The herbicide glyphosate is the main ingredient in Monsanto’s Roundup weed killer. This product has been used for more than 40 years on farms, residential lawns, and on golf courses. Environmentalists have been conducting a scaremongering campaign asking for a world-wide ban.
Glyphosate was classified as a probable human carcinogen by the World Health Organization (WHO) in March 2015, based on very sketchy evidence. However, in November 2015, the European Food Safety Authority determined that glyphosate was unlikely to pose a carcinogenic hazard to humans. In May 2016, the Joint Food and Agriculture Organization meeting on pesticide residues (another subdivision of the WHO), concluded that glyphosate was unlikely to pose a carcinogenic risk to humans from exposure through the diet.
A new study published December 12, 2017 by the Environmental Protection Agency concludes that glyphosate and its metabolites are not likely to be harmful to humans, neither as a carcinogen, nor harmful in other ways. You can read the entire 216-page report here.
The EPA reviewed thousands of studies relating to glyphosate effects on humans and other animals. The EPA’s main conclusion: “In summary, considering the entire range of information for the weight-of-evidence, the evidence outlined above to potentially support the ‘suggestive evidence of carcinogenic potential’ descriptor are contradicted by other studies of equal or higher quality and, therefore, the data do not support this cancer classification descriptor.” The strongest support is for “not likely to be carcinogenic to humans.” (See info graphic at end of this post.)
This story has been largely ignored by the mainstream media. I did find mention by Reuters which noted that the EPA reported that glyphosate is not likely to be carcinogenic to humans and found “no other meaningful risks to human health” when glyphosate, the world’s biggest-selling weed killer, is used according to its label instructions.
There was also mention in the LATimes which pointed out that the EPA finding contradicted “California regulators, who have included the chemical on the Proposition 65 list of probable carcinogens.”
As Steve Milloy pointed out in a June 19, 2017, Washington Times article, it’s time to dismantle the chemical scaremongering industry.
For additional background see Is glyphosate, used with some GM crops, dangerously toxic to humans? From the Genetic Literacy Project (link). They point out:
Toxicity is all about dosage; this applies to all substances. Some chemicals like aflatoxin and botulin are toxic in small doses, while others like vitamin D and caffeine have low toxicity, becoming dangerous only at higher doses.
Let’s take a closer look at glyphosate. Glyphosate is derived from an amino acid, glycine. It acts against plants by suppressing an essential biochemical mechanism commonly found in plants, but not in animals. According to the Extension Toxicology Network, a joint pesticide information project by Cornell University, Michigan State University, Oregon State University and University of California at Davis, and funded by US Department of Agriculture, glyphosate is non-volatile, minimizing exposure through inhalation, and undergoes little metabolism in the human body. If accidentally consumed, glyphosate is excreted mostly unchanged in feces and urine, so it doesn’t stay in the body and accumulate.
The EPA has also determined that glyphosate has “minimal” ecological effects. Glyphosate is only slightly toxic to birds and fish, and it binds tightly to the soil, reducing the possibilities of leaching. Microbes in the soil then break glyphosate down so it doesn’t accumulate in the soil. According to plant pathologist Steve Savage, glyphosate has also replaced mechanical tillage to destroy weeds, which is “a substantial positive for the environment because of reduced erosion and retention of soil carbon.”
So how toxic is glyphosate exactly? To examine toxicity, one must look at the LD50 value given to the chemical in question. LD50 is a standard measure of acute toxicity for chemicals, expressed in the amount of chemical (milligrams) per body weight (kg) that it took to kill fifty percent of a population of test animals. Because LD50 is a standard measure, it is used to compare toxicities of compounds; the lower the number, the more toxic it is.
Glyphosate has a LD50 of 5600 mg/kg based on oral ingestions in rats, according to EPA assessments (PDF), placing it in Toxicity Category III. The EPA ranks chemicals in four categories, I being the most toxic and IV being the least. The EPA has also found that glyphosate does not cause cancer. To compare, caffeine has a much lower LD50 of 192 mg/kg based on oral ingestions in rats.
These words are followed by a chart of LD50 for many common substances.
Food Scares – WHO vs Bacon
Genetically modified food, nothing to fear
GMO modified rice eliminates methane emissions and increases nutrition
UPDATE 10/11/18: Documents seen by Reuters show how a draft of a key section of the International Agency for Research on Cancer’s (IARC) assessment of glyphosate – a report that has prompted international disputes and multi-million-dollar lawsuits – underwent significant changes and deletions before the report was finalised and made public.
The edits identified by Reuters occurred in the chapter of IARC’s review focusing on animal studies. This chapter was important in IARC’s assessment of glyphosate, since it was in animal studies that IARC decided there was “sufficient” evidence of carcinogenicity.
One effect of the changes to the draft, reviewed by Reuters in a comparison with the published report, was the removal of multiple scientists’ conclusions that their studies had found no link between glyphosate and cancer in laboratory animals.
In one instance, a fresh statistical analysis was inserted – effectively reversing the original finding of a study being reviewed by IARC.
In another, a sentence in the draft referenced a pathology report ordered by experts at the U.S. Environmental Protection Agency. It noted the report “firmly” and “unanimously” agreed that the “compound” – glyphosate – had not caused abnormal growths in the mice being studied. In the final published IARC monograph, this sentence had been deleted.
Reuters found 10 significant changes that were made between the draft chapter on animal studies and the published version of IARC’s glyphosate assessment. In each case, a negative conclusion about glyphosate leading to tumors was either deleted or replaced with a neutral or positive one. Reuters was unable to determine who made the changes. (Source