Saturday, December 15, 2007

What Happens to Our Trash?

You probably take the trash out at least once a week. If you live in a house, then you most likely put it in a trash can, which you place at the curb in front of your house on trash day. Then once a week a large garbage truck will stop at your house and empty your trash into the truck. If you live in an apartment or condominium, then you probably put your trash into a larger metal bin that holds other people's trash also. Then, just like if you lived in a house, a garbage truck comes and empties all the trash into it and takes the trash away. This routine takes place everyday in the United States, but what ultimately happens to your trash?

Some of your trash can be recycled including plastic bottles, aluminum soda cans, glass bottles, newspaper, and more! These recyclable items are cleaned, processed, and eventually manufactured into new (and sometimes different) products that can be sold for a profit. For example, plastic bottles can be recycled and made into fleece clothing! In 2006, the Environmental Protection Agency estimated that over 251 million tons of solid waste was generated in the USA by all the residents, businesses, and institutions. That same year, over 82 million tons of trash was recycled!

Most of your trash will go to a landfill, which is a carefully designed structure that is built into or on top of the ground. Trash is isolated from the surrounding environment (e.g., groundwater, air, rain) through the use of both a bottom liner (usually made of clay or plastic) and a daily covering of soil on top of the buried trash. Keeping the trash isolated like this does not allow it to decompose (i.e., breakdown or degrade into smaller pieces) like it would if it was present in the environment as litter or in a compost pile. The purpose of a compost pile is to bury the trash in a way that it decomposes quickly through biodegradation. Some common items that we use everyday are biodegradable, which means these items can break down safely, and relatively quickly, by biological means into the raw materials of nature and disappear into the environment.

However, not all kinds of trash can break down easily and may remain unchanged in the environment for over 100 years or even forever! You will investigate this during the following experiment. With this in mind, we must be careful not to be wasteful since much of our trash may remain as trash forever. We should also strive to recycle as many relevant items (like paper, cans, glass bottles, etc.) as we can.

Little Lion Experiment:

In this experiment, you will determine if some of the common items that you throw away are biodegradable.

Items Needed

  • 5 plastic quart-sized bags (preferably with a zipper closure)
  • compost or garden soil (the soil can be from your actual garden or it can be obtained from a local recycling center or store)
  • water
  • 5 straws
  • a permanent marker
  • a variety of 5 materials to test for biodegradability. Some materials you could use include chewing gum with packaging, toilet and facial tissue, paper bags, newspaper, styrofoam, aluminum foil, leaves, grass clippings, cotton rags, banana peel; do not use animal products).


  1. Fill each of the plastic bags with three cups of uniformly moistened soil.
  2. Thoroughly wet each material to be tested and blot away any excess water from the surface.
  3. Place each of the testing materials into its own plastic bag. Make sure that the item is in good contact with the soil and can be easily observed through the bag.
  4. Insert one plastic straw at one edge of each bag, and zip the bag closed so that the straw sticks out of one side of the bag. This will allow some air into the bag. Be careful not to insert the end of the straw into the soil.
  5. Use the permanent marker to label each bag with the date, the material being tested, and soil type.
  6. Use the permanent marker to label each bag with the date, the material being tested, and soil type.
  7. Record your daily and weekly observations of each material for at least 1 month in a journal. You can continue the experiment for as long as you like.

Did any of the materials degrade after a week? After a month? You will find that some of the materials will fully degrade after a few weeks, while some may never degrade fully unless you continue the experiment for many years - over 100 years in some cases! Check out this website for a table that estimates how much time it takes for some commonly used products to biodegrade when they are in the environment as litter:

For disposal: Remove the straws from bags and add a chemical disinfectant (e.g., Lysol or Clorox) to the bags before throwing them out for good.