What are microplastics?
The National Oceanic and Atmospheric Administration defines microplastics as small pieces of plastic less than 5 mm in length, although scientists often consider slightly bigger pieces, up to 1.5 mm in length, microplastics as well.
Where do microplastics come from?
The better question might be, where don’t they come from? These pieces of plastic, often no bigger than a sesame seed, come from many sources but are all man-made. You’ve heard of the Five Gyres, heaps of waste swirling in the world’s oceans? Those objects, whether in those gyres or simply cast into the waterways, gradually degrade into smaller pieces. Lost fishing gear is a likely contributor. Another source of microplastics are synthetic fabrics, which shed into washing machines and then enter the wastewater system. Some cosmetics and personal care products are responsible for a subset of microplastics called microbeads.
What is the difference between microbeads and microplastics?
Microbeads are tiny beads of plastic found in cosmetics like exfoliating scrubs and some toothpastes, as well as byproducts of biomedical research. They started showing up in these products 50 years ago but didn’t come to the public’s attention as a hazard until 2013, when research showed millions of them were showing up in the Great Lakes. Maine was one of the first states to ban these petrochemicals, in March 2015, and the federal government followed suit, passing the Microbead-Free Waters Act of 2015 that December. The United Kingdom’s ban on microbeads goes into effect this July.
Why should we be worried about microplastics?
For starters, nobody wants to eat plastic. But plastic that has degraded due to exposure to the elements also provides a welcoming surface for other toxins, like PCBs (Polychlorinated biphenyls) to attach to. A fish that ingests the plastic in this tiny form may well pass it up the food chain, until it arrives on our dinner plates. The impact of ingesting microplastics on humans is being studied, but no conclusions have yet been reached.
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