Subject: Re: leaded gas ban
One of the real heroes of the effort to eliminate lead pollution is Clair Patterson:
https://en.wikipedia.org/wiki/...

In the 1950s he was trying to obtain the age of the earth using the decay of uranium into lead as the clock and realized that there was too much lead present. He figured out that this sudden increase in environmental lead was coincident with the introduction of tetra-ethyl lead in gasoline as an anti-knock agent. He developed one of the first "clean rooms" at CalTech to minimize the environmental lead and was able to obtain an accurate age of the earth. He spent the rest of his academic career fighting for the removal of lead from consumer products. Shockingly, leaded gas is still used for small airplane engines, 40 years after it was banned from auto engines.

Rgds,
HH/Sean