11.   The CFCs destroy ozone, and have created a marked thinning in the layer over the South Pole.

12.   This conflicts with theories that the atmosphere is pulled into the swirling hole, where its ozone is destroyed before it is spun back out.

13.   What the sources share in common is chlorine, which in reactive forms destroys ozone, then recombines to cause further destruction.

14.   Chemicals, such as those used in refrigeration, in fumigants and fuel additives are believed to destroy ozone.

15.   CFCs produce chlorine, which react in polar clouds to destroy ozone.

16.   Concern that the damage could spread prompted the ban on refrigerants and spray propellants that can destroy ozone.

17.   Despite their proof, some researchers questioned whether CFCs were responsible for destroying ozone.

18.   In both cases, the chemicals escape into the atmosphere and, through a complex chemical process, destroy ozone.

19.   Man-made chemicals believed to destroy ozone are called chloroflurocarbons, which are used in aerosols and refrigeration.

20.   Starting in October, warmer temperatures reduce the ability of chlorine and other gases to destroy ozone.