In the US? Not really. Its sale is banned for use in cars. Wikipedia says there are a few exceptions for aircraft, farm equipment, and marine engines, but even in those fields I've never heard of it being used. It's also been pretty much phased out worldwide with a few tiny exceptions. What exactly are you referring to?

100LL is still a super common aviation fuel. It has a relatively low amount of tetra-ethyl lead, it it’s there.

I'm referring both to avgas (there's a measurable effect in populations near airfields) and leaded automobile fuel in a few countries in the world.

You're right, but only technically. Leaded gas is in use in GA aircraft only. The overall contribution this makes to atmospheric pollution is infinitesimal. Diesel garbage trucks are worse for society the amount of leaded gas we still burn.

where?