https://en.wikipedia.org/wiki/Hyperoxia
This was a screenshot I took months ago while watching a Geology Hub upload on YT. It was a lightbulb moment for my understanding of mass extinction events, (the largest was 250ma). I’ve referenced this multiple times, so thought I might share. Perhaps you find it as interesting as I do.
I’d think that the aerosolized lead from leaded gasoline did far worse than any plastic or change in CO₂. There’s still lots of volatile pollutants, like CO and hexavalent-anything out there.