Technogenic catastrophs (results)

In the upper layer of the earth atmosphere – stratosphere – the phenomenon of a clear reduction of ozone concentrating has increased in the last decades. This reduction is supposed to be caused by anthropogenic changes. The fact caused a special interest from mankind by the reason that the stratospheric ozone protects the earth’s surface from the ultraviolet rays of the sun. The ozone hole, first discovered in 1986, in the southern hemisphere above the Antarctic was 1000 km large. It appeared every August, but disappeared in December or January. In the northern hemisphere on the Arctic it appeared another hole, however it was of a smaller size.


As the result that the ozone layer is getting thinner, the ultraviolet radiation fallen to the earth increases, which on its hand causes the increase the possibility in skin cancer.


It is considered that the main source of these halogen atoms in the stratosphere is photodissociation of chlorofluorocarbon (CFC) compounds, commonly called freons. And of bromofluorocarbon compounds known as halons. These compounds are transported into the stratosphere after being emitted at the surface. Both ozone depletion mechanisms strengthened as emission of CFCs and halons increased. Producing these materials began in the 20-th century, from early twenties. They are used as ideally safe fridge-agents, deodorant fillers, electric equipment cleaners, fire put up material, plant-protecting means. It is considered that the molecules getting in the atmosphere don’t dissolve for decades and reaches the stratosphere, where under the influence of the ultraviolet rays of the sun it dissolves and produces chlorine atoms. These ones work as a catalysts of dissolving ozone molecules. It is thought that one molecule chlorine-fluorine-carbon dissolves 100 thousand ozon molecules.

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