A report released in June 2022 by the Centers for Disease Control and Prevention (CDC) has revealed that over 80% of urine samples drawn for a U.S. health study contained glyphosate, a chemical used to kill weeds – and linked to cancer. The CDC analyzed 2,310 urine samples, from a representative group of Americans. From that sample, 1,885 showed detectable traces of the chemical. This is the first time the CDC has examined the extent of human exposure.
According to Alexis Temkin, a toxicologist at the Environmental Working Group, glyphosate is the most widely used herbicide in the U.S. It is the second most used herbicide in the home and garden market, according to the Environmental Protection Agency (EPA). According to The Guardian, U.S. farmers now spray over 200 million pounds of it on their fields annually.
Glyphosate, the active ingredient in the Roundup brand and many other products, was developed and patented by Monsanto in the 1970s, and registered as a pesticide in the U.S. in 1974. Glyphosate controls more than 150 weed species. Monsanto Co. increased its Roundup sales dramatically after introducing genetically engineered crops in the 1990s. The chemical is sprayed directly over food crops. Bayer has owned Roundup since it acquired Monsanto in 2018.
Glyphosate has been widely observed in soil, crop products, animals, humans and water. Residue has been found in many food products, including baby food. The Center for Environmental Health has found residue levels in many cereals, producing lawsuits.
Scientists began pressing in 2016 for more research on the health impact of the chemical. According to a 2017 paper led by Paul Mills, Professor of Family Medicine and Public Health at the University of California San Diego School of Medicine, glyphosate levels in human urine have risen steadily since the 1990s. In a 2019 study, Professor Lianne Sheppard, of the University of Washington’s Department of Environmental and Occupational Health Sciences, co-authored a 2019 paper summarizing 19 studies that indicated high levels of glyphosate in human urine.
Other agencies have called glyphosate a major health threat. In March 2015, the World Health Organization’s International Agency for Reseach on Cancer (IARC) stated that glyphosate is “probably carcinogenic to humans” and found “strong” evidence of genotoxicity for glyphosate and its formulations. Professor Sheppard has published research showing that glyphosate exposure increases the risk of non-Hodgkin lymphoma by 41 percent. Professor Mills has linked glyphosate to liver disease. The CDC notes that glyphosate has been associated with respiratory effects and developmental effects.
The US Environmental Protection Agency (EPA) is required, under the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”), to regulate pesticides, which include herbicides. Review is required every 15 years. The EPA has gone back and forth in its view on glyphosate. The EPA first approved glyphosate in 1974. In 1985, following experiments showing tumors on rodents, EPA classified glyphosate as a possible carcinogen. In 1991, EPA reinterpreted that study and found evidence of non-carcinogenicity. The EPA stated in its January 2020 Interim Registration Review that glyphosate is not a risk.
The EPA’s controversial decision has not held up in court. In May 2021, the Ninth Circuit Court of Appeals held that EPA approval of a pesticide’s label does not create immunity. On June 17, 2022, the Ninth Circuit Court of Appeals rejected the 2020 EPA analysis as “not supported by substantial evidence” and ordered a re-examination.
Monsanto and Bayer have long maintained that Roundup and glyphosate are safe. In many cases, they’ve gone to court, in multiple countries. Settlement efforts have also produced limited results. Bayer faces about 138,000 lawsuits, alleging their weed killer causes disease.
On June 21, 2022, the U.S. Supreme Court rejected a Bayer appeal without comment, ending an effort to terminate thousands of lawsuits claiming that Roundup causes cancer and Monsanto failed to warn. The appeal challenged a $25 million judgment in favor of Edwin Hardeman, upheld by the Ninth Circuit Court of Appeals in May 2021. Hardeman sued Monsanto in 2016, claiming he developed non-Hodgkin’s lymphoma after using Roundup to fight poison oak and other weeds on his California property. Roundup did not carry a cancer warning label, as required under California law. After a week-long trial in 2019, a unanimous jury found Monsanto liable and awarded Hardeman $80 million (later reduced by the judge to $25 million). The courts rejected the defendant’s argument that the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) bars additional label requirements by states.
Bayer has said that it will replace glyphosate in its residential products in 2023, but will still use it in farm products.