Also the lead we dumped into the environment didn’t just go away when we stopped dumping it (actually we’re still dumping lead into the environment, just less nowadays). Lead was one of the oldest “forever chemicals” known for bioaccumulating before all those synthetic organo-halogen compounds came onto the scene.
Unfortunately low level poisining is still prevelant today. Banning it from use in gas (and paint) only reduced acute lead poisining https://en.m.wikipedia.org/wiki/Lead_poisoning#History
Also the lead we dumped into the environment didn’t just go away when we stopped dumping it (actually we’re still dumping lead into the environment, just less nowadays). Lead was one of the oldest “forever chemicals” known for bioaccumulating before all those synthetic organo-halogen compounds came onto the scene.