Ozone holes are holes that you cannot mend. They are formed in places where the thinner the ozone layer of the Earth.
Ozone is a compound of oxygen atoms. If the molecule of the usual two oxygen atoms, in the molecule of ozone three of them.
The ozone layer is located in the stratosphere at a height of approximately 25 kilometers from the earth's surface. It is very important because it protects the Earth from the most active of cosmic rays, which without it could kill all life on the planet. By the way, this deadly radiation and forms for us against same - the ozone layer! Under the action of solar radiation from molecules of oxygen to form ozone molecules.
The ozone hole is not yet in the full sense of the holes: just the ozone layer in some places depleted as, say, secondhand shirt on his elbow. However, on the planet through these holes gets more intense UV rays than before, when the ozone layer was solid.
And the blame for the appearance of the ozone hole again people. There is, of course, they tore the ozone layer in the literal sense. But produced large quantities of chemical compounds, primarily chlorinated and fluorinated hydrocarbons, which, rising in the atmosphere, can slowly destroy ozone. For a long time people have used these harmful gases in aerosol cans, refrigerators, air conditioners. Think again, have signed an international agreement, which has committed to cease production harmful to the ozone layer substances. Now many cans emblazoned the words: "a Friend of ozone". These words are written in different languages. But the ozone layer is one on the entire planet. And from ozone holes can suffer all its inhabitants.