2008 2008
OMTEX CLASSES -09 OMTEX CLASSES -09
PROJECT ON OZONE LAYER PROJECT ON OZONE LAYER INDEX
INDEX
NAME OF THE TOPIC COVERED Teacher NAME OF THE TOPIC COVERED Teacherss Signature
Signature
1. The ozone layer: What is it? 1. The ozone layer: What is it? 2. Ozone depletion: Who is
2. Ozone depletion: Who is responsible?
responsible?
3. The ozone hole: Why over 3. The ozone hole: Why over Antarctica?
Antarctica?
4. SOCIETAL ASPECTS 4. SOCIETAL ASPECTS
5. Ozone depletion and skin cancer: What 5. Ozone depletion and skin cancer: Whatss the connection?
the connection?
6. What about other illnesses? 6. What about other illnesses? 7. Ozone depletion: Not a farmer
7. Ozone depletion: Not a farmers bests best friend.
friend.
8. Collaborative Global Government 8. Collaborative Global Government Efforts
Efforts
9. Ozone and health 9. Ozone and health 10.DISCUSSION 10.DISCUSSION 11.SUMMARY 11.SUMMARY 1 1
I. The ozone layer: What is it? I. The ozone layer: What is it?
The ozone layer is a portion of earths atmosphere that contains high levels of o The ozone layer is a portion of earths atmosphere that contains high levels of o zone. The
zone. The
atmosphere is divided into five layers: the troposphere, the stratosphere, the m atmosphere is divided into five layers: the troposphere, the stratosphere, the m esosphere,
esosphere,
the thermosphere, and the exosphere. The troposphere is the layer closest to ear the thermosphere, and the exosphere. The troposphere is the layer closest to ear th and is
th and is
where all weather happenings occur. The stratosphere is located directly above t where all weather happenings occur. The stratosphere is located directly above t he
he
troposphere, about 10-50 kilometers above the planet, and houses the ozone layer troposphere, about 10-50 kilometers above the planet, and houses the ozone layer
at an at an
altitude of 20-30 kilometers. The mesosphere is located approximately 50-80 kilo altitude of 20-30 kilometers. The mesosphere is located approximately 50-80 kilo meters
meters
above the earth, while the thermosphere rests at an altitude of approximately 10 above the earth, while the thermosphere rests at an altitude of approximately 10 0-200
0-200
kilometers above the earths surface. Finally, the boundary of the outermost laye kilometers above the earths surface. Finally, the boundary of the outermost laye r, the
r, the
exosphere, extends roughly to 960-1000 kilometers above the earth. For a visual exosphere, extends roughly to 960-1000 kilometers above the earth. For a visual of the
of the
lowermost three layers of our atmosphere, refer to Figure 1 below. lowermost three layers of our atmosphere, refer to Figure 1 below.
Ozone (O3) is a triatomic molecule, consisting of three oxygen atoms. It is an a Ozone (O3) is a triatomic molecule, consisting of three oxygen atoms. It is an a llotrope of
llotrope of
oxygen that is much less stable than the diatomic species O2. Ground-level ozone oxygen that is much less stable than the diatomic species O2. Ground-level ozone
is an air is an air
pollutant with harmful effects on the respiratory systems of animals. Ozone in t pollutant with harmful effects on the respiratory systems of animals. Ozone in t he upper
he upper
atmosphere filters potentially damaging ultraviolet light from reaching the Eart atmosphere filters potentially damaging ultraviolet light from reaching the Eart h
hss
surface. It is present in low concentrations throughout the Earth
surface. It is present in low concentrations throughout the Earths atmosphere. Its atmosphere. It has
has
many industrial and consumer applications. Ozone therapy is a controversial alte many industrial and consumer applications. Ozone therapy is a controversial alte rnative
rnative
medicine practice; mainstream scientific medicine has found ozone to be harmful medicine practice; mainstream scientific medicine has found ozone to be harmful to
to
humans and equipment intended to be used for ozone therapy is banned in the Unit humans and equipment intended to be used for ozone therapy is banned in the Unit ed
ed
States. Ozone, the first allotrope of a chemical element to be described by scie States. Ozone, the first allotrope of a chemical element to be described by scie nce, was
nce, was
discovered by Christian Friedrich Schönbein in 1840, who named it after the Gree discovered by Christian Friedrich Schönbein in 1840, who named it after the Gree k word
k word
for smell (ozein), from the peculiar odor in lightning storms.[3] The odor from for smell (ozein), from the peculiar odor in lightning storms.[3] The odor from a lightning
a lightning
strike is from ions produced during the rapid chemical changes, not the ozone it strike is from ions produced during the rapid chemical changes, not the ozone it self
self
Figure 1: Earth
Figure 1: Earths atmosphere is divided into layers, which have various characteris atmosphere is divided into layers, which have various characteri stics.
stics.
Source: NOAA Aeronomy Laboratory, 1998 Source: NOAA Aeronomy Laboratory, 1998
The ozone found in our atmosphere is formed by an interaction between oxygen The ozone found in our atmosphere is formed by an interaction between oxygen molecules (composed of two oxygen atoms) and ultraviolet light. When ultraviolet molecules (composed of two oxygen atoms) and ultraviolet light. When ultraviolet
light light
hits these oxygen molecules, the reaction causes the molecules to break apart in hits these oxygen molecules, the reaction causes the molecules to break apart in
to single to single 2
atoms of oxygen (UV light + O2 --> O + O). These single atoms of oxygen are very atoms of oxygen (UV light + O2 --> O + O). These single atoms of oxygen are very reactive, and a single atom combines with a molecule of oxygen to form ozone (O3 reactive, and a single atom combines with a molecule of oxygen to form ozone (O3 ),
),
which is composed of three atoms of oxygen (2O + 2O2 --> 2O3). which is composed of three atoms of oxygen (2O + 2O2 --> 2O3).
The ozone layer is essential for human life. It is able to absorb much harmful u The ozone layer is essential for human life. It is able to absorb much harmful u ltraviolet
ltraviolet
radiation, preventing penetration to the earth
radiation, preventing penetration to the earths surface. Ultraviolet radiation (Us surface. Ultraviolet radiation (U V) is
V) is
defined as radiation with wavelengths between 290-320 nanometers, which are harm defined as radiation with wavelengths between 290-320 nanometers, which are harm ful
ful
to life because this radiation can enter cells and destroy the deoxyribonucleic to life because this radiation can enter cells and destroy the deoxyribonucleic acid (DNA)
acid (DNA)
of many life forms on planet earth. In a sense, the ozone layer can be thought o of many life forms on planet earth. In a sense, the ozone layer can be thought o f as a
f as a
UV filterUV filter or our planetor our planetss built in sunscreenbuilt in sunscreen (Geocities.com, 1998). Without the ozone(Geocities.com, 1998). Without the ozone layer, UV radiation would not be filtered as it reached the surface of the earth
layer, UV radiation would not be filtered as it reached the surface of the earth . If this
. If this happened,
happened, cancer would break out and all of the living civilizations, and all specancer would break out and all of the living civilizations, and all spe cies on
cies on
earth would be in jeopardy
earth would be in jeopardy (Geocities.com, 1998). Thus, the ozone layer essential(Geocities.com, 1998). Thus, the ozone layer essential ly
ly
allows life, as we know it, to exist. allows life, as we know it, to exist.
In order for scientists to evaluate how much ozone is in the layer, a unit of me In order for scientists to evaluate how much ozone is in the layer, a unit of me asurement
asurement
called the Dobson Unit is employed. A Dobson Unit is a measurement of how thick called the Dobson Unit is employed. A Dobson Unit is a measurement of how thick a
a
specific portion of the ozone layer would be if it were compressed into a single specific portion of the ozone layer would be if it were compressed into a single
layer at layer at
zero degrees Celsius with one unit of atmospheric pressure acting on it (standar zero degrees Celsius with one unit of atmospheric pressure acting on it (standar d
d
temperature and pressure - STP). Thus, one Dobson Unit (DU) is defined as .01 mm temperature and pressure - STP). Thus, one Dobson Unit (DU) is defined as .01 mm thickness at standard temperature and pressure. Figure 2 shows a column of air o thickness at standard temperature and pressure. Figure 2 shows a column of air o ver
ver
Labrador, Canada. Since the ozone layer over this area would form a 3 mm thick s Labrador, Canada. Since the ozone layer over this area would form a 3 mm thick s lab,
lab,
the measurement of the ozone over Labrador is 300 DU. the measurement of the ozone over Labrador is 300 DU.
3 3
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II. Ozone depletion: Who is responsible? II. Ozone depletion: Who is responsible?
It is important to recognize the sources of ozone depletion before one can fully It is important to recognize the sources of ozone depletion before one can fully understand the problem. There are three main contributors to the ozone problem: understand the problem. There are three main contributors to the ozone problem: human
human
activity, natural sources, and volcanic eruptions (See Figure 3). activity, natural sources, and volcanic eruptions (See Figure 3).
Figure 3: Humans cause more damage to the ozone layer than any other source. Figure 3: Humans cause more damage to the ozone layer than any other source. Source: Geocities.com, 1998
Source: Geocities.com, 1998
Human activity is by far the most prevalent and destructive source of ozone depl Human activity is by far the most prevalent and destructive source of ozone depl etion,
etion,
while threatening volcanic eruptions are less common. Human activity, such as th while threatening volcanic eruptions are less common. Human activity, such as th e
e
release of various compounds containing chlorine or bromine, accounts for release of various compounds containing chlorine or bromine, accounts for approximately 75 to 85 percent of ozone damage. Perhaps the most evident and approximately 75 to 85 percent of ozone damage. Perhaps the most evident and destructive molecule of this description is chloroflourocarbon (CFC). CFCs were destructive molecule of this description is chloroflourocarbon (CFC). CFCs were first
first
used to clean electronic circuit boards, and as time progressed, were used in ae used to clean electronic circuit boards, and as time progressed, were used in ae rosols and
rosols and
coolants, such as refrigerators and air conditioners. When CFCs from these produ coolants, such as refrigerators and air conditioners. When CFCs from these produ cts are
cts are
released into the atmosphere, the destruction begins. As CFCs are emitted, the m released into the atmosphere, the destruction begins. As CFCs are emitted, the m olecules
olecules
float toward the ozone rich stratosphere. Then, when UV radiation contacts the C float toward the ozone rich stratosphere. Then, when UV radiation contacts the C FC
FC
molecule, this causes one chlorine atom to liberate. This free chlorine then rea molecule, this causes one chlorine atom to liberate. This free chlorine then rea cts with an
cts with an
ozone (O3) molecule to form chlorine monoxide (ClO) and a single oxygen molecule ozone (O3) molecule to form chlorine monoxide (ClO) and a single oxygen molecule (O2). This reaction can be illustrated by the following chemical equation: Cl + (O2). This reaction can be illustrated by the following chemical equation: Cl + O3 --> O2
O3 --> O2
+ ClO. Then, a single oxygen atom reacts with a chlorine monoxide molecule, caus + ClO. Then, a single oxygen atom reacts with a chlorine monoxide molecule, caus ing
ing
the formation of an oxygen molecule (O2) and a single chlorine atom (O + ClO --> the formation of an oxygen molecule (O2) and a single chlorine atom (O + ClO -->
Cl + Cl +
O2). This threatening chlorine atom then continues the cycle and results in furt O2). This threatening chlorine atom then continues the cycle and results in furt her
her
destruction of the ozone layer (See Figure 4). Measures have been taken to reduc destruction of the ozone layer (See Figure 4). Measures have been taken to reduc e the
e the
amount of CFC emission, but since CFCs have a life span of 20-100 years, previou amount of CFC emission, but since CFCs have a life span of 20-100 years, previou sly
sly
emitted CFCs will do damage for years to come. emitted CFCs will do damage for years to come. 4
Figure 4: A pictorial explanation of how the interaction of CFCs and UV radiatio Figure 4: A pictorial explanation of how the interaction of CFCs and UV radiatio n
n
damage the ozone layer. damage the ozone layer. Source: Geocities.com, 1998 Source: Geocities.com, 1998
Natural sources also contribute to the depletion of the ozone layer, but not nea Natural sources also contribute to the depletion of the ozone layer, but not nea rly as much
rly as much
as human activity. Natural sources can be blamed for approximately 15 to 20 perc as human activity. Natural sources can be blamed for approximately 15 to 20 perc ent of
ent of
ozone damage. A common natural source of ozone damage is naturally occurring ozone damage. A common natural source of ozone damage is naturally occurring chlorine. Naturally occurring chlorine, like the chlorine released from the reac chlorine. Naturally occurring chlorine, like the chlorine released from the reac tion
tion
between a CFC molecule and UV radiation, also has detrimental effects and poses between a CFC molecule and UV radiation, also has detrimental effects and poses danger
danger
to the earth. to the earth.
Finally, volcanic eruptions are a small contributor to ozone damage, accounting Finally, volcanic eruptions are a small contributor to ozone damage, accounting for one to
for one to
five percent. During large volcanic eruptions, chlorine, as a component of hydro five percent. During large volcanic eruptions, chlorine, as a component of hydro chloric
chloric
acid (HCl), is released directly into the stratosphere, along with sulfur dioxid acid (HCl), is released directly into the stratosphere, along with sulfur dioxid e. In this
e. In this
case, sulfur dioxide is more harmful than chlorine because it is converted into case, sulfur dioxide is more harmful than chlorine because it is converted into sulfuric
sulfuric
acid aerosols. These aerosols accelerate damaging chemical reactions, which caus acid aerosols. These aerosols accelerate damaging chemical reactions, which caus e
e
chlorine to destroy ozone. chlorine to destroy ozone. 5
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OMTEX CLASSES -09 OMTEX CLASSES -09
III. The ozone hole: Why over Antarctica? III. The ozone hole: Why over Antarctica?
When the topic of the ozone layer arises, many people immediately think of the h When the topic of the ozone layer arises, many people immediately think of the h ole
ole
over Antarctica, but few know why the hole is actually there. In 1985, British s over Antarctica, but few know why the hole is actually there. In 1985, British s cientists
cientists
discovered this hole. A special condition exists in Antarctica that accelerates discovered this hole. A special condition exists in Antarctica that accelerates the
the
depletion of the ozone layer. Every Arctic winter, a polar vortex forms over Ant depletion of the ozone layer. Every Arctic winter, a polar vortex forms over Ant arctica.
arctica.
A polar vortex is
A polar vortex is a swirling mass of very cold, stagnant air surrounded by stronga swirling mass of very cold, stagnant air surrounded by strong westerly winds
westerly winds (Roan, 126). Since there is an absence of sun during Arctic winter(Roan, 126). Since there is an absence of sun during Arctic winter s, the
s, the
air becomes incredibly cold and the formation of ice clouds occurs. When the sun air becomes incredibly cold and the formation of ice clouds occurs. When the sun
returns returns
in the spring, the light shining on the nitrogen oxide filled ice particles acti in the spring, the light shining on the nitrogen oxide filled ice particles acti vates the
vates the
formation of chlorine. This excess of ozone destroying chlorine rapidly accelera formation of chlorine. This excess of ozone destroying chlorine rapidly accelera tes the
tes the
depletion of the ozone layer. Finally, when the polar vortex breaks up, the rapi depletion of the ozone layer. Finally, when the polar vortex breaks up, the rapi d
d
dissolution decreases. It is evident that the effects of the polar vortex are dr dissolution decreases. It is evident that the effects of the polar vortex are dr amatic.
amatic. ForFor
about two month every southern spring, the total ozone declines by about 60% ove about two month every southern spring, the total ozone declines by about 60% ove r most
r most
of Antarctica. In the core of the ozone hole, more than 75% of the ozone is lost of Antarctica. In the core of the ozone hole, more than 75% of the ozone is lost
and at and at
some altitudes, the ozone virtually disappeared in October, 1993
some altitudes, the ozone virtually disappeared in October, 1993 (Nilsson, 19). T(Nilsson, 19). T he
he
average size of the ozone hole is larger than most continents, including South A average size of the ozone hole is larger than most continents, including South A merica,
merica,
Europe, Australia, and Antarctica, and the maximum size of the ozone hole in 199 Europe, Australia, and Antarctica, and the maximum size of the ozone hole in 199 6 was
6 was
larger than North America (See Figure 5). Finally, one must note that the
larger than North America (See Figure 5). Finally, one must note that the holehole oveove r
r
Antarctica is truly a
Antarctica is truly a holehole only in the Antarctic spring, when the depletion is extonly in the Antarctic spring, when the depletion is ext remely
remely
severe due to the vortex. severe due to the vortex.
Figure 5: On average, the size of the ozone hole is larger than many countries. Figure 5: On average, the size of the ozone hole is larger than many countries. Source: Geocities.com, 1998
Source: Geocities.com, 1998
The hole above Antarctica has clearly proven to be detrimental. Plankton, organi The hole above Antarctica has clearly proven to be detrimental. Plankton, organi sms that
sms that
live on carbon, light, and nutrients such as nitrogen, are near the bottom of th live on carbon, light, and nutrients such as nitrogen, are near the bottom of th e food
e food 6
chain, and are accustomed to low levels of UV. In December of 1994, on the islan chain, and are accustomed to low levels of UV. In December of 1994, on the islan d of
d of
Bacharcaise off Antarctica, increased levels of UV radiation decreased the numbe Bacharcaise off Antarctica, increased levels of UV radiation decreased the numbe r of
r of
photoplankton dramatically. Photoplankton are the main source of food for krill, photoplankton dramatically. Photoplankton are the main source of food for krill,
which which
in turn are the main source of food for various birds and whales in the Antarcti in turn are the main source of food for various birds and whales in the Antarcti c region
c region
(See Figure 6). (See Figure 6).
Figure 6: Ultraviolet radiation proved detrimental to this Arctic food chain in Figure 6: Ultraviolet radiation proved detrimental to this Arctic food chain in December, December, 1994. 1994. Source: Nilsson, 1996 Source: Nilsson, 1996
At this time, due to the decreased number of photoplankton, the krill level was At this time, due to the decreased number of photoplankton, the krill level was so low
so low
that it could not support the penguin population. Thus, some penguins were force that it could not support the penguin population. Thus, some penguins were force d to
d to
travel up to two hundred miles in search of food, but most returned with none. travel up to two hundred miles in search of food, but most returned with none. Furthermore, when summer came, only approximately ten of the 1800 hatched pengui Furthermore, when summer came, only approximately ten of the 1800 hatched pengui n
n
chicks survived. This tragedy illustrates the fact that even underwater creature chicks survived. This tragedy illustrates the fact that even underwater creature s are not
s are not
protected from harmful UV rays, and is a perfect example of the entire food chai protected from harmful UV rays, and is a perfect example of the entire food chai n being
n being
affected due to an increase in the UV radiation as a result of the thinning ozon affected due to an increase in the UV radiation as a result of the thinning ozon e layer.
e layer. 7
2008 2008 OMTEX CLASSES -09 OMTEX CLASSES -09 SOCIETAL ASPECTS SOCIETAL ASPECTS
The most obvious, and perhaps most important connection between society and the The most obvious, and perhaps most important connection between society and the ozone
ozone
layer is the fact that scientific research suggests depletion of the ozone layer layer is the fact that scientific research suggests depletion of the ozone layer
directly and directly and
indirectly endangers the health of the population. Research has focused on conne indirectly endangers the health of the population. Research has focused on conne ctions
ctions
between the depleting ozone layer and skin cancer, immuno-suppression, cataracts between the depleting ozone layer and skin cancer, immuno-suppression, cataracts , and
, and
snow blindness. snow blindness.
IV. Ozone depletion and skin cancer: What
IV. Ozone depletion and skin cancer: Whats the connection?s the connection?
Exposure to UV radiation increases the risk of skin cancer and causes damage to Exposure to UV radiation increases the risk of skin cancer and causes damage to the
the
DNA in the skin cells. DNA is extremely sensitive to UV radiation, especially UV DNA in the skin cells. DNA is extremely sensitive to UV radiation, especially UV -B
-B
radiation. UV radiation is located in the optical radiation portion of the elect radiation. UV radiation is located in the optical radiation portion of the elect romagnetic
romagnetic
spectrum, while UV-B radiation is a subdivision of the ultraviolet spectrum and spectrum, while UV-B radiation is a subdivision of the ultraviolet spectrum and consists
consists
of a wavelength of 280 to 315 nanometers. Thus, DNA is especially sensitive to r of a wavelength of 280 to 315 nanometers. Thus, DNA is especially sensitive to r adiation
adiation
with a wavelength between 280 and 315 nanometers (See Figure 7). with a wavelength between 280 and 315 nanometers (See Figure 7).
Figure 7: UV-B, the most harmful radiation to humans and plants, has a wavelengt Figure 7: UV-B, the most harmful radiation to humans and plants, has a wavelengt h of
h of
280-315 nanometers, as measured on the electromagnetic spectrum. 280-315 nanometers, as measured on the electromagnetic spectrum. Source: Nilsson, 1996
Source: Nilsson, 1996
When UV radiation hits the skin, it can cause the cell to
When UV radiation hits the skin, it can cause the cell to lock uplock up and scramble orand scramble or delete
delete
DNA information. This action causes confusion in the DNA, and the body loses con DNA information. This action causes confusion in the DNA, and the body loses con trol
trol
of the growth and division of the cell. If the conditions are right, the cell ma of the growth and division of the cell. If the conditions are right, the cell ma y become
y become
cancerous. It is important to note that not all affected cells turn into skin ca cancerous. It is important to note that not all affected cells turn into skin ca ncer, for
ncer, for
many can repair themselves. However, continual exposure to UV radiation increase many can repair themselves. However, continual exposure to UV radiation increase s the
s the
risk of skin cancer due to cumulative damage of the DNA. risk of skin cancer due to cumulative damage of the DNA.
Skin cancer can be divided into two categories: melanoma and non-melanoma. The Skin cancer can be divided into two categories: melanoma and non-melanoma. The melanoma form of skin cancer is the more dangerous of the two. This type of canc melanoma form of skin cancer is the more dangerous of the two. This type of canc er has
er has 8
the ability to spread quickly throughout the body and invade other cells. On the the ability to spread quickly throughout the body and invade other cells. On the
other other
hand, non-melanoma skin cancer is not to be taken lightly either, but is a less hand, non-melanoma skin cancer is not to be taken lightly either, but is a less serious
serious
form of the disease. Non-melanoma skin cancers are not usually life threatening, form of the disease. Non-melanoma skin cancers are not usually life threatening,
and and
removal is relatively routine. However, treatment does include radiation therapy removal is relatively routine. However, treatment does include radiation therapy
or or
surgery. The concern of many is that sunburn may lead to increased risk of acqui surgery. The concern of many is that sunburn may lead to increased risk of acqui ring skin
ring skin
cancer. Some forms of cancer are associated with sunburn, while other forms are cancer. Some forms of cancer are associated with sunburn, while other forms are not.
not.
Melanoma skin cancer is a form that sunburns may play a leading role in. Jan van Melanoma skin cancer is a form that sunburns may play a leading role in. Jan van
der der
Leun, a Dutch scientist, explains that,
Leun, a Dutch scientist, explains that, light hitting the outer layer of the skinlight hitting the outer layer of the skin , the
, the
epidermis, triggers the production of some substances which diffuse into the der epidermis, triggers the production of some substances which diffuse into the der mis
mis
below. The dermis is filled with blood vessels, and the chemical substances caus below. The dermis is filled with blood vessels, and the chemical substances caus e them
e them
to dilate, making the skin red and warm to the touch
to dilate, making the skin red and warm to the touch (Nilsson, 83).(Nilsson, 83).
The bottom line is that UV ray exposure increases the risk of skin cancer. Howev The bottom line is that UV ray exposure increases the risk of skin cancer. Howev er,
er,
controversy lies around the question of whether or not the depletion of the ozon controversy lies around the question of whether or not the depletion of the ozon e layer
e layer
will lead to more sunburns, and in turn, more skin cancer. Some scientists sugge will lead to more sunburns, and in turn, more skin cancer. Some scientists sugge st that
st that
the skin will gradually adapt to higher UV-B levels as the ozone gradually deple the skin will gradually adapt to higher UV-B levels as the ozone gradually deple tes
tes
(Nilsson, 83). The opponent to this theory would state that the thinning of the (Nilsson, 83). The opponent to this theory would state that the thinning of the ozone
ozone
layer would lead to more human UV-B exposure. This increased UV-B exposure would layer would lead to more human UV-B exposure. This increased UV-B exposure would ,
,
in turn, increase the damage to the DNA making it difficult for the cell to corr in turn, increase the damage to the DNA making it difficult for the cell to corr ect the
ect the
damage before it divides. This damage accumulates over time and increases the ch damage before it divides. This damage accumulates over time and increases the ch ances
ances
that a cell will turn cancerous. In addition, since UV-B radiation damages the i that a cell will turn cancerous. In addition, since UV-B radiation damages the i mmune
mmune
system, it is much more likely that a cell will turn cancerous.
system, it is much more likely that a cell will turn cancerous. In animal studiesIn animal studies ,
,
immunosuppressive effects caused by UV-B have indeed been shown to play an immunosuppressive effects caused by UV-B have indeed been shown to play an important role in the outcome of both melanoma and non-melanoma skin cancers important role in the outcome of both melanoma and non-melanoma skin cancers (Nilsson, 105). Furthermore, Nilsson (81) states that
(Nilsson, 105). Furthermore, Nilsson (81) states that for the non-melanoma skinfor the non-melanoma skin cancers, the evidence is compelling and there are estimates that each percentage cancers, the evidence is compelling and there are estimates that each percentage
decrease decrease
in the stratospheric ozone will lead to a two percent increase in the incidence in the stratospheric ozone will lead to a two percent increase in the incidence of these
of these cancers.
cancers. Thus, if the ozone depletes by ten percent over a certain time period, 2Thus, if the ozone depletes by ten percent over a certain time period, 2 50,000
50,000
more people would be affected by these cancers each year (Nilsson, 81). more people would be affected by these cancers each year (Nilsson, 81).
Due to controversy in the scientific community, it is difficult to clearly state Due to controversy in the scientific community, it is difficult to clearly state
whether or whether or
not ozone depletion will lead to an increased risk of skin cancers, but scientis not ozone depletion will lead to an increased risk of skin cancers, but scientis ts agree on
ts agree on
the fact that UV-B radiation plays a large role in the formation of cancer. Thus the fact that UV-B radiation plays a large role in the formation of cancer. Thus , it may
, it may
very well be that as the
very well be that as the UV filterUV filter we call the ozone layer thins, the increased amwe call the ozone layer thins, the increased am ount of
ount of
UV-B radiation posed on human skin may contribute to an increased amount of skin UV-B radiation posed on human skin may contribute to an increased amount of skin cancer. Yet, one can only weigh all the evidence and speculate, for science has cancer. Yet, one can only weigh all the evidence and speculate, for science has yet to
yet to provide a
provide a cut and drycut and dry answer for society to base its judgments on.answer for society to base its judgments on. 9
V. Ozone depletion and immuno-suppression V. Ozone depletion and immuno-suppression
Ozone depletion is also suggested to cause immuno-suppression. This theory was f Ozone depletion is also suggested to cause immuno-suppression. This theory was f irst
irst
explored in the 1960s when guinea-pigs, who were exposed to an allergen, showed explored in the 1960s when guinea-pigs, who were exposed to an allergen, showed a
a
lowered immune system response after they had been irradiated with UV (Nilsson, lowered immune system response after they had been irradiated with UV (Nilsson, 101).
101).
In addition, another study showed that UV radiation had the same effect on anima In addition, another study showed that UV radiation had the same effect on anima ls as
ls as
X-ray treatment and chemical immuno-suppression. Logically, all three factors supp ray treatment and chemical immuno-suppression. Logically, all three factors supp ressed
ressed
the immune system. the immune system.
Scientists Edward de Fabo and Frances Noonan conducted a study to investigate ex Scientists Edward de Fabo and Frances Noonan conducted a study to investigate ex actly
actly
which portion of the UV spectrum has the power to suppress the immune system. In which portion of the UV spectrum has the power to suppress the immune system. In
this this
experiment, de Fabo and Noonan employed filters that were able to separate UV ra experiment, de Fabo and Noonan employed filters that were able to separate UV ra diation
diation
wavelength by wavelength. They subjected mice to UV rays and measured the effect wavelength by wavelength. They subjected mice to UV rays and measured the effect s at
s at
precise intervals on the UV range.
precise intervals on the UV range. When de Fabo and Noonan started to match the pWhen de Fabo and Noonan started to match the p arts
arts
of the spectrum that gave the most immuno-suppression with the absorption spectr of the spectrum that gave the most immuno-suppression with the absorption spectr a of
a of
different compounds in the skin, they found an almost perfect match
different compounds in the skin, they found an almost perfect match UCA, theUCA, the compound previously thought of as sunscreen (Nilsson, 102).
compound previously thought of as sunscreen (Nilsson, 102). Nilsson (107) describNilsson (107) describ es
es
urocanic acid (UCA) as antenna-like because it attracts UV rays. When UV radiati urocanic acid (UCA) as antenna-like because it attracts UV rays. When UV radiati on hits
on hits
the skin, it causes UCA within the skin to change molecular structure from trans the skin, it causes UCA within the skin to change molecular structure from trans -UCA to
-UCA to
cis-UCA. This transformation interacts with a number of cells in the skin and se cis-UCA. This transformation interacts with a number of cells in the skin and se nds a
nds a
signal to the immune system, causing it to hinder its reaction. If the UVA has c signal to the immune system, causing it to hinder its reaction. If the UVA has c aused
aused
damage to the DNA, then the possibility exists for a cancer growth (See Figure 8 damage to the DNA, then the possibility exists for a cancer growth (See Figure 8 ).
).
Figure 8: UV radiation causes the transformation of trans-UCA to the form cis-UC Figure 8: UV radiation causes the transformation of trans-UCA to the form cis-UC A,
A,
damaging DNA and causing the immune system to suppress. damaging DNA and causing the immune system to suppress. 10
2008 2008
OMTEX CLASSES -09 OMTEX CLASSES -09
VI. What about other illnesses? VI. What about other illnesses?
Like immuno-suppression and skin cancer, science is not able to provide society Like immuno-suppression and skin cancer, science is not able to provide society with a
with a
confident answer to the question: Will the depletion of the ozone layer cause an confident answer to the question: Will the depletion of the ozone layer cause an
increased increased
number of cataract cases? Cataracts are a condition that begin with blurry visio number of cataract cases? Cataracts are a condition that begin with blurry visio n and in
n and in
some cases, develop into blindness. It has been proven that UV light can damage some cases, develop into blindness. It has been proven that UV light can damage the
the
DNA, membranes, and proteins in the eye, and in animal studies, this damage has DNA, membranes, and proteins in the eye, and in animal studies, this damage has resulted in scattered light and the formation of opaque areas in the eye. It was resulted in scattered light and the formation of opaque areas in the eye. It was
estimated estimated
by the Environmental Effects Panel of the United Nations Environment Programme t by the Environmental Effects Panel of the United Nations Environment Programme t hat
hat
for each percent decrease in ozone, the number of people developing blindness wo for each percent decrease in ozone, the number of people developing blindness wo uld
uld
increase by approximately 100,000 to 150,000 people (Nilsson, 113). However, thi increase by approximately 100,000 to 150,000 people (Nilsson, 113). However, thi s
s
estimation was contradicted by a team of Dutch scientists, who stated,
estimation was contradicted by a team of Dutch scientists, who stated, it is notit is not scientifically justifiable to quantify the effects of UV radiation on the eye, i scientifically justifiable to quantify the effects of UV radiation on the eye, i f such effects
f such effects
are present under normal circumstances
are present under normal circumstances (Nilsson, 113). The UNEP then published an(Nilsson, 113). The UNEP then published an updated statement and included information that poor diet and diseases, such as updated statement and included information that poor diet and diseases, such as diabetes,
diabetes,
also contribute to cataract development. Thus, it must be recognized that catara also contribute to cataract development. Thus, it must be recognized that catara cts can
cts can
result from poor nutrition, poor hygiene, and diabetes, and not solely from incr result from poor nutrition, poor hygiene, and diabetes, and not solely from incr eased UV
eased UV radiation. radiation.
Research has been conducted to investigate a link between cataracts and UV radia Research has been conducted to investigate a link between cataracts and UV radia tion.
tion.
Some epidemiological studies have shown that UV-B radiation and formation of cat Some epidemiological studies have shown that UV-B radiation and formation of cat aracts
aracts
do have a positive relationship. For example, a study conducted with Chesapeake do have a positive relationship. For example, a study conducted with Chesapeake Bay
Bay
fishermen asked these fishermen to disclose whether or not they wore sunglasses fishermen asked these fishermen to disclose whether or not they wore sunglasses while
while
working and during outdoor recreational activities. Then, radiation measurements working and during outdoor recreational activities. Then, radiation measurements
were were
taken throughout the area to probe for a correlation. The results of this study taken throughout the area to probe for a correlation. The results of this study showed a
showed a
weak positive dose-response relationship with UV-B exposureweak positive dose-response relationship with UV-B exposure (Nilsson, 117). Thus,(Nilsson, 117). Thus, in
in
this study, one would argue that increased UV radiation would lead to increased this study, one would argue that increased UV radiation would lead to increased rates of
rates of
cataracts. Many other studies have been conducted to examine this phenomenon, an cataracts. Many other studies have been conducted to examine this phenomenon, an d
d
none have shown a strongly correlated causal relationship between UV-B and catar none have shown a strongly correlated causal relationship between UV-B and catar acts,
acts,
but many suggest the possibility of a relationship. In summary, there is again n but many suggest the possibility of a relationship. In summary, there is again n o
o cut andcut and dry
dry answer explaining what will happen to the number of cases of cataracts as theanswer explaining what will happen to the number of cases of cataracts as the ozone
A short-term health problem that will increase as the level of ozone decreases i A short-term health problem that will increase as the level of ozone decreases i s
s
snowblindnesssnowblindness oror welderwelders arc flash.s arc flash. This phenomenon is a result of sunburn of theThis phenomenon is a result of sunburn of the conjunctiva and cornea and is
conjunctiva and cornea and is characterized by blurred vision, severe pain, photocharacterized by blurred vision, severe pain, photo phobia,
phobia,
profuse tearing, and eyelid spasms
profuse tearing, and eyelid spasms (Ozone.org, 1998). The condition occurs after(Ozone.org, 1998). The condition occurs after exposure to UV-B radiation and does not result in permanent damage. The symptoms exposure to UV-B radiation and does not result in permanent damage. The symptoms usually vanish after a few days. It is obvious to recognize the controversy surr usually vanish after a few days. It is obvious to recognize the controversy surr ounding
ounding
theories which state that depletion of the ozone layer causes health problems. W theories which state that depletion of the ozone layer causes health problems. W hile one
hile one
resource may provide the reader with one answer, the next source may provide the resource may provide the reader with one answer, the next source may provide the opposite theory. It is evident that UV radiation causes various health problems, opposite theory. It is evident that UV radiation causes various health problems,
but what but what
is not so clear is to what degree a depleting ozone layer will magnify the occur is not so clear is to what degree a depleting ozone layer will magnify the occur rence of
rence of
these problems. these problems.
VII. Ozone depletion: Not a farmer
VII. Ozone depletion: Not a farmers best friend.s best friend. 11
2008 2008
OMTEX CLASSES -09 OMTEX CLASSES -09
Another common, yet, highly debated concern with regards to the depleting ozone Another common, yet, highly debated concern with regards to the depleting ozone layer
layer
is crop and plant damage. As it has been well stressed, depletion of the ozone l is crop and plant damage. As it has been well stressed, depletion of the ozone l ayer
ayer
results in higher UV-B radiation on the earth
results in higher UV-B radiation on the earths surface. Ironically, while plantss surface. Ironically, while plants use light
use light
as their main fuel for growth, a delicate balance must be achieved in order for as their main fuel for growth, a delicate balance must be achieved in order for the plant to
the plant to
survive. If a plant is exposed to too much UV radiation, the DNA of the plant ma survive. If a plant is exposed to too much UV radiation, the DNA of the plant ma y
y
become damaged due to penetration of harmful UV radiation into sensitive areas o become damaged due to penetration of harmful UV radiation into sensitive areas o f the
f the
plant. UV radiation also causes problems in the photosynthetic machinery by hamp plant. UV radiation also causes problems in the photosynthetic machinery by hamp ering
ering
the photosynthesis process, the cell membrane by altering the transportation of the photosynthesis process, the cell membrane by altering the transportation of essential
essential
potassium, and the cell
potassium, and the cells skeleton by affecting cell growth and morphology. With ts skeleton by affecting cell growth and morphology. With t his
his
information taken into account, it would seem logical that increased UV radiatio information taken into account, it would seem logical that increased UV radiatio n from
n from
the depleting ozone layer would lead to plant damage. However, it is not that si the depleting ozone layer would lead to plant damage. However, it is not that si mple.
mple.
Some plants actually employ a mechanism that allows them to protect themselves f Some plants actually employ a mechanism that allows them to protect themselves f rom
rom
UV damage. Thus, research suggests that if ozone depletion became serious enough UV damage. Thus, research suggests that if ozone depletion became serious enough , the
, the
plants without the protective mechanisms would die out, but the plants with thes plants without the protective mechanisms would die out, but the plants with thes e
e
mechanisms would be able to replace the extinct plants, and not affect the level mechanisms would be able to replace the extinct plants, and not affect the level
of of
productivity in the ecosystem (Nilsson, 54). Thus, much depends on which plants productivity in the ecosystem (Nilsson, 54). Thus, much depends on which plants survive.
survive.
To further investigate the affect of UV radiation on plants, experiments have be To further investigate the affect of UV radiation on plants, experiments have be en done to
en done to
study the effects of UV-B levels on crop yield (Nilsson, 52). The results conclu study the effects of UV-B levels on crop yield (Nilsson, 52). The results conclu ded that
ded that
in approximately 50% of the crops, an increased UV-B level lead to a decrease in in approximately 50% of the crops, an increased UV-B level lead to a decrease in
crop crop
yield. Specifically, the corn yield was reduced by 28 percent; and beans, squash yield. Specifically, the corn yield was reduced by 28 percent; and beans, squash , and
, and
various forms of peas were also found to be sensitive to UV-B radiation. One wou various forms of peas were also found to be sensitive to UV-B radiation. One wou ld
ld
logically conclude that the depletion of the ozone layer would lead to a reducti logically conclude that the depletion of the ozone layer would lead to a reducti on in the
on in the
yield of crops. However, science may offer a solution by being able to breed cro yield of crops. However, science may offer a solution by being able to breed cro ps that
ps that
are resistant to UV radiation. are resistant to UV radiation.
The answer to the question of decreased crop yield and existence of plants as a The answer to the question of decreased crop yield and existence of plants as a result of a
result of a
thinning ozone layer is not scientifically definitive. However, it is important thinning ozone layer is not scientifically definitive. However, it is important because if
because if
the ability of plants to intake carbon dioxide and regulate the amount of carbon the ability of plants to intake carbon dioxide and regulate the amount of carbon
dioxide in dioxide in
2008 2008
OMTEX CLASSES -09 OMTEX CLASSES -09
VIII. Collaborative Global Government Efforts VIII. Collaborative Global Government Efforts
As a result of the many concerns that a thinning ozone layer poses to society an As a result of the many concerns that a thinning ozone layer poses to society an d the
d the
environment, the U.S. government and many international agencies have been relat environment, the U.S. government and many international agencies have been relat ively
ively
active in attempting to monitor, regulate, and solve the problem. Perhaps the mo active in attempting to monitor, regulate, and solve the problem. Perhaps the mo st well
st well
known acts to help control the depletion of the ozone layer were the Montreal Pr known acts to help control the depletion of the ozone layer were the Montreal Pr otocol,
otocol,
and the London Ozone amendment to the Montreal Protocol. On September 14, 1987, and the London Ozone amendment to the Montreal Protocol. On September 14, 1987, delegates from 43 countries met to discuss threats of the thinning ozone layer. delegates from 43 countries met to discuss threats of the thinning ozone layer. After
After
much discussion, the delegates agreed to halt production and consumption of CFCs much discussion, the delegates agreed to halt production and consumption of CFCs
at at
1986 levels by the year 1990. In addition, nations also agreed to reduce CFCs 20 1986 levels by the year 1990. In addition, nations also agreed to reduce CFCs 20
percent percent
by January 1, 1994 and an additional 30 percent by January 1, 1999 (Roan, 208-9) by January 1, 1994 and an additional 30 percent by January 1, 1999 (Roan, 208-9) . This
. This
was known as the Montreal Protocol. Even though this protocol helped the state o was known as the Montreal Protocol. Even though this protocol helped the state o f the
f the
ozone layer, the results were not significant enough. Thus, shortly after the ozone layer, the results were not significant enough. Thus, shortly after the implementation of the protocol, in 1990, it was amended. This amendment recruite implementation of the protocol, in 1990, it was amended. This amendment recruite d
d
more countries, bringing the total number involved to almost 100. The new goals more countries, bringing the total number involved to almost 100. The new goals were to
were to
eliminate the use of all CFCs by the year 2000, and to help set up a fund so tha eliminate the use of all CFCs by the year 2000, and to help set up a fund so tha t
t
developing countries may find alternates to using CFCs. The name of this amendme developing countries may find alternates to using CFCs. The name of this amendme nt
nt
was the London Ozone Agreement. Thus, many nations recognized the need for rapid was the London Ozone Agreement. Thus, many nations recognized the need for rapid and dramatic action in fighting the war with CFC responsible ozone depletion. and dramatic action in fighting the war with CFC responsible ozone depletion. 13
Ozone and health Ozone and health
Ozone in air pollution Ozone in air pollution
There is a great deal of evidence to show that high concentrations (ppm) of ozon There is a great deal of evidence to show that high concentrations (ppm) of ozon e,
e,
created by high concentrations of pollution and daylight UV rays at the earth
created by high concentrations of pollution and daylight UV rays at the earths sus su rface,
rface,
can harm lung function and irritate the respiratory system.[16][23] A connection can harm lung function and irritate the respiratory system.[16][23] A connection
has also has also
been shown to exist between increased ozone caused by thunderstorms and hospital been shown to exist between increased ozone caused by thunderstorms and hospital admissions of asthma sufferers.[24] Air quality guidelines such as those from th admissions of asthma sufferers.[24] Air quality guidelines such as those from th e World
e World
Health Organization are based on detailed studies of what levels can cause measu Health Organization are based on detailed studies of what levels can cause measu rable
rable
health effects. health effects.
A common British folk myth dating back to the Victorian era holds that the smell A common British folk myth dating back to the Victorian era holds that the smell
of the of the
sea is caused by ozone, and that this smell has
sea is caused by ozone, and that this smell has bracingbracing health benefits.[25] Neithhealth benefits.[25] Neith er of
er of
these is true. The characteristic
these is true. The characteristic smell of the seasmell of the sea is not caused by ozone, but byis not caused by ozone, but by the
the
presence of dimethyl sulfide generated by phytoplankton, and dimethyl sulfide, l presence of dimethyl sulfide generated by phytoplankton, and dimethyl sulfide, l ike
ike
ozone, is toxic in high concentrations.[26] ozone, is toxic in high concentrations.[26]
The United States Environmental Protection Agency has developed an Air Quality i The United States Environmental Protection Agency has developed an Air Quality i ndex
ndex
to help explain air pollution levels to the general public. 8-hour average ozone to help explain air pollution levels to the general public. 8-hour average ozone concentrations of 85 to 104 ppbv are described as
concentrations of 85 to 104 ppbv are described as Unhealthy for Sensitive GroupsUnhealthy for Sensitive Groups,, 105
105
ppbv to 124 ppbv as
ppbv to 124 ppbv as unhealthyunhealthy and 125 ppb to 404 ppb asand 125 ppb to 404 ppb as very unhealthyvery unhealthy.[27] The.[27] The EPA has designated over 300 counties of the United States, clustered around the EPA has designated over 300 counties of the United States, clustered around the most
most
heavily populated areas (especially in California and the Northeast), as failing heavily populated areas (especially in California and the Northeast), as failing
to comply to comply
with the National Ambient Air Quality Standards. with the National Ambient Air Quality Standards. Health Effects of UV Radiation
Health Effects of UV Radiation
Overexposure to UV radiation is the main cause of skin cancer. UV rays can trigg Overexposure to UV radiation is the main cause of skin cancer. UV rays can trigg er the
er the
development of skin cancer by creating changes in the cells of the skin. In some development of skin cancer by creating changes in the cells of the skin. In some
cases, cases,
the UV rays cause direct damage to the cells. Tans and sunburns, for example, ar the UV rays cause direct damage to the cells. Tans and sunburns, for example, ar e both
e both
signs that UV rays have damaged the skin. In other cases, UV rays can cause skin signs that UV rays have damaged the skin. In other cases, UV rays can cause skin
cancer cancer
indirectly, by weakening the immune mechanisms in skin and the rest of the body. indirectly, by weakening the immune mechanisms in skin and the rest of the body.
Most often, skin cancer is the result of overexposure to UV rays from the sun. T Most often, skin cancer is the result of overexposure to UV rays from the sun. T here are
here are
three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and m three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and m alignant
alignant
melanoma. The last one can be fatal if not treated early. Many studies of skin c melanoma. The last one can be fatal if not treated early. Many studies of skin c ancer
ancer 14 14
show links between malignant melanomas and an individual
show links between malignant melanomas and an individuals intolerance to suns intolerance to sun exposure. The studies indicate that people who have suffered severe and frequent exposure. The studies indicate that people who have suffered severe and frequent sunburns during childhood are at greater risk of developing melanoma. The featur sunburns during childhood are at greater risk of developing melanoma. The featur es most
es most
closely associated with intolerance to sun exposure include fair or freckled ski closely associated with intolerance to sun exposure include fair or freckled ski n, blue
n, blue
eyes, and light-coloured or reddish hair. eyes, and light-coloured or reddish hair.
The two other types of skin cancer tend to develop later in life on areas of ski The two other types of skin cancer tend to develop later in life on areas of ski n that have
n that have
been exposed repeatedly to the sun, such as the face, neck, or hands. Basal and been exposed repeatedly to the sun, such as the face, neck, or hands. Basal and squamous
squamous
cell carcinomas progress slowly and rarely cause death because they usually do n cell carcinomas progress slowly and rarely cause death because they usually do n ot
ot
spread to other parts of the body. spread to other parts of the body.
Overexposure to ultraviolet radiation has also been linked to a number of other Overexposure to ultraviolet radiation has also been linked to a number of other health
health
effects, including sunburns, cataracts, premature aging of the skin, and weakeni effects, including sunburns, cataracts, premature aging of the skin, and weakeni ng of the
ng of the
immune system. immune system.
Minimizing Your Risk Minimizing Your Risk
There is no quick fix for the ozone layer. Once they get into the environment, o There is no quick fix for the ozone layer. Once they get into the environment, o zone-depleting chemicals
zone-depleting chemicals
disintegrate very slowly, so they are likely to be with us for a long time. Whil disintegrate very slowly, so they are likely to be with us for a long time. Whil e governments around the world
e governments around the world
deal with the source of the problem, it is important to take steps to avoid over deal with the source of the problem, it is important to take steps to avoid over exposure to ultraviolet radiation.
exposure to ultraviolet radiation.
These guidelines will help you protect your family from the sun
These guidelines will help you protect your family from the suns harmful rays:s harmful rays:
Seek shade if you are taking part in outdoor activities when the UV index is thr Seek shade if you are taking part in outdoor activities when the UV index is thr ee ee or higher. or higher.
Cover up. Wear long-sleeved shirts, long pants, gloves, and a broad-brimmed hat Cover up. Wear long-sleeved shirts, long pants, gloves, and a broad-brimmed hat or visor. Avoid see-through clothing when possible.
or visor. Avoid see-through clothing when possible.
Avoid sunbathing for the purpose of tanning, especially between 11:00 a.m. and Avoid sunbathing for the purpose of tanning, especially between 11:00 a.m. and 4:00 p.m. in the summer when the sun
4:00 p.m. in the summer when the suns rays are strongest.s rays are strongest.
Use sunscreen lotion and reapply it often, as directed on the label. Look for a Use sunscreen lotion and reapply it often, as directed on the label. Look for a
broad spectrumbroad spectrum sunscreen with a sun protection factor (SPF) of at least 15.sunscreen with a sun protection factor (SPF) of at least 15.
Wear sunglasses that screen out ultraviolet radiation. Your eyes have no built-i Wear sunglasses that screen out ultraviolet radiation. Your eyes have no built-i n
n
defence against the sun, and damage to the eye from UV rays can lead to defence against the sun, and damage to the eye from UV rays can lead to cataracts.
cataracts.
Do not think you are safe just because the sky is cloudy. The sun
Do not think you are safe just because the sky is cloudy. The suns harmful rayss harmful rays can get through fog, haze, and light cloud cover.
15 15
Children Need Extra Protection Children Need Extra Protection
Children and teenagers have more sensitive skin than adults, so they need extra Children and teenagers have more sensitive skin than adults, so they need extra protection
protection
if they are going to be out in the sun for a long time. Sunburn may increase the if they are going to be out in the sun for a long time. Sunburn may increase the
risk of risk of
skin cancer later in life, so it is best to get children used to wearing protect skin cancer later in life, so it is best to get children used to wearing protect ive clothing
ive clothing
and sunscreen lotion from the start. and sunscreen lotion from the start.
At the very least, young children should wear a sunhat, T-shirt, and shorts. Whe At the very least, young children should wear a sunhat, T-shirt, and shorts. Whe n you put
n you put
sunscreen on children, pay special attention to the parts that are most exposed, sunscreen on children, pay special attention to the parts that are most exposed,
including including
their ears, face, neck, shoulders and back, knees, and the tops of their feet. A their ears, face, neck, shoulders and back, knees, and the tops of their feet. A void using
void using
sunscreen on babies. Cover them and keep them in the shade instead. sunscreen on babies. Cover them and keep them in the shade instead.
It is important to protect against ultraviolet radiation all year round; not jus It is important to protect against ultraviolet radiation all year round; not jus t in the
t in the
summer. You can continue to enjoy outdoor activities, as long as you take steps summer. You can continue to enjoy outdoor activities, as long as you take steps to protect
to protect
yourself when the UV index is three or higher to avoid sunburns and overexposure yourself when the UV index is three or higher to avoid sunburns and overexposure .
. 16 16
2008 2008 OMTEX CLASSES -09 OMTEX CLASSES -09 DISCUSSION DISCUSSION
Regardless of the details of the arguments, it is obvious that the depletion of Regardless of the details of the arguments, it is obvious that the depletion of the ozone
the ozone
layer is a serious problem that poses many consequences to society. Although sci layer is a serious problem that poses many consequences to society. Although sci entific
entific
controversy exists, the possibility seems high that the depletion of the ozone l controversy exists, the possibility seems high that the depletion of the ozone l ayer will
ayer will
prove detrimental if action is not taken. For example, research shows the strong prove detrimental if action is not taken. For example, research shows the strong possibility of a number of health risks associated with increased UV-B exposure possibility of a number of health risks associated with increased UV-B exposure as a
as a
direct result of the thinning ozone layer. These health risks include skin cance direct result of the thinning ozone layer. These health risks include skin cance r, immunosuppression,
r, immunosuppression, cataracts, and
cataracts, and snowblindness.snowblindness.
Furthermore, the possibility that increased UV-B radiation results in lower crop Furthermore, the possibility that increased UV-B radiation results in lower crop
yields yields
should provide a
should provide a wake upwake up call to those who feel the thinning ozone layer is not acall to those who feel the thinning ozone layer is not a problem. For if we are not able to breed UV-B resistant plants, the world
problem. For if we are not able to breed UV-B resistant plants, the worlds food ss food s upply
upply
would become dramatically decreased, resulting in higher levels of famine and would become dramatically decreased, resulting in higher levels of famine and malnutrition.
malnutrition.
Studies from Antarctica tell society that increased UV radiation can directly af Studies from Antarctica tell society that increased UV radiation can directly af fect the
fect the
food chain. Recall the decrease in food supply as a result of reduced levels of food chain. Recall the decrease in food supply as a result of reduced levels of photoplankton in Antarctica. This may seem like an isolated, non-significant, an photoplankton in Antarctica. This may seem like an isolated, non-significant, an d remote
d remote
problem; however, this incident illustrates the dangers of reduced food supply a problem; however, this incident illustrates the dangers of reduced food supply a nd
nd
alteration of the food chain as a result of the thinning ozone layer. Even thoug alteration of the food chain as a result of the thinning ozone layer. Even thoug h the
h the
photoplankton were located at the bottom of the food chain, the whole chain was photoplankton were located at the bottom of the food chain, the whole chain was affected. In the future, problems like this could potentially affect the global affected. In the future, problems like this could potentially affect the global food web and
food web and
result in an overall decrease in food supply. Thus, realize that the dangers pos result in an overall decrease in food supply. Thus, realize that the dangers pos ed by
ed by
ozone depletion are real now, and will be in the future, if action is not taken. ozone depletion are real now, and will be in the future, if action is not taken.
17 17
Take Action: Teamwork does the trick Take Action: Teamwork does the trick Although the earth will be able to
Although the earth will be able to healheal itself if the CFC level continues to stayitself if the CFC level continues to stay as it is,
as it is,
the depletion of the ozone layer is still a problem that society should be conce the depletion of the ozone layer is still a problem that society should be conce rned with.
rned with.
In order for earth to repair the damage humans have posed on the ozone layer, so In order for earth to repair the damage humans have posed on the ozone layer, so ciety
ciety
must take an active role. There are many tasks individuals can involve themselve must take an active role. There are many tasks individuals can involve themselve s in to
s in to
help combat the problem of ozone depletion. First of all, one can simply check p help combat the problem of ozone depletion. First of all, one can simply check p roduct
roduct
labels for ozone friendly status. Many companies have gone to great lengths to r labels for ozone friendly status. Many companies have gone to great lengths to r emove
emove
CFCs from their products. These products do not do as much damage to the ozone l CFCs from their products. These products do not do as much damage to the ozone l ayer,
ayer,
and thus, are denoted as
and thus, are denoted as ozone friendly.ozone friendly. A collaborative effort by society not usiA collaborative effort by society not usi ng
ng
products with CFCs is a major step toward the healing of the ozone layer. products with CFCs is a major step toward the healing of the ozone layer.
Unfortunately, many products still used in society are detrimental to the ozone Unfortunately, many products still used in society are detrimental to the ozone layer. For
layer. For
example, CFCs marketed under the trade name
example, CFCs marketed under the trade name FreonFreon are used in appliances withare used in appliances with refrigerants such as refrigerators and air conditioners. When individuals must d refrigerants such as refrigerators and air conditioners. When individuals must d ispose of
ispose of
products with refrigerants in them, certain actions must be taken in order to pr products with refrigerants in them, certain actions must be taken in order to pr event the
event the
CFCs from escaping from the disposed product. For example, when an agency, such CFCs from escaping from the disposed product. For example, when an agency, such as a
as a
waste hauling company, comes to pick up the unwanted appliance, check to make su waste hauling company, comes to pick up the unwanted appliance, check to make su re
re
refrigerant-recovery equipment is used by the agency. This equipment allows for refrigerant-recovery equipment is used by the agency. This equipment allows for the
the
disposal of refrigerants without damage to the ozone layer. disposal of refrigerants without damage to the ozone layer.
Society can also help the problem of ozone depletion through education, as well Society can also help the problem of ozone depletion through education, as well as
as
through various donations. If individuals contribute time or money to environmen through various donations. If individuals contribute time or money to environmen tal
tal
agencies focused on healing the ozone layer, the agencies will be able to organi agencies focused on healing the ozone layer, the agencies will be able to organi ze
ze
activities promoting the understanding of the ozone problem. If society is educa activities promoting the understanding of the ozone problem. If society is educa ted
ted
through these means, more individual efforts will be taken to make
through these means, more individual efforts will be taken to make ozone smartozone smart decisions such as using
decisions such as using ozone friendlyozone friendly products.products.
Although thinning ozone may not directly affect the generation growing up today, Although thinning ozone may not directly affect the generation growing up today,
future future
generations depend on the actions taken now. Thus, it is important for society t generations depend on the actions taken now. Thus, it is important for society t o
o
recognize that the thinning ozone layer is a problem and to take action in order recognize that the thinning ozone layer is a problem and to take action in order
to ensure to ensure
the safety and survival of future generations. the safety and survival of future generations. 18
