Paul Morris wrote:

> Around an electric discharge there certainly _is_ a higher
> concentration of ozone, but in these days of holes in the ozone
> layer, my advice is -- run all the old motors you can, whilst trying
> not to breath too much of the stuff into your lungs.  Just a thought.

I assume Paul is injecting a little gentle humour into the great
ozone debate.  (He is a former chemistry teacher and a great
raconteur.) This note is for those who may have taken his remarks
seriously.

Ground level ozone has nothing whatsoever to do with ozone in the
upper atmosphere.  The ozone hole is caused largely by halogen
reactions driven by sunlight.  The halogens come largely from our
use of CFCs, etc., and drift into the upper atmosphere.  Ground level
ozone is unpleasant for humans, can help to cause photochemical smogs,
and never reaches the upper atmosphere to fill that hole.

To badly misquote Orwell: "Stratospheric ozone good, ground level
ozone bad."

Jeffrey Borinsky, London