@nprofile1q... @nprofile1q... when we put tetra ethyl lead in the petrol worldwide it was a short term efficiency gain and profit generator (as TEL is cheaper than higher octane hydrocarbons), but in doing so we further polluted everywhere where motor vehicles went, poisoned people (especially kids/youths) to the point some committed criminally impulsive behaviour, and the stuff still clagged up engines if there was too much of it (this is mentioned in many of my 20th century books about automotive engineering and I have a fair few)

And yet it was the 21st century before it was gone (and some Global Majority countries only finally banned it from road fuel just a few years ago)