Mountainous Plateau Creates Ozone 'Halo' Around Tibet

ozone descends with it. "Most people think about the mountains as one of the areas you can go to get clean air," said Semple, head of the Division of Plastic Surgery at Sunnybrook and Women's College Health Sciences Centre, a teaching hospital affiliated with U of T. "It may be that when you're up high in the mountains that the good ozone actually becomes bad ozone--because no matter where ozone comes from you don't want to breathe it."