Ozone layer depletion: Humans and animals in immediate danger

Naomi Branch

There are an immense amount of characteristics of the Earth that make life sustainable; the Ozone layer is one of the most important features that make the Earth well suited for life. The Earth’s atmosphere is composed of five layers: the Troposphere, Stratosphere, Mesosphere, Thermosphere, and the Exosphere. The Ozone layer is located between the Troposphere and the Stratosphere, between 15-30km above the Earth’s surface.

Layers of the atmosphere, conceptual illustration - Stock Image - F027/1838  - Science Photo Library
Diagram of the Earth’s layers

The Ozone layer is named after its high concentration of ozone. It is composed of triatomic oxygen molecules that absorb lethal ultraviolet radiation from the sun. According to a study conducted by Mary Peyton Wall, ozone is a molecule composed of three oxygen atoms. Ozone is formed when heat and sunlight create a photochemical reaction of splitting oxygen molecules into two oxygen molecules by solar energy. The process of producing ozone is dependent on sunlight, making ozone produced at higher rates when near lower latitudes due to the concentration of high solar radiation around the equator.

Another study conducted by the United States Environmental Protection Agency found that the Ozone layer protects living things from too much ultraviolet radiation from the sun.

Over the years, depletion of the ozone layer has been occurring because of the release of chemical substances into the atmosphere by humans. Studies conducted by the writers of UKessays environmental studies department, have found that there has been an increase in ozone depleting substances (ODS)  that were in the atmosphere. The high levels of ODS have resulted in the ozone layer thinning by 30-50% over the Arctic and Antarctic; and by 3-5% globally since 1980.

The process of depletion is initiated when ozone depleting substances (ODS) such as chlorine and bromine and chlorofluorocarbons (CFCs), mostly from human sources, are released into the atmosphere. The gases accumulate in the atmosphere, then are moved to the stratosphere through vertical mixing. The chlorine, bromine, and CFCs are initially non-reactive gases, but they are converted into reactive compounds by UV radiation. The reactive gases then produce chemical reactions that destroy the ozone layer.

Chlorofluorocarbons | BioNinja
Chemical reaction depletes the ozone

After the chemical reactions take place, the gases are moved back to the troposphere where they are removed from the atmosphere through precipitation.

Studies conducted by the European Commision found that the negative effects of ozone depletion can have an incredibly negative impact on human health.

Again, the depletion of the ozone layer increases the amount of ultraviolet beams that reach the Earth’s surface. 

First, increased exposure of ultraviolet beams will increase the risk of a person having skin cancer according to studies conducted by Leonard H. Goldberg, MD. One in five Americans will develop skin cancer in their lifetime. The most serious form of skin cancer is melanoma. Melanoma is deemed extremely dangerous because of its ability to spread to other organs rapidly if it is not treated at an early stage. Less deadly nonmelanoma skin cancers are basal cell carcinomas and squamous cell carcinomas. Both nonmelanoma skin cancers are less likely to spread to other parts of the body.

What Is Skin Cancer? & Signs, Symptoms, Etc. - Carecover
Diagram of different types of skin cancer

Other UV-related skin disorders include actinic keratoses and premature aging of the skin. 

Actinic keratoses are skin growths that occur on parts of the body that are over exposed to the sun according to studies conducted by Leonard H. Goldberg, MD. The most common parts of the body where actinic keratoses are found is the face, hands, forearms. Actinic Keratoses are a risk factor for developing squamous cell carcinoma. Constant exposure to the sun will also cause premature aging, making the skin become thick, wrinkled, and leathery.

Increased exposure to UV beams can increase the risk of cataracts. Cataracts are a form of eye damage in which a loss of transparency in the lens of the eye clouds vision. If left untreated, cataracts can lead to blindness. Although cataracts can be cured with eye surgery, they diminish the eyesight of millions of Americans and cost billions of dollars in medical care each year.

UV radiation also negatively affects the developmental processes of plants. A study conducted by the National Park Service found that the depletion of the ozone layer causes considerable damage to agricultural crops and plants in natural ecosystems. Ozone damages plants by entering leaf openings called stomata and oxidizing (burning) plant tissue during respiration. This damages the plant leaves and causes reduced survival.

Plant leaves showing symptoms of ozone injury

According to studies conducted by the NASA Ozone Observatory, ozone symptoms usually occur between the veins on the upper leaf surface of older and middle-aged leaves, but may also involve both leaf surfaces (bifacial) for some species. The type and severity of injury is dependent on several factors including duration and concentration of ozone exposure, weather conditions, and plant genetics.

If not slowed, the depletion of the ozone layer can leave irreversible effects on human life and plant life.

Categories: Environment, Health, science

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