Extensions and Enrichment

1. If you end the investigation after Part 4, you can use Parts 5 and 6 as an extension (see Concluding the Investigation).

2. See suggestions below under Resources.

3. Have students conduct independent study on the illegal trade in ozone-destroying compounds, for example, chlorofluorocarbons (CFCs) used in air conditioners. Altogether, CFC factories are still operating in at least 10 countries. These CFCs are illegally traded, as exemplified by:

• A black market has also developed in the United States. CFCs ranked second to illegal drugs in Custom Service seizures in 1997 in southern states like Texas, California and Florida. Out of the 150,000 tons of CFCs produced in the U.S. for export in 1996, some 10,000 tons were smuggled back into the U.S. from Mexico and sold at 10 times its purchase price in Mexico.

• CFC smugglers use sophisticated techniques to outwit customs officials. For example, they hide CFC cylinders in larger cylinders of a legal gas, add nitrogen to CFC cylinders to raise the pressure and thus make it appear as another substance, and they pump water into virgin CFCs to make it indistinguishable from (legal) recycled CFCs.

• Russia is a large source of CFCs, with annual trade amounts to around 30,000 tons in 1997 equivalent to a tenth of the legal trade in 1993 and enough to delay the healing of the ozone layer by several years. Europe is a major destination.

For additional information on illegal trade in CFCs see: http://www.cotf.edu/ete/modules/ozone/uvmenace.html

http://www.emagazine.com/november-december_1997/1197updates.html

http://www.gn.apc.org/ecosystem/ol9610.htm

Have you used this investigation?
How did you extend this investigation? Share your enrichment ideas with other teachers! Email your suggestions to Sarah Bednarz.