Lead poisoning was discovered in a year that is denoted with "B.C.E".
It wasn't news when the additive was invented for gasoline in the 20s, and it wasn't news all through the 70s.
Of course blame it on the corporations. On GM specifically, who also lobbied for jay-walking to become illegal so their cars would stop getting bad press for killing people.
If you live by a small airport frequented by personal aircraft, you're getting bombarded by lead.
Now just imagine living next to a teaching airport that does aerial laps around the neighborhood.