That's incorrect, after invention of a leaded fuel, the first health concerns were raised in 1 or 2 years of production, and major heath investigation happened in 4 years time. We just lobbied (bribed) our way to continue using it regardless for half a century. And even a century later leaded fuel is widely used even in the USA, and probably even worse in other countries.

You're totally right, my choice of language should have been better. Thanks for the correction!

Is the situation all that different for plastics? I'm not sure. We've been running health studies on them for a while and the harmful effects of BPA, Teflon, PFAS, and the androgenic affects of most polymers are pretty well known at this point.

My point is mainly that how long we've been using something is not a great way to determine safety.