Ozone Layer Poisoning
The poisoning of the Earth’s ozone layer is increasingly attracting
worldwide
concern for the global environment and the health effects of life
on the Planet
Earth. There is not just one particular cause for the
ozone’s depletion; the
accumulation of different pollutants into our ozone
layer has all added up and
equaled a worldwide problem. There is not just one
effect from the poisoning of
the ozone, but instead multiple ramifications
from diseases to death. The damage
to the ozone is increasing with every
second; moreover, there are many ways we
can help reduce the problem and
preserve the ozone layer. Ozone is a pale blue
gaseous form of oxygen, in
chemical form it is also known as O3. Ozone can be
beneficial or harmful
depending on its location in the Earth’s atmosphere. If
the ozone is located
in the troposphere (which extends from the surface of the
Earth up to
approxiametly10 miles) it is a harmful pollutant and a major
component in
smog and other environmental health problems. Such tropospheric
ozone can
damage plastic, rubber, plant and animal tissue. Ozone located
approximately
10-25 miles above the Earth’s surface, in a part of the
Earth’s
atmosphere called the stratosphere is very beneficial. The ozone is a
major
factor that makes life possible on Earth. About 90% of the planet’s
ozone is
in the ozone layer. Ozone in this layer shields and filters out the
Earth
from 95-99 percent the sun’s ultraviolet radiation. A low level of ozone
does
not protect or prevent the sun’s ultraviolet rays from reaching the
surface
of the Earth, therefore, overexposing life on Earth causing many
diseases.
The depletion of the ozone is caused by many factors, but the one
cause that
will be elaborated on in the next paragraph is the main reason our
ozone is
continuously being poisoned. The major cause in the depletion of
the
Earth’s ozone layer is because of the release of chlorofluorocarbons
into the
atmosphere. Chlorofluorocarbons also known as CFCs, are industrially
produced
chemical compounds that contain the elements chlorine, fluorine,
carbon, and
sometimes hydrogen that will break down the protective ozone in
the atmosphere.
Since CFCs are heavier than air, the process of CFCs
reaching the ozone will
generally take from two to five years to get into the
stratosphere. When CFCs
reach the stratosphere, the sun’s ultraviolet
radiation cause them to break
apart. Therefore, the chlorine atoms inside the
CFCs are released and will react
with ozone, starting a chemical destruction
cycle of ozone. To show the extent
of destruction chlorine can produce, one
chlorine atom can break apart more than
100,000 molecules of ozone.
Chlorofluorocarbons are not naturally produced
chemical, but shockingly are
all man-made products. CFCs products and other
ozone depleting substance are
everywhere and come in all forms such as: aerosol
spray cans, industrial
cleaning agents, insulators, Styrofoam’s, coolants,
auto air conditioners,
home air conditioners and refrigerators (see next the pie
chart on next page
for more information). Majority of CFCs contributing to
depletion is the auto
air conditioners in our cars. The CFCs inside auto and
home air conditioning
systems, as well as in refrigerators can leak out, and
eventually will rise
into the atmosphere destroying the ozone layer. According
to Greenpeace, "The
manufactures of CFCs and other ozone depleting products
include: Dupont,
Elf-Atochem, ICI, LaRouche, Rhone Poulenc, Nippon Halon, and
Allied
Signal" (Greenpeace). The total value of all the ozone depleting
products
since 1986 exceeded $30.6 billion, with the United States producing a
large
majority of the products. There are other elements and man-made
chemicals
that contribute to the ozone depletion. Any form of elemental
bromine that
reacts with ozone is very violotile. For examaple, methyl
bromide is a compound
that is used as a pesticide and fumigant; the break
down of bromine atoms in
pesticides due to the sun’s rays, can be more than
40 times as destructive to
ozone molecules than chlorine atoms. Halons which
are used in fire extinguishers
contain bromine and are also depleters of the
ozone. Another product that is
destructive is methyl chlorofoam, in which are
solvents in industrial processes.
Hydrochlorofluorocarbons are known as
HCFCs, they are categorized as class II
ozone depleting substances because
these products do not deplete the ozone as
much as CFCs. HFCs are currently
being used as replacements for CFCs, even
though they deplete the ozone to
some extent. Man-made chemicals are not the
only way ozone depletion can
occur; natural depletion is also a reason the ozone
layer is thinning.
Natural depletion is another reason why ozone depletion takes
place.
Ultraviolet light in the atmosphere breaks down the ozone molecules
into
molecular oxygen and atomic oxygen, in a process called photolysis.
Natural
hydrogen oxides account for nearly 11% of all natural depletions.
Nitrogen
oxides are responsible for 50-70% of all natural depletions.
Volcanoes and
oceans naturally emit large amounts of chlorine, but they
easily dissolve in
water and are washed out by rain, therefore, the chlorine
does not reach the
stratosphere to deplete the ozone. Natural depletors are
factors we really do
not have much control over; however, we do have control
over the man-made
chemicals. The thinning of the ozone layer that protects us
from ultraviolet
radiation is increasing and ramifications will have numerous
worldwide effects
on human life. Statistics and laboratory experimental
studies have proven the
increase exposure to ultraviolet rays can cause
actinic keratoses, melanoma and
nonmelanoma cancers. Excessive or even mild
exposure to ultraviolet radiation
can also cause eye diseases such as:
cataracts (loss of focus in the lens which
clouds vision), pterygium (tissue
growth on the white of the eye that can block
vision), skin cancers around
the eyes, blindness, and degeneration of the
macula. According to the
Envionment Protection Agency, "It is estimated that a
sustained 10 percent
loss of ozone could lead to a 26 percent increase in the
number of cases of
nonmelanoma skin cancer per year worlwide" and "At the
same time, 1.6 million
additional cataract cases per year could occur" (Envionment
Protection
Agency). The increase of ultraviolet radiation because of the
reduction of
ozone will also immune systlem suppression. Scientist have found
that
overexposure to the sun can alter the function and distribution of
white
blood cells (disease- fighting cells) in humans, resulting in a weaker
immune
system to fight diseases and a worldwide increase in sickness.
Ultraviolet
radiation also attacks DNA in individual cells, this process
destroys the basic
building blocks of life. The depletion of the ozone layer
will just as
dramatically effect plants as much as it would the humans. In
plants and trees
the increase in ultraviolet radiation will interfere with
photosynthetic
activity, metabolism, flowering, life cycles and growth. The
ultraviolet
radiation could get so high that it may start burning trees and
eventually
forrests’, in the process destroying our sources of oxygen that we
need to
survive. The increase in radiation will start to diminish crops and
other food
sources. Starting with the depletion of the ozone layer, the
domino effect of
the extinction of biological systems on Earth would continue
to plants and then
on to the marine ecosystem. The effects of poisoning of
the ozone layer will
lash out on the marine ecosystem. The marine ecosystem
would severely suffer
from the thinning ozone and the increase exposure to
ultrviolet radiation.
Starting with phytoplankton, the foundation of
acquatic food chains, would loose
their mobility, reproduction ability, a
decrease in photosythetic activity and
orientation in these small organisms.
Scientific proof has demonstrated a direct
reduction in phytoplankton
production due to ozone depletion-related increases
in ultraviolet radiation.
Damage to the early developmental stages of shrimp,
fish, crabs, amphibians
and other animals has also been linked to ultraviolet
radiation exposure.
Greenpeace said, " a sustained 16% ozone depletion could
lead to a loss of up
to 7 million tons of fish per year." Furthermore, the
population of all other
animals would be in danger because of the diminishing
supply of smaller
acquatic creatures. Animals, the most innocent victims of the
ozone depletion
will have to pay for their lives first. With exposure to
ultraviolet
radiation animals will eventually develop tumors similar disease to
humans,
such as: eye tumors, to burning skin,changes in pigmentation, skin
cancers,
and eventual suppression of the immune system. Domestic animals
may
experience loss of hair, cancers, light skin and eye diseases. Skin and
eyes
tumors exclusively in cows, goats, sheeps, horses, dogs, and cats.
Through the
direct effect of exposure to ultraviolet radiation and the
indirect effects on
the limited food species further down the chain, most
animals if not all would
be doomed. The retention our ozone is so important
that every life form on Earth
depends upon the protection of the ozone layer,
against the sun’s harmful
emmision of radiation. During the late 1970’s,
scientist discovered a"hole" in the ozone over the skies of Antartica. The
"holes" in the
ozone in Antartica has increased since and only appears in the
seasonal
springtime. According to Greenpeace, "Measurements of ultraviolet
rays in
Antarctica in 1993 were 50% higher than in 1991 and 1992"
(Greenpeace). Recent
surveys of the ozone layer in Antarctica, have been
reported in the annual
spring-time up to a 90% decrease in ozone. In
Antarctica a decrease in
stratospheric temperature is a coincidence, with the
general increase in the
lower atmospheric temperatures. Some speculate this
is because of the reduced
ozone above Antarctica and the carbon dioxide
warming in the troposphere.
Antarctica is not the only place in the world
with holes in the ozone, Canada
and the Artic also have their own ozone
depletion worries. The Arctic and parts
of Canada’s ozone levels have
increasingly dropped. According to the
Environmental Protection Agency,
one-third of the Northern Hemisphere is
depleted; ozone levels over the
Arctic are at an all-time low of up to 45%
depletion from Greenland to
Scandnavia to Western Siberia. Over the last 30
years, temperatures have been
studied and determind that a 0.5 Celsius degree
increase had taken place per
decade. The Arctic as a result. has experienced
melting ice packs, a weaker
cooling trend, and a decline in actual ice area.
Parts of Canada has also
experienced a drop in ozone levels by 15%. Scientists
feel through the years
1998-2000 to be the most vulnerable period when
accumalated atmospheric
chlorine and bromine levels from human made elements
will be at it’s peak.
One of the first major steps in trying to stop the ozone
depletion took place
in September of 1987, negotiators from around the world met
in Montreal to
sign a treaty that limits the use of CFCs and halons. Soon after
the minds of
science gathered in Montreal, the Montreal Protocol was signed so
that in
developed countries the production and consumption of CFCs would
be
diminished by the year 2000. The Clean Air Act Amendments of 1990 was
amended to
control ozone depleting chemicals in the United States. This Clean
Air Act
created an excise tax on all CFC products, that would increase year
to year and
gradually phase out the production of CFCs. The use of CFCs are
currently banned
in the United States. "In December of 1995 over 100 nations
agreed to phase
developed countries’ production of the pesticide methyl
bromide, predicted to
cause about 15% of ozone depletion by the year 2000.
The production of CFCs in
developing countries will have ceased by the year
2010" (Greenpeace). Just a
couple years ago on December 16, 1997 the
Antarctica Protocol was finally
ratified after six years of lobbying. The
Antartica Protocol bans mining for a
minimum of 50 years and designates the
whole continent and its marine ecosystem
as a "natural reserve devoted to
peace and science" (Greenpeace). There are
many ways individuals can slow the
rate of ozone depletion, through careful
product purchasing of appliances
that do use ozone depleting substances.
Immediately repair any leaks in
your refrigerator and make sure all CFCs are
recoverd and properly recycled
before any refrigerator is scrapped. Avoid buying
all products that contain
Ozone depleting substances such as: carbon
tetrachlorides in dry-cleaning
agents, halons found in fire extinguishers,
methyl chlorofoam in degreasers
and propellants, and anything insulated in
styrofoam. Consider alternatives
to air conditioning systems in your houses,
such as: insulating your homes,
install fan cooling systems, apply coats of
reflective seal on your roof to
keep heat out, and vents hot attic spaces to get
hot air out of your homes.
Be sure maintainance your cars air conditioning
systems so that no freon
leaks. In conclusion, the protection and conservation
of our ozone is vital
for the continuation of all biological systems and life
forms on earth. Even
with all the laws and CFC bans, we must all contribute a
little something to
nurse our fragile ozone layer back to health. If we decide
to let things go
on the way they are, extinction will start with the marine
ecosystems, then
the plants will start to die out, the animals will starve or
die of diseases
and eventually we will fall right in line as the final
domino
falls.
Bibliography
Firor, John. The Changing Atmosphere
A Global Challenge. New Haven: Yale
University Press, 1990. 26-43.
Stoker, Stephen. "Ozone." Vol. 14. 14ed.
Chicago: Fetzer, 1996. 894.
Environmental Protection Agency. "Ozone
Depletion." [Internet Online].
December 24, 1997. http://www.epa.gov/ozone/science/effects.html
.
Greenpeace. "Ozone Depletion." [Internet Online]. date accessed: July
24,
1999. http://www.greenpeace.org . Microsoft Encarta Encyclopedia
98.
"Ozone." [Computer program]. 1998ed. Microsoft Corporation.