Ozone Layer Project[1]

2008 OMTEX CLASSES -09 PROJECT ON OZONE LAYER INDEX

NAME OF THE TOPIC COVERED Teacher Teachers Signature 1. The ozone layer: What is it? 2. Ozone depletion: Who is responsible? 3. The ozone hole: Why over Antarctica? 4. SOCIETAL ASPECTS 5. Ozone depletion and skin cancer: What What s the connection? 6. What about other illnesses? 7. Ozone depletion: Not a farmer farmers best friend. 8. Collaborative Global Government Efforts 9. Ozone and health 10.DISCUSSION 11.SUMMARY 1

2008 OMTEX CLASSES -09 I. The ozone layer: What is it? The ozone layer is a portion of earths atmosphere that contains high levels of o zone. The atmosphere is divided into five layers: the troposphere, the stratosphere, the m esosphere, the thermosphere, and the exosphere. The troposphere is the layer closest to ear th and is where all weather happenings occur. The stratosphere is located directly above t he troposphere, about 10-50 kilometers above the planet, and houses the ozone layer at an altitude of 20-30 kilometers. The mesosphere is located approximately 50-80 kilo meters above the earth, while the thermosphere rests at an altitude of approximately 10 0-200 kilometers above the earths surface. Finally, the boundary of the outermost laye r, the exosphere, extends roughly to 960-1000 kilometers above the earth. For a visual of the 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 llotrope of oxygen that is much less stable than the diatomic species O2. Ground-level ozone is an air pollutant with harmful effects on the respiratory systems of animals. Ozone in t he upper atmosphere filters potentially damaging ultraviolet light from reaching the Eart hs surface. It is present in low concentrations throughout the Earth Earth s atmosphere. It has many industrial and consumer applications. Ozone therapy is a controversial alte rnative medicine practice; mainstream scientific medicine has found ozone to be harmful to humans and equipment intended to be used for ozone therapy is banned in the Unit ed States. Ozone, the first allotrope of a chemical element to be described by scie nce, was discovered by Christian Friedrich Schönbein in 1840, who named it after the Gree k word for smell (ozein), from the peculiar odor in lightning storms.[3] The odor from a lightning strike is from ions produced during the rapid chemical changes, not the ozone it self

Figure 1: Earth Earths atmosphere is divided into layers, which have various characteri stics. Source: NOAA Aeronomy Laboratory, 1998 The ozone found in our atmosphere is formed by an interaction between oxygen molecules (composed of two oxygen atoms) and ultraviolet light. When ultraviolet light hits these oxygen molecules, the reaction causes the molecules to break apart in

to single 2

2008 OMTEX CLASSES -09 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 ), 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 ltraviolet radiation, preventing penetration to the earth earth s surface. Ultraviolet radiation (U V) is defined as radiation with wavelengths between 290-320 nanometers, which are harm ful to life because this radiation can enter cells and destroy the deoxyribonucleic acid (DNA) of many life forms on planet earth. In a sense, the ozone layer can be thought o f as a filter or our planet planets built in sunscreen sunscreen (Geocities.com, 1998). Without the ozone UV filter layer, UV radiation would not be filtered as it reached the surface of the earth . If this happened, cancer would break out and all of the living civilizations, and all spe cies on earth would be in jeopardy jeopardy (Geocities.com, 1998). Thus, the ozone layer essential ly 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 asurement called the Dobson Unit is employed. A Dobson Unit is a measurement of how thick a specific portion of the ozone layer would be if it were compressed into a single layer at zero degrees Celsius with one unit of atmospheric pressure acting on it (standar d 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 ver Labrador, Canada. Since the ozone layer over this area would form a 3 mm thick s lab, the measurement of the ozone over Labrador is 300 DU.

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2008 OMTEX CLASSES -09 II. Ozone depletion: Who is responsible? 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: human activity, natural sources, and volcanic eruptions (See Figure 3).

Figure 3: Humans cause more damage to the ozone layer than any other source. Source: Geocities.com, 1998

Human activity is by far the most prevalent and destructive source of ozone depl etion, while threatening volcanic eruptions are less common. Human activity, such as th e release of various compounds containing chlorine or bromine, accounts for approximately 75 to 85 percent of ozone damage. Perhaps the most evident and destructive molecule of this description is chloroflourocarbon (CFC). CFCs were first used to clean electronic circuit boards, and as time progressed, were used in ae rosols and coolants, such as refrigerators and air conditioners. When CFCs from these produ cts are released into the atmosphere, the destruction begins. As CFCs are emitted, the m olecules float toward the ozone rich stratosphere. Then, when UV radiation contacts the C FC molecule, this causes one chlorine atom to liberate. This free chlorine then rea cts with an 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 + O3 --> O2 + ClO. Then, a single oxygen atom reacts with a chlorine monoxide molecule, caus ing the formation of an oxygen molecule (O2) and a single chlorine atom (O + ClO --> Cl + O2). This threatening chlorine atom then continues the cycle and results in furt her destruction of the ozone layer (See Figure 4). Measures have been taken to reduc e the amount of CFC emission, but since CFCs have a life span of 20-100 years, previou sly emitted CFCs will do damage for years to come. 4

2008 OMTEX CLASSES -09

Figure 4: A pictorial explanation of how the interaction of CFCs and UV radiatio n damage the ozone layer. Source: Geocities.com, 1998 Natural sources also contribute to the depletion of the ozone layer, but not nea rly as much as human activity. Natural sources can be blamed for approximately 15 to 20 perc ent of ozone damage. A common natural source of ozone damage is naturally occurring chlorine. Naturally occurring chlorine, like the chlorine released from the reac tion between a CFC molecule and UV radiation, also has detrimental effects and poses danger to the earth. Finally, volcanic eruptions are a small contributor to ozone damage, accounting for one to five percent. During large volcanic eruptions, chlorine, as a component of hydro chloric acid (HCl), is released directly into the stratosphere, along with sulfur dioxid e. In this case, sulfur dioxide is more harmful than chlorine because it is converted into sulfuric acid aerosols. These aerosols accelerate damaging chemical reactions, which caus e chlorine to destroy ozone. 5

2008 OMTEX CLASSES -09 III. The ozone hole: Why over Antarctica? When the topic of the ozone layer arises, many people immediately think of the h ole over Antarctica, but few know why the hole is actually there. In 1985, British s cientists discovered this hole. A special condition exists in Antarctica that accelerates the depletion of the ozone layer. Every Arctic winter, a polar vortex forms over Ant arctica. A polar vortex is a swirling mass of very cold, stagnant air surrounded by strong westerly winds winds (Roan, 126). Since there is an absence of sun during Arctic winter s, the air becomes incredibly cold and the formation of ice clouds occurs. When the sun returns in the spring, the light shining on the nitrogen oxide filled ice particles acti vates the formation of chlorine. This excess of ozone destroying chlorine rapidly accelera tes the depletion of the ozone layer. Finally, when the polar vortex breaks up, the rapi d dissolution decreases. It is evident that the effects of the polar vortex are dr amatic. For about two month every southern spring, the total ozone declines by about 60% ove r most of Antarctica. In the core of the ozone hole, more than 75% of the ozone is lost and at some altitudes, the ozone virtually disappeared in October, 1993 1993  (Nilsson, 19). T he average size of the ozone hole is larger than most continents, including South A merica, Europe, Australia, and Antarctica, and the maximum size of the ozone hole in 199 6 was larger than North America (See Figure 5). Finally, one must note that the hole hole ove r Antarctica is truly a hole hole only in the Antarctic spring, when the depletion is ext remely severe due to the vortex.

Figure 5: On average, the size of the ozone hole is larger than many countries. Source: Geocities.com, 1998

The hole above Antarctica has clearly proven to be detrimental. Plankton, organi sms that live on carbon, light, and nutrients such as nitrogen, are near the bottom of th e food 6

2008 OMTEX CLASSES -09 chain, and are accustomed to low levels of UV. In December of 1994, on the islan d of Bacharcaise off Antarctica, increased levels of UV radiation decreased the numbe r of photoplankton dramatically. Photoplankton are the main source of food for krill, which in turn are the main source of food for various birds and whales in the Antarcti c region (See Figure 6).

Figure 6: Ultraviolet radiation proved detrimental to this Arctic food chain in December, 1994. Source: Nilsson, 1996 At this time, due to the decreased number of photoplankton, the krill level was so low that it could not support the penguin population. Thus, some penguins were force d to 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 n chicks survived. This tragedy illustrates the fact that even underwater creature s are not protected from harmful UV rays, and is a perfect example of the entire food chai n being affected due to an increase in the UV radiation as a result of the thinning ozon e layer. 7

2008 OMTEX CLASSES -09 SOCIETAL ASPECTS The most obvious, and perhaps most important connection between society and the ozone layer is the fact that scientific research suggests depletion of the ozone layer directly and indirectly endangers the health of the population. Research has focused on conne ctions between the depleting ozone layer and skin cancer, immuno-suppression, cataracts , and snow blindness. IV. Ozone depletion and skin cancer: What What s the connection? Exposure to UV radiation increases the risk of skin cancer and causes damage to the DNA in the skin cells. DNA is extremely sensitive to UV radiation, especially UV -B radiation. UV radiation is located in the optical radiation portion of the elect romagnetic spectrum, while UV-B radiation is a subdivision of the ultraviolet spectrum and consists of a wavelength of 280 to 315 nanometers. Thus, DNA is especially sensitive to r adiation 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 h of 280-315 nanometers, as measured on the electromagnetic spectrum. Source: Nilsson, 1996 When UV radiation hits the skin, it can cause the cell to lock up up and scramble or delete DNA information. This action causes confusion in the DNA, and the body loses con trol of the growth and division of the cell. If the conditions are right, the cell ma y become cancerous. It is important to note that not all affected cells turn into skin ca ncer, for many can repair themselves. However, continual exposure to UV radiation increase s the risk of skin cancer due to cumulative damage of the DNA. 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 er has 8

2008 OMTEX CLASSES -09 the ability to spread quickly throughout the body and invade other cells. On the other hand, non-melanoma skin cancer is not to be taken lightly either, but is a less serious form of the disease. Non-melanoma skin cancers are not usually life threatening, and removal is relatively routine. However, treatment does include radiation therapy or surgery. The concern of many is that sunburn may lead to increased risk of acqui ring skin cancer. Some forms of cancer are associated with sunburn, while other forms are not. Melanoma skin cancer is a form that sunburns may play a leading role in. Jan van der Leun, a Dutch scientist, explains that, light hitting the outer layer of the skin , the epidermis, triggers the production of some substances which diffuse into the der mis below. The dermis is filled with blood vessels, and the chemical substances caus e them to dilate, making the skin red and warm to the touch touch  (Nilsson, 83). The bottom line is that UV ray exposure increases the risk of skin cancer. Howev er, controversy lies around the question of whether or not the depletion of the ozon e layer will lead to more sunburns, and in turn, more skin cancer. Some scientists sugge st that the skin will gradually adapt to higher UV-B levels as the ozone gradually deple tes (Nilsson, 83). The opponent to this theory would state that the thinning of the ozone 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 ect the damage before it divides. This damage accumulates over time and increases the ch ances that a cell will turn cancerous. In addition, since UV-B radiation damages the i mmune system, it is much more likely that a cell will turn cancerous. In animal studies , 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 cancers  (Nilsson, 105). Furthermore, Nilsson (81) states that for the non-melanoma skin cancers, the evidence is compelling and there are estimates that each percentage decrease in the stratospheric ozone will lead to a two percent increase in the incidence of these cancers. cancers. Thus, if the ozone depletes by ten percent over a certain time period, 2 50,000 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 whether or

not ozone depletion will lead to an increased risk of skin cancers, but scientis ts agree on the fact that UV-B radiation plays a large role in the formation of cancer. Thus , it may very well be that as the UV filter filter we call the ozone layer thins, the increased am ount of 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 yet to provide a cut and dry dry answer for society to base its judgments on. 9

2008 OMTEX CLASSES -09 V. Ozone depletion and immuno-suppression Ozone depletion is also suggested to cause immuno-suppression. This theory was f irst explored in the 1960s when guinea-pigs, who were exposed to an allergen, showed a lowered immune system response after they had been irradiated with UV (Nilsson, 101). In addition, another study showed that UV radiation had the same effect on anima ls as Xray treatment and chemical immuno-suppression. Logically, all three factors supp ressed the immune system. Scientists Edward de Fabo and Frances Noonan conducted a study to investigate ex actly which portion of the UV spectrum has the power to suppress the immune system. In this experiment, de Fabo and Noonan employed filters that were able to separate UV ra diation wavelength by wavelength. They subjected mice to UV rays and measured the effect s at precise intervals on the UV range. When de Fabo and Noonan started to match the p arts of the spectrum that gave the most immuno-suppression with the absorption spectr a of different compounds in the skin, they found an almost perfect match  UCA, the compound previously thought of as sunscreen (Nilsson, 102). 102).  Nilsson (107) describ es urocanic acid (UCA) as antenna-like because it attracts UV rays. When UV radiati on hits the skin, it causes UCA within the skin to change molecular structure from trans -UCA to cis-UCA. This transformation interacts with a number of cells in the skin and se nds a signal to the immune system, causing it to hinder its reaction. If the UVA has c aused 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 A, damaging DNA and causing the immune system to suppress. 10

2008 OMTEX CLASSES -09 VI. What about other illnesses? Like immuno-suppression and skin cancer, science is not able to provide society with a confident answer to the question: Will the depletion of the ozone layer cause an increased number of cataract cases? Cataracts are a condition that begin with blurry visio n and in some cases, develop into blindness. It has been proven that UV light can damage the 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 estimated by the Environmental Effects Panel of the United Nations Environment Programme t hat for each percent decrease in ozone, the number of people developing blindness wo uld increase by approximately 100,000 to 150,000 people (Nilsson, 113). However, thi s estimation was contradicted by a team of Dutch scientists, who stated, it is not scientifically justifiable to quantify the effects of UV radiation on the eye, i f such effects are present under normal circumstances circumstances (Nilsson, 113). The UNEP then published an updated statement and included information that poor diet and diseases, such as diabetes, also contribute to cataract development. Thus, it must be recognized that catara cts can result from poor nutrition, poor hygiene, and diabetes, and not solely from incr eased UV radiation. Research has been conducted to investigate a link between cataracts and UV radia tion. Some epidemiological studies have shown that UV-B radiation and formation of cat aracts do have a positive relationship. For example, a study conducted with Chesapeake Bay fishermen asked these fishermen to disclose whether or not they wore sunglasses while working and during outdoor recreational activities. Then, radiation measurements were taken throughout the area to probe for a correlation. The results of this study showed a exposure  (Nilsson, 117). Thus, weak positive dose-response relationship with UV-B exposure in this study, one would argue that increased UV radiation would lead to increased rates of cataracts. Many other studies have been conducted to examine this phenomenon, an d none have shown a strongly correlated causal relationship between UV-B and catar acts, but many suggest the possibility of a relationship. In summary, there is again n o cut and dry dry answer explaining what will happen to the number of cases of cataracts as the ozone

layer depletes, but when one examines the effects of UV-B radiation on the eyes, it is suggested that ozone depletion is likely to increase one one s risk of developing cata racts. A short-term health problem that will increase as the level of ozone decreases i s snowblindness or welder welders arc flash. flash. This phenomenon is a result of sunburn of the snowblindness conjunctiva and cornea and is characterized by blurred vision, severe pain, photo phobia, profuse tearing, and eyelid spasms spasms (Ozone.org, 1998). The condition occurs after 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 ounding theories which state that depletion of the ozone layer causes health problems. W hile one 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, but what is not so clear is to what degree a depleting ozone layer will magnify the occur rence of these problems. VII. Ozone depletion: Not a farmer farmers best friend. 11

2008 OMTEX CLASSES -09 Another common, yet, highly debated concern with regards to the depleting ozone layer is crop and plant damage. As it has been well stressed, depletion of the ozone l ayer results in higher UV-B radiation on the earth earth s surface. Ironically, while plants use light as their main fuel for growth, a delicate balance must be achieved in order for the plant to survive. If a plant is exposed to too much UV radiation, the DNA of the plant ma y become damaged due to penetration of harmful UV radiation into sensitive areas o f the plant. UV radiation also causes problems in the photosynthetic machinery by hamp ering the photosynthesis process, the cell membrane by altering the transportation of essential potassium, and the cell cells skeleton by affecting cell growth and morphology. With t his information taken into account, it would seem logical that increased UV radiatio n from the depleting ozone layer would lead to plant damage. However, it is not that si mple. Some plants actually employ a mechanism that allows them to protect themselves f rom UV damage. Thus, research suggests that if ozone depletion became serious enough , the plants without the protective mechanisms would die out, but the plants with thes e mechanisms would be able to replace the extinct plants, and not affect the level of productivity in the ecosystem (Nilsson, 54). Thus, much depends on which plants survive. To further investigate the affect of UV radiation on plants, experiments have be en done to study the effects of UV-B levels on crop yield (Nilsson, 52). The results conclu ded that in approximately 50% of the crops, an increased UV-B level lead to a decrease in crop yield. Specifically, the corn yield was reduced by 28 percent; and beans, squash , and various forms of peas were also found to be sensitive to UV-B radiation. One wou ld logically conclude that the depletion of the ozone layer would lead to a reducti on in the yield of crops. However, science may offer a solution by being able to breed cro ps that are resistant to UV radiation. The answer to the question of decreased crop yield and existence of plants as a result of a thinning ozone layer is not scientifically definitive. However, it is important because if the ability of plants to intake carbon dioxide and regulate the amount of carbon dioxide in

the air is altered, the consequences for society are detrimental. 12

2008 OMTEX CLASSES -09 VIII. Collaborative Global Government Efforts As a result of the many concerns that a thinning ozone layer poses to society an d the environment, the U.S. government and many international agencies have been relat ively active in attempting to monitor, regulate, and solve the problem. Perhaps the mo st well known acts to help control the depletion of the ozone layer were the Montreal Pr otocol, 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. After much discussion, the delegates agreed to halt production and consumption of CFCs at 1986 levels by the year 1990. In addition, nations also agreed to reduce CFCs 20 percent by January 1, 1994 and an additional 30 percent by January 1, 1999 (Roan, 208-9) . This was known as the Montreal Protocol. Even though this protocol helped the state o f 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 d more countries, bringing the total number involved to almost 100. The new goals were to eliminate the use of all CFCs by the year 2000, and to help set up a fund so tha t developing countries may find alternates to using CFCs. The name of this amendme nt 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. 13

2008 OMTEX CLASSES -09 Ozone and health

Ozone in air pollution

There is a great deal of evidence to show that high concentrations (ppm) of ozon e, created by high concentrations of pollution and daylight UV rays at the earth earth s su rface, can harm lung function and irritate the respiratory system.[16][23] A connection has also 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 e World Health Organization are based on detailed studies of what levels can cause measu rable health effects. A common British folk myth dating back to the Victorian era holds that the smell of the sea is caused by ozone, and that this smell has bracing bracing health benefits.[25] Neith er of these is true. The characteristic smell of the sea sea is not caused by ozone, but by the presence of dimethyl sulfide generated by phytoplankton, and dimethyl sulfide, l ike ozone, is toxic in high concentrations.[26] The United States Environmental Protection Agency has developed an Air Quality i ndex to help explain air pollution levels to the general public. 8-hour average ozone concentrations of 85 to 104 ppbv are described as Unhealthy for Sensitive Groups Groups, 105 ppbv to 124 ppbv as unhealthy unhealthy and 125 ppb to 404 ppb as very unhealthy unhealthy.[27] The EPA has designated over 300 counties of the United States, clustered around the most heavily populated areas (especially in California and the Northeast), as failing to comply with the National Ambient Air Quality Standards. Health Effects of UV Radiation Overexposure to UV radiation is the main cause of skin cancer. UV rays can trigg er the development of skin cancer by creating changes in the cells of the skin. In some cases, the UV rays cause direct damage to the cells. Tans and sunburns, for example, ar e both signs that UV rays have damaged the skin. In other cases, UV rays can cause skin cancer 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 here are three types of skin cancer: basal cell carcinoma, squamous cell carcinoma, and m alignant melanoma. The last one can be fatal if not treated early. Many studies of skin c ancer 14

2008 OMTEX CLASSES -09 show links between malignant melanomas and an individual individual s intolerance to sun exposure. The studies indicate that people who have suffered severe and frequent sunburns during childhood are at greater risk of developing melanoma. The featur es most closely associated with intolerance to sun exposure include fair or freckled ski n, blue eyes, and light-coloured or reddish hair. The two other types of skin cancer tend to develop later in life on areas of ski n that have been exposed repeatedly to the sun, such as the face, neck, or hands. Basal and squamous cell carcinomas progress slowly and rarely cause death because they usually do n ot spread to other parts of the body. Overexposure to ultraviolet radiation has also been linked to a number of other health effects, including sunburns, cataracts, premature aging of the skin, and weakeni ng of the immune system. Minimizing Your Risk There is no quick fix for the ozone layer. Once they get into the environment, o zone-depleting chemicals disintegrate very slowly, so they are likely to be with us for a long time. Whil e governments around the world deal with the source of the problem, it is important to take steps to avoid over exposure to ultraviolet radiation. These guidelines will help you protect your family from the sun sun s harmful rays:  Seek shade if you are taking part in outdoor activities when the UV index is thr ee or higher.  Cover up. Wear long-sleeved shirts, long pants, gloves, and a broad-brimmed hat or visor. Avoid see-through clothing when possible.  Avoid sunbathing for the purpose of tanning, especially between 11:00 a.m. and 4:00 p.m. in the summer when the sun suns rays are strongest.  Use sunscreen lotion and reapply it often, as directed on the label. Look for a spectrum sunscreen with a sun protection factor (SPF) of at least 15. broad spectrum  Wear sunglasses that screen out ultraviolet radiation. Your eyes have no built-i n defence against the sun, and damage to the eye from UV rays can lead to cataracts.  Do not think you are safe just because the sky is cloudy. The sun sun s harmful rays can get through fog, haze, and light cloud cover.

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2008 OMTEX CLASSES -09 Children Need Extra Protection Children and teenagers have more sensitive skin than adults, so they need extra protection if they are going to be out in the sun for a long time. Sunburn may increase the risk of skin cancer later in life, so it is best to get children used to wearing protect ive clothing and sunscreen lotion from the start. At the very least, young children should wear a sunhat, T-shirt, and shorts. Whe n you put sunscreen on children, pay special attention to the parts that are most exposed, including their ears, face, neck, shoulders and back, knees, and the tops of their feet. A void using 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 t in the summer. You can continue to enjoy outdoor activities, as long as you take steps to protect yourself when the UV index is three or higher to avoid sunburns and overexposure . 16

2008 OMTEX CLASSES -09 DISCUSSION Regardless of the details of the arguments, it is obvious that the depletion of the ozone layer is a serious problem that poses many consequences to society. Although sci entific controversy exists, the possibility seems high that the depletion of the ozone l ayer will 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 as a direct result of the thinning ozone layer. These health risks include skin cance r, immunosuppression, cataracts, and snowblindness. snowblindness. Furthermore, the possibility that increased UV-B radiation results in lower crop yields should provide a wake up up call 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 world s food s upply would become dramatically decreased, resulting in higher levels of famine and malnutrition. Studies from Antarctica tell society that increased UV radiation can directly af fect the 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 d remote problem; however, this incident illustrates the dangers of reduced food supply a nd alteration of the food chain as a result of the thinning ozone layer. Even thoug h the 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 food web and result in an overall decrease in food supply. Thus, realize that the dangers pos ed by ozone depletion are real now, and will be in the future, if action is not taken.

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2008 OMTEX CLASSES -09 Take Action: Teamwork does the trick Although the earth will be able to heal heal itself if the CFC level continues to stay as it is, the depletion of the ozone layer is still a problem that society should be conce rned with. In order for earth to repair the damage humans have posed on the ozone layer, so ciety must take an active role. There are many tasks individuals can involve themselve s in to help combat the problem of ozone depletion. First of all, one can simply check p roduct labels for ozone friendly status. Many companies have gone to great lengths to r emove CFCs from their products. These products do not do as much damage to the ozone l ayer, and thus, are denoted as ozone friendly. friendly. A collaborative effort by society not usi ng 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 layer. For example, CFCs marketed under the trade name Freon Freon are used in appliances with refrigerants such as refrigerators and air conditioners. When individuals must d ispose of products with refrigerants in them, certain actions must be taken in order to pr event the CFCs from escaping from the disposed product. For example, when an agency, such as a waste hauling company, comes to pick up the unwanted appliance, check to make su re refrigerant-recovery equipment is used by the agency. This equipment allows for the disposal of refrigerants without damage to the ozone layer. Society can also help the problem of ozone depletion through education, as well as through various donations. If individuals contribute time or money to environmen tal agencies focused on healing the ozone layer, the agencies will be able to organi ze activities promoting the understanding of the ozone problem. If society is educa ted through these means, more individual efforts will be taken to make ozone smart smart decisions such as using ozone friendly friendly products. Although thinning ozone may not directly affect the generation growing up today, future generations depend on the actions taken now. Thus, it is important for society t o recognize that the thinning ozone layer is a problem and to take action in order to ensure the safety and survival of future generations. 18

2008 OMTEX CLASSES -09 SUMMARY The ozone layer is essential for protecting society from harmful UV radiation by acting as a filter. However, this protective layer has been thinning due to three main sou rces: human activity, natural sources, and volcanoes. Human activity is responsible fo r the most damage to the ozone layer, thus, society should recognize that much can be done to prevent ozone layer damage. In 1985, in a region over Antarctica, the yearly polar vortex had caused the ozo ne layer to deplete so greatly, that it could be classified as a hole. In 1996, this hole wa s large enough to cover Antarctica. The depletion of the ozone layer does not come without problems. Scientific rese arch has suggested the probability that increased UV-B radiation as a result of the t hinning ozone layer leads to increased cases of skin cancer, immuno-suppression, catarac ts, and blindness due to radiation damage of the DNA. Additionally, experiments have snow blindness shown a correlation between increased UV radiation and crop damage due to UV radiation damaging the plants plants DNA. Some scientists, however, feel that this will not be a problem in the future due to the possibility of breeding UV resistant crops an d plants. Many national governments and agencies recognized the problem of ozone depletion , and therefore, united in 1987 to sign the Montreal Protocol. This agreement was implemented to decrease CFC levels in order to help protect the thinning ozone l ayer. Clearly, ozone depletion is a dangerous problem due to possible disease outbreak s and famine as a result of increased UV-B radiation. However, society can collectivel y attempt to combat this problem by relatively simple means such as education and the practice of ozone smart smart behavior. For if society acts now, future generations will be handed a safe and healthy planet. 19