Ozone Pollutant and Protector

Two forms of the element oxygen are found in nature the life-sustaining diatomic oxygen, O2, and ozone, O3, which is a pale blue gas with a strong odor. The concentrations of ozone in the air around us are usually too low for the color and the odor to be apparent, but sometimes when we stand next to an electric motor, we notice ozone s characteristic smell. This is because an electric spark passing through oxygen gas creates ozone. 

Nitrogen dioxide, NO2, is a red-brown gas that contributes to the brown haze associated with smog. 

The oxygen atoms react with oxygen molecules to form ozone molecules. 

This smog is worst from May to September, when the days are long and the sunlight intense. 

Now that we have seen the conditions that lead to too much O3 in the air we breathe and why that is a problem, we need to know why depleting the ozone in the upper atmosphere, creating too little ozone there, can also be a problem. Let s start with a little information about our atmosphere. Atmospheric scientists view the atmosphere as consisting of layers, each with its own characteristics. The lowest layer, which extends from the surface of the earth to about 10 km (about 6 miles) above sea level. 

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