Crudely put, the idea is that lead in gasoline meant lead in auto fumes, which mean lead in the air. Lead in the air meant lead entering the body through the l

Crudely put, the idea is that lead in gasoline meant lead in auto fumes, which mean lead in the air. Lead in the air meant lead entering the body through the lungs, which meant mass low-grade lead poisoning / developmental problems. Less crudely put: http://en.wikipedia.org/wiki/Tetraethyllead#Toxicity http://en.wikipedia.org/wiki/Tetraethyllead#Toxicity