Did some looking. much of the generic data on Ozone does not get terribly specific. It may take trying to find the actual data from the actual monitoring units.

Quote Originally Posted by Thorne View Post
I can't find any information regarding the natural concentration of ozone in water. In fact, unless the water is pure, the ozone would quickly react with any contaminants, destroying the ozone.

And ozone (O3) IS a pollutant at low levels. It can cause headaches, burning in the eyes, and respiratory irritation. People with resperatory problems already are particularly affected. So monitoring those levels is very important. And I would expect the monitoring to occur in those areas which are most likely to have high concentrations.