THE THINNING THE OZONE LAYER

    The ozone layer is a region in the stratosphere,situated between 17 and 25 kilometers above the Earth's surface.

    The thinning of the ozone layer has been recorded by scientists since the 1970.In 1985, it was reported that the stratospheric ozone concentrations over the Antartica had declined by 40% since 1977.The atmosphere in this area has very low ozone concentration, resuslting in the formation of an ozone hole.Consequently, nitraviolet radiation has since risen by 7% in a decade in the northern hemispere and in the southern hemisphere, the increase is 10%.
    
     The deticiction of the ozone layer is mainly due to the increasing levels of chlorofluorocarbons(CFCs) in the atmosphere. CFCs are a group of chemical compound that contain chlorine, carbon and fluorine.These gases are used as coolants in airconditioners and refrigerators, as propellants in aerosol cans and as foaming agents in the making of stryofoam packinging.Since these chemical are stable, they can persists in the environment for as long as 75 to 100 years.

Writen by Nurul Aini Sani.