Combining your two comments on plastic that I have read in the last week or two, with that of the nylon posts (from sylas) previously, yes, I thought the whole mystique around Atlantis was that of an "advanced" civilization that did not share any of it's technology (that must have made nylon and plastics). So bad assumption on my part I guess.
The rest made me curious on plastic front, how do you make plastic without distilling oil? How does one distill oil without industrialization?
How do you know how long it takes plastic to break down? Last I read, plastic is not "breaking down" as organics do, it just gets smaller and smaller and the evidence of it will never disappear. It's why microplastics are in everything, from the deepest oceans, to the highest peaks (including the
human blood stream).