https://www.reddit.com/r/science/comments/9rlx2p/location_of_large_mystery_source_of_banned_ozone/ https://www.reddit.com/r/science/comments/9rlx2p/location_of.

https://www.reddit.com/r/science/comments/9rlx2p/location_of_large_mystery_source_of_banned_ozone/ https://www.reddit.com/r/science/comments/9rlx2p/location_of... also has interesting information about CFC sources coming from chlor-alkali plants.