Upper Ozone Level example essay topic

In 1839, a German scientist Christian Schobein was a professor of chemistry at the University of Basel in Switzerland. In addition to his teaching duties, he regularly performed secret experiments in hopes of finding out which substances make up the Earth's atmosphere. So Schonbein combined and separated a number of liquids and gases. During one of these experiments, Schonbein passed an electric charge thought a glass beaker of water, be noticed a very familiar odor. He first thought it was the result of electrically charge oxygen atoms but he last realized that he had found a new substance. He named this new substance ozone, after the Greek word oz ein, meaning "to smell".

Ozone is a gas and is a form of oxygen. Each molecule of ozone contains three atoms of oxygen. Molecules are tiny building blocks that form all gases, liquids, and solids. Each one of these molecules can be broken down even smaller into tinier building blocks called atoms, which are the basic particles of all matter. Because each molecule of ozone is composed of three atoms, ozone is referred to 03. Ozone gas is colourless but has a strong odor.

The "electrical" smell that often lingers after a summer thunderstorm is the smell of ozone. The ozone molecule is unstable; it has a tendency to break apart and join with other atoms. This process, which is called, oxidation, can be destructive. For Example, rust develops on iron when oxygen atoms in the ozone combine with iron atoms. Similarly, ozone can weaken other materials such as nylon or rubber. In large amounts can even kill living cells.

For this reason, scientists have to monitor ozone levels constantly. Schobein himself invented a very primitive way of measuring levels of ozone levels. First, he soaked a piece of paper with a chemical. As the chemical dried the ozone in the air oxidized it. This process turned the paper blue.

The more ozone that was around the darker the paper turned. Schonbein placed a new piece of paper outside everyday in order to measure the levels of ozone in the air. In time, scientists came to refer to this technique as the Schonbein Paper Method (SPM). But unfortunately, this method shoes only if the ozone levels are light, moderate, or heavy, so it is not very precise.

A better method for measuring ozone levels was developed by the French in 1876. A scientist by the name of Charles Soret who had been studying weather and ozone, decided that Schonbein's way weren't accurate enough for him. So Soret planned his own approach at measuring ozone levels that would be more accurate than Schonbein papers. He measured ozone by observing the way it reacted with chemicals dissolved in water. Using this method, he was able to more accurately measure ozone.

Soret measured the air nearly every day for thirty-four years. Later, scientists were able to compare the ozone levels of past and present. Modern scientists have an even more accurate method for measuring ozone. This method is called gas chromatography. This process works by filtering and burning gases containing ozone. The device used in this process is so precise that it can detect a single molecule of ozone among one million other molecules.

There are two general types of ozone: low-level and upper-level ozone. Low-level ozone exists near the earth's surface in the lowest portion of the atmosphere. This is why scientists refer to it as low-level ozone. This lowest atmospheric layer, occupying the space between the earth's surface and an altitude of about six to nine miles, is called the troposphere. Scientist also refer to low-level ozone as troposphere. Troposphere ozone, which can be harmful to living things, is created in many ways, Usually, ozone is produced when sunlight reacts with chemicals released into the air.

Sometimes, human activities are responsible for the creation of ozone. Exhausts for gasoline burning cars and trucks, for example, contain various pollutions, including hydrocarbons and nitric oxide. These substances react with each other and also with sunlight, creating ozone in the process. Emissions form coal, gas, and oil burning utility plants and vapours from paint strippers, dry cleaners methods, and charcoal lighter fluids also produce ozone when they mix with sunlight.

Fire, whether it occurs naturally or is set by human beings, is also a source of low-level ozone. The smoke from fire contains the chemicals that when mix with sunlight produce a chemical reactions which yields the ozone molecule. For example, at harvest time down in Brazil of the sugarcane plant, thousands of fires are set burning off the excess amounts of sugarcane and the left over stalks. Because Brazil is so close to the equator and it receives the most amount of the suns rays, more than the north or the south, creating major amounts of ozone pollution and that is not a good thing.

Other sources of trospheric ozone are completely natural. During electrical storms, bolts of lightning rip through the troposphere, separating the atoms of some oxygen molecules. Some of these atoms combine with other oxygen molecules to create ozone. There are other ways nature makes low-level ozone. Ozone forms when sunlight combines with methane gas, a gas produced and given by decaying plant and animal tissue and by the gaseous waste of grazing animals like cows and sheep.

Another natural source of troposphere ozone was not fully understood by scientists until the late 1980's. In 1987, William Chameidas, Ronald Lindsay, and Jennifer Richardson, all of the Georgia Institute of Technology, studied ozone levels around Atlanta, Georgia. They found that the amount of ozone in the air was far too much to be attributed to cars and factories alone. The researchers finally concluded that trees in the Atlanta are creating ozone.

The researchers found that trees released hydrocarbons during photosynthesis. This is the process green plants use sunlight to create energy. When these hydrocarbons react with sunlight and pollutants, they create low-level ozone. Trees generate large amounts of hydrocarbons. In fact, Chameides and the others found that the amount of hydrocarbons released by trees, in the Atlanta region, was about the same as the amount emitted by all cars and industrial facilities in the same area. This does not mean that trees pollute.

Atmospheric scientist Jack Fishman of the National Aeronautics and Space Administration's Langley Research Center, explains: "Actually, trees don't pollute... In a natural forest environment, the concentration of [pollutants from engine exhausts] is usually very low, so the hydrocarbon given off by trees is harmlessly transformed into substances other than ozone". (Ral off, 1990) Only when the hydrocarbons, released by the trees, combine with other pollutants, given off by fuel burning activities of humans, is the ozone molecule created, and too much of it. The second general type of ozone exists in the upper portion of the earth's atmosphere and is called upper-level ozone. This layer of the atmosphere, extending from about twelve to twenty four miles above the planets surface, is known as the stratosphere. Therefore, scientists also refer to upper-level ozone as stratosphere ozone.

This ozone layer blocks the most dangerous of the sun's rays and prevents them from harming living things on earth. This role as protector of life below began billions of years ago when there was little oxygen in the air. When ocean plants first appeared on earth, most had to stay below the water's surface. This was to avoid ultraviolet light, a kind of solar ray that damages living tissue.

Ultraviolet light flooded the primitive earth, making the development of life a slow, painstaking process. As the oxygen given off by the early plants slowly built up in the atmosphere, some of it floated high into the stratosphere. There, the oxygen molecules encountered sunlight that was stronger than what reached the surface. This combination of sunlight and oxygen molecules produced ozone, a gas that could readily absorb ultraviolet light.

With protection provided by the ozone layer, plants thrived in the ocean and on its surface. The amount of oxygen in the air increased and formed more ozone. Eventually, the stratospheric ozone layer grew thick enough to protect more advanced forms of life forms from ultraviolet radiation. Life evolved onto land and into millions of varieties of plants and animal species known today, including human beings. The nature of ozone appears to go against common sense. On the one hand, there is low-level, troposphere ozone, which is classified as a pollution; there is the upper-level, stratospheric ozone that is essential to the existence of life.

The amount of both kinds of ozone is changing. Low level ozone is increasing, while the upper-level ozone is decreasing. Scientists disagree on what these changes mean but it appears that there is too much of one kind and too little of the other. Researchers are trying to determine how these levels of ozone will affect the world environment and people's lives.

While too much low-level ozone can be harmful, exactly the opposite is true for upper-level ozone. Because ozone high in the stratosphere absorbs incoming ultraviolet light from the sun, it keeps most of these destructive rays from reaching the earth's surface. Ultraviolet radiation is so lethal that without the stratosphere ozone layer, the existence of life on earth would be nearly impossible. All living organisms would suffer from too much mutation in the organism that all of its major organs would just stop working; and the organism would die. Until the 1970's and 1980's, most people, including scientists, took the ozone layer more or less for granted. They assumed it was one of the earth's natural features and that it would always remain the same, This attitude changed in 1984 when scientist found a huge hole in the ozone layer over Antarctica, the continent covering the planet's south pole.

Since then, researchers have discovered that the stratosphere ozone shield is growing thinner and weaker. As this happens, more ultraviolet light reaches the earth's surface. This is why scientists and government officials around the world are increasingly concerned about the possible health effects of upper-level ozone depletion. At the beach, when people lie under a warm summer sun, many leave with attractive golden tans while others, especially those with fair skin, get painful red sunburns. Ultraviolet rays striking and damaging the cells on the skin's surface cause both the tans and sunburns. Scientists and doctors have known for a long time that repeated exposure to ultraviolet radiation causes skin cancer.

In general, light-skinned people have the highest risk, while dark-skinned people of a much lower risk. This is because darker skin contains more of the pigment melanin, which blocks out most of the ultraviolet light. About ninety percent of all skin cancers occur on the head and the neck, mainly because these are the areas of the body that are most often left uncovered and exposed to the sun. As might be expected, skin cancer rates are highest for people who frequently work or play outside in the sun.

About 400,000 to 600,000 cases of skin cancer occur in the United States each year. (Heppenheimer, 1990) Many of these cases are caused by too much exposure to ultraviolet rays from the sun. Most skin cancer, if caught early, is curable. But about six thousand people still die each year from the disease. As the intensity of ultraviolet radiation increases, cancer rates and deaths may also increase. Many scientists expect that as upper-level ozone decreases, the intensity of ultraviolet radiation at the earth's surface will increase.

According to the EPA, Environmental Protection Agency, for every 1 percent decrease in the ozone layer, ultraviolet rays reaching the earth's surface will increase two percent. This, in turn, could cause an 8 percent rise in skin cancer in the United States, every year. (Heppenheimer, 1990) Ultraviolet light is also a major cause of eye cataracts. These are patches of opaque, or light blocking, tissue that form in the eyes and can lead to partial or complete blindness.

Laboratory experiments have shown that ultraviolet rays are 250 times more likely than regular light to cause cataracts. According to the EPA, if the present rate of ozone depletion continues for the next forty years, the increased ultraviolet radiation could cause as many as ten million extra cases of cataracts in the United States alone. (Heppenheimer, 1990) Animals and people are not the only creatures harmed by ultraviolet rays. Many microorganisms that produce nutrients in the soil die from overexposure to these rays. The microorganisms are extremely sensitive to change in the intensity of the rays.

So continued upper-level ozone depletion could potentially decrease soul fertility, especially in tropical biomes where ultraviolet radiation is naturally more intense. Plants, too, can suffer from increased doses of ultraviolet rays. According to researchers Robert C. Worrest of the EPA, scientists have tested about two hundred species of land plants, but mostly food crops, for sensitivity to ultraviolet light. He found that it reduces the crop yield, the stem and leaves don't grow as much and the total dry weight is lessened. Worrest and his colleagues stress that scientific knowledge in this area is still limits and that thousands of other plant species have not yet been tested. They call for more worldwide studies.

More information, they say, will help prevent potentially serious crop losses that might ozone depletion continues. All these potentially harmful effects of ultraviolet radiation are a cause for concern to scientists and government leaders around the world. Researchers work to discover the reasons why this ozone depletion occurs. They also search for ways to slow and eventually halt the destruction of upper-level ozone.

This research is relatively new. Until a few years ago, no one knew about the Antarctic ozone hole or even that a decrease of upper-level ozone was possible. The discovery of ozone depletion came in the early 1970's. Before that, scientists paid little attention to the ozone layer. This was mainly because they did not yet thoroughly understand the chemistry of the upper atmosphere. In 1970, two atmospheric scientists independently made the same suggestion.

Paul Crutzen, then researcher at the University of Stockholm in Sweden, and Harold Johnson, a researcher at the University of California at Berkeley, each suggested that exhaust from high flying airplanes would introduce large amounts of pollutants into the atmosphere. These pollutants, the scientists said, might seriously damage the ozone layer. Crutzen and Johnson's idea generated a great deal of publicity because, at the time, several countries were considering building fleets of supersonic aircraft that would fly high in the atmosphere. The United States, France, and Great Britain all proposed launching these passenger carrying craft. The United States eventually cancelled its plans. This was partly due to fear of damaging the upper ozone level.

Meanwhile, both France and Great Britain built their supersonic fleets. Now, only a few of the aircraft are in use, and they have not noticeably affected the upper ozone level. The next step in the search for the ozone-destroying culprit came in 1974. Richard Stolarski and Ralph Cicerone, both of the University of Michigan, did a study for the National Aeronautics and Space Administration (NASA). They wanted to see if exhaust from the space shuttles would affect the ozone layer. They found that one element in the exhaust, chlorine, did affect the ozone layer.

Further studies showed that a single chlorine atom will likely destroy between ten thousand and a hundred thousand ozone molecules. Chlorine's potential for eliminating ozone is enormous. Efforts by various governments and organizations to do something about ozone-related problems are already underway. These efforts fall into two general categories.

Attempts to eliminate low-level ozone pollution and attempts to slow the depletion of the upper ozone layer. The battle in the United States started back in the 1970's when the EPA was formed in hope of helping prevent all the pollution across the world. The whole idea behind the EPA was to help all countries of the world eliminate the major environment problems; the one really major one was the depletion of the ozone layer. The EPA first started in the United States and had a goal that by 1976 to have the whole country to meet a set standard for pollution. Not everyone was compiling with these standards so the deadline was extended to 1982. The plan was to have a "catalytic converter" which would go on passenger cars.

As the exhaust passed through the catalytic converter a chemical reaction would take place removing the pollutants that would exit the muffler of the car and enter into the atmosphere. Amazing, after just five years, in 1987, across the country all reports of pollution was down in all urban areas. But the efforts weren't as good as everyone expected, the amount of pollution in rural areas had greatly increased, this confused scientists for quite awhile. It seemed that the converters weren't removing the nitrogen oxides from the exhaust of fuel burning vehicles, and the wind carried the oxides far out into the countryside. These nitrogen oxides mixed with the hydrocarbons given off by trees and that created tons of low-level ozone, for the poor country folk to deal with.

The EPA had yet again to deal with the problem they have now come up with new standards and all cities Worldwide must comply with. All cars must be equipped with a converter that will remove nitrogen oxides before releasing the exhaust into the air and that industrial companies most install state of the art converters on all hatches that lead chemicals into the atmosphere to remove any chlorine that might escape. These new standards must be met by the year 2010 any disobeying Countries or Cities will be forced to pay plenties. About the upper-level ozone, not that much can be done by use seeing's how the earth naturally created that protection barrier against ultraviolet rays. All industrial, the small businessman, and individuals alike have to take their part in saving the ozone, our planet, us and even our future generations. If we give the ozone a break it will eventually rejuvenate itself and return back to normal but it will take time, so be smart about what you do, install a clean burning converter on your car, and ensure many healthy generations to come..