Yes, I said deaths, not depths. The recent Veritasium video below is saddening and frustrating.
Thomas Midgley Jr. (*) is arguably the single greatest mass murderer in human history, responsible for over 100 million people’s deaths and environmental disasters by two of his inventions: the addition of lead to gasoline (deaths by lead poisoning and reduced human intelligence by poisoning the environment, not counting the millions killed by speeding cars) and the creation of freon which caused the ozone hole in our atmosphere.
(* Amended: Midgley, not Charles Kettering who hired him. No one corrected me on my error, which tells me either no one’s a stickler for details or no one read this post. ^_^)
Lead has been known for about 7000 years of human civilization since we learnt to work metal. Its low melting point (328°C, about the same temperature as burning wood) made it easy to extract from rocks. But its use has poisoned the world, its rise in use demonstrated by ice cores in the Antarctic. Lead has been used as a roofing material and paint (re: the toxic fumes from the Notre Dame fire in Paris), in solder (welding, computers, etc.) and in water pipes. What politicians have done to the poor in Flint, Michigan should be called a crime agaist humanity.
How different would the world be (ourselves, the environment) if lead’s melting point were a thousand degrees higher, closer to nickel, iron, cobalt, and copper? Unlike radioactivity which can be contained and slowly deteriorates, lead (and arsenic, mercury, selenium, etc.) is a poison that stays permanently in the environment and human bodies. And we put it there in the name of profit.
At 18:10, he mentions the rise and decline of both lead levels in children and violent crime in society with a twenty year lag. But he doesn’t ask or mention why it declined.
In 1981, the US and other countries started phasing out and banning the use of lead as an additive in gasoline. By the mid 1990s, the majority of countries had stopped using it in cars. It was only in 2021 that Algeria, the last country still using leaded gas, finally banned it.