The document discusses ozone, the ozone layer, and ozone depletion. It defines ozone as a triatomic form of oxygen found in the upper and lower atmosphere, and the ozone layer as absorbing 97-99% of the sun's ultraviolet light. The ozone layer is being destroyed by chemicals like CFCs released from industries and vehicles. Low temperatures in the upper atmosphere allow chlorine and bromine to destroy ozone, forming a hole. Overexposure to ultraviolet rays due to ozone depletion increases risks of skin cancer, eye damage, immune system damage, and DNA damage. Actions are needed to limit chemicals that deplete ozone and encourage plant growth to increase oxygen production.

1. Ozone depletion
k.Varun kumar

2. What is ozone?
Ozone is a triatomic form of oxygenOzone is a triatomic form of oxygen
found in earth’s upper and lowerfound in earth’s upper and lower
atmosphere.atmosphere.
The layer is a layer absorbs 97%-99% ofThe layer is a layer absorbs 97%-99% of
the sun’s high frequency ultraviolet light,the sun’s high frequency ultraviolet light,
which s potentially damaging to thewhich s potentially damaging to the
forms on earthforms on earth

3. What is ozone layer?
 The ozone layer is a layer in earth’s
atmosphere which contains relatively high
concentrations of ozone (O3)(O3)..
 The ozone layer, situated in the stratosphere
about 15 to 30 km above the earth’s surface.
 Ozone protects living organisms by
absorbing harmful ultraviolet radiation (UVB)
from the sun. The ozonelayer is being
destroyed by CFCs and other substances.
 Ozone depletion progressing globally expect
in the tropical zone.

4. How hole is formed?
 A combination of low temperatures and
elevated chlorine and bromine
concentrations are responsible for the
destruction of ozone layer in the upper
stratosphere thus forming a hole.

5. Also caused by the green house gases
which are released by industries and
vehicles

6. Meteorological mechanism
 Moment of air from one place to another in
the upper stratosphere.
 Cold temperature in the upper atmosphere
causes nitric cid to freeze into crystals
forming wispy pink clouds.

7. Effects o plant growth

8. What are the effects of over
exposure to UV rays ?
 Skin cancer
 Eye damage such as cataracts
 Immune system damage
 Reduction in phytoplankton
 Damage to DNA in various life-forms ( this
has been observed in Antarctic ice-fish that
lack pigments to shield them from ultra violet
which they have never needed them before)

9. Cont….
 Overexposure: increase risk of non-
melanoma and malignant melanoma and
malignant melanoma skin cancer
 Possibly other things too that we don’t know
about them

10. Skin cancer

11. phytoplankton
 Phytoplankton: (phytoplankton uses carbon
dioxide, releases oxygen, and converts
minerals to a form that animals can use)

12. cataracts

13. Damage of immune system

14. Damage of DNA

15. How to protect ozone?
 Minimize high altitude aircrafts
(oxygen reduction and water
vapour deposition)
 Minimize rocket flight ( water
vapour deposition)
 Encourage growth of plants that
produce that produce oxygen,
discourage deforestation
 Decrease/ control release of
known ozone depleting chemicals
(such as CFCs chlorine fatigue
syndrome) where remotely
possible. Subsidize production of
safer alternatives where possible.

16. Actions taken individually
 Don’t use the car so much
 Turn of the lights and the faucet when not in
use
 Use blankets to stay warm in the winter, wear
thinner clothes in the summer to stay cool
instead of an A.C
 Try to use products which are labeled
“ozone-friendly”

17. Cont…
 Vehicle air conditioning units should
regularly be checked for leak
 Ensure technicians repairing your
refrigerator or air conditioner recover
an recycle the old CFCs so they are
not released into the atmosphere
 Suggest school activities to increase
awareness of the problem and to
initiate local action
 Minimize industrial refrigerators which
releases chlorine

18. CFC-12 released in troposphere
Carried into stratosphere in
the tropics by slow rising
circulation
CFC-12 photolyzed in
stratosphere by solar UV,
releasing Cl
Cl catalytically destroys
O3
Cl reacts with CH4 or
NO2 to form non-
reactive HCl or
ClONO2
Cl released by
PSCs
How does chlorine get from our refrigerators
to the Antarctic stratosphere?

19. Now you decide

21. Thank you 