Microplastics – What’s the big deal?
We’re a month into 2017. Who made New Year’s resolutions? And, who is still keeping them? I typically don’t make resolutions, but this year I did. And, I’m still onboard. My resolution is to reduce my use of plastics. And not just plastic bags and bottles. I’m also ridding my life of the toothpaste with scrubbing bubbles (plastic) and my exfoliating soap (more plastic).
Our world is surrounded by plastic. Since the mid-twentieth century, plastic has been an integral part of our lives. However, plastic debris is a major concern due to its wide spread use and its persistence in the environment.
When we think of plastic, we often envision the large plastic that we can see. Plastic bags, plastic cups, Styrofoam, you know…the big stuff. But plastic also comes in the millimeter size range. Inconspicuous plastic debris—called “microplastics” —has become a major concern because of its widespread presence in surface waters, sediments, and a diverse number or marine organisms.
Microplastics are plastic particles smaller than 1/5 of an inch in size. They include:
1) pieces degraded from larger plastic items, and include those made from polyethylene (plastic bags, bottles), polystyrene (food containers), nylon, polypropylene (fabrics), or polyvinyl chloride (water pipes);
2) nurdles, which are pre-production resin pellets used to manufacture plastic items and as fillers for toys and squishy pillows; and
3) microbeads, which are added to many personal care products (such as toothpaste and soap).
Major sources of microplastics in water bodies include wastewater from wastewater treatment plants (WWTPs) and runoff from urban, landfill, and industrial areas. Microplastics are difficult to remove during the wastewater treatment process because they are small, buoyant, and easily carried with wastewater to water bodies.
Accidental release is another notable source of microplastics. For example, accidental losses of industrial plastic resin pellets (industrial raw material) during shipping activities have been reported to be a source of microplastics in the ocean. Larger plastics over time degrade and fragment into smaller pieces.
As plastics fragment and disintegrate, microplastics become available for ingestion by a wide range of aquatic organisms and can potentially cause harm. Microplastics are small enough to be ingested by animals low in the food chain, such as free floating plankton. Ingested microplastics can result in a physical obstruction of the digestive system, which causes the animal to stop eating because it feels full. Animals that eat too much plastic die of starvation.
In laboratory studies, very small microplastics have also been shown to inhibit photosynthesis in microscopic algae. There is also a concern that toxic chemicals such as PCBs, PAHs, and bisphenol-A in the plastics themselves may transfer to marine organisms as they ingest microplastics, although more research is needed.
Both vertebrates (animals with backbones, including humans, fish, and birds) and invertebrates are at risk for toxic chemical contamination due to microplastic ingestions, but there is an additional concern for vertebrates because it’s possible the plastics or plastic-associated toxins may accumulate up the food chain. Some non-lethal effects of microplastics in vertebrates can include reduced reproductive fitness, reduced predator avoidance, and poor feeding ability.
So, can you see why I am sticking to my New Year’s resolution? If you’d like to jump onboard, here’s some tips:
• Cut back on the use of plastic, especially single-use plastics like water bottles, straws, and shopping bags.
• Read labels on personal care products (body wash, deodorant, toothpaste, facial scrub, makeup) and avoid products containing polyethylene.
• If possible, wear clothing made from natural materials rather than synthetic (acrylic, nylon, polyester, polypropylene) fabrics.
• Practice good litter control.
• Reduce, reuse, and recycle.
Source: Yun-Ya Yang, Ignacio A. Rodriguez-Jorquera, Maia McGuire, and Gurpal S. Toor. 2015. Contaminants in the Urban Environment: Microplastics, University of Florida, EDIS SL435. 6pp.
Additional resources: http://stjohns.ifas.ufl.edu/Sea/microplastics/multimedia.html