Ozone layer depletion.

Ozone layer holes
The Antarctic ozone hole is no longer a local or regional problem. It is a global affair. It needs to be concerted to face the dangers that the future may pose. Some may wonder why all this global interest in the issue of weights? The answer lies in the seriousness of health and environmental effects, not only on humans, but on animals, plants and other ecosystems.
The UNEP Environmental Assessment Working Group said in a report published in November 1991 that depletion of the ozone layer and the resulting increase in ultraviolet radiation could accelerate the rate of smog that remains in the atmosphere for days. As happened in London in 1952 when the haze smelled the atmosphere of this city and around its day to night over a few days, and led to losses.
The death toll has reached about 4,000. It will also corrode armor
Ozone may lead to an increase in the rate of non-permanent skin cancer by 26%.
UVB rays play a major role in the formation of melanoma, the most dangerous type, which means an estimated 300,000 skin cancer cases per year. The United States will only have about 180 million cases in 80 years, If the international community does not act effectively to stop the depletion of the ozone layer.

Another health hazard of the deterioration of the ozone layer is the occurrence of white water disease, (ie cataracts). According to the report of the United Nations (above), depletion of ozone at a rate of 10% may cause the injury of about 1.7 million people annually, the disease due to exposure to ultraviolet light, in addition to the eye disease of water blue, because of its inability to resist this radiation, and quantities Increased UV radiation, which penetrates the ozone layer, weakens the effectiveness of the human immune system, making people more susceptible to infectious diseases, caused by viruses such as scabies, as well as from bacteria such as tuberculosis and other parasitic diseases.
The negative effects of ozone depletion on humans alone do not stop. The destruction of the ozone layer and the widening of the hole in this layer contribute to the warming of the Earth's surface and thus lead to global warming.
Perhaps the most affected areas are the tropical region, due to high temperature, solar power. Some studies suggest that half of the plants studied are UVB-sensitive and their yields are small and the size of their leaves is affected, as some reports suggest, the likelihood of a 23 percent reduction in soybean production due to exposure to this type of radiation. In addition, chemical structures, for some plant species, may change due to this situation, thereby compromising their mineral content and nutritional value, in general.
On the other hand, there are concerns that the microorganisms found in sea and ocean waters known as phytoplankton may be weakened by exposure to ultraviolet rays. These organisms are an important basis for the food chain in the ecological environment of freshwater and saline, especially fish, shrimp and others.
Phytoplankton also plays a large role in absorbing carbon dioxide in the atmosphere, thereby reducing the impact of warming
Thermal, it also releases the oxygen necessary for the continuation of life.


What is ozone?
The ozone element consists of atmospheric oxygen and the difference between it and molecular oxygen is that the first is tripartite while the molecular oxygen, as its natural state is inhaled, is composed of two atoms of oxygen,
Molecular oxygen, which reaches the lower atmosphere to ozone above the tropics, is caused by high-energy ultraviolet radiation, with waves of 240-300 nm. From there, ozone spreads in the atmosphere at altitudes of 20 to 50 km above the Earth's surface. Ozone is an important component of the atmosphere, with a concentration of about 1 microgram per gram of air. However, ozone-rich air breathing affects the respiratory system and the nervous system, resulting in shortness of breath, headache and fatigue. Age and youth, so schoolchildren in Los Angeles, where ozone levels are high, are forced to stay indoors when the ozone concentration in the air reaches 35 parts per million. For more than a quarter of a century, researchers at the US space agency have tried to use ozone as a fuel to launch spacecraft, and some have described it as a demonic element.
Ozone in the industrial pollution of atmosphere caused by nitrogen oxides and compounds known as "chlorofluorocarbons"
Nitrogen oxides and nitrogen dioxide, which originate from pre-sound aircraft that fly through the ozone layer and penetrate it, stimulate ozone degradation by chemical reactions.

The first to present real scientific predictions of the seriousness of chlorofluorocarbons (CFCs) on the ozone layer were Doland and Molina, a chemist at Atmospheric Chemistry at the University of California, USA, who in 1974 created laboratory conditions similar to those located in the center and outside the upper layers of the atmosphere, Where the protective ozone layer is concentrated. It has been shown that these compounds effectively destroy ozone molecules. These two worlds assumed that chlorofluorocarbons (CFCs) could ultimately destroy 20 to 30 percent of the entire ozone shield, threatening all life on the planet with dire consequences. While many scientists have doubts about the expectations of Doland and Molina, As for the Arctic region, which includes heavily populated countries in North America, Europe and Asia, they also suffer from the same impact, but less so than in the South Pole (5% to 10% in 1969-1979). ), It was found that the ozone layer in the northern region had faded during the same period by 1.7% to 3% and grew this decline, later to a higher rate is 4% to 5% per decade, twice what was originally expected.

Do we lose one day such scenes?


Urgent negotiations
With regard to the serious situation of the ozone layer, a global body of 100 scientists met in 1987 to discuss all available information and make decisions to resolve the issue. In the same year, the United Nations called for urgent negotiations to reduce the production and use of chlorofluorocarbons (CFCs). On September 15, 1987, 91 countries signed the Montreal Protocol. These countries agreed to reduce their production of chlorofluorocarbons and 90% World production. The objective of the Protocol was amended in 1990 in London to become strictly prohibited in 2000.

Solutions.
There is consensus among governmental and non-governmental organizations in the world that environmentally acceptable alternatives to CFCs and halons will provide encouraging results in the long term. But the difficulty in protecting the ozone layer lies in the technical and financial constraints and the most developed alternatives to meet the environmental, economic and industrial requirements and thermal cooling and cooling by acoustic waves. In this context, a US company provided a small refrigerator with a sterling cycle, which is based on the principle of heating a fixed volume of gas such as hydrogen or helium leads to high pressure. The company claimed that the efficiency of the refrigerator is better compared to the traditional refrigerator.
In Mexico, scientists have succeeded in making ice molds by harnessing solar energy. In this regard, a Star-type thermo-acoustic cooling device has also been manufactured and tested superior to the Discovery spacecraft.

The references
Dotto. L. and Schiff. H. the ozone ware. - Douhledy (1978)
Brum. C .; Mckane. L. and karp. C. Biology: - Exploring Life. Second Edition. John Wiley .and Sons. Inc. New York (1994)
3 - Abdul Hamid Ghazi bin Hassan. Environmental pollution: the great concern for the inhabitants of the Earth Magazine Caravan. Volume (41) Number (Page:
42-47

1. Abdullah Al-Nunish. Ozone layer: Tens of millions develop skin cancer and eye clenching if the ozone layer continues to erode. Environment Forum. Vol. 6. Issue No. 2 (June 7, 1993).
2. Ozone protection: alternatives to fluorocarbon compounds. Environment Forum. Special Supplement. Issue (2): Page 1 - 8 (September 1994).

Source // http://www.cars2arab.com/vb/showthread.php?t=5392&page=1