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A Shattered Sky

Essay by   •  February 24, 2011  •  Essay  •  942 Words (4 Pages)  •  1,636 Views

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In Janice Armes essay, "A Shattered Sky," she argues that life on earth is dependent upon a balance by nature and its ability to stabilize itself. She states that the large amounts of chlorofluorocarbons released into the atmosphere is the cause of the rapid rate of ozone depletion in the stratosphere. The satellite photos of the ozone layer above Antarctica show proof of rapid ozone depletion. Ozone depletion harms humans because extended exposure to UV radiation can cause melanoma and retinal damage. Education and awareness about CFCs and their effect on the ozone layer is an important responsibility individuals need to take to prevent the unnecessary use of CFCs. I agree with Janice Armes and believe that humans need to reduce usage of CFCs and find better alternatives.

CFCs are compounds made up of chlorine, fluorine and carbon atoms. They where considered a miracle gas because they are inert. Thomas Midgley Jr., the co-inventor of CFC-12, demonstrates the non-toxicity of Freon when he "Famously filled his lungs with Freon and extinguished a candle at a meeting of the American Chemical Society in1930" (Vordersrasse, para9). The most used and familiar compounds are made by the DuPont corporation under the trademark name Freon (Chlorofluorocarbons). CFCs are used as refrigerants, solvents, aerosol propellants, and foaming agents.They are classified by the EPA as class I chemical, which are chemicals with a ozone depletion potential of 0.2 and higher. Compounds containing bromine such as halons are even more destructive to the ozone layer and some have ozone depletion potentials of 10-12. Halons are used in handheld fire extinguishers and fire suppression systems.

The stratosphere, the second layer of Earths atmosphere, contains the ozone layer (Phillips para5). Ozone (O3) is naturally produced and destroyed within the ozone layer through a process of solar radiation and the Chapman reactions (Vorderstrasse, para25). CFCs do not directly destroy ozone, but are broken down by high levels of UV radiation and release chlorine (Ozone Depletion Processes, Para2). Chlorine in the ozone layer creates a catalytic destruction of ozone, in which one chlorine atom destroys up to 100,000 molecules of ozone.

Ozone depletion from chlorine was first discovered in 1973, and one year later two scientist, Sherwood Roland and Mario Molina publish their findings in a research article. This led to a ban on the CFCs in the use of aerosols by the U.S. and other countries in 1978(Ozone Depletion: When Less Is Not Enough 9). In 1985, the British Antarctic Survey discovered that the ozone layer above the South Pole has been in decline since the 1970's; they published their findings in the science journal Nature during the same year (9). In 1987, the U.S. signed the Montreal Protocol, which set limits on the use of cfcs, halons, and other ozone depleting substances (10). A ban on the production and importation of cfc-12 and halons in U.S. was enacted in 1996 (Ozone Science: The Facts Behind The Phaseout para18).

The thinning ozone layer allows a greater amount of ultraviolet radiation to pass through the atmosphere and reach earth's surface. This poses many health risks to people and can affect their everyday life. Overexposure to the suns radiation can cause some types of skin cancer. The EPA states in their sunwise program that melanoma, the most serious type of skin cancer, is the fastest growing forms of cancer in the U.S. The other forms of skin cancer are basal cell carcinomas and squamous cell carcinomas; basal cell carcinomas are the most common forms of skin cancer tumors, they can penetrate the bone and cause severe damage, squamous cell carcinoma can grow in large masses and spread to many other parts of the body (Health Affects of Overexposure to the Sun Para3). Other types of health affects from overexposure to UV radiation include: premature skin ageing, actinic keratoses skin growths, cataracts, and pterygium.

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