Lead bans in America varied by state, the end date on that wikipedia page is a misleading number in that leaded gasoline use had been substantially reduced starting many years earlier. There was a major drop in leaded gasoline starting in the early 70s, by 1980 it was down over 50% from peak. By 1986 it was down over 90%.
I can't speak to the implementation of lead reduction leading to the outright ban in Brazil, but in the USA the outright ban was more of an after-the-fact recognition of the reality rather than an enforcement action.
You misunderstand. I meant the federal law was an after-the-fact-recognition of what many states had already done. Kind of like the way DOMA (defense of marriage act) was struck down by SCOTUS only after a bunch of states started recognizing gay marriage or how marijuana is likely to be legalized at the federal level only after enough states have already legalized it.
I can't speak to the implementation of lead reduction leading to the outright ban in Brazil, but in the USA the outright ban was more of an after-the-fact recognition of the reality rather than an enforcement action.