I’m contemplating throwing this question at Cecil, but wondered if it had been brought up on the message board.
Is Glyphosate really in our food supply to the extent that some sources are claiming? 200-300 ppb in my cereal seems to be way over the top, but then has any level been defined as a problem yet?
This looks like the study they’re talking about. And there are a lot of footnotes.
First and foremost, the EPA has identified a maximum Average Daily Intake of glyphosate not to exceed 75 micrograms/per kg of bodyweight. The EU standard is lower – 0.3 micrograms. Some will argue that even those numbers are too high, but that’s the standard for now.
Second, assuming your daily breakfast cereal is corn flakes, the number in the study is <75 ppb, which works out to about 1.5% of the FDA tolerance level. However, instant oatmeal samples were found with up to 1,327 ppb of glyphosate. That’s an astounding number, but still WAY below the FDA tolerance level of 30,000 ppb.
It appears that the highest numbers come not from using glyphosate as a herbicide, but from the older use of spraying crops a few days before harvest, so the leaves fall off, making harvest is easier. This paper calls it a “common practice.” I don’t know how common the practice is – I’ve never seen a farmer who wanted to spend the money to dessicate a crop unless the crop matured late and they were worried about getting the crop in before the weather turned bad.
That said, the study detected glyphosate levels >75 ppb (I’m guessing that was the lowest detectable level) in 10 out of 24 foods or ingredients tested - fewer than half. But this paper doesn’t break down how many samples of each food were tested. Clearly there’s a difference between one sample being tested with high levels, and 100 samples tested, all having high levels.
I have some other thoughts, but they aren’t GQ material.
good info - I’m not sure I feel better though… 
IMO you have nothing to worry about. But let’s consider the data.
Typically, acceptable exposure levels are set very conservatively. A mix of epidemiology and animal experiments will be done to figure out the maximum dose that dose not cause any detectable health problems. Then acceptable exposure levels are set a few orders of magnitude lower, to account for the possibility of unknown health effects, and for particularly vulnerable individuals (e.g. children or people with other health problems).
To give some specific numbers (from here), the minimum dose of glyphosate that definitely causes problems in animal studies (the “lowest observed effect level”, or LOEL) is ~1000 milligrams per kilogram body weight per day. The maximum dose of glyphosate that does not cause detectable problems (the “no observed effect level”, or LOEL) is 100-500 mg/kg/day. The precise numbers vary, depending on how the experiment was done.
Now I certainly wouldn’t want to expose myself to a dose that probably doesn’t cause obvious problems in rats. There could be more subtle effects that aren’t detectable in small experiments, or through disease or a quirk of my biology I might be particularly susceptible. Public health officials understand this, and set acceptable exposure figures much lower. The US Acceptable Daily Intake is set much, much lower, at 1 mg/kg/day in the US, and 0.5 mg/kg/day in the EU (it looks like kunilou mixed up the prefix, and has slightly different numbers from different agencies).
Now let’s say your entire diet consists of the instant oatmeal with the highest glyphosate levels. In round numbers, 500 g of instant oatmeal (dry) gives you ~2000 Calories, and at 2 ppm contains a whopping 1 mg of glyphosate. If you weigh a rather sleight 50 kg, you’re getting 0.02 mg/kg glyphosate.
That’s an order of magnitude lower than acceptable levels, and nearly four orders of magnitude lower than the lowest dose that ever caused an observable problem.
Maybe you’re worried that the “acceptable limits” are part of an evil conspiracy to corrupt your precious bodily fluids. Well, if you eat a much more reasonable diet, and perhaps take a few precautions like rinsing produce, your exposure will be a few more orders of magnitude lower.
You take much bigger risks every time you get in a car, or swim in a pool.
(FYI, technical terms help cut through the bullshit when searching for toxicology information. A search for “Glyphosate LOEL” pulls up mostly respectable sources, and the critical sources are at least citing real data.)
I don’t feel like doing the math or research, but I’d bet you could find all sorts of nasty stuff in higher concentrations in that cereal, in the milk you’re eating that cereal in, or in your orange juice or coffee you’re drinking along with it.
Take a look at the FDA’sDefect Levels Handbook. Warning: you may never use spices in your cooking again.
Some of it reads like a menu. 
For instance, with your 100 gram serving of tomato sauce you have your choice of:
Average of 30 or more fly eggs
OR
15 or more fly eggs and 1 or more maggots
OR
2 or more maggots
I think I’d order the 15 fly eggs, over easy, with one maggot, well done.
If you look further down, you can also have mold with it at no extra charge.
I have seen farmers dispute the claim that Roundup is commonly sprayed on crops as a dessicant. For example:
*"It is not routine for U.S. wheat producers to use Roundup, or other formulations of glyphosate, for pre-harvest applications. Most of the states in the wheat belt have drier climates, so getting additional help in maturing out the crop from a desiccant, like Roundup, isn’t necessary as much of the field will dry out and ripen on its own.
Although Roundup is labeled for pre-harvest applications, there is a standard pre-harvest interval (PHI) of at least seven to 14 days before harvest can take place, if the herbicide is applied to the wheat crop. Glyphosate, the active ingredient of Roundup, is used to control perennial weeds, although a very small percentage of producers also use it as a desiccant to evenly ripen a field of wheat for harvest."*
http://texaswheat.org/glyphosate-treated-wheat-claims-vs-facts.html
Alarmist reports about glyphosate residues showing up in food, tampons etc. have truly gotten ridiculous. Apart from ignoring the fact that the dose makes the poison (and as noted, such glyphosate levels are miniscule), these folks have falsely concluded that glyphosate is some kind of super-toxin. I doubt the “contamination” problem is worse than in pre-Roundup days, when much more toxic herbicides were used on crops.
Yeah, while it’s something you almost certainly don’t want to have colossal exposures to, it’s not inherently toxic to a person like it is to a plant. In plants glyphosate inhibits a specific plant enzyme that is involved with the synthesis of a handful of amino acids. It’s also only taken up through the leaves. So it’s extremely effective against vigorously growing leafy plants, like say… weeds, but not so much against other things that don’t have that particular enzyme.
That’s not to say that it’s absolutely non-toxic, but that it’s not directly lethal. A more accurate analogy is that glyphosate is to plants what nerve gas is to people- both block/inhibit enzymes and are extremely lethal to organisms that rely on those enzymes to live.
Whatever toxicity there is, is likely incidental and most likely made manifest through long-term, large-scale exposures, like being a farm worker who sprays glyphosate for decades. The amount you’d get in your food is so minute that you’re probably looking at more danger from whatever residual fallout that fell on that farmland in the 1950s than you are from the glyphosate.
(slight digression/rant)
There seems to be a sort of sympathetic magic concept on the part of the anti-“chemicals” crowd that says that since glyphosate is SO effective on plants, that it MUST be toxic to people in some similar way, and that this toxicity directly stems from its synthetic provenance. It’s just a bunch of ignorant hooey being thrown around by people who don’t understand it, and who are working entirely from gut feelings and uninformed fear, instead of from rational analysis and clear, informed thought.
I really wish that the govt. or media would quit giving them equal time; they’re the biological/toxicological equivalents of “alternative fact” purveyors.
Glyphosate gets shrieked about largely because its use is largely tied in with genetically modified glyphosate-resistant crops. And since GMO Bad and Monsanto Evil, glyphosate is Satan’s own herbicide causing grievous harm, as contrasted with pre-glyphosate farming where weeds were controlled by positive thoughts and fairy dust.
Here’s an article that describes earlier herbicides (and their FAR greater toxicity) and how their use has mostly fallen off dramatically since GM crops came on the scene (unfortunately, it seems that atrazine is still in heavy use, but we don’t hear scare stories about it even though its effects are way more concerning than glyphosate’s).
Anti-GMOers will have a better argument if 2,4-D use ramps up considerably due to introduction of 2,4-D resistant GM crops. That’s not something whose residues we want to see markedly boosted in soil, water and foods.
What it all boils down to (or should) is that 1) we’re in a constant battle against weeds and pests to produce the food we need, while development of resistance makes our chemical/genetic tools gradually obsolete, and 2) farmers need to use wise crop management techniques including crop rotation, instead of just growing one thing and relying on the Magic Spray Du Jour to solve their pest/weed problems.