Sandwalk: Glyphosate (Roundup®) is safe

Monday, February 23, 2026

Glyphosate (Roundup®) is safe

There have been dozens of studies on the possible harmful effects of glyphosate. There are many well-funded organizations and tons of lawyers who would like nothing better than to sue Monsanto/Bayer into bankruptcy for promoting Roundup® and there are many environmental and health organizations who claim that glyphosate is harmful to humans.

The claims that glyphosate causes cancer and other ill effects in humans fall into three main categories.

Studies showing a link between glyphosate exposure and cancer: These are mostly studies on animals (rats and mice) that are exposed to large amounts of a certain chemical. Lots of chemicals are associated with cancer in such studies; for example, digesting huge amounts of salt results in cancer and so does ingesting large amounts of alcohol. In the case of glyphosate, most of the studies are not reproducible and in those that are, the effect (cancer) is small and the dosage of glyphosate is equivalent to drinking many liters of Roundup® every day for years. If you are stupid enough to do that then cancer is the least of your problems.
Juries have awarded millions to "victims" of glyphosate: Juries are notoriously bad at evaluating scientific controversies. Smart lawyers can always find scientists or pseudoscientists who are willing to support non-scientific claims. Juries can't recognize a scientific consensus as long as opponents get equal time on the witness stand. Besides, juries are usually very sympathetic to people who have suffered from cancer or any other disease and they are more than willing to award a large cash settlement from a company who they perceive as being able to afford it. Cases that have been decided by judges do not usually find that glyphosate is to blame. (For reasons that aren't clear to me, lawyer scam is a serious problem in the United States but less of a problem in other countries.)
Some agencies err on the side of caution: Some government agencies have at times published reports claiming that glyphosate may cause, or probably causes, cancer in humans. In some cases these agencies are cherry-picking a few animal studies that show an association between glyphosate and cancer and ignoring the majority that don't. In others, they are focusing on studies showing that megadoses of glyphosate cause problems while downplaying the fact that so do other chemicals like salt.

In discussing the possible harmful effects of glyphosate it's also important to recognize that establishing a true causal link between two things requires a mechanism that explains the linkage. For example, if glyphosate really causes cancer in humans then how does it do that? There is no known mechanism whereby a simple chemical like glyphosate can induce mutations in DNA.

Given the millions of farmers and suburban gardeners who slop Roundup® on themselves on a regular basis, you'd think it would be easy to come up with consistent and reproducible scientific evidence of some who have died of cancer or, at least suffered serious health problems because of exposure to glyphosate.

Hasn't happened. The vast majority of the scientific studies find no harmful effects of Roundup® on humans.

You may not like Monsanto/Bayer and genetically-modified food for ethical reasons or because the company exploits third-world farmers. These are valid, if controversial, reasons for opposing the spread of genetically-modified crops. Personally I don't have a problem with genetically modified foods, but I do have a problem with the power of large international for-profit companies.

Express your opposition, if it's rational and scientifically based, but don't fall into the trap of opposing GM foods because you think glyphosate is dangerous.

I'm attaching a list of other posts that I've made on this subject (see below). But I'm not really an expert on all the studies that have been done. My friend Ian Musgrave is a molecular pharmacologist¹ at the University of Adelaide in Australia. He IS an expert. He has written a lot about the false claims of the dangers of glyphosate.

Here's the link to an article from 2018 where he is responding to a court decision: Stop worrying and trust the evidence: it’s very unlikely Roundup causes cancer.

Here's a more recent article (2024) that was also prompted by a court decision where a judge found no evidence that Roundup causes cancer: Federal Court finds insufficient evidence Roundup weedkiller causes cancer. What does the science say?. It's a good read because it points out that there is a controversy within the scientific/medical community but it summarizes the reasons why we should be skeptical of claims about the harmful effects of glyphosate.

He discusses all the points I make at the top of this post.

Those who believe glyphosate causes cancer often refer to the International Agency for Research on Cancer’s (IARC) 2015 report that classified the herbicide as “probably carcinogenic to humans”. This was based on "convincing evidence that these agents cause cancer in laboratory animals."

However, IARC arrived at its conclusion using a narrower base of evidence than other peer-reviewed papers and governmental reviews. Also, unlike other regulatory bodies, it flags any possibility of causing cancer, rather than risk from plausible exposures.

The Food and Agriculture Organization/World Health Organization joint meeting on pesticide residues report in 2016 concluded that glyphosate was unlikely to pose a carcinogenic risk to humans from exposure through the diet.

... Australia’s regulator, the Australian Pesticides and Veterinary Medicines Authority, reviewed the safety of glyphosate after IARC’s determination and concluded, "there is no reliable evidence that products containing glyphosate pose a risk of causing cancer in humans."

Ian Mugrave is implying that most knowledgeable experts think that glyphosate is safe and I agree with him. This point of view needs to be covered in the media.

1. He's also passionately interested in observational astronomy.

1 comment :

Steve Watson said...: I heard something a couple of months ago to the effect that some study demonstrating the safety of glyphosate had undisclosed conflicts of interest (something like that; sorry I didn't pay it that much attention and don't recall the details). I assume that's what kicked off the current media interest. I'm assuming for the present that it was just one study called into question, and doesn't affect the overall picture.; Monday, February 23, 2026 5:41:00 PM

Quotations

The old argument of design in nature, as given by Paley, which formerly seemed to me to be so conclusive, fails, now that the law of natural selection has been discovered. We can no longer argue that, for instance, the beautiful hinge of a bivalve shell must have been made by an intelligent being, like the hinge of a door by man. There seems to be no more design in the variability of organic beings and in the action of natural selection, than in the course which the wind blows.Charles Darwin (c1880)

Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory.

Charles Darwin (1859)

Science reveals where religion conceals. Where religion purports to explain, it actually resorts to tautology. To assert that "God did it" is no more than an admission of ignorance dressed deceitfully as an explanation...

Peter Atkins

Quotations

The world is not inhabited exclusively by fools, and when a subject arouses intense interest, as this one has, something other than semantics is usually at stake. Stephen Jay Gould (1982)
I have championed contingency, and will continue to do so, because its large realm and legitimate claims have been so poorly attended by evolutionary scientists who cannot discern the beat of this different drummer while their brains and ears remain tuned to only the sounds of general theory. Stephen Jay Gould (2002) p.1339
The essence of Darwinism lies in its claim that natural selection creates the fit. Variation is ubiquitous and random in direction. It supplies raw material only. Natural selection directs the course of evolutionary change. Stephen Jay Gould (1977)
Rudyard Kipling asked how the leopard got its spots, the rhino its wrinkled skin. He called his answers "just-so stories." When evolutionists try to explain form and behavior, they also tell just-so stories—and the agent is natural selection. Virtuosity in invention replaces testability as the criterion for acceptance. Stephen Jay Gould (1980)
Since 'change of gene frequencies in populations' is the 'official' definition of evolution, randomness has transgressed Darwin's border and asserted itself as an agent of evolutionary change. Stephen Jay Gould (1983) p.335
The first commandment for all versions of NOMA might be summarized by stating: "Thou shalt not mix the magisteria by claiming that God directly ordains important events in the history of nature by special interference knowable only through revelation and not accessible to science." In common parlance, we refer to such special interference as "miracle"—operationally defined as a unique and temporary suspension of natural law to reorder the facts of nature by divine fiat. Stephen Jay Gould (1999) p.84

Quotations

My own view is that conclusions about the evolution of human behavior should be based on research at least as rigorous as that used in studying nonhuman animals. And if you read the animal behavior journals, you'll see that this requirement sets the bar pretty high, so that many assertions about evolutionary psychology sink without a trace.

Jerry Coyne
Why Evolution Is True

I once made the remark that two things disappeared in 1990: one was communism, the other was biochemistry and that only one of them should be allowed to come back.

Sydney Brenner
TIBS Dec. 2000

It is naïve to think that if a species' environment changes the species must adapt or else become extinct.... Just as a changed environment need not set in motion selection for new adaptations, new adaptations may evolve in an unchanging environment if new mutations arise that are superior to any pre-existing variations

Douglas Futuyma

One of the most frightening things in the Western world, and in this country in particular, is the number of people who believe in things that are scientifically false. If someone tells me that the earth is less than 10,000 years old, in my opinion he should see a psychiatrist.

Francis Crick

There will be no difficulty in computers being adapted to biology. There will be luddites. But they will be buried.

Sydney Brenner

An atheist before Darwin could have said, following Hume: 'I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one.' I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist

Richard Dawkins

Another curious aspect of the theory of evolution is that everybody thinks he understand it. I mean philosophers, social scientists, and so on. While in fact very few people understand it, actually as it stands, even as it stood when Darwin expressed it, and even less as we now may be able to understand it in biology.

Jacques Monod

The false view of evolution as a process of global optimizing has been applied literally by engineers who, taken in by a mistaken metaphor, have attempted to find globally optimal solutions to design problems by writing programs that model evolution by natural selection.

Richard Lewontin

More Recent Comments

Monday, February 23, 2026

Glyphosate (Roundup®) is safe

1 comment :