Tag: global environmental change

Thinning of ozone layer increases the amount of ultraviolet radiations reaching the earth surface. The increased UV-B radiation increases incidence of cataract, skin cancers herpes, dimming of eyesight, photo burning, snow blindness and deficient functioning of immune system. 

• Ozone depletion occurs when chlorofluorocarbons (CFCs) present in aerosols and refrigerants are released into the stratosphere. 
• Ultraviolet radiations from the sun break these CFCs molecules and release the chlorine atoms.
• Chlorine atom reacts with the ozone (O₃) molecules and starts the ozone destruction cycle.
• So, the correct answer is 'Chlorofluorocarbons'.

Ozone gas is found in the stratosphere of the atmosphere. The ozone layer protects the earth from the harmful ultraviolet rays emitted from the sun. Ozone layer depletion has many adverse serious environmental effects. It may result in global warming. The ultraviolet radiations exposure leads to skin cancer like malignant melanoma. It also increases the rate of ageing in an individual. It also has harmful effect on the eyes. It may cause cataract. Immune system is also affected by this harmful ultraviolet radiations. Apart from humans, ozone layer depletion affects marine, aquatic and other forms of life as well.

• The ozone layer or ozone($O _3$) shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet(UV)radiation.
• Overexposure to UV radiation may cause skin cancer, damage of the eye and the suppression of the immune system.
  
• Hence The harmful radiations are absorbed by ozone layer UV.
• So, the correct answer is 'UV'.

Ozone is an inorganic molecule and a light blue gas with a pungent odor that is prevalent in the stratosphere just below the atmosphere of the earth. Without ozone, plants and animals would be receiving so much radiation from the sun that it would be difficult, if not impossible, for life to even survive here. The effects of no ozone to protect these harmful rays would be that all life here on earth would soon burn up, essentially. Although most associated with the atmosphere, ozone is also a powerful oxidant with many industrial and consumer uses. However, it must be used with extreme caution. The high oxidizing potential of ozone causes damage to mucous and respiratory tissues in animals and also damages tissue in plants at extremely high levels. In commercial agriculture, ozone can be used in conjunction with other chemicals and gases as a control for certain noxious weeds or pests.