Ozone

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Ozone

Ozone (O3) is a molecule consisting of three oxygen atoms, similar to the oxygen

we breathe (O2), however oxygen consists of only two oxygen atoms. In the

stratosphere, a region high up in the upper atmosphere, light rays are

responsible for the breaking down of oxygen (O2), breathable oxygen into its two

separate oxygen atoms. Lone oxygen atoms are markedly reactive. When a lone

oxygen atom comes into contact with a breathable oxygen molecule (O2) it

combines to form ozone (O3). The ozone layer is a small residual amount of

ozone concentrated in a band in the upper atmosphere. This band of concentrated

ozone resides approximately between twenty and forty kilometers high in the

stratosphere. The ozone layer reactions that both create and destroy ozone has

come into a dynamic equilibrium. This dynamic equilibrium is very delicate and

resulted during atmospheric formation (Environment Canada, 1996). Ozone, however,

is very rare even in the ozone layer. Oxygen makes up approximately twenty

percent of air and ozone makes up only 3 x 10-5 percent of air. Furthermore,

this minuscule amount of ozone is enough to protect the earth from most

ultraviolet light. Ozone prevents most UV-B radiation from reaching the surface

of the earth (Environment Canada, 1996). Ozone is very important to life on

earth because the harmfulness of high-energy UV-B radiation stems from the high

energy of these light rays, enabling them to penetrate deeply into water, plant

tissue and epidermal tissue of animals. Increased UV-B radiation results in

harming the metabolic system of cells and ultimately damage to genetic material

present in effected cells. Living organisms on the surface of the earth have

always been exposed to some, and only slightly differing levels of UV-B

radiation depending of geographic location and season. Through evolution,

cellular repair mechanisms have evolved to safeguard cells against damage done

by UV-B radiation. With the increase in the UV-B radiation, more damage is done

to cellular functions then the natural protection system can deal with

(Environment Canada, 1996). Life on earth would more or less be void if not for

the formation of the ozone layer during atmospheric formation (Porter, 1996).

With out the ozone layer the harmful UV-B radiation would not allow the growth

of autotrophic plants, resulting in reduction in oxygen production; ultimately

the destruction of most living organisms on the earth surface would result.

Increased UV-B radiation has been linked to many incidence of increased health

problems among humans. UV-B radiation leads to increase skin cancer, eye damage,

and possible inhibition of the immune system (Health Canada). These incidence

have been noticed in humans, and it is presumed that these problems will occur

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