The Ozone layer is a stratum of gas found in the upper atmosphere which guards the human beings and other living organisms from harmful ultraviolet rays from the sun. This layer is made up of ozone gas which is triatomic molecule, comprising of three oxygen molecules (O3) (Ebi & McGregor, 2008). It is an irritating, colorless and corrosive gas. It is also a very strong oxidizing agent and therefore at the lower atmosphere, it exhibits some harmful effects on the respiratory systems of animals and corrodes sensitive parts of plants.
Ozone cannot be stored for long periods or transported like other industrial gases. This is because it decays quickly to the prevalent diatomic oxygen (O2) and therefore it can only be produced on site (Hov & O Hov, 1997). The atmosphere is stratified with the troposphere as the lowest layer. Stratosphere is the layer that is most immediate from troposphere ranging from six to thirty miles above the surface of the earth (Hov & O Hov, 1997). The variations in the layers occur due to temperature and pressure changes in the atmosphere.
Much of the air (90%) is held in the lowest 10% of the atmosphere due to the compressibility property of gases. Much of the Ozone is found in the stratosphere although it can also be found in small traces in the lower atmosphere. It is very beneficial at the upper atmosphere since it absorbs nearly 97 percent of the ultraviolet radiation from the sun. However, there exist a number of environmental problems from the gas at both layers of the atmosphere. Ozone is the only chemical compound in the troposphere where the variation between the actual atmospheric levels and poisonous levels is so minor (Ebi & McGregor, 2008).
There is gradual increase in Tropospheric ozone especially in the northern hemisphere where emissions of human origin have been on the rise. At ground level, ozone is destructive to human health, materials and plants. It affects the respiratory membranes and other lung tissues of organisms, thereby inhibiting their respiratory function. When individuals are exposed to high concentration of ozone, they develop complications associated with their respiratory system such as pneumonia, asthma, chronic obstructive pulmonary disease and other respiratory illnesses.
In most cases, these illnesses if not well manned can lead to premature deaths(Ebi & McGregor, 2008). This problem is caused by human activities, majorly in the transport and petrochemical industries. Although the gas is not produced directly from car engines and industrial processes, combustion of the gasoline based engines results to emission of unstable organic compounds into the atmosphere. Several reactions between these compounds and sunlight follow, resulting to formation of ozone at the source of the pollution (Hov & O Hov, 1997).
Since the process of ozone formation is dependant on sunlight, it is in higher concentrations within the tropics and during summer in the Polar Regions. Moreover, it can be incidentally formed from the diatomic oxygen when electrical discharges occur. Large electric motors that use brushes, laser printers and photocopiers can also produce ozone due to the repeated sparking inside them (Ebi & McGregor, 2008). The chemical composition of ozone contributes to its harmfulness to living organisms.
It is thermodynamically an unstable molecule and can undergo ozone photolysis in the presence of UV light leading to production of the hydroxyl radical (OH). The radical is important in removal of hydrocarbons from the air but on the other hand, the products end up forming smog (Hov & O Hov, 1997). Due to its strong oxidation capabilities, ozone attacks all polymers that contain double bonds within their chain structure. For example natural rubber is vulnerable to attack, causing cracks to develop on the its surface which deepens with time.
The rate of growth of the crack depends on the ozone concentration in the atmosphere. Ground level ozone is a major component of smog which has remained to be the most difficult problem in America. It causes negative impacts on human health, such as irritation of the respiratory track, coughing and even decreased lung function in the long run (Hov & O Hov, 1997). In addition, it causes invisibility during flights, something that can turn out very catastrophic.
It is also worth to mention that, smog affects even vegetation by causing discoloration, damage and loss of leaves which can hinder photosynthesis from taking place (Ebi & McGregor, 2008). Furthermore, the molecular orbitals in ozone have strange and continually changing resonating forms. This occurs because of the three atomic nuclei which try to share the uneven compliment of electrons. Due to this, ozone is easily split by a halogen radical, a property that led many industrialized nations to withdraw from production of certain halocarbons.
Similarly, it is unsafe to use some halocarbons as refrigerants and aerosols (Ebi & McGregor, 2008). On the contrary, stratospheric ozone is considered to be beneficial due to its ability to filter harmful ultraviolet rays from the sun. However, there are alarming dangers on the eventual fate of the living organisms on the earth due to the recent depletion of this layer. Since the intensity of the radiation from the sun is constant, reduction in ozone levels will translate to less protection (Titus, 1986). Exposure to ultraviolet rays causes skin cancer in human beings.
In case of plants, the rays affect their physiological and developmental processes. Its effects extend to marine ecosystems whereby, the radiation causes damage to the early stages of development in fish, and other marine organisms (Titus, 1986). Solution to this problem can only be realized by tackling the factors causing it, which are mainly of human origin. Using alternative sources of energy instead of petroleum products, results to dual benefits (Hov & O Hov, 1997). First of all, it is a step towards minimizing formation of the ground-level ozone that is caused by burning of petroleum based fuels.
In addition, it will result to reduction in emission of harmful gases that damage the stratospheric ozone.
Ebi, L. K. , & McGregor, G. ( 2008, Nov). Climate Change, Tropospheric Ozone and Particulate Matter, and Health Impacts. Retrieved May 21, 2010, from: http://ehp03. niehs. nih. gov/article/fetchArticle. action? articleURI=info:doi/10. 1289/ehp. 11463#Ozone Hov, 0. , & O Hov. (1997). Tropospheric ozone research: tropospheric ozone in the regional and sub-regional context. Michigan: Springer. Titus, G. J. (1986). Stratospheric ozone. Regensburg: Environmental Protection Agency.