How have plastics substituted for lead in paint and gasoline additives (genuinely curious)?

Pipes I'm quite familiar with (lead/PVC). It's my understanding gas tends to use ethanol as a substitute, not plastics? No clue about paint. It's also my understanding the vast majority of microplastics found are for plastics designed to be small (e.g. micro beads in soaps) and clothing (e.g. polyester material strands) and not from fragments of larger plastic components (e.g. PVC pipes).

Gasoline is not substituted with ethanol. It's a combination of improved engine design and non-lead additives to provide the necessary anti-detonation properties.

I meant ethanol as one of the substitutes for lead (previously a common additive) in gasoline which was often used before to better control compression and combustion. Are microplastics or plastics used to better control combusion engines now?

I meant ethanol was not substituted for lead AFAIK - the lead was replaced with MTBE in practice, and then the story of ethanol blending has more to do with CO2 emissions reduction (or in the case of Australia, a conservative prime minister somehow getting away with a levy on milk to bail out his mate's ethanol plant and mandating 10% blending in fuel at the pumps).

Ethanol was the original anti knock agent, but afaik was actually replaced by tetraethyl lead originally.

Interesting, thanks.

That's kind of a false dichotomy though, isn't it?

Huh? i assumed we went from lead to copper and not straight to plastic

Copper is toxic, too. Don't overeat liver!

Then we'd just complain about an overabundance of minerals in our body.

Seeing that humans have a far higher tolerance for copper compared to other animals we can assume that this was indeed at some point in our history a major problem.

In germany we have a ton of copper pipes and there are no copper minerals going into the water as soon as the oxidatinlayer is there.

Its still standard having copper pipes here; we use plastic after the water arrives at the room.