Sure, I think all of that is completely reasonable - and quite likely. The only thing that gives me concern in addition to this is leaded fuel and similar such

Sure, I think all of that is completely reasonable - and quite likely. The only thing that gives me concern in addition to this is leaded fuel and similar such stories over time. We now know longterm exposure to leaded fuel causes all sorts of nasty things including reduced IQ and reduced impulse control. Of course lead is a neurotoxin but neurotoxicity is all about the amount of exposure -- fluoride, for instance, is also a neurotoxin in sufficient quantities. The amount of lead fumes people were being exposed to was negligible on a parts per x basis. Try to put your mindset into a time before we knew this, and when governments and substantial amounts of industry funded research were mostly all declaring leaded fuel safe. The idea that exposure to negligible ambient levels of fumes could, over time, lead to lowered IQ, reduced impulse control, and other factors sounds really just quite absurd. In the past several decades now we've seen a huge array of companies now rushing to introduce all sorts of engineered consumables into the marketplace. This is not just genetic engineered food products, but also purely chemical compounds such as aspartame (first introduced in 1981), sucralose (first introduced in 1998), etc. And now factor in the recent discovery that our gut biome seems to be connected to far more than we ever thought in our body. And we have mostly no real clue whatsoever how these things are affecting people. Safety trials tend to be short term and only concerned with overt physical affects - a standard by which leaded fuel was also deemed harmless. This was what stood out to me about your comment. I think there are quite a large number of questions yet to be answered about how what we're eating in recent decades has been affecting us. And we're only just beginning to be able to pursue these answers at the same time that an ever greater number of engineered products are being introduced for consumption.