1.   Recent studies suggest that ozone depletion is to blame for widespread blindness among sheep in southern Chile, on the edge of the Antarctic ozone hole.

2.   Gunson said findings from the Atlantis flight suggest that chlorine is recombining in the Antarctic ozone hole as hydrochloric acid and chlorine nitrate.

3.   Measurement of the size and intensity of the Antarctic ozone hole is an international operation in which cooperation between NASA and the Russian space agency has become important.

4.   Antarctic ozone depletion starts in July, when sunlight triggers chemical reactions in cold air trapped over the South Pole during the Antarctic winter.

5.   But officials cautioned that the decreased size of the ozone hole is not an indication of the recovery of Antarctic ozone levels.

6.   Cooling of the stratosphere over Antarctica is also predicted to make the seasonal Antarctic ozone hole worse and longer-lasting, they said.

7.   Destruction of the Antarctic ozone protective layer appeared to level out this year, but a scientist warned Wednesday it could get worse in years to come.

8.   Greenbelt, Md. -- NASA discusses new evidence that man-made chlorine in stratosphere is cause of Antarctic ozone hole.

9.   That potential threat could include heavily populated areas of Europe and North America, unlike the relatively small number of people endangered by the Antarctic ozone thinning.

10.   The cause of the Antarctic ozone depletion is the chlorine and bromine released by man-made chemical compounds such as chlorofluorocarbons which are contained in some aerosols.