said "Mysterious new man-made gases pose threat to ozone layer" the BBC BBC News "Mysterious new man-made gases pose threat to ozone layer" http://www.bbc.com/news/science-environment-26485048 "Mysterious new man-made gases pose threat to ozone layer" BBC News BBC BBC News ^ said Mysterious new man-made gases pose threat to ozone layer. BBC said "Mysterious new man-made gases pose threat to ozone layer" said told told BBC "Mysterious new man-made gases pose threat to ozone layer" BBC