 In this picture we are seeing how the ozone layer is destroyed and the effects of that destruction. Certain compounds such as chlorofluorocarbons, CFCs are released into the atmosphere by human activities and these CFCs particularly they are very very unreactive at the atmospheric or ground level and they go all the way up to the stratosphere and then the CFCs dissociate or give up the chlorine. Each chlorine atom is capable of destroying or basically turning ozone into oxygen and which again doesn't have the same capability as ozone does in shielding us from the UV radiation. Once that ozone layer or the number of ozone molecules in that layer goes down, more and more UV rays can pass through the atmosphere and reach the surface and can cause more skin cancer and cataract in older people.