Microplastics continue to threaten the health of the Great Lakes
Researchers finding that microplastics in the form of microbeads and microfibers are causing immediate and long-term impacts on aquatic life in the Great Lakes.
Not so long ago, when we thought of plastic pollution in the oceans and Great Lakes, we were reminded of beverage bottles and the six-pack rings used in multi-packs of beverages strewn along shoreline as well as floating off-shore in clumps. In the past few years scientists have made us aware of a much less obvious and more insidious microplastic pollution in the form of microbeads and microfibers.
Microbeads are tiny plastic spheres, less than fve millimeters in diameter, which are used in beauty products such as facial scrubs and body washes and even in toothpastes. Their purpose is to scrub away dead skin and then wash down the drain. Because they are too tiny for water treatment plants to filter, they end up in the Great Lakes. According to a Scientific American article, the major worry is that the microbeads can resemble food for fish such as yellow perch or even turtles and seagulls. If the animals eat the inert beads, they can be deprived of nutrients from their natural diet or get lodged in their stomachs or intestines interfering with digestion. Lorena Rios-Mendoza of the University of Wisconsin-Superior and her team of researchers found 1,500 to 1.7 million plastic particles per square mile (2.5 square kilometers) in the Great Lakes with the highest concentration in Lake Erie. Rios also studies plastic debris and persistent organic pollutants (POPs) and reports that the bits of plastic are essentially “solid oil” and “absorb certain chemicals like a sponge.” The pollutants can remain in the environment for more than 50 years, accumulating in fish and other organisms and traveling up the food chain after being ingested by other species.
What can we do?
At this point there is no practical way to remove the microbeads already in the lakes. “Plastic doesn’t biodegrade so once it’s in the water, it doesn’t just disappear, “states Rio-Mendoza. Michigan State University Extension offers some tips for reducing the usage of products containing the troubling pollutant. Look for products that contain natural ingredients instead of plastics. Experts at Michigan State suggest looking at the ingredients for words like “polypropylene” and “polyethylene” and stop buying these products. They suggest that using non-microbead cleansing products and a washcloth can produce results as good as the products containing plastic exfolients. Some of the natural ingredients that are available include: pumice, oatmeal, apricot pits, and walnut husks. Fortunately, there are several cosmetic companies already using some of these natural materials in their products. Other companies are currently developing environmentally friendly alternatives. Several states have already banned the use of microbeads, the first being Illinois in 2014, and others have legislation pending (for example, Minnesota). Jennifer Daley, a research fellow at the University of Michigan maintains that we have only scratched the surface of the problems polymers may be posing to the Great Lakes.
Microfibers have received less attention than the problems posed by microbeads. Microfibers are extremely fine filaments made of petroleum-based materials like polyester and nylon which are woven into fabrics. More and more, these tiny bits of plastic which are synthetic fibers from garments, cleaning cloths, and other consumer products are showing up in sampling nets. “When we launder our clothes, some of the little microfibers will break off and go down the drain to the wastewater treatment facility and end up in our bodies of water,” stated Sherri “Sam” Mason, a chemist with the State University of New York at Fredonia. The Journal of Science and Technology reported in 2011 that fibers are so tiny that people don’t realize a fleece pullover can shed thousands of them with each washing. Microfibers account for about four percent of the plastic litter that Mason and her students have collected from the Great Lakes. These fibers seem to be getting stuck inside fish in ways that other plastics are not. “The longer the plastic remains inside an organism, the greater the likelihood that it will impact the organism in some way,” Mason said.
For more information about microplastics in the Great Lakes, read the MSU Extension article, “Microplastics are in the Great Lakes— where do they come from and are they a problem?”