1.   A WMO spokesman said danger to humans was reduced because periods of high ozone depletion coincided with a low sun and frequently cloudy skies, limiting ultra-violet radiation.

2.   Although Massachusetts has made progress in reducing ozone levels, state monitors on Cape Cod and in southeastern Massachusetts showed high ozone levels on Sunday and Monday.

3.   A recent study out of California seems to show that exposure to high ozone levels might cause children to develop the condition.

4.   But hazy atmospheric conditions and high ozone readings do not always go together.

5.   By forcing individual species to evolve tolerance or die, it should then be possible to work out the long-term effects of high ozone levels.

6.   Despite the high ozone levels last week, this summer has not produced a major new air-pollution episode.

7.   High ozone levels also indicate the presence of other chemicals that produce ozone when they react in sunlight.

8.   In addition, high ozone days common during the summer often mean increases in emergency room visits.

9.   In Houston, high ozone levels last generally through November.

10.   Lake Arrowhead was unique in that it has high ozone levels, but low levels of other pollutants.