A large amount of ODS (Ozone Depleting Substances) like CFCs, N2O, halons, SO2, CH4, Cl (Chlorine radicals)-are released by advanced countries like the USA, Japan, European countries, and throughout the world. In the stratosphere, these are released, they drift towards poles and reach there before the coming of winter. In winter (temp. 85oC) over Antarctica, ice clouds are formed and no sunrise is received in polar areas. UV rays catalyze the release of Cl atoms from CFCs. With the coming of the spring season, Cl- atoms react with ozone in the presence of sunlight and convert 03 into 02 causing ozone depletion/thinning of ozone shields in the stratosphere called ozone hole. This hole disappears in summer due to the free mixing of air in Antarctica with the rest of the global air. Effect of Enhanced UV Radiation,
(i) Snow blindness or inflammation of the cornea
(ii) Skin cells get damaged and development of skin cancer occur
(iii) Damage to nucleic acids and proteins,
(iv) Immunity gets reduced.
(v) In humans, there are plenty of cataracts.