Urban Environmental Quality and Human Health: Conceiving a Sustainable Future

Impact of Plastics on the Environment

What happens to plastics when we are done with them? The students will say that we throw them away or recycle them. Plastics that are thrown away end up in our landfills and most surprisingly the ocean. Students can be motivated or "hooked" into the issue by viewing a video of, "The Pacific Garbage Patch." ³

Nine percent of the trash in landfills is plastic.⁴ Polymers and plastics that degrade in a landfill release carbon dioxide and/or methane into the air.⁵ Those that remain unchanged or that do not degrade take up precious space in our already overflowing landfills. The other pressing issue is leachate. Leachate is the liquid that leaches or drains into the ground from landfills.⁶ Liquids that leak into the ground get into the groundwater which flows into rivers, lakes, and other bodies of water (see appendix for diagram). This liquid smells and is contaminated with many chemicals that poison our ecosystem.

The North Pacific subtropical gyre is a 10 million square mile oval located north of Hawaii that sailors avoid due to the clockwise swirl of currents that make passage difficult. It is also the home to an area of enough plastic debris to equal twice the size of Texas hence, the name, "The Pacific Garbage Patch". This is the largest landfill in the world.⁷ It is estimated that ninety percent of the trash floating in the ocean is plastic.⁸

Plastic is not biodegradable but photodegradable: it breaks down into small bits when exposed to sun and water. In this area the ratio of plastic bits to plankton is six to one. So, you can imagine that a hungry animal could easily ingest a great deal of plastic. This plastic will block their digestive systems as well as possibly contaminate them, the water and air with the chemicals in plastic.

These tiny bits of plastic are called nurdles or mermaid tears ⁹ (ask the students why they think the term "mermaid tears" is used). Nurdles are preproduction plastic pellets, plastic resin, or bits from larger plastic pieces that have broken down. When plastics break down in the ocean, landfills or in food packaging the chemicals that were added in manufacturing are released into the water, air, food and products.

There are some staggering statistics on the amounts of plastics and plasticizers being produced in the U.S. In 2002, nearly two hundred and forty million pounds of DEHP was used in the production of fourteen and a half billion pounds of PVC (used for food packaging, house siding, water pipes, coating on electrical lines, and mattress covers). Two point three billion pounds of BPA was produced in 2006. Human consumption of plastic may reach three hundred pounds per person by the year 2010.¹⁰ Since only about five percent of plastics are recycled each year what is happening to the billions of pounds that are not recycled? The enormous amount of plastic being produced and discarded is cause for alarm.

BPA is one of the most common chemicals found in groundwater due to lack of recycling. When products are not recycled they end up in landfills which leach chemicals into the groundwater that eventually flows into rivers and streams.

DEHP is a phthalate added to PVC as a plasticizer (earlier I stated that plasticizers are added to hard plastics like PVC to give them flexibility). There are six phthalate plasticizers on the market however; DEHP is the most widely used. Unfortunately, the fifteen billion pounds of PVC produced each year are difficult to recycle due to the chemical make up. It ends being incinerated or in landfills and the DEHP is leached into the groundwater and air. DEHP is found in human fluids.¹¹