Depletion of the ozone layer

Sources[ edit ] The photochemical mechanisms that give rise to the ozone layer were discovered by the British physicist Sydney Chapman in The ozone molecule is unstable although, in the stratosphere, long-lived and when ultraviolet light hits ozone it splits into a molecule of O2 and an individual atom of oxygen, a continuing process called the ozone-oxygen cycle.

Depletion of the ozone layer

However, various factors have led to the depletion and damage of this protective layer. Learn more about the process, causes, and effects of ozone layer depletion. May 31, Formation of Ozone Ozone is a colorless gas found in the upper atmosphere of the Earth.

It is formed when oxygen molecules absorb ultraviolet photons, and undergo a chemical reaction known as photo dissociation or photolysis. In this process, a single molecule of oxygen breaks down into two oxygen atoms. The free oxygen atom Othen combines with an oxygen molecule O2and forms a molecule of ozone O3.

The process of absorption of harmful radiation occurs when ozone molecules split up into a molecule of oxygen, and an oxygen atom. The oxygen atom Orecombines with the oxygen molecule O2 to regenerate an ozone O3 molecule.

Thus, the total amount of ozone is maintained by this continuous process of destruction, and regeneration. Ultraviolet radiations UVRare high energy electromagnetic waves emitted from the Sun.

Ozone layer depletion first captured the attention of the whole world in the latter half ofand since then, a lot of research has been done to find its possible effects and causes.

Various studies have been undertaken to find out possible solutions. Let us take a look at some of the causes and effects of ozone layer depletion.

Depletion of the ozone layer

A combination of low temperatures, elevated chlorine, and bromine concentrations in the upper stratosphere are responsible for the destruction of ozone.

The production and emission of chlorofluorocarbons CFCsis the leading cause of ozone layer depletion. These are often found in vehicle emissions, byproducts of industrial processes, refrigerants, and aerosols.

ODS are relatively stable in the lower atmosphere of the Earth, but in the stratosphere, they are exposed to ultraviolet radiation and thus, they break down to release a free chlorine atom.

Chlorine Monoxide ClO This free chlorine atom reacts with an ozone molecule O3and forms chlorine monoxide ClOand a molecule of oxygen. Now, ClO reacts with an ozone molecule to form a chlorine atom, and two molecules of oxygen.

The free chlorine molecule again reacts with ozone to form chlorine monoxide. The process continues, and this results in the depletion of the ozone layer. Ultraviolet rays of the Sun are associated with a number of health-related, and environmental issues. Let us take a look at how ozone depletion affects different life forms.

Impact on Humans Skin cancer: Exposure to ultraviolet rays poses an increased risk of developing several types of skin cancers, including malignant melanoma, and basal and squamous cell carcinoma. Direct exposure to UV radiations can result in photokeratitis snow blindnessand cataracts.

Effects of UV rays include impairment of the immune system. Increased exposure to UV rays weakens the response of the immune system. Accelerated aging of skin: Constant exposure to UV radiation can cause photo allergy, which results in the outbreak of rashes in fair-skinned people.

Ozone chemicals can cause difficulty in breathing, chest pain, throat irritation, and hamper lung functioning. Effects on Amphibians Ozone depletion is listed as one of the causes for the declining numbers of amphibian species.Ozone layer depletion, is simply the wearing out (reduction) of the amount of ozone in the stratosphere.

Unlike pollution, which has many types and causes, Ozone depletion has been pinned down to one major human activity. What is it? The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation.

It contains high concentrations of ozone (O 3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of. The term ‘ozone hole’ refers to the depletion of the protective ozone layer in the upper atmosphere (stratosphere) over Earth's polar regions.

People, plants, and animals living under the ozone hole are harmed by the solar radiation now reaching the Earth's surface—where it causes health problems, from eye damage to skin cancer.

The ozone layer has historically protected the Earth from the harmful UV rays, although in recent decades this protection has diminished due to stratospheric ozone depletion. Figure \(\PageIndex{1}\): These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from to This "ozone hole" has extended to cover an area as large as .

Ozone layer depletion increases the amount of UVB that reaches the Earth’s surface. Laboratory and epidemiological studies demonstrate that UVB causes non-melanoma skin cancer and plays a major role in malignant melanoma development.

In addition, UVB has been linked to the development of cataracts. Ozone depletion: Ozone depletion, gradual thinning of Earth’s ozone layer caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities.

The thinning is most pronounced in the polar regions, especially over Antarctica.

ozone depletion | Facts, Effects, & Solutions |