Two thoughts about agrochemicals consumed in our food.
1. The data suggest that glyphosate in grains, at concentrations present at the legally permitted level (30 ppm), disrupts the growth of many common gut microbes and encourages the growth of others. The adjuvants added to glyphosate in the final Roundup product are almost certainly significantly more toxic to gut microbes than glyphosate itself, and we have even less information about the impact of these.
Here are two of the papers from which I draw these conclusions, for anyone who is interested or wants to discuss them. (I would sincerely like to be persuaded that my interpretation is wrong or unlikely):
What effect this disruption of human gut flora might have on the immune system or metabolism has to my knowledge not been studied.
2. One of the things about agrochemical toxicity studies is that they are almost always only looking for gross pathological reactions to a given compound. Subtler reactions are not studied. If an agrochemical compound might make a consumer feel crummy but is otherwise nontoxic, that would be missed by the safety studies. To see how it could be possible for a compound to be nontoxic but still detrimental to a human’s sense of well-being, one only has to look at the antihypertensives in medicine: perhaps the most effective drugs that physicians have to improve patient outcomes in cardiovascular disease, the antihypertensives are nontoxic when given at therapeutic doses, but nonetheless make many people feel subjectively worse. This is part of the reason that patients sometimes do not take their antihypertensive medications.
Toxicity does not measure how a compound will make one subjectively feel; it measures gross disturbance in biological functioning. Thus, could agrochemicals cause subjective discomfort while being technically nontoxic at the concentrations commonly consumed in food? This is not an inconsequential question. If the purpose of agrochemicals is to improve human well-being, and if agrochemicals subjectively produced the opposite effect, this would call at least some aspect of their stated purpose into question. That this question has not been tested seems to me to be an important oversight.