Plastic materials do not decompose by Julie Peller Ph.D.

By

Green Junction

As part of my research on plastic materials, my students have been analyzing plastic fragments and microplastics collected near the Lake Michigan shoreline. We narrowed our sampling locations to two areas in Northwest Indiana that are approximately 30-40 feet from the shore. The area of each collection is comparable to a small office space, an extremely small section of the Lake Michigan beaches. In our recent outing, we picked up hundreds of pieces of plastic but probably cleaned up only a fraction of this garbage. While most of the collected plastic pieces were on top of the sand, we also gathered up some buried pieces. 

We determine the type and extent of weathering and then utilize these real-world plastic fragments in several experiments. The identity of the plastic garbage has been informative and tells us that this plastic garbage most likely comes from the lake. The vast majority are the types of plastics that are lighter (less dense) than water. Consequently, they travel on top of the water and are transported via wave action and wind onto the sand. We collected many nurdles, which are the microplastics manufactured by plastic companies and used by other companies to make plastic stuff. Nurdles, shown in the 2nd photo, are mostly spherical in shape.

I want to emphasize that this is a tiny fraction of the plastic waste residing on our beaches, yet it is a true sign of our times – our world of plastics, materials that are not nature-compatible. Plastic materials break into smaller pieces but do not decompose. Unless we make significant changes, this plastic waste problem will only intensify. Most used plastic becomes waste, so the best action moving forward is reduction. Consider taking part in the international Plastic-free July campaign (more next week), working with others to implement solutions, and spreading the word about the enormous problems associated with the over-manufacturing of plastic materials. Mostly, please consider what this means for our youth, for their future..  

Julie Peller, Ph.D., is an environmental chemist (Professor of Chemistry at Valparaiso University ). She has been writing a weekly column called The Green Junction for the past seven years and is helping to move the call of Laudato Si to action forward. Her Research Interests are advanced oxidation for aqueous solutions, water quality analyses, emerging contaminants, air quality analyses, Lake Michigan shoreline challenges (Cladophora, water, and sediment contaminants), and student and citizen participation in environmental work.