Ozone Layer Depletion

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International Journal of Environmental Science and Development, Vol.2, No.1, February 2011 ISSN: 2010-0264

Ozone Layer Depletion and Its Effects: A
Review
Sivasakthivel.T and K.K.Siva Kumar Reddy

Abstract - There are many situations where human activities
have significant effects on the environment. Ozone layer
damage is one of them. The objective of this paper is to review the origin, causes, mechanisms and bio effects of ozone layer depletion as well as the protective measures of this vanishing layer. The chlorofluorocarbon and the halons are potent ozone depletors. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received at the surface of the earth and the effect of this on human health and on the

environment. The prospects of ozone recovery remain uncertain. In the absence of other changes, stratospheric ozone
abundances should rise in the future as the halogen loading falls in response to regulation. However, the future behaviour of
ozone will also be affected by the changing atmospheric
abundances of methane, nitrous oxide, water vapour, sulphate aerosol, and changing climate.
Index Terms – Bio effects, chlorofluorocarbon, Ozone Layer Depletion, Protection.

I. INTRODUCTION
The ozone layer is a layer in Earth's atmosphere which
contains relatively high concentrations of ozone (O3). This
layer absorbs 93-99% of the sun's high frequency ultraviolet light, which is potentially damaging to life on earth [1]. Over 91% of the ozone in Earth's atmosphere is present here.[1] It is mainly located in the lower portion of the stratosphere from approximately 10 km to 50 km above Earth, though the

thickness varies seasonally and geographically[2]. The ozone layer was discovered in 1913 by the French physicists
Charles Fabry and Henri Buisson. Its properties were
explored in detail by the British meteorologist G. M. B.
Dobson, who developed a simple spectrophotometer (the
Dobson meter) that could be used to measure stratospheric
ozone from the ground. Between 1928 and 1958 Dobson
established a worldwide network of ozone monitoring
stations which continues to operate today. The "Dobson unit", a convenient measure of the total amount of ozone in a
column overhead, is named in his honor.
A. Ozone
Without ozone, life on Earth would not have evolved in the
way it has. The first stage of single cell organism
development requires an oxygen-free environment. This type
of environment existed on earth over 3000 million years ago. As the primitive forms of plant life multiplied and evolved,

Manuscript Received, 27 November, 2010.
*T.Sivasakthivel and K.K.Siva Kumar Reddy, M.Tech - Thermal
Engineering,, Department of Mechanical Engineering,, N.I.T Silchar, Assam, India
*Email: sivasakthivel.t@gmail.com

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they began to release minute amounts of oxygen through the
photosynthesis reaction (which converts carbon dioxide into
oxygen) [3].
The buildup of oxygen in the atmosphere led to the
formation of the ozone layer in the upper atmosphere or
stratosphere. This layer filters out incoming radiation in the "cell-damaging" ultraviolet (UV) part of the spectrum. Thus
with the development of the ozone layer came the formation
of more advanced life forms. Ozone is a form of oxygen. The
oxygen we breathe is in the form of oxygen molecules (O2) two atoms of oxygen bound together. Normal oxygen which we breathe is colourless and odourless. Ozone, on the other
hand, consists of three atoms of oxygen bound together (O3). Most of the atmosphere's ozone occurs in the region called
the stratosphere. Ozone is colourless and has a very harsh
odour. Ozone is much less common than normal oxygen. Out
of 10 million air molecules, about 2 million are normal
oxygen, but only 3 are ozone. Most ozone is produced
naturally in the upper atmosphere or stratosphere. While
ozone can be found through the entire...
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