September 16 is observed as the World Ozone Day. It is the day in 1987 the Montreal Protocol was signed. The damage caused to the Ozone layer is a matter of serious concern. This year, Antarctic stations have recorded ozone values more than 50 pr cent below the pre-ozone hole norms, and satellite images confirm that these large losses are widespread within the ozone hole. Although ozone depletion of this magnitude is common during each ozone hole season, it is remarkable to find these low values so early in September, one or two weeks earlier than in any previous year...editorial