I know nothing about the NYC / Giuliani subject so no comment on that part. But I wanted to say I really appreciate your edit. I admire your willingness to check your own bias and then consider the possibility that it misled you.
My priors (from a Bayesian perspective) that lead, which in high doses provably can result in brain damage, can have more subtle effects on behavioral inhibition and executive function is pretty high, but I still do not know that I would feel confident saying the evidence is clear.
The 90's was when the first generation not exposed to tetraethyl lead reached their teens