[burpsnard]

Part of the controversy is around what constitutes a demonstration of safety.

One is "i fed it 50 rabbits and they were all fine the next morning";

another is "LD50 (50% died) within 24hrs of consuming X milligrams per kg of rabbit weight, which well above expected levels present in food";

Another is "more tumours in these 500 rats who were fed glyphosphate - exposed crops, than in these other 500 genetically identical rats fed the same but organic version, after 9 months"

[saalweachter]

I actually haven't seen this brought up for glyphosate but with respect to GMO crops, we've basically run an experiment where we've "autopsied" a billion livestock a year, and there was no observed increase in eg tumor rates when we transitioned from feeding them organic crops to GMO crops.

The same data probably applies to glyphosate, since the two go hand in hand (which is also why many activists get upset about glyphosate specifically, versus everything else that gets sprayed on crops, because it is associated with GMO glyphosate-resistant crops).

[AnimalMuppet]

But how old are those livestock? A year? Two? "Didn't cause tumors in the first two years" is a bit lower bar than I want for something that humans will eat long term.

[saalweachter]

Yeah, the sample set will be highly biased towards young animals. There will old animals as well -- the ultimate fate of the breeding stock is the same -- but I'm not familiar enough with the study I'm referencing to know if any problems in that subsample would be obvious.

It's not obvious to me that you would expect there to be problems that only show up after years but not in young animals with exposure from birth -- young animals are fast-growing, and fast-growing things are very susceptible to poisons of all flavors. (It's the basis of chemotherapy: you give the patient a poison, and the fast-growing cancer dies faster than the rest of the person.) Which is to say, a study of animals fed a substance for only the first tenth of their life is way, way more useful than a study that only looks at the second tenth, because of the rapid development during that time. Whether that makes the full lifespan data "useful incremental data", "vitally important data" or "uselessly redundant" I don't know enough to have an intuition on.

[Valgrim]

Except the GMO data definitely can't be applied to glyphosate. There is no reason GMOs should have the same metabolic effects as glyphosate.

[nordsieck]

> Except the GMO data definitely can't be applied to glyphosate. There is no reason GMOs should have the same metabolic effects as glyphosate.

One of the most prevalent genetic modifications to crops is glyphosate resistance[1].

I suppose it's possible that many farmers are buying glyphosate resistant crops but not using glyphosate as a weed control measure. However, that seems... unlikely.

___

1. https://www.ers.usda.gov/amber-waves/2018/december/trends-in...

[saalweachter]

You do have the practice in the far north (Saskatchewan, UK and some parts of the Dakotas) of using glyphosate as a desiccant on some grain crops to compensate for the short growing season, which probably affects the human food supply disproportionately (wheat is occasionally used for animal feed, but its use is trivial compared to corn and soy).

But given that the allowable limits for glyphosate in animal feeds is an order of magnitude or two higher than for people foods, I really would be surprised if livestock hasn't been eating a lot of it for the last twenty or thirty years.

[deogeo]

Yet another is "bees exposed to X were more vulnerable to parasite Y, but this only revealed itself in regions where parasite Y is present, and the effect could not be detected otherwise". I believe that's how they were able to produce so many studies saying neonicotinoids are safe for bees.