Derek Lowe has a sensible article about glyphosphate, the herbicide otherwise known as Roundup. Glyphosate is scary: it’s a chemical, don’t you know, and it kills weeds, so who knows what it’s doing to your children and your cats; even scarier, some crops are being genetically modified to be resistant to glyphosate, and then proteins that protect against Roundup might end up in your cornflakes.
And now some people are raving that glyphosate causes autism, because of course every chemical compound that they don’t understand causes behavioral problems that we don’t like. We must have a scapegoat. It doesn’t matter that it has never been found to have an effect on humans.
An extensive scientific literature indicates that glyphosate is specifically not genotoxic, is not a carcinogen or a teratogen, nor has any specific adverse health effect ever been demonstrated to have been caused by exposure to or low-level consumption of glyphosate. It has little effect on non-target organisms other than plants; a contributing factor to this is that glyphosate inhibits an enzyme found in plants. This enzyme is not found in humans, other mammals, birds, fish, or insects.
The use of glyphosate on herbicide tolerant crops has proven problematic to anti-GMO activists since adoption of the technology promotes the switch to a chemical with a lower environmental impact quotient and lower toxicity.
Lowe explains the statistical nature of risk, and the cautious style of chemical classifications, that allows almost any chemical to be judged as risky to some degree, and feeds sensationalist misreadings. All the data really seems to be saying that it does nothing to animals, but let’s cover our bets and keep an eye on it.
I even have an anecdote about Roundup. We tried to see if it has any early teratogenic effects. The results are sadly unpublishable (for very bad reasons) so it’s safe to summarize them here.
We have a simple assay for developmental errors. Zebrafish pop out a bunch of eggs every morning when the lights come on, and we clean them up and separate them out into beakers, with about 100ml of water for 50 embryos. For our controls, we use fish tank water, the same stuff the adults are swimming around in. It’s got fish pee in it, bacteria, fungal spores, even tiny invertebrates (check your home aquarium water — would you drink it?). We use that because it does have some challenges for growing embryos, and provides a good background for comparisons — we lose 5-10% of the embryos, usually to fungal growth, in these situations.
I had a student who wanted to test local water sources for potential teratogens. So they collected jugs of water from nearby ponds and streams, which are rich with agricultural runoff. We then grew embryos in simple, unfiltered water from Lake Crystal, or the Pomme de Terre river, or nearby ponds, just to see if we had any preliminary effect worth pursuing. This is why we use crude tank water for the controls — those sources would also be complex and biologically rich.
Here’s the boring result: nothing happened. Fish grew happily in water from a shallow pond full of duck poop with an ethanol plant on one side and a dairy farm on the other, with no detectable disorders or effects on the rate of development. In fact, the pond water embryos were healthier in one sense — they had reduced mortality from fungal infections than embryos in tank water. Tentative explanation for that: tank water might specifically be a breeding ground for fungi that thrive on fish, or the fungi might be more sensitive to agricultural chemicals than the fish are. Anyway, it was a negative result.
Then we thought to push it, and see if we could get any deleterious effect from those agricultural chemicals, so I bought a gallon of Roundup at the hardware store, and we did a dilution series. Nope, nothing. We had embryos growing in a concentration of several percent glyphosate, and they didn’t seem to mind at all. We used concentrations that were approximately ten times what Monsanto recommends that you spray directly on your lawn, and the zebrafish didn’t care.
Now of course this was a limited and preliminary experiment. All we were examining was survival and basic morphology, and we were only looking at early developmental events, like gastrulation and neurulation and the earliest twitching behaviors, and we can say with some confidence that those were unaffected. We did not look at older animals, so if it were an endocrine disruptor (it isn’t) for instance, we wouldn’t know it. We also don’t have a test for fish autism.
I can also say that I wouldn’t drink glyphosate, but not because I’m afraid it would give me cancer. It’s because the straight stuff is kind of oily and smells nasty. So those stunts where people give Monsanto executives a glass of Roundup and dare them to drink it are really misleading — they’re not going to drink it because concentrated-just-about-anything is unpleasant.
I think the bottom line is that making a claim about the deleterious effects of a substance requires actual data, and not cherry-picking suggestive and vaguely defined effects.
It also says that the file drawer effect is a problem. I suspect there have been lots of preliminary experiments that see nothing, and are abandoned as unpublishable, like ours. That effect is also complicated. You can’t tell me just to take the data we got and publish that, because it really was just a quick pilot experiment to see if there was something worth pursuing. It’s not just that a negative result is unpublishable, but that we didn’t see enough of an effect to make it worth our while to invest enough time and effort to make the results thorough and robust enough to even consider getting it into publishable shape. And thus science staggers on.
Perhaps a silly question from a non-scientist, but would it be good if there was a place where the results of these kind of tests could be published?
In anti-GMO articles (such as in recent Consumer Reports, before I let my subscription expire) they show a graph of the dramatic increase of use of glyphosate since the introduction of “Roundup-Ready” GMO crops. What they do not show is use of alternative herbicides during the same time frame. Glyphosate vs. atrazine? Not even close. I would pick glyphosate in a heartbeat.
I wouldn’t drink a glass of any herbicide, whether it’s from Monsanto or happyorganichippie.com. The anti-GMO crowd tend to recommend vinegar as weed control, and I certainly wouldn’t drink a glass of that.
There are places where negative results can be published, and that’s a good thing. But this was a very preliminary test to see if there was anything interesting worth chasing down in detail. Getting these data in shape, with enough numbers and comparisons to make it robust, would require a lot of work on my part, all for a paper that would disappear into an archive somewhere.
And we’ve got other things that look more promising.
Let me guess: a high correlation between brain damage and voting Republican.
I was going to ask if you checked the fish for autism, as a joke, but you had it covered. I must say I agree it would be hard to publish in any of the more informal journals if they were peer reviewed. There are so many variables in it, but still a good effort with interesting results.
OK, so my fall-back joke is to say that you are obviously a tool of Big Ag. How much did they pay you?
“Glyphosphate”? I think you need to lower the ph of your post.
Roundup contains a surfactant, which has been found to be toxic to fish embryos and aquatic invertebrates. So I think you do need longer term follow-up studies. It’s called Promax and it’s an ethoxylated amine From the manufacturer:
Roundup PROMAX herbicide is not labeled for direct application to water and any such
application would be a violation of federal law and strictly prohibited. However, Roundup
PROMAX herbicide has been evaluated for toxicity to aquatic species and has been classified as
“slightly toxic” to aquatic invertebrates and “moderately toxic” to fish based on acute toxicity
studies with standard aquatic test species.
http://www.monsanto.com/products/documents/glyphosate-background-materials/promax_surfactant_overview.pdf
Just don’t drink MEPs’ urine! (I know that’s a rather specialised fetish, but I just thought I should warn you all.)
“Dilutions”? You going all homeopath on us? ;)
#8: That’s another variable. We didn’t even try to sort out all the factors found in local pond water — first step was to see if the whole gemisch had any interesting effects, and then if it did, start separating out the components. We didn’t have to get that far.
We also didn’t try to sort out all the chemicals in roundup — we just zapped embryos with the whole solution at various concentrations. We didn’t see any toxic effects at reasonable dilutions — I suppose we could have tried the undiluted stuff, but we also tried to adjust pH and have survivable volumes of, you know, water for the fish.
Sure, we can always suggest longer, more thorough studies, and I’m not claiming our pilot study was exhaustive (I even characterized it as an anecdote). I’m not motivated to do that work, though because a) if anything, it’s going to be tiny effects, and b) I’m not an environmental toxicologist, I was just looking to see if there were any useful experimental probes into the developmental processes that interest me. There weren’t.
Just a couple of days ago this article from The Intercept appeared on my feed. I like Greenwald’s site, but it struck me as a bit of fearmongering, though it would take hours to follow the numerous links and see if there’s anything wrong. Good to see this article tackles some of the same sources in a more scientifically informed way.
The Intercept article isn’t fearmongering at all. There has been a good deal of research showing toxicity of the so-called “inert” ingredients in Roundup. The most commonly used surfactant in Roundup formulations has been banned in Europe.
Also, notice how the suspect chemical always points to something very difficult to detect in the short term? Autism being the current demon of choice, but anything nebulous or long delayed in visibility will do.
The effect on animals is secondary. Glyphosate [and atrazine] have been blamed for a part of the decrease in milkweed which is a major factor in the decline of Monarch butterflies. Not good for the ecosystem, but the same can be said about mono-cropping and suburban development.
@15: “The effect on animals is secondary. Glyphosate [and atrazine] have been blamed for a part of the decrease in milkweed which is a major factor in the decline of Monarch butterflies.”
Yep.
I wonder if large quantities of surfactant could interfere with water’s ability to hold dissolved Oxygen. If so, that would be toxic to fish.
Moarscienceplz #17, here is a report from the UN Fisheries and Aquaculture Department. In section 3.2.6 surfactants are discussed. One paragraph is the most applicable.
Emphasis mine.
The lead paragraghs deal with two people who worked in agriculture for decades, so they are middle-aged or older, who contracted non-Hodgkin’s lymphoma, which you are more likely to get the older you are. Then it mentions another 4 people with nHL are suing Monsanto. So, out of the hundreds of thousands or more people who are exposed to Roundup chronically in America they have found 6 with a disease that happens to also appear in people who don’t get exposed to Roundup.
Smells like fearmongering to me.
Nerd @#18
Oh yeah, I didn’t even think about the lipids that make up cell membranes. So I guess huffing Dawn dishwashing soap is going to get scratched off my to-do list.
;-)
Actually, that molecule looks like it would make a decent chelating ligand for a transition metal, at least after it’s been deprotonated a couple of times. I’ll have to check that….
Yep…..http://pubs.acs.org/doi/abs/10.1021/ic00089a017
interesting I would have expected some small negative result from your tests. still I will keep my own use of roundup to a minimum as I do all such things
weed killers do do one thing really well that is reduce plant life. The soil plants are growing in where lots of herbicides are used has a noticeable difference from other soils. “wild soils” in the same area with the same mineral makeup as well as garden soil that has not been repeatedly exposed to weed killers. I am sure there are many factors involved what they all are I do not know.
The difference in the health of the embryos you found that were living in the pond water sounds like something I would pursue.
uncle frogy
Also, notice how the suspect chemical always points to something very difficult to detect in the short term? Autism being the current demon of choice, but anything nebulous or long delayed in visibility will do.
We would expect a correlation between the onset of the autism “epidemic” and use of glyphosate in various areas. I.e.: if the autism rates start to spike 3 years after the glyphosate goes into use, then that might actually be interesting.
Spoiler: no spike.
With respect to the comment above “I wouldn’t drink herbicide” – it depends on the mechanism of the herbicide. If I recall how glyphosate works it interferes with non resistant plants’ ability to produce necessary amino acids or something like that, so their cells die. It can’t possibly bother you unless you’re a plant of the type that depends on that particular process succeeding. Of course there may be additives. If you cut your glyphosate with tequila, you may get really fucked up.
The World Health Organization seems to disagree.
Is the WHO scaremongering?
Oops, my bad. I usually read linked articles before commenting, but I didn’t this time.
I’d be more worried about the weeds that are gaining resistance to glyphosphate. There are a lot of them, and plants like to share. Won’t be useful for too many more decades.
About the only herbicide I’d consider drinking is the one I use on our brick paving out back – boiling water. Very effective as a herbicide in paving, and it also kills ants. Plus, it has the added advantages of being cheap, and if I have any left over, I can get a cup of tea out of it.
They told us asbestos was perfectly safe.
They told us Thalidomide was perfectly safe.
They told us DDT was perfectly safe.
Don’t be so smug as to blame common people for reservations against the Chemiekeule and using Earth’s biosphere as one big test lab for gene editing. We’re burnt children who dread the fire.
We’ve lived through the post-WWII period and seen time and again the failure of Better Living Through Chemistry. Instead of creating a super-scientific paradise on Earth, the corporate-chemical complex only gave us acid rain, ozone holes and carcinogenic aluminum sprays.
Let me be clear, I know just as well the New Age woo-peddlers and anti-vaxxers are wrong and dangerous, but the reasonable skepticism out there against further industrial intrusion into our everyday lives doesn’t come out of nowhere, and sneering at it as if you aped Dawkins only makes things worse.
“fish autism” – you test for that by looking for disruptive behavior in fish schools.
I linked to multiple published studies by Rick Relyea here over a period of several years. That was in the context of extended discussions of surfactants (to paraphrase Ewan, “POEA? Never heard of it. Plan Colombia? No concern of mine.”)
While we may not currently know of a direct correlation between glyphosate and cancer, we do know of its harmful affects on the gut biome, which is an integral part of our immune and nervous systems:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4093745/
I used to bash the anti-GMO crowd just like any other scientist for lack of holy grail RCT studies on the subject, but have since done my own research and am now extremely interested in food and environmental health. Why do you think depression, diabetes, cardiovascular disease, alzheimer (type 3 diabetes) and obesity are so rampant in our “modern” era? It’s all in the food we eat! And part of it has to do with the shit they’re spraying on our food, i.e. glyphosate, which as pointed out in the above article disrupts aromatic amino acid production (phenylalanine, tyrosine, and tryptophan). As we know, tryptophan is essential for serotonin production and our gut microbes regulate our blood levels! (http://www.cell.com/cell/abstract/S0092-8674(15)00248-2). No wonder we are so “chemically imbalanced” with serotonin, and glyphosate is everywhere (even if you only eat organic foods).
As we also know, it’s not just chemicals like glyphosate either that affect our health. It’s our omega 6:3 ratio (our cell membranes function better with a much lower ratio than the standard American diet allows; I encourage everyone to read about DHA), vitamin D deficiency (http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152441) and chronically repeated spikes in blood sugar from refined carbohydrates over a lifetime (Alzheimer, diabetes and cardiovascular disease).
A lot of this stuff has been in our basic biochemistry textbooks for decades! The problem with waiting around for RCT’s to give us answers is that they may never happen! (Especially when you have multi-billion dollar companies like Monsanto behind their products). You also have to wade through the bullshit the scientific literature puts out (i.e. Lipitor’s 33% risk reduction in heart attacks over a 3.3 year period, where 2 people out of 100 had heart attacks while on Lipitor and 3 people had heart attacks while NOT taking Lipitor, which does equal a 33% risk reduction, but is a 1% absolute risk reduction really worth taking this drug for? Our medical views on cholesterol is another big topic of discussion).
Anyway, I’m a big fan of this blog, but wanted to point out that scientific disciplines don’t often have the best communication with one another, especially in the literature.
In those earlier discussions, a number of issues were raised by me and others related to biotech, including: concerns about the corporate control of land and seeds, particularly in relation to political and economic power and the reduction of hunger and poverty; corporate attempts to control research done on their products; corporate cooptation of government agencies and charitable foundations; corporate corruption of scientists and academic institutions; governments and foundations pushing agricultural methods on poor farmers and local communities rather than local democratic decisions being made about what to grow and how; crop diversity; biodiversity; weed resistance; pesticide effects on amphibians; the marginalization of non-GE approaches that might be preferable in any number of ways; the history of many of these companies of causing great environmental and human harm, lying, and refusing to take responsibility; crop resilience in the face of change related to global warming; crop yields; long-term sustainability; local sovereignty and self-sufficiency; insecurity resulting from the integration of local agriculture into capitalist markets and export-centered production; corporate influence on the media, including science publications; and on and on and on.
When the IAASTD, based on the work over three years of 400 experts from around the world, reached conclusions that were unacceptable to the agro-chemical companies, they walked out.
Talking just about this one issue concerning “glyphosphate, the herbicide otherwise known as Roundup” (which it isn’t – Roundup is glyphosate, which has long been off patent, plus surfactants, etc.) is somewhat like responding to criticisms of Evo Psych or “race realism” with general statements about human evolution. Yes, Roundup is chemicals. So is Agent Orange, another Monsanto product.
@PZ – So the results were too preliminary to publish. Thanks for replying.
Asbestos perfectly safe? They might have said that in good faith over a century ago, although even then there was anecdotal evidence at least that it was not benign. By the 1930’s there was solid evidence it caused cancer, so anyone claiming it was perfectly safe was lying through their teeth and/or unqualified to be making the claim. As for the other two examples, it is because of exactly those examples (plus many others from around the same time frame) that ‘modern’ pesticides and pharmaceuticals are subjected to the testing regimes that they are.
We should always be cautious adding new chemicals into the environment in industrial quantities, but there is significantly less cause for cynicism than some would have us believe.
I’m surprised to have gotten through the comments section without someone labeling PZ a Monsanto Shill.
so, then vaccines really do cause autism?
uh, did you miss the whole “correlation does not equal causation” part of your science education?
@ Ichthyic
Did I say anything about autism in my post? No. Anyone can see vaccines DO NOT CAUSE autism; however, there definitely IS a cause out there, whatever that may be (environmental, heavy metals, foods, gut-brain axis, etc.) we don’t yet know.
Also, it’s not just a correlation between carbohydrate intake and diabetes, CV disease and Alzheimer. This is in fact causation, my friend. So what did I miss? Are you assuming I don’t know how to critically evaluate the literature? They do teach statistics and epidemiology ad nauseam in medical school. What they don’t teach is nutrition. Do you know what advanced glycation end products are or what they do? Do you know what repeated spikes in blood sugar does to vascular endothelium? Why is diabetes a MAJOR risk factor for cardiovascular disease? Why does having diabetes DOUBLE your risk for Alzheimer?
https://www.ncbi.nlm.nih.gov/pubmed/?term=Diabetes+mellitus+and+the+risk+of+dementia%3A+The+Rotterdam+Study.+Neurology.+1999+Dec+10%3B53(9)%3A1937-42.
Think about it. Or wait around for that randomized controlled trial that will never happen.
JT-MD, 32
Care to provide some numbers for that claim about glyphosate being everywhere? And I’m also thinking you might have some issues with convincing SC (Salty Current) about mental illness being caused by any sort of chemical imbalances.
@38
Well, we have broadened the diagnosis for autism, it’s no wonder than the number of diagnoses have gone up. But so what if they have? Even if there is a cause, literally so what?
@ 39 – MattP
Thanks for calling me out on that… did not provide anything to back that up. But check out this study and tell me what you think: http://www.ncbi.nlm.nih.gov/pubmed/24549493
Regarding SC (Salty Current) views on mental illness – after skimming the link you sent and the blog it appears SC is suggesting there are no biologic markers (i.e. genes) to detect mental illness, which I completely agree with. This doesn’t have anything to do with “chemical imbalances” per se (I apologize for oversimplifying). What I propose, and many other health practitioners are only beginning to realize is that mental health has a significant environmental component (i.e. food!). For example, I know this is purely anecdotal, but think about it as you wish, I have several colleagues who have VERY successfully treated post-partum blues and depression with 10 grams of DHA daily. I would encourage everyone to read about this incredible molecule.
The bottom line is that I think we really need to look at what we’re eating. Our bodies are not evolutionarily designed to be littered with these pesticides (not to mention the standard American diet), which mess with our gut biome and may be responsible for a litany of disease. I think genetically modifying crops to be resistant to plant-based viruses/disease is probably okay, but modifying with pesticide genes and then spraying everything with pesticides is a completely different story.
Here is another article on glyphosates disruption of the rate-limiting step in the synthesis of the aromatic amino acids, tryptophan, tyrosine, and phenylalanine, in the shikimate pathway of bacteria, archaea and plants: http://www.ncbi.nlm.nih.gov/pubmed/16569053
JT-MD, 41
Then you need to re-read their comments and the responses to them. They believe psychiatry to be a dangerous pseudoscience; a marketing campaign by big pharma (not completely wrong there; I would love to ban direct marketing as it wastes money that could go toward R&D and/or decreasing drug costs); a frequent human rights violation (definite point when the non-violent are forcibly medicated where side effects suck). They do not believe there is any validity to mental illness because mental illnesses as defined in the DSM are based only on psychological function and not biological activity, which completely ignores the fact that the brain displays far greater complexity and variety in both structure and chemistry than other organs like the lung, liver, and kidney. We do not know the many constantly changing and interconnected causes of depression or anxiety or schizophrenia, so we cannot immediately determine the exact medication that will provide the greatest benefit with the minimum of side effects. Instead we have the current hit-or-miss system where those whose lives are disrupted by mental illness can get prescriptions for medications that may or may not provide any relief (start with one medication that messes with any number of neurotransmitters and observe effects for a few weeks/months as long as no dangerous side effects occur; if no relief, switch to a different drug or add another; repeat until find some combination that helps and alter over time as necessary). In my case, fluoxetine has been consistently somewhat effective, mirtazapine was disastrous, buspirone did absolutely nothing, and bupropion did little to nothing.
Anecdote indeed… and seriously, 10 grams (twenty 500mg capsules; fifty 200mg capsules) a day?
Another anecdote: 40mg of fluoxetine daily keeps my debilitating anxiety sufficiently decreased that I usually do not try to starve and/or shit myself to death; it essentially leaves me incapable of feeling like I’m being stabbed in the abdomen by a pitchfork wielding asshole anytime I get nervous. From 16yo to first starting medication at 25yo, my diet was fairly well-balanced (very little fast-food or frozen prepared stuff) with quite a bit of variety but my bowels remained so very, very disruptive (at least 4~6 very gassy, mucus-laden, very urgent movements a day just about every weekday). Bowels slowly calmed down within a few weeks of starting a low dose of fluoxetine for anxiety and severe depression (still cannot remember much of 2010~2012 because depression borked my memory). Stopped all treatment for a while because university health center psychiatrist adding mirtazapine fucked everything up (still cannot sleep well because of weird, vivid dreams, but still better than the 30 minute intervals of crap sleep between night-sweats and vivid dreams that seemed almost like flashbacks) which is when – about a year later – the anxiety/depression starving and shitting thing got really bad (lost ~30 pounds in 40~50 days). Used part of leftover supply to survive that episode and finally properly restarted fluoxetine many months later when I remembered that a general practitioner can usually prescribe it (psychiatrists in my area are not easy or cheap to see). What may actually have contributed to the start of the intestinal issues was a large dose of antibiotics that summer when my brother was having surgery and I absolutely had to get over a case of strep or bronchitis very quickly so as not to get him sick. The anxiety has always been a problem and the mild depression started in early middle school (sitting or lying alone in the back seat of the car after getting home from school crying and/or wrapping a seat belt around my neck for no damn reason – fun times).
Back to glyphosate: I no longer have access to any journals, so cannot read much of anything except the abstracts. Of course, even abstracts can sometimes be pretty useful and these two here and here are definitely something for my brain to chew on. Concentrations in downstream water supplies seem largely dependent on time between application and next rain/watering with significant run-off, and glyphosate preferentially binding with particulate matter suspended in the water means the actual concentration of available glyphosate in the water is rather limited. Fertilizer run-off seems to cause much more damage by fueling aglae blooms.
The amount of human introduced pesticide is tiny compared to what the plants have already evolved to protect themselves and the residues of human introduced pesticide that make it to the edible components sold in markets are tinier still. The vast majority of the pesticides in food are already produced naturally by the plant, and although humans have been intentionally propagating crops for several thousand years we are still pests that interfere with their survival. It is only natural that they will try to kill us for eating them.
Which is not particularly new. Glyphosate has long been known (20+ years) to interfere with EPSPS and the production of certain essential amino acids which is why glyphosate is not significantly harmful to anything that is not a plant or micro-organism that uses the shikimic acid pathway.
@MattP
The bacteria in our gut utilize the shikimate pathway.