Earth Watch: Glyphosate, The Planet's Most Popular Herbicide, Leaves A Heavy Environmental Footprint

In 2016, professionals from prestigious universities and advocacy organizations across the U.S., the U.K., and Canada published a consensus statement of concern about the human health and environmental risks associated with glyphosate-based herbicides.1 Yet, glyphosate, the active ingredient in the weedkiller Roundup, remains the most used herbicide in the world. It's reportedly sprayed three times more than all other pesticides on U.S. crops and is also used as a pre-harvest drying agent on staple foods including barley, oats, wheat, and beans.2 3 4 Parks, playgrounds, golf courses, and residential lawns are frequently doused with it, and its overall use has increased approximately 100-fold since its debut in the 1970s.5


Glyphosate is everywhere, which begs the question—what are the long-term environmental impacts of the planet's most-used herbicide? Evidence is mounting, from honeybees to earthworms to soil and plant health, that the environmental toll is much higher than its proponents claim. Consider a sampling.

Impairs insect immune function

Researchers concluded glyphosate might factor in the current decline of insect populations, according to a study published in the journal PLOS Biology in 2021. So how is a chemical, supposedly only lethal to weeds, harmful to insects? It inhibits melanin production, essential to their immune defense, leaving them more susceptible to pathogens. The study also found an alarming twist in the implications to public health—glyphosate enhances the susceptibility of a species of mosquito, A. gambiae, to the human malaria parasite. That finding implies it could potentially enhance the mosquitos’ ability to infect humans with malaria.6

“Perturbs the gut microbiota of honeybees”

Glyphosate could potentially be a factor in honeybee decline, according to a 2018 study at the University of Texas, Austin. The study found that exposing bees to glyphosate at levels currently in the environment reduced the abundance of their gut microbial species. When their normal microbiota was disturbed, they suffered increased weight gain, increased pathogen susceptibility, and increased mortality within hives.7


Earth Watch: Glyphosate, The Planet's Most Popular Herbicide, Leaves A Heavy Environmental Footprint

Reduces earthworm reproduction and function

Earthworms are often called soil engineers, helping to enhance soil nutrient availability, root penetration, and water filtration. So the fact that a team of Austrian researchers found Roundup exposure reduced the productivity and reproductive capabilities of two earthworm species is bad news for soil and plant health. The 2015 study published in the journal Scientific Reports showed that the surface casting activity (soil-enriching nutrient deposits)8 of one species was almost non-existent three weeks after exposure to Roundup, and reproduction of the other species declined by 56 percent after three months.9

Depletes mineral availability in food

Glyphosate was patented as a pipe cleaner before becoming the world’s most used herbicide because of its efficiency as a chelating agent.10 11 Now, that same function may be a “key factor in nutrient deficiencies in crops.” Studies have found that glyphosate residue or drift reduces the uptake of essential minerals like manganese, iron, and zinc in non-target plants, making them more susceptible to disease.12 These deficiencies continue through the food chain, impacting animal and human nutrition.13


What you can do

Because glyphosate is used in large amounts on genetically-modified crops, a common misconception is that by choosing non-GMO verified foods, you are avoiding glyphosate. In reality, it’s used on many conventional crops, even those that are certified non-GMO. Consequently, products containing ingredients that have never been genetically modified, like wheat and oats, consistently have high levels of glyphosate residue.14 15 While non-GMO verification is crucial in bringing awareness and transparency to the GMO issue, it is not an indicator of glyphosate levels in food. The best way to vote with your dollar against the environmental impacts of glyphosate while also reducing your exposure to it is to choose the certification that prohibits its use altogether: organic.16 17


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  2. Dempsey, Pam. “Breaking down the Use of Glyphosate in the U.S.” Investigate Midwest, 27 Aug. 2019,
  3. “Bill Would Ban LATE-HARVEST Spraying of Roundup Weedkiller on Oats.” Environmental Working Group, 10 Aug. 2021,….
  4. Benbrook, Charles M. “Trends in Glyphosate Herbicide Use in the United States and Globally.” Environmental Sciences Europe, Springer Berlin Heidelberg, 2 Feb. 2016,
  5. “Rhr: The Harmful Effects of Glyphosate-and How to Reduce Them.” Chris Kresser, 3 Aug. 2021,
  6. Smith, Daniel F. Q., et al. “Glyphosate Inhibits Melanization and Increases Susceptibility to Infection in Insects.” PLOS Biology, Public Library of Science,
  7. Motta, Erick V. S., et al. “Glyphosate Perturbs the Gut Microbiota of Honey Bees.” PNAS, National Academy of Sciences, 9 Oct. 2018,
  8. Tutaki, Emily, and New Zealand Ministry for Culture and Heritage Te Manatu Taonga. “Earthworm Casts.” Te Ara Encyclopedia of New Zealand – Te Ara Encyclopedia of New Zealand, Ministry for Culture and Heritage Te Manatu Taonga, 14 Nov. 2012,
  9. Gaupp-Berghausen, Mailin, et al. “Glyphosate-Based Herbicides Reduce the Activity and Reproduction of Earthworms and Lead to Increased Soil Nutrient Concentrations.” Nature News, Nature Publishing Group, 5 Aug. 2015,
  10. “The Toxic Trail of Glyphosate & the Organic Methods to MANAGE WEEDS!” Organic Without Boundaries, 1 July 2019,
  11. “A Short History of Glyphosate.” Organic Consumers Association, 6 Sept. 2017,
  12. Kanissery, Ramdas, et al. “Glyphosate: Its Environmental Persistence and Impact on Crop Health and Nutrition.” Plants (Basel, Switzerland), MDPI, 13 Nov. 2019,
  13. “Biochemical Functions of Micronutrients.” Advances in Obesity, Weight Management & Control, MedCrave Publishing, 27 Jan. 2017,
  14. “Glyphosate Contamination in Food Goes Far BEYOND OAT PRODUCTS.” Environmental Working Group, 10 Aug. 2021,….
  15. “Roundup for BREAKFAST, Part 2: In New TESTS, Weed Killer Found in All Kids' Cereals Sampled.” Environmental Working Group, 10 Aug. 2021,….
  16. Wilcox, Meg. “Organic Diets Quickly Reduce the Amount of Glyphosate in People's Bodies.” EHN, EHN, 8 Mar. 2021,
  17. “Organic's Top TEN Scientific Breakthroughs in 2015.” OTA, 28 Dec. 2015,