Over the next few days GallonDaily will highlight some of the emerging issues being discussed at the SETAC meeting in Long Beach, CA.

Plastics in the oceans received a significant amount of discussion at SETAC 2012 but not so much related to plastic bag use. It appears that a growing percentage of the microparticle plastics found in the oceans comes from our clothes. When clothes made of synthetic fibres are washed, the wash water may contain as much as 1900 microparticles of plastic fibre per litre. One estimate is that each year almost 50 tons of plastic microparticles from clothes washing are finding their way into the Pacific Ocean from cities west of the Rocky Mountains.

These particles are mostly so small that they bypass sewage treatment systems and end up in rivers and lakes. The small size means that the rate of sedimentation is very slow so they remain suspended in the water column for many years and are readily ingested by smaller organisms.

There’s no obvious solution to this problem. Filtering of wash water is probably not practical for particles of this microscopic size but the emerging research does suggest that manufacturers and brandowners of synthetic fibre clothing may be facing this issue in the years ahead.

Disclaimer: much of the work presented at SETAC is in progress and not yet peer reviewed. That’s why GallonDaily is not providing our usual links to published sources for this series of articles.