Jun 13 2014

Moms for Pseudoscience – Roundup Edition

I really resent groups that transparently try to take the moral high ground, or appropriate an entire category of people, to bolster their personal ideology. The Thinking Moms Revolution (TMR) is one such group. Sorry, you don’t speak for moms, and your group is certainly not based on thoughtfullness.

A recent blog post in the HuffPo is clear pro-organic propaganda, borrowing the “mom” meme from TMR and another such group, Moms Across America. The theme of the blog is that glyphosate, the active ingredient in the herbicide Roundup, is a horrible toxin that is destroying our health, but luckily these plucky moms are going to take on the EPA and demand safety for our children (because the EPA obviously can’t do their job without help from non-scientist ideologues).

I went through a couple of overloaded irony meters reading the post, especially with this section: “Swaying Decision Makers With Science.” The article, rather, is a series of anecdotes, misrepresentations, and cherry-picked factoids masquerading as science for the purpose of ideological advocacy. No, eating organic is not going to cure your child of autism.

The author, Ronnie Cummins, who is the Director of the Organic Consumers Association, actually goes there. If you believe him then glyphosate (and by implication, not eating organic) causes autism, celiac disease, breast cancer, leaky-gut syndrome, Alzheimers, infertility, and non-Hodgkin’s lymphoma. It even worsens the toxicity of vaccines (in case you thought they were going to get off the hook).

The point of attaching “moms” to these claims is simple. If I criticize the pseudoscience he is peddling, then I am attacking moms. It’s its own logical fallacy, a false ad-hominem fallacy, taking an argument about science and evidence and falsely presenting it as if it is a personal attack against a beloved group.

RFK actually wrote an article (also in the HuffPo) called, “Attack on Mothers.” in case the point was being made too subtly.

As just one example of the shoddy reasoning used by Cummins is this statement: “His urine had 8.7 parts per billion of glyphosate — eight times more than is allowed in drinking water in the EU.”

This is another common mistake, or strategy, depending on your perspective – make false comparisons. What does the level in urine have to do with the allowable level in drinking water?

First, there is a little cherry picking going on here. The EPA reports:

The MCLG for glyphosate is 0.7 mg/L or 700 ppb. EPA has set this level of protection based on the best available science to prevent potential health problems.

Hmmm – they set their safety level at 700 ppb, but Cummings doesn’t mention that. Well, maybe the US is an outlier because we are actually run by Monsanto. The World Health Organization says:

WHO’s current position on glyphosate is that its health-based value is orders of magnitude higher than concentrations normally found in drinking-water, so that the establishment of a numerical guideline value is not deemed necessary.

In other words, they don’t even bother with a safety limit because the levels in drinking water are orders of magnitude below any concern.

What about the EU limit? From what I can find the EU limits any pesticide to 0.1 mg/L – that would equal 100 ppb, not the 1 ppb that Cummings claimed. But what’s a couple orders of magnitude?

In any case, this all has nothing to do with safe limits in the urine.The levels reported indicate exposure, but not necessarily any health risk.

His reporting of the science has links to article by Mercola, which says a lot. He also links to studies without really representing what they say. For example, in the paragraph where he claims that glyphosate makes vaccines more toxic, he links to this study looking at industrial exposure to multiple herbicides and pesticides (not just glyphosate). He provides no evidence to back up his allegedly scientific claims.

He also reports:

“Glyphosate is a chelator that deprives living things of vital nutrients, vitamins and minerals. This is how glyphosate kills plants.”

Really?  Every reference I found says:

“Once absorbed by the plant, glyphosate binds to and blocks the activity of the enzyme enolpyruvylshikimate-3-phosphate synthase (EPSPS). “

Blocking this enzyme keeps plants from growing and kills them. The enzyme is also not present in animals. It works better for his narrative, however, to say that glyphosate works by doing something that would be harmful to people, even if it’s not true. I also researched the specific claim that glyphosate is a chelator, and found a review that concludes:

(1) although there is conflicting literature on the effects of glyphosate on mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in GR crops is not affected by either the GR trait or by application of glyphosate; (2) most of the available data support the view that neither the GR transgenes nor glyphosate use in GR crops increases crop disease; and (3) yield data on GR crops do not support the hypotheses that there are substantive mineral nutrition or disease problems that are specific to GR crops.

Assuming someone was interested in finding out what the scientific evidence actually says, rather than creating a piece of scaremongering propaganda, what would one find in the published scientific literature?

A systematic review published on 2000 found:

Experimental evidence has shown that neither glyphosate nor AMPA bioaccumulates in any animal tissue. No significant toxicity occurred in acute, subchronic, and chronic studies.


Therefore, it is concluded that the use of Roundup herbicide does not result in adverse effects on development, reproduction, or endocrine systems in humans and other mammals. For purposes of risk assessment, no-observed-adverse-effect levels (NOAELs) were identified for all subchronic, chronic, developmental, and reproduction studies with glyphosate, AMPA, and POEA.

As pesticides go, glyphosate has very low toxicity, and any dose a person is likely to get exposed to is well below the safety limits. A 2012 review looking specifically at reproductive and developmental effects found:

In conclusion, the available literature shows no solid evidence linking glyphosate exposure to adverse developmental or reproductive effects at environmentally realistic exposure concentrations.

This includes exposure of farm workers spraying glyphosate, as the chemical is very poorly absorbed through the skin.

A 2011 review of epidemiological studies looking at the association of glyphosate and all non-cancer health outcomes found:

Our review found no evidence of a consistent pattern of positive associations indicating a causal relationship between any disease and exposure to glyphosate. Most reported associations were weak and not significantly different from 1.0.

And a 2012 study looking at cancer outcomes:

Our review found no consistent pattern of positive associations indicating a causal relationship between total cancer (in adults or children) or any site-specific cancer and exposure to glyphosate.


Of course the toxicity literature on any chemical is going to be complicated. When you look at the effects of any chemical on cells in a petri dish, you will usually see effects. If you give very high doses to animals, pushing the dose until toxicity occurs just to see what it takes and what happens, then of course you will find all kinds of toxicity.

This creates lots of studies with superficially scary results if you don’t know how to read the literature, or if you are looking for scary results to bolster your narrative.

The most relevant studies, however, are ones that look at health outcomes in humans at realistic exposure levels, including epidemiological studies looking for any correlation. Multiple reviews of these studies find no significant health concern for glyphosate. There are still some questions to be explored – for example studies showing a higher rate of lymphoma in workers exposed to multiple pesticides should be followed up.

Cummins article gets the science significantly wrong, cherry picks studies, cites dubious sources or sources that don’t back up his basic claims, and mixes this all in with emotional appeals and anecdotal evidence. The further irony here is that glyphosate appears to be one of the least toxic herbicides in use, and banning or restricting its use might result in increased use of more toxic herbicides.

Cummins seems hopeful that the mom groups were able to make their case and present their science before the EPA and that the EPA will now review the safety of glyphosate. I don’t share his prediction that the EPA will reverse the current regulation of glyphosate.

The EPA is usually very thorough at looking at all the relevant science and knowing how to put it into context. I don’t think they are going to be bamboozled by a horse and pony show. I guess we’ll see.

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