Teacher Site Map
Earth Systems Science Core
Science Home Page

In the O-Zone

Okay, take a deep breath, stretch your arms and pay attention. I don't want you to "zone" out  right now... Sorry for the bad joke; but let's talk about ozone.  You have heard of it, but what is it? Is it a good thing or a bad thing? The reality is that it is a little of both, depending on where it is.

Ozone is composed entirely of the element oxygen: three atoms worth. O3 is a highly reactive and unstable form of oxygen that, even at low levels, can be irritating and toxic to organisms. It is formed naturally in the upper atmosphere, but it can also be formed at ground level by a lightning strike.

Ozone is a strong oxidizer (takes away protons) of many organic compounds and is used commercially to bleach oils, waxes, and textiles. It can also be used as a deodorizer, a germicide and to sterilize water and air.

Ozone is good in the stratosphere, about six miles or 10 km above sea level. This area of the atmosphere naturally contains about six parts per million of ozone molecules. The surrounding ozone absorbs a large amount of harmful ultraviolet (UV) light. UV light can damage your skin, and this is why your mother probably smeared sun block all over you when you went swimming as a child.

Ozone near the ground is bad. It is very harmful to lung tissue, and for the reasons listed above is very harmful to plants and buildings. Ozone can accumulate at ground level from the reactions of light and chemicals produced by some industries and from car exhaust. On some days in some cities, the levels can get so high that it is hazardous to even go outside.



Ask your teacher about the activity "Ground Level Ozone Testing" in the NSTA publication The Science Teacher, December 1995. If they do not have a copy of the publication, they may write to the authors at The Nation Center of Atmospheric Research, NCAR, P.O. Box 3000, Boulder, Colorado 80307-3000, Attention: Carol McLaren

Review science lab safety rules here.

Get the plug-ins: Get Adobe Acrobat Reader and Get Quicktime Player. (The QuickTime plug-in is needed to play sounds and movies correctly.)

Want to share photos of you or your friends doing this activity? Send it in an e-mail with the following information:

  1. The title of the activity
  2. The URL (Internet address)
  3. Your name.

Remember that no pictures can be used that show student faces or student names on it. 

Teachers should view the Teacher Site Map to relate Sci-ber text and the USOE Earth Systems Science core.


Updated October 24, 2008 by: Glen Westbroek

Science Home Page | Curriculum Home Page | Earth Systems Science Core | USOE Home Page

Copyright Utah State Office of Education.