pes­ti­cides. When a trait is bred into a crop mak­ing it resis­tant to one par­tic­u­lar her­bi­cide, that her­bi­cide can be used with impunity against weeds while not affect­ing the pri­mary crop. This of course only works when farm­ers who plant these crops use that spe­cific herbicide.

The vast major­ity of com­mod­ity crops—including corn, soy­beans, canola, cot­ton and now alfalfa—have been bred to resist one best-selling her­bi­cide called glyphosate. Glyphosate is what is known as a broad-spectrum her­bi­cide, mean­ing it is designed to kill a wide vari­ety of weeds. Glyphosate is the pri­mary active ingre­di­ent in the exten­sively used Roundup her­bi­cide, and up until the year 2000 Roundup’s manufacturer—Monsanto—had pro­pri­etary rights to the com­pound. Since that time, Monsanto has con­tin­ued to use it, but now generic glyphosate has appeared from a num­ber of other man­u­fac­tur­ers, and even from China.

Because of the quan­tity of GMO crops designed to resist glyphosate, an unnerv­ing amount of this chem­i­cal is being employed. “The EPA recently came out with an esti­mate of glyphosate use,” Bill Freese, Science Policy Analyst with the Center for Food Safety, told Organic Connections. “It is for the year 2007, so it’s actu­ally prob­a­bly even higher now; but they’re esti­mat­ing that in agri­cul­ture in the US, 180 to 185 mil­lion pounds of glyphosate are used yearly. It’s a huge quan­tity, and it’s com­ing close to half of all her­bi­cides in use. If you include other appli­ca­tions like home and gar­den, com­mer­cial and indus­trial gov­ern­ment use, it’s up right around 200 mil­lion pounds. It’s prob­a­bly the most widely used pes­ti­cide in history.”

As one might imag­ine, such a sheer vol­ume of poi­son being applied to mil­lions of acres of farm­land might begin to man­i­fest neg­a­tive effects—and cred­i­ble sci­en­tists are telling us this is the case.

Effects on Plant, Soil, Animal and Human Biology

Glyphosate does not func­tion as a nor­mal pes­ti­cide might, directly killing the plant with which it comes in con­tact. Its action is actu­ally far sub­tler: it acts as a chelat­ing agent, whereby it binds itself to mol­e­cules, such as min­er­als, and holds them tightly, mak­ing them unavail­able to the plant or weed.

In fact, glyphosate was orig­i­nally patented as a chelat­ing agent and quite acci­den­tally became an her­bi­cide. “Glyphosate belongs to the chem­i­cal fam­ily of phos­pho­nates, which is a fam­ily of chelat­ing agents,” Dr. Arden Andersen, soil sci­en­tist, agri­cul­tural con­sul­tant and physi­cian, explained to Organic Connections. “Glyphosate was orig­i­nally patented by Stauffer Chemicals in the early 1960s as a descal­ing agent [used to remove min­eral residues inside dish­wash­ers, vents and the like]. It was only by serendip­ity that it got spilled, or some­thing, and it killed the weeds it con­tacted. It was sub­se­quently pur­chased by Monsanto, and the rest is his­tory. The key needed under­stand­ing to have is that glyphosate is a broad-spectrum chelat­ing agent and was orig­i­nally designed and patented as such. Its effect and use as an her­bi­cide have been afterthoughts.”

This chelat­ing action actu­ally leads to harm for plants, as it removes impor­tant trace min­er­als, a fact observed by Dr. Robert Kremer, micro­bi­ol­o­gist with the USDA Agricultural Research Service, who con­ducted a 15-year study on glyphosate’s effects on plants and root micro­bi­ol­ogy. Dr. Kremer is also an adjunct pro­fes­sor in the Division of Plant Sciences at the University of Missouri, where he teaches envi­ron­men­tal soil micro­bi­ol­ogy and advanced weed sci­ence. “Glyphosate is a chela­tor, which will bind with ele­ments such as man­ganese and cal­cium, and those sorts of nutri­ents, and immo­bi­lize them,” Dr. Kremer told Organic Connections. “In other words, it will make them unavail­able for plant uptake.

“As we have stud­ied the microor­gan­isms in root sys­tems over time, we have seen a shift toward more col­o­niza­tion of the roots with some par­tic­u­lar fungi that could, under cer­tain cir­cum­stances, be a detri­ment to crop growth,” Dr. Kremer con­tin­ued. “We also did a small side study in which we demon­strated that the glyphosate mol­e­cule is being trans­ported to the roots and released into the soil around the roots. There is a pos­si­bil­ity that this chem­i­cal being released through the root sys­tem inter­acts with cer­tain microor­gan­isms and maybe selects these at the expense of other microor­gan­isms there that might be ben­e­fi­cial to the plant.”

Dr. Don Huber, pro­fes­sor emer­i­tus at Purdue University, is a highly respected 55-year vet­eran micro­bi­ol­o­gist and plant pathol­o­gist. He too has been care­fully research­ing this issue and has paid spe­cial atten­tion to glyphosate’s effects on the trace min­eral man­ganese. “Manganese is an essen­tial micronu­tri­ent for pho­to­syn­the­sis and car­bo­hy­drate metab­o­lism, as well as for plant defense mech­a­nisms to a series of soil-borne pathogens,” Dr. Huber briefed Organic Connections. “It’s also impor­tant in defend­ing against stress such as drought and even excess water. In research­ing the impact of glyphosate on man­ganese avail­abil­ity, it became very appar­ent that the chelat­ing activ­ity of glyphosate had a direct effect on man­ganese avail­abil­ity for uptake, in addi­tion to being very toxic to the organ­isms that are respon­si­ble for mak­ing man­ganese avail­able to the plant and the soil we started with. There are sev­eral mech­a­nisms involved with glyphosate that we gen­er­ally don’t see with most of the other her­bi­cides, and the research led us to rec­og­nize why we’re notic­ing a gen­eral increase in a lot of plant dis­eases that we used to man­age fairly well.”

Unnamed Organism

But glyphosate’s fos­ter­ing of pathogen growth may not only be harm­ful to plants. In fact, there is recent research sug­gest­ing strong evi­dence that this char­ac­ter­is­tic could affect ani­mals fed GMO corn and soy­bean feed—and might poten­tially affect humans as well.

“Veterinarians have been report­ing a new, as-yet-unnamed organ­ism that is related to repro­duc­tive fail­ure,” Dr. Huber said. “They have iden­ti­fied genet­i­cally mod­i­fied plants as the source—especially soy­beans and corn. They’ve estab­lished this new organ­ism as the cause of that repro­duc­tive failure—infertility, mis­car­riage and spon­ta­neous abor­tions. The plant has been tied, as the source, to those sit­u­a­tions where you see con­di­tions favor­able for this organ­ism to pro­lif­er­ate. We don’t have the research to doc­u­ment a direct effect of glyphosate in increas­ing that pathogen, but the evi­dence is that it changes the envi­ron­ment to make the plant more con­ducive for that organ­ism to pro­lif­er­ate, and to thus be avail­able and in the grain and feed that the ani­mals receive.”

Click any image above to see a larger version.

What are the chances that this pathogen could trans­mit to humans? “It has been found in ani­mal tis­sues and in prod­ucts that would be con­sumed by humans,” Dr. Huber remarked. “This organ­ism infects a broad scope of ani­mals already—horses, cat­tle, pigs, sheep, goats and poul­try. To believe that it wouldn’t infect humans would be kind of naive at this point, I think. There’s a lot of research that needs to be done, but it would cer­tainly not be out of the ordi­nary to rec­og­nize that there’s also a poten­tial safety aspect as far as humans are involved.”

Several months ago, prior to the USDA approv­ing GMO alfalfa for plant­ing, Dr. Huber wrote a pri­vate let­ter to Secretary of Agriculture Tom Vilsack urg­ing him to study these find­ings before the approval of yet another glyphosate-resistant crop. “I wrote the let­ter to bring to Secretary Vilsack’s atten­tion the con­cerns a num­ber of us have, and to solicit his assis­tance and resources in get­ting the infor­ma­tion that we really need to thor­oughly under­stand the epi­demi­ol­ogy* of this organ­ism. It was writ­ten with the hope that it would be forwarded—which it was—to those groups within the USDA who would be respon­si­ble for respond­ing to that infor­ma­tion, and with the pos­si­bil­ity that there might be some resources allo­cated for really look­ing at all of the fea­tures of glyphosate, GMO organ­isms and this new organ­ism as they impacted our over­all crop and ani­mal pro­duc­tion system.”

Despite his let­ter and sub­mis­sion of follow-up peer-reviewed sci­en­tific data, Dr. Huber has, as yet, been unsuc­cess­ful in efforts urg­ing the USDA to con­duct broad and defin­i­tive stud­ies on this pathogen, its causes and its poten­tial harm­ful effects. “Dr. Huber has raised some really seri­ous con­cerns about poten­tial impacts of glyphosate on plant and ani­mal health,” Bill Freese, Science Policy Analyst with the Center for Food Safety, stated. “The USDA should seri­ously research this issue as more data is accumulated.”

Increasing Weed Resistance

As with any pes­ti­cide, increased use of the agent causes resis­tance in the pests to which it is being applied. “The glyphosate-resistant weed issue is reach­ing a really seri­ous stage,” said Freese. “One Iowa weed sci­en­tist was telling me that peo­ple are expect­ing these weeds to explode in Iowa in the next year or two. They’re creep­ing from the East and the South into the Midwest and peo­ple are start­ing to see them some­what in the North. Studies out there are already show­ing that weeds are going to evolve resis­tance to this and other her­bi­cides too. So prob­a­bly we’ll have weed pop­u­la­tions resis­tant to mul­ti­ple herbicides—kind of like an arms race between the crops and the weeds. They engi­neer a new resis­tance into a crop, and then you use tons of that her­bi­cide and the weeds develop resis­tance to the her­bi­cide. It’s totally unsus­tain­able agri­cul­ture, bad for the envi­ron­ment and human health, and it’s where this Roundup Ready model is leading.”

The Battle Continues

As Dr. Huber points out, issues such as the newly dis­cov­ered pathogen fos­tered by glyphosate can have far-reaching effects. “This organ­ism could have a tremen­dously neg­a­tive impact on our exports,” Dr. Huber said. “The organ­ism has been detected in our exported soy­bean prod­ucts, and repro­duc­tive fail­ure of increas­ing sever­ity is also being reported in other countries.”

Because of the lack of long-term stud­ies and con­clu­sive sci­ence show­ing these biotech cre­ations to be safe for human con­sump­tion, alarmed con­sumers are increas­ingly speak­ing out against GMOs and express­ing their desire to not have GMO foods avail­able in the mar­ket­place, espe­cially unla­beled. Natural prod­ucts retail­ers are tak­ing note—and some, such as Mile High Organics of Colorado, have gone all out to ensure that the prod­ucts they sell are 100 per­cent GMO free.

“I don’t believe that con­sumers should be deceived,” Michael Joseph, founder and CEO of Mile High Organics, told Organic Connections. “I don’t con­sider that the US gov­ern­ment is doing a good job of pro­tect­ing its cit­i­zenry, and some retail­ers are start­ing to step up and have done very well at edu­cat­ing their con­sumers. We really have found a strong and loyal con­sumer base that believes exactly the same thing, and peo­ple have thanked us. I’ve had peo­ple tell me that they think I’m essen­tially doing work that should be done by the government.”

Equally vocal are food activists and nat­ural food advo­cates such as best-selling writer and edu­ca­tor Anna Lappé, author of Diet for a Hot Planet: The Climate Crisis at the End of Your Fork and What You Can Do about It. “Our reg­u­la­tors have allowed genet­i­cally mod­i­fied foods to enter into our food sys­tem with­out tak­ing seri­ously the con­cerns, not only about pub­lic and ani­mal health, but also about the impact of GMOs on bio­di­ver­sity, on pest and weed resis­tance, and other neg­a­tive externalities—as econ­o­mists would say—that should have been red flags about this tech­nol­ogy from the begin­ning,” Lappé told Organic Connections.

“The real under­ly­ing issue is that we don’t even need this tech­nol­ogy,” Dr. Arden Andersen con­cluded. “We already have the where­withal, the sci­ence, the tech­nol­ogy and the prod­ucts to solve every prob­lem that has been pro­posed to need genetic engi­neer­ing tech­nol­ogy. So when you think about it, if we already have the tech­nol­ogy to solve all of those prob­lems, why are cer­tain peo­ple want­ing to pur­sue genetic engi­neer­ing? It is cer­tainly not from a need per­spec­tive; it’s not from a sci­ence perspective—it’s strictly for want of monop­o­liza­tion and greed. That’s it.”

*epi­demi­ol­ogy: the study of the inci­dence, trans­mis­sion and con­tain­ment of epi­demic disease.