The Science of Dioxin

February 17, 2016 | Commercial Litigation | Complex Torts & Product Liability

Study Finds Glyphosate Is Most Used Pesticide in the United States

A study has concluded that the pesticide in the United States with the most “intensive and widespread use” is glyphosate, and that it likely will “remain the most widely applied pesticide worldwide for years to come.”

The Study

Charles M. Benbrook, formerly a research professor at Washington State University (“WSU”), is the author of “Trends in glyphosate herbicide use in the United States and globally,” published in Environmental Sciences Europe. He said that he found that, since 1974 in the United States, over 1.6 billion kilograms of glyphosate active ingredient have been applied, or 19 percent of the estimated global use of glyphosate. According to Dr. Benbrook, glyphosate use around the globe has risen almost 15-fold since so called “Roundup Ready” genetically engineered glyphosate-tolerant crops were introduced in 1996, and that two-thirds of the total volume of glyphosate applied in the United States from 1974 to 2014 has been sprayed in the last 10 years. Dr. Benbrook said that the corresponding share globally was 72 percent.

He also stated that, in 2014, farmers sprayed enough glyphosate to apply ~1.0 kg/ha (0.8 pound/acre) on every hectare of U.S.-cultivated cropland and nearly 0.53 kg/ha (0.47 pounds/acre) on all cropland worldwide.

Among other things, the study also stated:

  • With “few exceptions,” contemporary levels of glyphosate in the air, water, and food result in typical human exposure estimates that remain “well below” the “levels of concern” or “Acceptable Daily Intakes” established by regulatory bodies around the world;
  • Still, “a growing body of literature” points to “possible, adverse environmental, ecological, and human health consequences following exposure to glyphosate” and/or its primary metabolite, aminomethylphosphonic acid (“AMPA”); and
  • Environmental studies encompass “possible glyphosate impacts” on “soil microbial communities and earthworms, monarch butterflies, crustaceans, and honeybees.” (citations omitted)

The study acknowledged that “[f]or years, glyphosate has been regarded as among the least chronically toxic herbicides for mammals” and that glyphosate “is a moderate dose herbicide with relatively low acute and chronic mammalian toxicity, to the extent mammalian risk is accurately reflected in required EPA toxicology studies,” although it noted that, in 2015, glyphosate was classified as a “probable human carcinogen” by the International Agency for Research on Cancer.

The paper concluded by stating that the “frequency and levels of glyphosate and residues in a variety of foods are increasing, and more refined dietary-risk assessments should be carried out.”

It should be noted that, from June 2012 – May 2015, Dr. Benbrook served as a research professor at WSU and that his program there received funding from foundations, organic food companies, and coops. Dr. Benbrook acknowledged that he currently serves as an expert witness in litigation focused on the labeling of foods containing genetically engineered ingredients.

Learn more:

Monsanto Sues California to Prevent Listing of Glyphosate Under California’s Prop 65, at;

EFSA Concludes that Glyphosate Is “Unlikely to Pose a Carcinogenic Hazard to Humans,” at;

Monsanto Empanels Group to Review IARC Classification of Glyphosate, at


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