I wouldn't say that any of those are bullshit per se. Leaded gasoline reduced knocking/increased compression in contemporary engines, asbestos is a top-notch i

I wouldn't say that any of those are bullshit per se. Leaded gasoline reduced knocking/increased compression in contemporary engines, asbestos is a top-notch insulator, and DDT did kill a lot of bugs. Each just has really unfortunate side-effects, most of which were known at the time--if not appreciated widely enough.