However it is not widely known how much, so many people were mislead, for so long. It is no exaggeration to say that the evidence sadly, clearly, shows that leaded petrol was responsible for poisoning the whole planet, increasing crime and making most humans stupider than they otherwise would be. [Further reading is listed at the foot of this essay.]
Aided by the human inability to face and understand chronic issues, Thomas Midgley Junior and the Ethyl Corporation undertook one of the most egregious big lies in history (making the tobacco lobby's systematic lying look like a kindergarten effort) successfully, for decades, with the result that a simplistic mechanism to make internal combustion engines run without pre-detonation had the worst side effect in history.
"There had been three inquiries into the question of this spirit in the United States. Those committees had not found any actual evidence that harm had resulted from the ordinary use of Ethyl petrol. They did recommend that certain precautions should be adopted in regard to its manufacture and distribution in the garages. Before condemning the Ministry of Health the experience of the United States should be taken into consideration. During the whole of the five years in which the spirit had been in use there, no one had been able to discover a single case of lead poisoning resulting from the use of this substance, although its consumption ran into several hundred million gallons a year."VISCOUNT GAGE in the HOUSE OF LORDS March 29, 1928. [Extract from “The Times” 30/3/28]
Sadly, Viscount Gage's report was of a fool's paradise everyone was corraled into, with research manipulated and closed down by the Ethyl Corporation, and even at the end of the lie, delayed by a decade.
Thomas Midgley went on to develop CFCs, and collected a bunch of medals and awards thanks to his pioneering work as the most poisonous human ever. (If you think about it, a fictionalised account of his achievements would be regarded as impossible to believe, including the manner of his death.) He might be excused blame for the impact of CFCs on the grounds of ignorance, but there is do doubt he knew that leaded petrol was highly toxic and lied about it.
Thankfully there is a hero in this story as well, scientist Clair Cameron Patterson who was surprised to find the presence of lead across the environment while researching something else, and then became convinced that we had to stop using lead as widely as we were, despite being sidelined, attacked, slighted and belittled by the establishment manipulated by the Ethyl Corporation.
I mangled the famous Churchill speech about 'the few' above. In fact it was leaded fuel that was one of the factors that enabled the RAF's fighters to perform well enough to hold the line. It was just one of many aspects of the use of tetraethyl lead, which continues today in moderated, controlled form in piston aero-engine use as well.
But remember kids, whatever the nice Viscount says, lead is bad for you.