Therefore, we want a layer of ozone far above us where it can protect us from harmful radiation but we do not want excessive concentrations of it at ground level where it can harm our respiratory tracts.

 Ozone comes from many different sources, both natural and man-made. Lightning produces ozone. Some people describe ozone as the "fresh" or "clean" smell in the air after a storm.

 Office copiers and laser printers can produce ozone concentrations as high as those encountered outdoors, but the level is usually limited to a particular room or area. 

 Of more concern is the ground-level ozone resulting from industrial emissions and the emissions of internal combustion engines such as in automobiles and airplanes. These industrial and automotive sources emit chemicals called volatile organic compounds (or VOCs) and oxides of nitrogen. The VOCs may be unburned fuel or by-products of various industrial processes, while the oxides of nitrogen are usually combustion products. In the presence of sunlight, 50 to 100 different chemical reactions are initiated in the air which in turn, produce many new molecules. One of the products produced is ozone.

 Some people refer to all air pollution as "smog" as though all pollution were the same. Originally, smog was an English coinage referring to smoke from coal fires plus fog - rarely a problem in the United States.

  Particulant matter in the air can also harm our respiratory tracts. Particulates are tiny solid or liquid particles such as automotive exhaust, dust, smoke, topsoil and pollen. A variety of sources produce particulates. The ozone-producing process also produces fine particulate matter.

  One can learn to recognize the smell of ozone as one can learn to recognize any smell. HDHHS is studying the feasibility of training people to recognize the smell of ozone so if necessary, each person may take action. Susceptible people such as the elderly, the very young or those with respiratory problems should go indoors, preferably into air conditioning. 

 We presently have ozone warnings and alerts. An Ozone Alert is a kind of weather forecast issued by the Texas Natural Resource Conservation Commission. An alert is declared when meteorological conditions are expected to favor the formation of excessive ozone.

The federal government has identified concentrations of ozone, above which, susceptible people are at risk. Any day in which these standards are exceeded in any one hour is an Ozone Exceedance Day.

 High concentrations of ozone may be a natural, and to some extent, unavoidable by-product of modern civilization. Perhaps the best way to protect our bodies from the effects of ozone is to avoid it by heeding ozone warnings and alerts.

  It is also incumbent on us as concerned members of the community to minimize our personal production of VOCs, and particulate matter.

How Nature Uses Ozone

Ozone is product of natural phenomena such as lightning and volcanoes, and plays a role in the photochemical process which replaces certain elements necessary for plant growth in the soil.