An anonymous reader quotes a report from Ars Technica: Plastic is durable -- very, very durable --
which is why we like it. Since it started being mass-produced in the 1950s, annual production has increased 300-fold. Because plastic is so durable, when our kids grow up and we purge our toy chests, or even just when we finish a bottle of laundry detergent or shampoo, it doesn't actually go away. While we're recycling increasing amounts of plastic, a lot of it still ends up in the oceans. Floating garbage patches have brought some attention to the issue of our contamination of the seas. But it's not just the waters themselves that have ended up cluttered with plastic. A recent survey shows that a staggering amount of our stuff is coming ashore on the extremely remote Henderson Island. Henderson Island is a UNESCO World Heritage site in the Pitcairn Group of Islands in the South Pacific, roughly half way between New Zealand and Peru. According to UNESCO, Henderson is one of the best examples we have of an elevated coral atoll ecosystem. It was colonized by Polynesians between the 12th and 15th centuries but has been uninhabited by humans since then. It is of interest to evolutionary biologists because it has 10 plant species and four bird species that are only found there. Despite its uninhabited status and its extremely remote location, a recent survey of beach plastic on Henderson Island revealed that the island has the highest density of debris reported anywhere in the world: an estimated minimum of 37.7 million items weighing 17.6 tons. This represents the total amount of plastic that is produced in the world every 1.98 seconds.
Further reading: Here And Now