Plastic (not so) Fantastic

six pack copy

I bent down and picked up a plastic six-pack ring from the ground, cut it apart with my pocket knife and tossed it into the back of the car.

“What are you doing?” he asked.

“Cutting it up,” I replied.

“But why?”

“Ever seen those photos of ducks or other birds caught up in one of these?” He nodded, “Well if you cut them up before you trash them, that won’t happen.”

Back then, that was our major concern about discarded plastic items – six-pack rings, grocery bags, etc. Poor landfill practices and littering spread those things around and ‘dump chickens’ (seagulls) and other creatures got caught up in them. Newer practices and enforcement have greatly reduced the problems associated with landfills, but people haven’t changed.

A quick wander around the internet can show you that plastic trash is still a problem. Turtles, birds, fish – all kinds of creatures – still get enmeshed. The photos are horrible, as are the conditions, but I don’t agree that banning plastic bags or plastic straws is the solution.

Properly disposed and managed, trash should never get into the environment. However, anything that is littered, spilled and not cleaned up, or managed poorly so that critters get into it ends up on the ground. From the ground, it is washed or blown into drainages along with storm water, where it flows and maybe degrades its way downstream, ultimately ending up buried in sediment, caught in a lake or reservoir, or reaches the ocean. Clean Water Action states, “Most marine debris (80%) comes from trash and debris in urban runoff, i.e. land-based sources. Ocean-based sources, such as overboard discharges from ships and discarded fishing gear, account for the other 20%”.

Large pieces of plastic not only have a direct physical impact on marine life (entanglement, etc.), but can serve to change the actual marine environment. Floating plastics can serve to distribute pathogens or interfere with predator-prey relationships.

Plastics are degraded by exposure to UV rays, i.e.: sunlight. So, plastics in the ocean should degrade over time, even if it takes hundreds of years. But buried plastics will barely ever degrade at all. The organization CMORE has evaluated the degradation rates of various materials in the ocean. They estimate that a cardboard box takes 2 months to degrade; a newspaper – 6 weeks; a photo-degradable beverage holder – 6 months; plastic bags – 10-20 years; a plastic bottle – 100 years; a plastic beverage holder – 400 years; monofilament fishing line – 600 years.

However, degradation just reduces the plastic to its more elemental parts. William Harris, reporting on a Japanese study, noted, “researchers … found that plastic in warm ocean water can degrade in as little as a year. This doesn’t sound so bad until you realize those small bits of plastic are toxic chemicals such as bisphenol A (BPA) and PS oligomer. These end up in the guts of animals or wash up on shorelines, where humans are most likely to come into direct contact with the toxins.”

NOAA states, “Eventually, larger plastics will degrade into smaller and smaller pieces. These smaller plastic pieces (smaller than 5mm in size) are termed ‘microplastics’ and also include originally manufactured products such as microbeads found in cosmetics and personal care products, industrial scrubbers used for abrasive blast cleaning, and resin pellets used in the plastic manufacturing process.” They also note that ‘Microfibers’ generated from washing synthetic clothing made of polyester and nylon are another type of microplastic found in the oceans. Fish and other marine creatures ingest these microplastics, which are not digested and interfere with the animal’s ability to survive.

Plastics of all kinds are increasing in the world’s oceans. Various schemes are being tested to collect ocean plastics using mechanical techniques. These tend to focus on the massive trash vortexes found across the globe, where ocean currents concentrate floating trash. Some proposed systems are automatic, using wave action or currents to drive the trash into collection systems, and others are as basic as trawlers scooping up the trash. Each system also has the problem of what to do with the trash once collected.

When I was a kid, we had drinking straws that were paper. They weren’t as hardy as the modern-day plastic ones, but they worked most of the time. We had paper cups for soft drinks that usually came in glass bottles that could be returned for a deposit. We used paper bags to carry our groceries.

But lets not kid ourselves. This isn’t something that banning plastic straws or grocery bags will fix. Obviously we need to improve our storm water collection systems to screen out trash of many kinds. We also need to tighten our industrial and commercial material handling practices to minimize pollution of surface waters with plastics and microplastics.

But basically, it’s more of a people problem than a technology problem:

Plastic straws don’t kill fishes; people kill fishes.

Additional information:

Steve Tarlton, Down in the Dumps, 07/24/15, Writes of Nature

Steve Tarlton, Littering, 1/12/17, Writes of Nature

Steve Tarlton, Paper or Plastic, 7/28/16, Writes of Nature

Center for Microbial Oceanography: Research and Education

William Harris, How long does it take for plastics to biodegrade? How Stuff Works

Clean Water Action, The Problem of Marine Plastic Pollution

NOAA Marine Debris Program

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