Human activities effectively punched a hole in it, through the use of gases like chlorofluorocarbons CFCs in spray cans and refrigerants, which break down ozone molecules in the upper atmosphere. While some extra UV rays slip through the ozone hole, their net effect is to cool the stratosphere more than they warm the troposphere.
So, this increase in UV rays cannot explain the warming of the planet's surface. In our present study, we shall discuss how ozone layer depletion is affecting human health and we shall also discuss some recommendations to minimize ozone depletion and its adverse effects on human health.
The ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated [2]. Ozone layer is also naturally broken down but there is a balance between its formation and natural depletion.
As a result the total amount of ozone remains constant. But ozone layer thickness varies with altitude and seasonal change. Ozone concentration is highest between 19 - 23 km [6]. Most of ozone is formed at equator where there is maximum sunshine but with winds it travels at high altitude and get accumulated in stratosphere [1].
Ozone hole is created in the region where ozone layer has been depleted. Ozone holes are first discovered in Antarctica in Few years ago ozone holes are also discovered in arctic region. Since rate of ozone depletion is increasing 0. Due to depletion of Ozone UV rays are penetrating in troposphere and leading to more ozone formation in troposphere which is causing injurious effects on our health as ozone is toxic for our body [8].
Ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is disturbed. Although natural phenomenon can cause ozone depletion but human activities such as CFCs are now accepted as major cause of depletion [9]. All ozone depleting chemicals contain chlorine and bromine [10]. CFCs are highly volatile and non combustible so they are very quickly evaporated and can easily reach in stratosphere where ozone is present here they start depleting ozone molecules.
These CFCs have also adverse affects on human health [11]. According to the chemical model for ozone destruction proposed about 20 years ago, the photolysis of Cl 2 O 2 is key to ozone depletion reaction.
But now atmospheric researchers studied that the rate of this reaction is not extremely high as it was thought previously so we can no longer say that CFCs are the main cause of ozone depletion [12]. Another major cause of large scale ozone depletion is Rocket launches. It has been studied that unregulated rocket launches can result in much more ozone depletion than CFCs. It is estimated that if rocket launches will be let unregulated then it would cause huge ozone loss by the year than the CFCs have done [1].
Global warming also leads to ozone layer depletion. Due to global warming and green house effect most of the heat is trapped in troposphere which is the layer below the stratosphere.
Nitrogenous Compounds emitted by human activities in small amount like NO, N 2 O and NO 2 are considered to be greatly responsible for the depletion of ozone layer [13]. Ozone depletion is affecting the human health and environment negatively, as it allows the penetration of UV radiations to reach the Earth.
These radiations can cause severe diseases in humans such as skin cancer, eye damage and genetic mutations etc. Furthermore the ozone depletion is affecting the aquatic life, biogeochemical cycles, air quality and also contributing in Global warming but in this review paper our main focus is on the effects of ozone depletion on human health [1]. The major cause of blindness in this world is cataracts. There would be 0. Eye lens can be damaged by oxidative agents.
Oxidative oxygen produced by UV radiation can severely damage eye lens and cornea of eye is also badly damaged by UV radiation [15] -[17]. Photokeratitis, cataract, blindness all are caused due to UV rays [18]. Exposure to UV radiations can cause skin cancer. UV radiations alter the structure of biomolecules and thus lead to different diseases [10] [19] Skin is the most often exposed part of body to UV radiations There are two types of skin cancer, Melanoma and Non-melanoma.
Melanoma is most serious form of cancer and is often fatal, while non-melanoma is most common type and less fatal. Depletion of ozone layer leads to both Sun burn and skin cancer [20]. UV radiations are also responsible for breast cancer and leukemia [18]. Epidemiological studies of Melanoma indicate that the incidence of melanoma is increasing in those countries having high ratio of cases [21] - [23]. As UV radiations can penetrate more easily in thin skin so there is greater number of incidence is found in thin skinned people.
It is found that the incidence of Melanoma is more in children than adults. The chance of incidence of melanoma is correlated with UV exposure furthermore the survival chance of melanoma is less in boys as compared to girls [24] [25]. As the intensity of radiation increases in summer so the risk of melanoma in thin skinned people is increased in summer and it is more in females as compared to males as their skin is thinner than males [26] [27]. There is considerable relationship between melanoma risk and intermittent sun exposure and sunburn history [28].
In the image below, the upper ranges of possible effects from the ozone changes are indicated by the open bars, and the lower ranges are indicated by the solid bars. As shown in the figure, the increase in carbon dioxide is the major contributor to climate change. Carbon dioxide concentrations are increasing in the atmosphere primarily as the result of the burning of coal, oil, and natural gas for energy and transportation.
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