you may remember back a decade or so when I wrote several posts on Alzheimer's/Dementia and its so called *discovery* along the French/German borders (thus the name origins) where they had started using coal tar slag for fertilizer back in the 1870's/80's...
I simply reversed engineered it all and traced it back... did these things exist before then? Most likely due to exposure to certain compounds found in slag (there are other contributing causes as well that are in large part a result of modern food production) from similar or other sources, albeit at a much, much lower rate of incidence.
the use of *slag* waste from energy/metal industries for fertilizer continues to this day...