I remain shocked how we in the United States knowingly poisoned generations with leaded gasoline. https://www.smithsonianmag.com/smart-news/leaded-gas-poison-... In searching for a substance that made gasoline less flammable (and hence stopped it from igniting outside of a cylinder, i.e. "knocking") we tried everything including adding melted butter! Lead along with a lot of other things worked well but we went with…
Leaded petrol has been banned from sale at gas stations by every country in the world. [0] Unlike many important issues (such as overuse of antibiotics), it did receive the attention it deserved, at least eventually.
Work is ongoing in phasing out the use of leaded fuels in aviation. I think it's mostly a matter of testing existing aviation-approved engines to ensure they still perform as required on the various unleaded petrol blends they hope to transition to.
(As I understand it though, leaded paint is far more of a problem in terms of lead poisoning, than use of leaded petrol in aviation. I was still surprised the article made no mention of aviation.)
Aside: Someone at Cessna apparently thinks the transition away from leaded petrol will reduce carbon footprint. [1]
[0] https://www.nationalgeographic.com/environment/article/final...
[1] https://www.flyer.co.uk/cessna-singles-ok-to-use-unleaded-fu...