A short (7 pages) story "...et in pulverem reverteri" by Janusz Zajdel covers similar future. It doesnt end well.

> After the plastic breaks down, the long polymer chains are converted into small fragments, which Gu hopes will either be used to make new plastics or will safely dissolve into the environment

Or will they persist as microplastics that end up in my bloodstream and every organ of my body?