Destruction Of The Ozone Layer example essay topic

Above the earth, approximately 30-50 kilometers, a layer of stable oxygen atoms covers the stratosphere, this called the ozone layer. It protects "all life" from the sun's harmful radiation. (US EPA). The ozone layer is very powerful; it protects the earth from dangerous UVB rays from the sun. (Frank 13) If the rays from the sun were to pass through the atmosphere it would be devastating because they have the ability to destroy skin cells in humans and animals. In 1974 two scientists discovered that certain commonly used compounds were destroying the protective ozone: chlorine, fluorine and bromine.

Researchers have found out that the "stratospheric ozone has declined for at least two decades, with losses about 10% in the winter and spring, and 5% in the summer and autumn". (Impacts of Depletion) As the ozone layer's power is declining, more and more UVB rays are entering the atmosphere and eventually we will have no protection from the sun. "Since the 1980's the annual ozone hole over Antarctica has been occurring only during the Antarctic spring". (US EPA) In the 1930's, commercial laboratories developed compounds of chlorine, fluorine, and carbon (called chlorofluorocarbons, or CFCs). (US EPA) These compounds can be found in normal household items such as refrigerators, spray cans, and air conditioners. (Frank 13) If such an item were used, CFCs would be released in the air and winds would carry them to the outer atmosphere of the Earth, the ozone layer.

It is because of their "atmospheric lifetimes" that allow them time to reach the stratosphere. There they are broken down and release chlorine or bromine which then decomposes ozone molecules containing oxygen. CFCs are so stable that they can only be broken down by UVB radiation. This is one of the main reasons they were widely used. They are also nonflammable, and inexpensive to produce. (US EPA) According to studies, by the 1970's, industry used about a million tons each year.

But CFCs aren't the only cause of "atmospheric depression."Natural sources", such as volcanic eruptions, also add to the destruction of the ozone layer even though their impact is not direct. Instead, they increase the rate at which the chlorine and bromine break down the ozone. (Impacts of Depletion). In fact, studies show that 85% of the chlorine found in the stratosphere is contributed by CFCs while "natural sources" contribute only 15%. (US EPA). If in time the ozone layer does diminish or even disappear, the effects of UVB rays from the sun would be disastrous.

Research shows that even a reduced amount of 7% of the "stratospheric ozone" could increase the number of cataracts in people exposed to the sun by 3% to 4%. The ultraviolet rays could create serious problems with the human skin, mainly affecting the DNA. If too many DNA cells are damaged, it can result in "faulty replication of DNA in a daughter cell". That could cause important genes to malfunction, which could lead to tumors or cancer. The Sun's rays would also harm the eyes because radiation is absorbed into the skin and outer areas of the eye. Because there is no discomfort or pain, it would be very easy to get long-term or even permanent damage to the eyes.

Frank 16) Because the ozone is depleting, there is a growing risk for people who stay in the sun. There are some helpful procedures you could do before you walk into the sun. Most important is using protective suntan lotion. You should always check the 'sp' or sun-proof strength to make sure that it is strong enough to last several hours. Sunglasses with UVB protective lenses are a very helpful accessory when driving or doing outdoor activities. Not only do they lower the risk of damage to your eyes but also they make you look good.

Using common sense whenever you are outside is advisable. Don't look directly into the sun. Don't stay in the sun too long. You might think getting a tan looks good, but the radiation you receive from the sun can result in premature aging or skin cancer. So whenever you " re at the beach or swimming at a pool, take care of your skin to keep it in healthy condition. The public really became aware of the destruction of the ozone layer due to CFCs in the 1970's when the US, Canada, Norway, and Sweden put a ban on the use of CFCs in aerosol sprays.

In 1987, the Montreal Protocol was signed further reducing the production of CFCs. Many organizations, such as the Environmental Protection Agency (EPA), set out to help reduce "wear" on our ozone. The US EPA has created programs to help reduce the problem including refrigerant recycling and product labeling. With the continuing decrease of CFC use, the EPA has projected that "the natural ozone production process will heal the ozone layer in about 50 years". (US EPA)

Bibliography

De Gruijl, Frank R. "Impacts of a Projected Depletion of the Ozone Layer". Consequences summer 1995: 13-21.
SIRS Researcher. 27 Apr. 2003 web U.
S. EPA: Ozone Depletion. 2002.
Environmental Protection Agency. 24 Apr. 2003 web Rowland, Dr.
F. Sherwood. "The Ozone Depletion Phenomenon". Beyond Discovery, TM: The Path from Research to Human Benefit. 27 Apr. 2003 web.