Why We Dump 28 Billion Pounds of Plastic into the Ocean

Hi I’m Dr. Sabrina Stierwalt, and I’m Everyday Einstein bringing you Quick and Dirty Tips to help you make sense of science.

Last week close to 8,000 people, including scientists from more than 50 countries, gathered in San Jose, California for the big annual meeting for the American Association for the Advancement of Science (AAAS). The AAAS meetings are unique because they bring together researchers from across all science disciplines, from biology to physics and chemistry to science education, to present their work.

One study highlighted at last week’s meeting and led by environmental engineer Jenna Jambeck was a look at just how much plastic we dump into the ocean. Jambeck and her team found that in 2010, 275 million metric tons of plastic were produced by the 192 coastal countries included in the study. Between 4.8 and 12.7 million metric tons (or between 10.6 and 28 billion pounds) of that plastic ended up in the ocean.

That’s between 360 and 950 times the weight of the Brooklyn Bridge in plastic!

Why isn’t all of this plastic being recycled? What can we do as individuals to reduce the amount of plastic that ends up in the ocean? Stay tuned to find out.

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We are dumping plastic into the ocean at an alarming rate, and these numbers will only get worse with population growth. Our oceanic trash piles are so big, we’re even naming them! The Great Pacific Garbage Patch is a patch (or more specifically several separate patches) of garbage that is over twice the size of Texas! 

It has been trapped by currents in the northern Pacific Ocean. The pile includes marine debris, chemical sludge, and, you guessed it, plastic.

To see why this plastic isn’t being recycled, we must first understand what makes up plastic.

What Is a Polymer?

Plastics are usually made up of polymers, or large chain molecules that can be broken up into many repeated parts. Most plastics are synthetic and require the use of petroleum-derived chemicals to produce, but some are natural.

The type of polymer or polymers that make up a specific plastic are noted by the resin identification code, or the small number you see printed inside the triangle on most plastic products. Numbers 1 through 6 refer to specific polymers, like polyethylene, polyvinyl chloride, or polypropylene, while the number 7 is used as a catchall for the remaining more than 2,000 kinds of polymers and polymer blends.

Plastics are very popular for packaging everyday items because they are easy to produce, relatively cheap, water-proof, and extremely versatile. We use them in our plumbing, our cars, our furniture, and our toys. In some cases, we can get multiple uses out of our plastics, but when it comes to recycling, not all plastics are created equal.

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Who Decides What Gets Recycled?

The type of plastic an object is made of is one of the most important determinations on whether or not that object will get reused or trashed. Part of the recycling process requires melting down used plastic items and merging them together to form newly ready-to-use plastic. Different polymers melt at different temperatures, however, and some, like the polyurethane in your mattress and the soles of your shoes, can only be melted and shaped once or else they can crack or even disintegrate.

These so-called thermoset plastics, are “set” once they are heated the first time and so can only be recycled if they are ground up and used as filler. However, since purer plastics (single polymers) are favored over polymer blends in the recycling process, adding this filler lowers the recycling potential for those future materials.

Some plastics don’t mix well when melted together and separate, much like oil and water do when mixed. These polymer layers can create structural issues in any second generation materials and are thus not desirable.

The shape of the container can also affect whether or not it gets recycled because it often reflects the purity of the plastic. Narrow-necked beverage bottles, for example, are almost always made out of polyethylene terephthalate or PETE (Code #1) with little to no additives or fillers. Because recycling facilities and those who purchase their materials know that these bottles can be trusted, they are almost always recycled, while other Code #1 containers are discarded since their purity is less certain.

Keep in mind though that plastic drinking bottles themselves are never made out of recyclable plastic so each one of those bottles you purchase in the store is made of brand new plastic. 

Although shape and polymer content matter, ultimately, the market decides what materials get recycled. If a plastic can be easily recycled, but there’s no market for it in its reused state, it is usually left for trash. On the other hand, some plastics like polystyrene (also called Styrofoam) can be recycled, but not cost effectively, and so instead end up in landfills or, unfortunately, our oceans.

3 Tips for Reducing your Plastic Use

Here are just 3 small (but effective) ways each one of us can reduce our plastic use:

1. Make purchases with the least amount of packaging whenever possible. Go for the eggs in the paper carton over those in Styrofoam. When buying fruit that needs to be peeled (like bananas, oranges, and avocados), don’t put it in an extra plastic bag from the produce department. You're just going to throw it away when you peel the skin. 

2. Give up the plastic items that aren’t necessary, like foregoing a straw in your drink and carrying your own reusable shopping bag or coffee cup.

3. When you can’t avoid plastic, buy things made of recycled plastic. This creates more demand and will encourage recycling centers to use more of the plastics they receive.

Check out the Domestic CEO's Go Green series for more easy tips on reducing the amount of trash your family creates.  

What strategies have you implemented to cut down on your use of plastic? Share them with us on the Everyday Einstein Facebook page or on my Twitter feed, where I’m @QDTeinstein. Or send me an email with your tips at everydayeinstein@quickanddirtytips.com.

Until next time, this is Dr. Sabrina Stierwalt with Everyday Einstein’s Quick and Dirty Tips for helping you make sense of science.