Content

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Content
Introduction
Ozone Formation
Ozone Depletion Process
Ozone Depletion And Our Health
International Prevention on Ozone Depletion.
How Individuals Can Prevent Ozone Depletion
Data and Graphs on Ozone Level
The End
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Introduction

• In 1995, there was an ozone hole " as large as
  the Europe over the south pole."
• In 1996, lively reduction of ozone was detected
  in north hemisphere.
• In the same year, the ozone hole over the south
  pole grew to be twice the size of Europe.
• The 1985 report of the discovery of an "ozone
  hole" over Antarctica focused attention on the
  idea that humans can have a significant impact on
  the global environment. For the past 20 years,
  stratospheric ozone depletion over Canada,
  Europe, and Japan was 1 every year. Some amazing
  phenomena listed below might impress you.
• March in 1997, ozone depletion of the north pole
  was less 1525 while compared with the data of
  last year. The most influenced areas were the
  north pole and center of Siberia.

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Natural Formation Breakdown of Ozone

• Ozone is constantly being produced and destroyed
  in a natural cycle. However, the overall amount
  of ozone is essentially stable.

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How Can Ozone Be Both Good Bad ?

• Ozone occurs in two layers of the atmosphere. The
  layer surrounding the earth's surface is the
  troposphere. Here, ground-level or "bad" ozone is
  an air pollutant that damages human health,
  vegetation, and many common materials. It is a
  key ingredient of urban smog.

• The troposphere extends to a level about 10 miles
  up, where it meets the second layer, the
  stratosphere. The stratospheric or "good" ozone
  layer extends upward from about 10 to 30 miles
  and protects life on earth from the sun's harmful
  ultraviolet rays (UV-b).

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What Is Happening to Good Ozone Layer?

• Ozone occurs naturally in the stratosphere and is
  produced and destroyed at a constant rate.
• But this "good" ozone is gradually being
  destroyed by manmade chemicals called
  chlorofluorocarbons (cfcs), halons, and other
  ozone depleting substances (used in coolants,
  foaming agents, fire extinguishers, and
  solvents).
• These ozone depleting substances degrade slowly
  and can remain intact for many years as they move
  through the troposphere until they reach the
  stratosphere.

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The Ozone Depletion Process

• 1--the ozone depletion process begins when
  cfcs and other ozone-depleting substances (ODS)
  leak from equipment
• 2--winds efficiently mix the troposphere and
  evenly distribute the gases. Cfcs are extremely
  stable, and they do not dissolve in rain. After a
  period of several years, ODS molecules reach the
  stratosphere, about 10 kilometers above the
  earth's surface

• 3--Strong UV light breaks apart the ODS
  molecule. CFCs release chlorine atoms, and halons
  release bromine atoms.
• 4--It is these atoms that actually destroy
  ozone, not the intact ODS molecule. It is
  estimated that one chlorine atom can destroy over
  100,000 ozone molecules before finally being
  removed from the stratosphere.

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Why Is Ozone Depletion More Severe Over the
Earths Poles?

• In 1985, scientists reported a thinning in the
  ozone layer over Antarctica. This proved to be a
  dramatic sign of a worldwide situation that is
  most accentuated in the south polar area due to
  its unique conditions.

• First, stable winter wind patterns contribute to
  extreme cooling over Antarctica, which allows
  polar stratospheric clouds(PSCs) to form. These
  clouds, coupled with ozone-depleting substances
  (ODSs), can dramatically accelerate the process
  of ozone destruction, causing a hole to
  develop. The hole forms during each southern
  hemisphere spring (September/October), when polar
  air is the coldest and the sun is just returning.
  As the sun warms the atmosphere, the
  stratospheric clouds disappear and ozone
  depletion slows down.

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How PSCs Release An Active Chlorine Atom ?

• PSCs is formed when HNO3 3H2O molecules are
  surrounded by sulphuric acid molecules which may
  produce during volcanic eruptions.
• PSCs is most common in south pole Stratospheric
  ozone than north pole, it is this molecules that
  catalyze the formation of Cl atom. (As the graph
  above)

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How Does the Depletion of "Good" Ozone Affect
Human Health and the Environment?
As the stratospheric ozone layer is depleted,
higher UV-b levels reach the earth's surface.
Increased UV-b can lead to

• More cases of skin cancer, cataracts(???), and
  impaired(??) immune systems.
• Damage to UV-b sensitive crops, such as soybeans,
  reduces yield.
• High altitude ozone depletion is suspected to
  cause decreases in phytoplankton, a plant that
  grows in the ocean. Phytoplankton is an important
  link in the marine food chain and, therefore,
  food populations could decline. Because plants
  "breathe in" carbon dioxide and "breathe out"
  oxygen, carbon dioxide levels in the air could
  also increase.

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Your Skin V.S UV Rays

• It is the tanning process(??) which provides both
  protection and a cancerous transformation of skin
  cells. Melanin(???)cells will be stimulated when
  you expose your skin to UV rays. The increasing
  amount of melanin cause your skin to become dark.
• Furthermore, the skin will lose its resilience
  due to prolonged exposure. It is the consequence
  of UV exposure which might cause your skin to
  become like leather and result in more serious
  skin cancers like Basal cell and Squamous(???)
  cell Carcinomas.

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What Is Being Done About the Depletion of Good
Ozone?

• The Montreal Protocol(???????), a series of
  international agreements on the reduction and
  eventual elimination of production and use of
  ozone depleting substances, became effective in
  1989. Currently, 160 countries participate in the
  Protocol. Efforts will result in recovery of the
  ozone layer in about 50 years.
• warning labels on all products containing CFCs or
  similar substances.
• prohibits nonessential ozone depleting products.
• prohibits the release of refrigerants used in car
  and home air conditioning units and appliances
  into the air..

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Measures In Hong Kong About Ozone Depletion.

• As a result, with international commitment under
  the Montreal protocol of 1987 and Hong Kong's own
  commitment under the ozone layer protection
  ordinance of 1989, ozone depleting substances
  would be gradually banned from further
  production.
• Chlorofluorocarbons (CFC), Hydrochlorofluorocarbon
  s (HCFC) and halons are in place to phase
  out(????) or replace existing installations that
  use these substances.
• Production of halon, which is mainly used for
  fire extinguishing purposes, has been banned
  since 1994 while the production of CFCs, mainly
  used in air-conditioning and refrigeration plants
  was banned in 1996. HCFCs, with similar
  applications to CFCs but used more often in
  smaller air-conditioners will be totally banned
  in 2030.

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CFC Replacement

• Achievements to 31 December 1999 include
• Retrofitting existing plants to enable the use
  of new refrigerant and replacement work for 120
  installations at 30 sites, 94 of which have been
  completed. New refrigerants(???) used include
  R134a, which cause much lower levels of global
  warming and a zero effect on ozone depletion.
• Replacement of 159 CFC cold room units at 52
  sites has been completed.
• Replacement of 314 halon installations at 80
  sites has been completed. The halon has been
  replaced by the more environmentally friendly
  FM200.

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What Can We Do ?

• Make sure that technicians working on your car
  air conditioner, home air conditioner, or
  refrigerator are certified by an EPA approved
  program to recover the refrigerant.
• Have your car and home air conditioner units and
  refrigerator checked for leaks. When possible,
  repair leaky air conditioning units before
  refilling them.
• Contact local authorities to properly dispose of
  refrigeration or air conditioning equipment.
• Protect yourself against sunburn. Minimize sun
  exposure during midday hours (10 am to 4 pm).
  Wear sunglasses, a hat with a wide brim, and
  protective clothing with a tight weave. Use a
  broad spectrum sunscreen with a sun protection
  factor (SPF) of at least 15 and 30 is better.

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How To Escape From The Hurt Of UV Rays ?

• No.1 UV-index attention !!!
• Keep your eyes on the media UVI forecast ! stay
  INDOORS as much as possible, when the index is up
  to 10. Avoid going out between 1000AM200PM.
• No.2 sunscreen for your baby !!!
• Babies and children need more protection than
  adults. Especially for those who are beyond one
  year old, they can not be directly exposed to the
  sun.!!!
• No.3 fad of wearing.
• Hats, umbrellas, sunglasses, and long sleeve
  clothing are the best arms against UV rays. Keep
  in mind that having one of them is better than
  none.

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• No.4Embrace the Number 15 !!!
• SPF15 is the best choice of your skin. And do not
  forget to apply sunscreen frequently about every
  23 hours. Plus, lips are also part of skin! Do
  not kiss sunshine without any protection.
• No.5 Snow and Sand are also the ghost of UV rays
  !!!
• Snow may reflect 80 of UV radiation, and sand
  may cause 17 reflection.Choosing sunglasses
  carefully will protect your eyes.
• No.6 Avoid to use a sunlamp and indoor sun-tan
  devices. .

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We live with ozone every day. It can protect life
on earthor harm it, but we have the power to
influenceozone's impact by the way we live.