Plastic Breaks Down in Ocean, after all -- and fast, into dangerous chemicals

Though ocean-borne plastic trash has a reputation as an indestructible, immortal environmental villain, scientists announced yesterday that some plastics actually decompose rapidly in the ocean. And, the researchers say, that's not a good thing.The team's new study is the first to show that degrading plastics are leaching potentially toxic chemicals such as bisphenol A into the seas, possibly threatening ocean animals, and us.

Scientists had previously thought plastics broke down only at very high temperatures and over hundreds of years.

The researchers behind a new study, however, found that plastic breaks down at cooler temperatures than expected, and within a year of the trash hitting the water. ...

The toxic compounds the team found don't occur naturally in the ocean, and the researchers thought plastic was the culprit.

The scientists later simulated the decomposition of polystyrene in the sea and found that it degraded at temperatures of 86 degrees Fahrenheit (30 degrees Celsius).

Left behind in the water were the same compounds detected in the ocean samples, such as styrene trimer, a polystyrene by-product, and bisphenol A, a chemical used in hard plastics such as reusable water bottles and the linings of aluminum cans.

Bisphenol A (BPA) has been shown to interfere with the reproductive systems of animals, while styrene monomer, a derivative of styrene trimer, is a suspected carcinogen.

The pollutants are likely to be more concentrated in areas heavily littered with plastic debris, such as ocean vortices, which occur where currents meet. ...

About 44 percent of all seabirds eat plastic, apparently by mistake, sometimes with fatal effects. And 267 marine species are affected by plastic garbage—animals are known to swallow plastic bags, which resemble jellyfish in mid-ocean, for example—according to a 2008 study in the journal Environmental Research by oceanographer and chemist Charles Moore, of the Algalita Marine Research Foundation.

Now, it seems, they also face the invisible threat of toxic, plastic-derived chemicals.

- via natgeo