Chlorofluorocarbons (CFCs) were once considered as a wonder chemical that can be used in many products. CFCs aren't flammable, they are not very toxic, and are relatively inexpensive to produce. In fact, 50 years ago they could be found as refrigerants, solvents and blowing agents, but back then they had no idea that CFCs would eventually cause the breakdown of the ozone layer over Antarctica.
In 1970 researchers started to observe different chemicals found in the ozone layer. One of the substances they narrowed in on is the CFCs. They noticed that when the atomic chlorine atom is released from the CFCs, it destroyed 100,000 ozone atoms. Because of the concern expressed by the researchers, a ban of CFCs was introduced in several countries, including the US. This did not solve the problem however, because CFCs and other ozone depletions substances started to be produced more often after new uses were found for them.
Countries became worried in the 80's and by 1985 the more developed countries developed a formalized international cooperation at the Vienna Convention. As a result the Montreal Protocol was signed in 1987. This protocol would have had the CFCs reduced in half by 1998.
Because of the increasing damage of the ozone layer in 1992, the countries decided to end the production of halos in 1994 and end the production of CFCs in 1996 in the developed countries.
The measures that had taken part have helped the ozone layer. Researchers believe the atomic chlorine levels will reach their peak soon and in the next 50 years the ozone layer should be able to rebuild itself.
Health.
Ozone depletion also causes major health problems because of the effects that the ultraviolet (UV) rays have on the body. These rays can cause skin cancer, premature aging, cataracts and immune system suppression.
There are two types of skin cancer that ozone depletion effects, melanoma and non-melanoma skin cancer.
