http://www.newsweek.com/map-shows-ozone-layer-north-america-1840268 > A NASA map shows the size of the Antarctic ozone hole at its largest point this year, when it spread to the size of North America. > The ozone layer protects life on Earth from the sun's ultraviolet rays. Where the ozone layer is thinner, there is more danger from UV rays, which put humans at risk of skin cancer, sunburns and cataracts.