The ozone layer absorbs ultraviolet rays emitted by the Sun.
The ozone layer is a component of the atmosphere . The notion of layer can be used to name something that covers something else or that area that overlaps with others to form a unit. Ozone , on the other hand, is a substance that is made up of three oxygen atoms per molecule.
The set of gases that surround the planet is called the atmosphere: ozone, oxygen, carbon dioxide, nitrogen and others. The atmosphere is divided into successive layers that go from the troposphere (closest to Earth) to the exosphere (farthest).
Ozone is found in the stratosphere , which develops between 10 and 50 kilometers high. This ozone layer is essential for life since it is responsible for absorbing the ultraviolet rays emitted by the Sun.
Importance of the ozone layer
The ozone layer, whose thickness varies, filters this radiation, minimizing its arrival at the Earth's surface. A reduction in the ozone layer, therefore, favors ultraviolet radiation reaching the Earth , a situation that can cause numerous problems for humans.
The use of various chemical compounds present in aerosols , fungicides, refrigerants and other products generates an increase in the concentration of bromine and chromium in the stratosphere, affecting the ozone layer. When the ozone layer is reduced, its radiation filtration capacity also decreases: the greater arrival of ultraviolet rays to the surface, in turn, increases cases of skin cancer , cataracts and other health disorders.
Although we often talk about an ozone hole , in reality there is no such hole in the ozone layer. What experts have detected is an abnormal decrease in the thickness of the aforementioned layer, more noticeable in certain regions.
The loss of ozone capacity puts health at risk.
Substances that affect it
At the end of the 1980s , the Montreal Protocol was signed, a treaty in which it was agreed not to use chemicals that could destroy the ozone layer, and thus began a long and slow path of recovery. However, since new substances have been used since then, which were not included in the document, in 2017 new threats to the integrity of the layer were discovered that could delay regeneration by three decades.
The study carried out in 2017 showed that the use of chlorine chemicals had increased considerably in recent times, both to make plastics and to remove paint. The 1987 treaty does not regulate the use of these compounds , most of which come from the Chinese industry.
Since the signing of the agreement, hydrochlorofluorocarbons and chlorofluorocarbons that caused anomalous depletion of the ozone layer were no longer used in several countries. The substances that generated concern thirty years later are those that have a short life span; one of them is dichloromethane , used as an industrial solvent. From 2007 to 2017 , the percentage of dichloromethane found in the atmosphere increased by 60%.
The second of the worrying compounds is 1,2-dichloroethane , used for the manufacture of PVC. Although until not long ago it was believed that the decomposition of these substances occurred before reaching the ozone layer, samples obtained in recent years have proven just the opposite.
The research also showed that cold winds carry these substances towards the Eastern Pacific from factories located in China , and that is where the air rises to the atmosphere at high speed; If its release had taken place in other parts of the planet, the impact would have been considerably less.