On one of the nature walks last week, David Lukas and his wife mentioned an article in Orion Magazine called Polymers are Forever.
The general gist of it is that there are enormous areas in the ocean that are covered in plastic trash, which seems to last just about forever. And eventually when plastics break down into their individual components, they are more toxic than their original components. Here's the stunning description of these areas of ocean trash, which Charles Moore, a captain, came across first in 1999 in the so-called Horse Latitudes:
By 2005, Moore was referring to the gyrating Pacific dump as 10 million square miles—nearly the size of Africa. It wasn’t the only one: the planet has six other major tropical oceanic gyres, all of them swirling with ugly debris. It was as if plastic exploded upon the world from a tiny seed after World War II and, like the Big Bang, was still expanding. Even if all production suddenly ceased, an astounding amount of the astoundingly durable stuff was already out there.