Explain ozone layer, its depletion and effects of ozone depletion.
Ozone layer:
The ozone layer or ozone shield is a region of Earth's stratosphere about 15–30km above the earth's surface which absorbs most of the Sun's ultraviolet radiation which contains a high concentration of ozone in relation to other parts of the atmosphere.
Ozone depletion:
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Reduction in the concentration of ozone or ozone layer is called ozone depletion.
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It is caused by certain chemicals called ozone depleting substances (ODS).
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The important ODS are chlorofluorocarbons (CFCs), halons, methyl bromide, nitrogen oxides and chlorine, CFCs such as carbon tetrachloride, CCl3 ; dichlorodifluoromethane, (CCl2 F2).
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Chlorofluorocarbons (CFCs) are commonly used as aerosol propellants, refrigerants, shaving foams, spray agents in scents, etc.
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Some ozone depleting substances (ODS) are released in the stratosphere by jets flying at height.
Effects of ozone depletion:
- Depleting the ozone layer allows more ultraviolet (UV) radiation to pass through it, which reaches the Earth's surface.
- The UV rays cause various harmful effects on human, animals, plants and environment such as follows :
Skin cancer.
- Damage of eyes and also increase in incidence of cataract disease in eyes.
- Damage to the immune system.
- Increased embryonic mortality in animals and humans
- Decreased crop yields.
- Reduced populations of phytoplankton, zooplankton and certain fish larvae that are important constituents of aquatic food chains.
- Smog formation.
Ozone layer:
The ozone layer or ozone shield is a region of Earth's stratosphere about 15–30km above the earth's surface which absorbs most of the Sun's ultraviolet radiation which contains a high concentration of ozone in relation to other parts of the atmosphere.
Ozone depletion:
-
Reduction in the concentration of ozone or ozone layer is called ozone depletion.
-
It is caused by certain chemicals called ozone depleting substances (ODS).
-
The important ODS are chlorofluorocarbons (CFCs), halons, methyl bromide, nitrogen oxides and chlorine, CFCs such as carbon tetrachloride, CCl3 ; dichlorodifluoromethane, (CCl2 F2).
-
Chlorofluorocarbons (CFCs) are commonly used as aerosol propellants, refrigerants, shaving foams, spray agents in scents, etc.
-
Some ozone depleting substances (ODS) are released in the stratosphere by jets flying at height.
Effects of ozone depletion:
- Depleting the ozone layer allows more ultraviolet (UV) radiation to pass through it, which reaches the Earth's surface.
- The UV rays cause various harmful effects on human, animals, plants and environment such as follows :
Skin cancer.
- Damage of eyes and also increase in incidence of cataract disease in eyes.
- Damage to the immune system.
- Increased embryonic mortality in animals and humans
- Decreased crop yields.
- Reduced populations of phytoplankton, zooplankton and certain fish larvae that are important constituents of aquatic food chains.
- Smog formation.
