The ozone layer is what protects the earth from harmful radiation. It can be described as a huge shield, or a protecting bubble, for the earth. The radiation is UVB and UVC light that causes cancer and other less pleasant diseases. The ozone layer consists of oxygen atoms, combined three and three. Lately, CFC’s have been starting to destroy the ozone layer. CFC is short for chlorofluorocarbons, a compound that can be found in everyday house hold objects, such as hairspray and refrigerators.
What it does to ozone is that it’s making the layer thinner. Today, the ozone layer has several areas where potential holes are starting to appear and the only way to prevent the ozone layer from dissolving is to decrease the amount of CFC’s we let out. An easy way of doing to is to separate the dangerous objects from normal trash, like throwing your used hairspray bottle in the right bin and not among leftovers and paper towels (or whatever your trash can contains).

Funny animation created by Evelina Goransson and Carles Lopez explaining the problems and solutions for the ozone hole. kjhgfda by evencarles

Like it? Create your own at It's free and fun!

Carles Lopez and Evelina Gorasson pledge to refrain from excessive usage of choloroflourocarbons and want to encourage others to do so, too.

external image ozone_layer.jpg


Materials and Equipment

black permanent marker
milk carton
hole punch
magnifying lens
digital camera

Experimental Procedure

Save a milk carton to use for your experiment. Clean and dry the carton thoroughly before use.
Cut the carton into four flat pieces by cutting along the side seams of the carton. Cut each side into 3 square pieces, each piece will be approximately 3 inches long and 3 inches wide. You will have a total of 12 squares when you are done.
Using the hole punch, punch a hole in one corner of each square.
Tie a piece of string through the hole to make a loop for hanging the square up, on a tree branch for example.
Make a data sheet to record where you place your squares, and what data you later will collect from them:
Square 1
Square 2
Square 3
  • Decide on your four locations. Good locations are: your back yard, a busy street corner, your school, a park, a shopping center, a parking lot, etc.
  • Write the name of each location in your data table. Include the cross streets (Cedar and Sacramento Street), the address (1234 Maple Street) or the name of the location (Tilden Park or Valley Mall) in your table.
  • Using your black permanent marker, draw a 1 inch by 1 inch box in the center of the white side (what used to be the inside of the carton) of each square.
  • Write the name of the location on the bottom of each square, you will use three squares for each location.
  • At each location, find a place to hang up three of your collection squares. You can hang the squares from a tree branch, sign post, light post, or any other safe landmark. If the location is busy with traffic, be sure to have an adult with you for safety.
  • Before you hang each square up, spread a thin layer of vaseline in the black box in the center of each square with your finger. Hang up the collection square.
  • Leave your collection squares for 3–5 days. It is best to leave them on days when there is no rain, so if you hear it is going to rain be sure to go and collect them even if you have not left them out for a full five days.
  • After you have waited, it is time to collect your data from the squares.
  • Revisit each location bringing your data table, magnifying glass and a digital camera.
  • Remove the squares one at a time. Each time, use your magnifying glass to count the number of visible particles you see stuck in the Vaseline inside the boxed area. Write the number in your data table.
  • Take a picture of the square. If your camera has a micro-setting for close ups, the pictures will turn out better.
  • Proceed to the next square and/or location until you have collected all of your data and filled out your data table.
  • For each location you will have collected three sets of data, so you will want to average the data to get a better result. First add together the three counts and write the answer in the "TOTAL" box. Then divide this number by 3 and write the answer in the "Average" box.
  • Now you are ready to make a graph of your data. Make a bar graph by writing a scale for the number of particles on the left side (y-axis) and then by drawing a bar up to the correct number of particles for each location. Remember to label each bar of your graph, or make a color key.
  • Print out your photos for your poster too.
  • Which sites had the most particulate matter in the air? Is this what you expected? Were each of your three counts the same or different? What do you think this tells you about the relative air quality at each location?


Try testing the air quality at the same location over a course of several weeks, replacing the collection squares every few days. How does the air quality change over time? Compare your data with the air quality forecast in your local newspaper; how well do they match up?
A rainy day can be very cleansing for the air. Compare air samples before and after a rainy day; are there less particles? Where do you suppose those particles go? What does this have to do with acid rain?