Pollution de l’environnement et changement climatique

Abstrait

Chlorofluorocarbons and its Effect on Ozone Layer and Ultimately on Human Health

Iqra Zulfiqar

At the University of California, Irvine, F. Sherwood Ronald and Mario J. Molina discovered that chlorofluorocarbons (CFCs) could deplete earth atmospheric ozone layer; the layer which blocks sun ultraviolet damaging rays. When the scientist reported their findings in 1974, CFCs were in a wide use in refrigeration, air conditioning and aerosol spray cans. CFCs are group of colorless, non-combustible and high volatile liquids also known as ferons. Because they are highly volatile substances, they can easily release into the air during production and use. The chemical breakdown of CFCs in the stratosphere release cl and Br atoms that destroy ozone molecules in catalytic cycles. Due to ozone layer destruction, the damaging Ultraviolet rays of sun pass through it and may be cause serious problems such as sun burn, skin damaging, skin cataracts, DNA damage and lungs diseases, effect on food shortage in human population, effect on human immunity and skin cancer in human. We should decrease the use of CFCs or replace its use by use of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) which decrease ozone layer with much lesser extent than CFCs.