Latest Update on Toxicity of Popular Weed Killer

Story at-a-glance

  • Government researchers warn the Roundup formula is far more toxic than glyphosate in isolation, due to synergistic interactions between various chemicals
  • Testing by the U.S. National Toxicology Program reveals glyphosate formulations such as Roundup “significantly altered” the viability of human cells by disrupting the functionality of cell membranes
  • The Ramazzini Institute in Italy is raising public funds to perform a comprehensive, independent, global glyphosate study. Stage 1 will investigate the chemical’s carcinogenicity and chronic toxicity potential
  • Monsanto’s plan to release a new crop of Bt soybeans for the U.S. market has been shelved. Entomologists believe the decision may have been triggered by the fact that insects are rapidly developing resistance to the pesticide-producing plants
  • May 3, the USDA released its highly problematic proposal for the labeling of foods containing GMOs. Call to action: Leave your public comment for the USDA before July 3

    In recent years, concerns over the health effects of glyphosate — the active ingredient in Roundup and other weed killer formulations — has risen exponentially. Researchers have discovered it not only may be carcinogenic,1 but may also affect your body’s ability to produce fully functioning proteins, inhibit the shikimate pathway(found in gut bacteria) and interfere with the function of cytochrome P450 enzymes(required for activation of vitamin D and the creation of nitric oxide and cholesterol sulfate)

    Glyphosate also chelates important minerals, disrupts sulfate synthesis and transport, interferes with the synthesis of aromatic amino acids and methionine, resulting in folate and neurotransmitter shortages, disrupts your microbiome by acting as an antibiotic, impairs methylation pathways, and inhibits pituitary release of thyroid stimulating hormone, which can lead to hypothyroidism.2,3

    Now, government researchers warn the Roundup formula is far more toxic than glyphosate alone. As reported by investigative journalist Carey Gillam:4

    “The tests5 are part of the U.S. National Toxicology Program’s (NTP) first-ever examination of herbicide formulations made with the active ingredient glyphosate, but that also include other chemicals. While regulators have previously required extensive testing of glyphosate in isolation, government scientists have not fully examined the toxicity of the more complex products sold to consumers, farmers and others.”

    Toxicology Testing Long Overdue

    The NTP testing was done by request from the U.S. Environmental Protection Agency (EPA) following the International Agency for Research on Cancer (IARC) reclassification of glyphosate as a Class 2A probable carcinogen three years ago.6 At the time, the IARC noted concerns about glyphosate formulations possibly having increased toxicity due to synergistic interactions.

    As it turns out, that’s exactly what the NTP testing found. According to the NTP’s summary of the results, glyphosate formulations “significantly altered” the viability of human cells by disrupting the functionality of cell membranes. Mike DeVito, acting chief of the NTP Laboratory, told Gillam, “We see the formulations are much more toxic. The formulations were killing the cells. The glyphosate really didn’t do it.”

    While first-phase results do not indicate that weed killers like Roundup are carcinogenic, it does show that the formulations are more toxic than glyphosate in isolation (for which evidence of carcinogenic potential does exist), and that they have the ability to kill human cells.

    Jennifer Sass, who works as a scientist with the Natural Resources Defense Council, added, “This testing is important, because the EPA has only been looking at the active ingredient. But it’s the formulations that people are exposed to on their lawns and gardens, where they play and in their food.”

    Despite public assurances that Roundup is harmless, internal documents from Monsanto, obtained through previous Freedom of Information Act (FOIA) requests, reveal the company itself is unclear about the toxicity of Roundup as it has not been thoroughly studied. Internal discussions also reveal Monsanto employees have not been convinced the product is harmless. For example, in a 2002 email, Monsanto executive William Heydens said, “Glyphosate is OK but the formulated product … does the damage.”7

    A 2003 company email8 from Monsanto toxicologist Donna Farmer, Ph.D., states, “You cannot say that Roundup is not a carcinogen … we have not done the necessary testing on the formulation to make that statement. The testing on the formulations are not anywhere near the level of the active ingredient.”

    Farmer also adds that, “We cannot support the statement about ‘no adverse effects whatsoever on flora, or fauna or on the human body.’ Adverse effects are seen on flora (glyphosate is meant to kill vegetation), adverse effects on fauna — in studies with laboratory animals — even death is seen (LDS0 studies for example) …” Yet another company email sent in 2010 said,9 “With regards to the carcinogenicity of our formulations we don’t have such testing on them directly.”

    Despite such internal discussions and doubts, in its “Benefits and Safety of Glyphosate” report published last year,10 Monsanto continues to claim that “Glyphosate-based herbicides are supported by one of the most extensive worldwide human health and environmental effects databases ever compiled for a pesticide product. Comprehensive toxicological and environmental fate studies conducted over the last 40 years have time and again demonstrated the strong safety profile of this widely used herbicide.”

    Ramazzini Institute Seeking Donations for Global Safety Study

    The highly respected Ramazzini Institute in Italy — which recently confirmed the link between cellphone radiation and Schwann cell tumors found by NTP researchers11,12,13 — is now raising funds14 to perform a comprehensive, global glyphosate study. Stage 1 would investigate the chemical’s carcinogenicity and chronic toxicity potential. The Institute explains its decision to look for public funding:

    “Aiming to produce independent and solid scientific evidence, the Ramazzini Institute has decided not to accept any funding for the study from the industry that produces glyphosate-based herbicides or from the organic farming or food industry — to avoid all conflicts of interest.

    Do you want to know if glyphosate is safe for you and your family? If you do, you can now help fund a study that you can trust. This is the most comprehensive independent study ever on the World’s most used herbicide, the study that you and your family deserve!”

    Bt Soybean Plan Scrapped

    In related news, Monsanto’s plan to release a new crop of Bt soybeans for the U.S. market has been scrapped. While the company claims plans were shelved due to low demand, entomologists have proposed it’s more likely due to the reality that insects are rapidly developing resistance to the pesticide-producing plants.

    The first generation of Bt soybeans, Intacta RR2 PRO, contain a single Bt protein called Cry1Ac. The second-generation of this product, Intacta 2 Xtend, adds two other Bt proteins — Cry1A.105 and Cry2Ab2 — plus dicamba tolerance. While Intacta 2 Xtend is still planned for release in South America in 2021, it will not be released in the U.S. According to a report by DTN/Progressive Farmer:15

    “[T]he Bt proteins in Intacta 2 — Cry1Ac, Cry1A.105 and Cry2Ab2 — have already been compromised by insect resistance in the U.S., where they are used extensively in Bt cotton and Bt corn. Texas A&M entomologist David Kerns and his colleagues have identified bollworm populations across the South with resistance to Cry1Ac and Cry2Ab.

    Resistance to Cry1A.105 and Cry2Ab2 has also been found in corn earworm populations in Maryland. Moreover, Cry1A.105’s similar mode of action to other Cry1 proteins on the U.S. landscape spells trouble for the trait, Kerns noted.

    It’s a vector stack — they’ve taken the active part of the toxin from several different Cry proteins — Cry1Ab, Cry1F and Cry1Ac — and put them into one … So cross resistance would be highly likely, and there is already established resistance to Cry1F in all bollworm populations. So I would suspect Cry1A.105 would not have much activity on our Helicoverpa zea [bollworm] populations.’”

    Vaccines for Plants Are Next

    As if genetically tinkering with plants to make them produce pesticide internally isn’t odd or unnatural enough, scientists are now working on plant vaccines. As explained by Regeneration International, RNA interference (RNAi) technology is being used “to develop biodegradable ‘vaccines’ intended to protect crops from pathogens.” The rationale for developing plant vaccines is to minimize the use of chemical pesticides.

    While we certainly need to eliminate agrochemicals from food production, RNAi technology is risky business and could produce any number of unforeseen consequences. In a letter to the editors of Yale Environmental 360 in response to its April 18 article, “Can ‘Vaccines’ for Crops Help Cut Pesticide Use and Improve Yields?”17 Regeneration International founding member Judith Schwartz writes, in part:18

    “As a journalist covering land management, I am extremely disappointed in the lack of skepticism demonstrated in this reporting. Any distinction between this and ‘chemical pesticides,’ or for that matter, ‘genetic engineering,’ is merely semantic; if gene editing is not considered genetic engineering that’s only because the companies say so. As we do not know if this technology is safe, how can we be sure that non-targeted genes are not deactivated? …

    This could dangerously impact insect, plant and/or mammal species and ecological stabilities … There are a growing number of farmers who are working with nature by means of no-till, cover-cropping and other ecological practices, who are finding that the best means of managing problem insects is biodiversity: the other insects that prey on them.

    Such farmers have been able to grow healthy crops while markedly reducing and often eliminating herbicides and pesticides. Independent research19 has shown that pesticide-treated croplands often have far more pests and impacts than untreated cropland. Aren’t problem pests a symptom of an out-of-balance ecology? Could not this RNAi experiment throw the ecology even further out of balance?

    How would this address the underlying problem, rather than merely boost the sale of pesticides? … [W]e can already produce enough food to feed 10 billion people; the challenge is in distribution, nutrient density and affordability. Nor is this the job of industrial agriculture. More than 70 percent of the world’s food is grown by small-holder farmers in the developing world …

    Given the limited research on RNAi technology that is not funded by entities that would benefit from its use, isn’t more critical analysis required? I would encourage your editorial staff to run an objective piece that goes into more details on the implications of RNAi technology and considers pest management alternatives.”


    by Dr Mercola