Free Essays,College Free Essays,Free College Essays at Anti Essays

STRATOSPHERIC POLLUTION

Ozone

The majority of ozone in the earth's atmosphere is found in the stratosphere. This high level ozone plays a crucial role, protecting animals and plants from the sun’s harmful ultra violet rays, and stabilizing the earth's climate. This ozone layer is incredibly unstable, since it is constantly being formed and broken down through interactions with UV radiation. But, as it is so reactive the ozone layer can easily be broken down by pollutant gases rising from the earth. CFC's and nitrous oxide are thought to be particularly responsible for the breakdown of the ozone layer.

Since the hole in the ozone layer has developed it has lead to –
1. An increase in skin cancers in animals and humans
2. A suppression of the human immune systems
3. Some inhibition to plant life, and an increased susceptibility to pests
4. Reduction in growth of phytoplankton, endangering the food chain
5. A decrease in aquatic life forms

Formation and Breakdown

Ozone in the stratosphere is a product of UV radiations acting on O2 molecules. The UV radiations split apart molecular O2 into free o atoms. These O atoms combine with the O2 to form ozone O3.
O ----------------UV----------> O + O
O + O <=====UV=====> O2

Ozone is thermodynamically unstable and decomposes to O .Thus a dynamic equilibrium exist b/n the production and decomposition of O3.In recent years there have been reports of the depletion of this layer because of the presence of certain chemicals in the stratosphere. The main reason is the release of CFC’s chlorofluorocarbon.


CHLOROFLUOROCARBONS are non reactive, non flammable, non toxic organic molecules and therefore used in refrigerators, AC’s, in the production of plastic foam and by the electronic industry for cleaning computer parts etc. Once CFC’s...