In order for children to understand the importance of the ozone layer in preventing UV rays from reaching the Earth's surface, you can demonstrate the effects of ultraviolet radiation upon specially designed UV beads. Provide beads to children and have them string them and make bracelets. While indoors, the beads will be white. When exposed to the sun's rays, the beads will turn color. Explain to students that this is what happens when they get a sunburn. Have children conduct an experiment with sunscreen. Apply sunscreen to half the beads and take the bracelets outdoors. Ask the children what they see. The beads with the most color are the ones without sunscreen.
A variation of this experiment is to observe how sunglasses protect the eyes. Have children set a pair of UV protecting sunglasses over one of the bracelets and leave the other bracelet exposed. Ask children to explain what has happened and discuss how ultraviolet rays can harm eyes and why the ozone layer is important in protecting us.
Have students brainstorm about things that may affect the Earth's ozone layer. Manufacturing plants, cars, trucks, air conditioners, refrigerators, plastic foam products and some cleaning solvents all emit manmade chemicals called CFCs (chlorofluorocarbons), which damage Earth's protective ozone layer. Provide magazines or do online searches for pictures of things that might cause ozone damage. Provide a large classroom chart and have students cut and paste the items they find to the chart. Discuss how each item may cause ozone damage.
After discussing the causes of ozone depletion, have children conduct out-of-classroom surveys to find items in their homes and community that may damage the ozone layer. Ask students to identify these items and what possible substitutions people could use to reduce ozone damage. Have each student present findings through either an oral or written report.
Students in grades 6 through 12 can use real-time data from the U.S. Environmental Protection Agency to graph and predict air quality and changes in the ozone layer. Sponsored by the U.S. Environmental Agency and Stevens Institute of Technology, students can log on to the project website and work through the various interactive lesson plans, see real-time data collections and develop their own investigation into air quality in the town where they live. Lesson plans can be taken from the website or designed to incorporate data students receive and graph on the website.