Microbeads are Not the Only Microplastics
Plastic particles smaller than 5 millimeters are ubiquitous in the aquatic environment. The sources of plastic particles are varied and include abrasives found in personal care products, “lint” from laundered synthetic garments, released industrial materials and weathered plastic debris, including shopping bags, food storage containers, drink bottles and plastic film.
In December 2015, President Obama signed a bill banning the use of microbeads in all personal care products. Most companies had already started phasing out microbeads due to reports of microplastics found in aquatic organisms and their associated potential health risk. However, microbeads are only a small fraction of microplastics found in monitoring studies, as observed by Richard Thompson and Dr. Mark Browne, two ecologists who noticed the majority of microplastics found in monitoring studies they conducted were fibers. Their research found that microplastic fibers predominantly came from clothes, rope, or packaging material. Dr. Browne was the first to research the sloughing of synthetic fibers from fabrics.
Patagonia, an outdoor clothing supplier, commissioned a study at the Bren School of Environmental Science and Management at the University of California, Santa Barbara by graduate student Stephanie Karba, to investigate whether or not fleeces and nylon jackets were contributing to microplastics in aquatic environments. In this yet-to-be-published study by Stephanie Karba, it was discovered that, during laundering, a single fleece jacket sheds as many as 250,000 synthetic fibers, whereas, an“aged” jacket released 80% more fibers than newer jackets. It was noted that “higher shedding in aged jackets is most likely due to the weakening of fibers as a result of wear, and higher shedding from the top-load washing machine is likely influenced by the central agitator found in these appliances.” Wastewater treatment plants on average remove 98% of microplastics as described in recent studies by US researcher Carr and colleagues (2016) and Scottish researchers Murphy and colleagues (2016). Polyester, the main fiber used in fleece, makes up the largest share of the plastics that are discharged in wasterwater effluent, but it only accounts for 10.8%of plastic found in the influent (Murphy et al., 2016).
The results from this Patagonia study will be presented at the Outdoor Retailer trade show in Salt Lake City this August in hopes to spur development of fibers that do not shed and avoid legislative action. Garment manufacturers are not the only stakeholders, since washing machines and washing detergents also play a role in the release of fibers during laundry, making this issue multi-faceted and complex.
I highlighted a few laundry strategies from the study mentioned to reduce shedding:
- Reduce the number of washings of synthetic garments
- Gentle cycle
- Shortest cycle
- Coolest temperature
- Gentle detergent
- Front loader without agitator
- Top loader without agitator
In other news, San Francisco just made an ordinance that requires food vendors, restaurants, delis, fast food establishments, vendors at fairs and food trucks in San Francisco to use compostable or recyclable to-go containers. Food vendors will be prohibited from using polystyrene foam (Styrofoam) for food service starting January 1, 2017. This is an aggressive step up from the various municipalities that ban or charge for plastic bags.
There seems to be a great deal of awareness and activism to curb our appetite for disposable plastic. Perhaps the education and possible changes to the garment, washing machine and clothing detergent industries could help reduce the influx of plastics into our waterways.
This blog post is in follow up to a newsletter article I wrote this spring that discussed microplastics and microplastic regulations happening in 2016. We are tracking, and will continue to track, the issue of microplastics in the environment here at Waterborne. Please reach out with any questions or comments at firstname.lastname@example.org.
Carr, S.A., Liu, J., and Tesoro, A.G. (2016). Transport and fate of microplastic particles in wastewater treatment plants. Water Research 91, 174–182.
Murphy, F., Ewins, C., Carbonnier, F., and Quinn, B. (2016). Wastewater Treatment Works (WwTW) as a Source of Microplastics in the Aquatic Environment. Environ. Sci. Technol.