How Long Will it Take to Decompose?

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During our discussions of reducing, reusing and recycling in our classes at all grade levels, the subject of styrofoam and the length of time it takes to disintegrate always amazes the students. The students are in awe about the fact that 30% of landfills worldwide are filled with styrofoam items, and they are also concerned that our school contributes to this problem because we use styrofoam trays in our lunchroom.  We did an experiment and found out that  we throw away approximately 242,000 styrofoam trays and plastic bowls each school year. We thought it would be interesting to put different types of paper and styrofoam out on our playground to see how long it would take each item to decompose or disintegrate. Each item was held down with bricks so that they would not be blown away. We found a protected area that would allow our objects to stay in place and not be bothered by afternoon or weekend visitors to our playground. On the first day of the experiment, students hypothesized how long it would take each item to decompose or disintegrate. Every week, each class visited the site to note the condition of each item and recorded the information in their science notebook. 

These are our findings:

February 22nd      Experiment set up.

Feb. 29th     Construction paper, notebook paper,

                  newspaper and cardboard were crinkled because of

                  moisture in the air.

                  Compostable container and styrofoam no change.

Mar. 6th       Construction paper, notebook paper, newspaper

                  and cardboard were faded and crinkled more than

                  before.

                     Compostable container and styrofoam were dirtier

                 

but showed no change.

Mar. 20th    Construction paper and notebook paper  

                  were just about gone because we had 3 days of

                  heavy rain.  Cardboard, compostable container and

                 styrofoam still showed no change.

March 27th  Newspaper and cardboard slowly breaking down.

                  Compostable container and styrofoam show no

                  change. They are just dirtier.

April 3rd     Newspaper and cardboard slowly changing.

                Compostable container and styrofoam show no

                considerable change.

April 17th   Same as above

May 1st      Same as above

May 11th   Same as above

 

Students monitored and checked their hypothesis for each item each week. Some of the students were correct, or close to being correct, about the amount of time the construction paper and notebook paper would take to decompose. They were shocked that the newsprint was taking longer to decompose than they thought. They were on target for the cardboard, compostable container and styrofoam. They knew it would take a long time, and maybe even forever, for for some of the items to decompose. We are going to leave the experiment in place and check it in the fall to see the condition of the cardboard, compostable container and styrofoam. They predict that, unfortunately, the styrofoam will not show a marked changed.

 Catherine Southwick

Science/Math/Garden Coordinator