At 20 - 50 kilometers above the Earth's surface in the atmosphere is a layer of ozone. The ozone molecule consists of three oxygen atoms.
Ozone is produced by sunlight. When ultraviolet light photons collide with oxygen molecules, an oxygen atom is split off from them, which, having joined another O molecule2forms O3 (ozone).
Ozone layer thickness
The ozone layer of the atmosphere is very thin. If all the available ozone in the atmosphere evenly covers an area of 45 square kilometers, we get a layer with a thickness of 0.3 centimeters. A little ozone penetrates with the streams of air into the lower layers of the atmosphere. When light rays react with substances contained in exhaust gases and industrial fumes, ozone is also formed.
The danger and usefulness of the ozone layer
On a hot foggy day in a gassed area, ozone levels can reach alarming levels. Ozone breathing is very dangerous, as this gas (triatomic oxygen) destroys the lungs. Pedestrians inhaling large amounts of ozone begin to choke and feel chest pain.
Trees and bushes framing the gassed highways, at high concentrations of ozone in the air, cease to grow normally. But if ozone is where it is supposed to be - at a high altitude, then it is very good for health. Ozone absorbs ultraviolet rays.These are the very rays from which the skin becomes tanned. But if an excess of ultraviolet radiation falls on the skin, then you can get a sunburn or get skin cancer.
Interesting fact: Scientists estimate that an increase in the area of the ozone hole by 1 percent causes an increase in the incidence of skin cancer by 3 to 6 percent.
What destroys the ozone layer?
Scientists learned about the ozone layer of the atmosphere in 70 years. The discovery was made that chlorine fluorine carbon derivatives (freons) - compounds used in refrigerators, air conditioners and aerosol cans - destroy ozone. Freons are released into the atmosphere every time you use a spray can with deodorant or hair spray.
Rising into the upper atmosphere, freon molecules interact with ozone molecules. Under the influence of solar radiation, freons produce chlorine, which breaks down ozone with the formation of ordinary oxygen. In the place of such interaction, the ozone layer is destroyed - disappears.
In 1978, based on data on the effect of freons on the ozone layer of the atmosphere, the government of the United States of America (USA) banned the production and sale of aerosols containing freons. True, aerosol manufacturers, and with them many scientists, consider the theory of the destruction of the ozone layer unconvincing. In 1985, English scientists made a startling discovery.
They discovered a huge “hole” in the ozone layer over Antarctica. This hole with an area of the United States appears annually in the spring. When the direction of the prevailing winds changes, the ozone hole is filled with ozone molecules from adjacent parts of the atmosphere, while the amount of ozone in neighboring areas decreases.For example, in the winter of 1992, the ozone layer over Europe and Canada became 20 percent thinner.
Scientists have found that in the sky above Antarctica, the concentration of perchloric acid anhydride is very high - a compound formed at the time of destruction of the ozone molecule by chlorine. The discovery of the British confirms that the widespread use of freons really creates the problem of ozone holes. Scientists estimate that a 1 percent decrease in ozone in the upper atmosphere causes an increase in the incidence of skin cancer by 3–6 percent, since atmospheric permeability to ultraviolet rays increases by 2 percent.
Ultraviolet rays, in addition, have a damaging effect on the body's immune system, making us more susceptible to infectious diseases, such as malaria. Ultraviolet rays also destroy plant cells - from trees to cereals.
Interesting fact: every spring a “hole” with the United States of America appears in the ozone layer over Antarctica.
Climate Impact
Even more disturbing, the depletion of the ozone layer can unpredictably change the Earth’s climate. The ozone layer traps heat dissipated from the surface of the Earth. As the amount of ozone in the atmosphere decreases, the air temperature decreases, the direction of the prevailing winds changes, and the weather changes. Droughts, crop failures, food shortages, and hunger can result. Some scientists have calculated that even if measures are taken and all activities that destroy the ozone layer are stopped, it will take 100 years to fully restore it.
