Roundup (glyphosate), Cancer and the Courts – What Does It All Mean

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Robert Pavlis

The great debate about Roundup causing cancer had a major shakeup in August 2018, when a court ruling went against Monsanto (parent company is Bayer) and awarded $289 million to Dewayne Johnson because Roundup caused his non-Hodgkin’s lymphoma. The courts have reduced the settlement to $78 million and Monsanto is appealing that.

A few months later two more lawsuits reached the same conclusion.

For the general public this was proof positive that glyphosate, the active ingredient in Roundup causes cancer.

But what are the facts?

Roundup (glyphosate), Cancer and the Court Cases - What Does It All Mean
Roundup (glyphosate), Cancer and the Court Cases – What Does It All Mean?

Roundup and Glyphosate

Bayer, owner of Monsanto, has been releasing numerous products using the Roundup brand name. These do not all contain glyphosate, while others contain glyphosate and much more toxic herbicides. One type of Roundup now contains vinegar and no glyphosate. Gardeners need to clarify which product they are talking about when they use the word Roundup. This post is about the traditional product containing glyphosate.

Court vs Science

The original court case was juried. That means the result was an accumulation of the ideas and thoughts of the members of the jury. Most of these people have no training to evaluate scientific data or scientific reports.

Any conclusion they reached tells us nothing about the actual scientific facts.

What I found interesting is that many people on social media, did not understand this. Instead they considered a court case, lasting a few weeks, to be more compelling than 30 years of scientific scrutiny by thousands of scientists.

Soil Science for Gardeners book by Robert Pavlis

Proof Presented at Trial

What was presented at trial? Here is a glimpse of some of it.

Johnson’s own doctors — including non-Hodgkin’s lymphoma experts at Stanford University — agreed that the cause of the cancer was unknown.”

But the plaintiff’s expert, Chadi Nabhan, pointed to the fact that Johnson is considerably younger than typical patients with non-Hodgkin’s lymphoma. The leap was then made; he must have gotten cancer by an unusual cause, like Roundup.

This is a clear case of incorrect use of logic. Even Dr. Nabhan acknowledged that up to 90% of such cancers are from unknown causes and that he did not know the cause for most of his patients.

The jury joined the dots and saw a clear link between Johnson’s cancer and Roundup, even though no such link was presented.

Controversial IARC Report

The controversial 2015 International Agency for Research on Cancer report was also presented at court.

The findings of this report are often quoted by the general public, as proof that glyphosate causes cancer because it classified glyphosate as “probably carcinogenic.”

Much of the public reads this and concludes glyphosate causes cancer. But that is not what the report says. It says it is probably carcinogenic and that there is not enough evidence yet to label it carcinogenic.

By the way, alcohol, bacon and painting your house are classified as definitely causing cancer, by IARC. Why do we not have law suits against companies making these products? The emotion against these products is lacking.

The IARC report has been reviewed and discussed extensively and most authorities don’t agree with the conclusion for a number of reasons. The main reason is that the study ignored most of the scientific evidence and included only a couple dozen studies from the thousands available. Even three groups within the World Health Organization, which is the parent organization of IARC, disagree with the findings.

15 other agencies including the EPA, World Health Organization, European Food Safety Authority, and the European Chemical Agency have done extensive analysis of the science and concluded that there is NO evidence that glyphosate causes cancer.

Since the IARC report was released, a new study looking at 50,000 workers who handle glyphosate found no link between it and cancer, including non-Hodgkin’s lymphoma.

Clearly the experts in this field do not accept the IARC conclusions but the jury did.

Glyphosate in Water and Mothers Milk

I am sure you have seen reports about finding glyphosate in drinking water and mothers milk, complete with headlines designed to scare you and sell advertising.

Lab tests today are so sensitive we can find just about any chemical anywhere. Finding the chemical means nothing, unless the amounts found are high enough. I analyzed this in Unnatural Fear of Roundup – Understanding Small Numbers.

California Doctors Support Monsanto

The California Medical Association, California Dental Association and California Hospital Association have taken legal steps to correct the conclusions of the Johnson court case. They filed an amicus brief with the courts voicing their opinion.

In short, they point out that “the answer to complex scientific questions such as that which the jury was required to resolve in this case should be based on accepted scientific evidence and rigorous scientific reasoning, not speculation and emotion”. A more detailed discussion can be found here.

It is not clear if this step will have any impact on the appeal, but it is good to see this group step up.

Emotion vs Science

Roundup causing cancer is a hot topic. A significant portion of the population feels that Roundup causes cancer, but much of their argument is based on misinformation, or emotion. We know that it is human nature to cling to beliefs even in the face of conflicting facts. Its part of our DNA.

The science in this case is very clear. There is no evidence glyphosate causes cancer. The fact that the trial ignored this fact exposes a deep flaw in the US legal system and probably others.

It took no time at all for lawyers to see some easy money here, and by June 2019, there were 18,400 pending cases in the US. A local Canadian legal firm has been advertising for “anyone who used Roundup” to contact them and make some money. The ambulance chasers have been busy.


Please limit comments to this subject and not other concerns about Roundup.



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Robert Pavlis

I have been gardening my whole life and have a science background. Besides writing and speaking about gardening, I own and operate a 6 acre private garden called Aspen Grove Gardens which now has over 3,000 perennials, grasses, shrubs and trees. Yes--I am a plantaholic!

40 thoughts on “Roundup (glyphosate), Cancer and the Courts – What Does It All Mean”

  1. Thanks for this post. I’m primarily an organic gardener because on a most scale it’s just more pleasant. However, I do use roundup on poison ivy and your post makes me more comfortable about that decision.

  2. As a 25 year horticulture professional reading your articles and books is like a breath of fresh air. Finally somebody taking the science to the general gardening public. I always tell people if an article did not have .edu behind it in the search bar it was garbage just disreguard it. I will have to change my soap box speeches to include your work!

  3. The agriculture health study has shown farmers have an extremely elevated risk of getting non hogkins lymphoma than the general public.

    Glyphosate contaminates everything and gets in their homes due to both poor hygeine practices and likely pesticide drift from the broadcast applications they have been doing since the invention of round up ready crops.

  4. Thanks for that useful post Robert. I am an environmental scientist and a large part of my work involves restoring and maintaining degraded native ecosystems. Without herbicides that work would be extraordinarily expensive. Glyphosate is part of the mix and there has been a huge furore locally (NZ) against this chemical in recent years, with some councils even banning its use! A lot of the argument comes down to the court case you note (making public bodies very nervous about potential litigation obviously) and various popular literature such as White Wash. I’m not sure the science will win out in the present age but your succinct summary is very refreshing and helpful. Appreciate it.

  5. Emotion vs science? I wonder, Robert, are you a scientist? When did you do your degree, in the ’70s?

    Are you a botanist? Because if you were you’d know that weed killers, pesticides and inorganic fertilizers are far from good. Even if you ignore the harm of human contact with these products, they still ruin the chemistry of the soil and eventually leave the soil barren and unable to sustain a nitrogen cycle on its own. These products are designed that way, to make you reliant on them.

    I find it ironic that you are so trusting of infamously predatory companies like Monsanto/Bayer and yet quite smugly accuse the layers that won the case of disingenuous greed. Right below your accusations was advertising for your book.

    Emotion vs science indeed.

    • Yes I am scientist with degrees in Chemistry and Biochemistry. So I deal with facts.

      Re: “weed killers, pesticides and inorganic fertilizers ….. ruin the chemistry of the soil “. Not true. The chemistry in soil does not change. Chemistry is the interaction between molecules and having different substances in soil won’t change that.

      Re: “and eventually leave the soil barren and unable to sustain a nitrogen cycle on its own” – We have been using these compounds for many years, and the soil is still not barren – in fact, productivity is at an all time high. It is not soil that sustains the nitrogen cycle, but the microbes in soil. The nitrogen from inorganic fertilizers is used by the microbes as a nitrogen source. The problem with our soil is a lack of carbon in the form of organic matter, and tilling is the major cause of this.

      I think I might know a bit more about soil than you – My next book, Soil Science For Gardeners is now available for preorder.

      I never said I was trusting of Monsanto – you are making stuff up. What I did in this post was look at the facts generated by thousands of scientists around the world and the recorded facts of the court cases. Not a single fact in this post came from Monsanto.

      Yes, it is emotion vs science – and you just proved it. Look at your reply. Did you present even one study or reference that contradicted the science? No. That would have been a science-based reply. Instead you started to personally attack me instead of the facts – that is an emotional response.


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