Ozone

Author: Muhammad Hamza Qureshi (Peshawar Model Degree College)

Ozone is an allotropic form of oxygen containing three oxygen atoms chemically bonded together. Ozone is present in second of the four layers of atmosphere called “stratosphere”. Ozone layer is very important for the lives of animals, plants and human beings in our precious Earth. Stratosphere acts as a layer of ozone around the Earth. Ozone molecules present in ozonosphere absorbs ultra-violent and high cosmic rays of Sun and protects the Earth from it.

Stratosphere extends from 11 km to 50 km above from the sea level. Due to present of ozone molecules in the stratosphere, it is also known as “ozonosphere”.

Ozone Depletion

About ozone depletion, well according to “World Health Organization” ozone depletion is defined as “The decrease in the concentration of ozone molecules in stratosphere (ozonosphere) is called ozone depletion”. OR we can also say that “the process of formation of holes in ozone layer is called ozone depletion”.

There are lot of reasons which causes ozone depletion including man made sources and natural sources. These sources causes ozone depletion  by emitting  pollutants like oxides of nitrogen (NOx), oxides of sulphur (SOx), carbon monoxide (CO) and CFC’s (Chloro Floro Carbons).

1:Man-made Sources:

Contribution of man –made sources causes ozone depletion much more than natural sources. Internal combustion from automobiles, industrial wastes, furnaces, thermal power plants, agriculture burning and emittion of smoke from jet engine airplanes, forest fires, soil pollution and the combustion of fossil fuels are main man-made pollution emitting sources.

2: Natural Sources:

Natural sources also have a major part in ozone depletion. Volcano eruptions, natural gas emission, electrical discharging inside clouds, soil erosion, pseudumonas bacteria (nitrogen producing bacteria), sulphate spray from oceans are major natural sources of pollutants.

Effects of Ozone Depletion

Ozone depletion adversely affects the lives of humans, animals, plants, crops, marine life and materials. I am describing each of them as follows:

1: Effect on Humans:

The high energized cosmic rays and UV radiations fall on earth due to ozone depletion. These UV radiations when interact with humans causes various dangerous and abnormal diseases in humans.  In a lot of cases, the UV rays, when interact with human cause’s skin cancer and sunburn. Skin cancer is an extremely dangerous disease which is caused due to the abnormal mitosis (cell division) in skin that eventually distributes in all of the body. Similarly these radiations also cause another extremely dangerous eye disease known as “CATARACTS”, it has been estimated that 12 million people have become blind due to this disease and 18 million have lost their part of eye sight. Pulmonary edema is another disease which causes swelling of lungs. In some cases It even causes death.

2: Effect on animals:

It has been estimated that UV radiations causes pink eye disease and blindness in most of the animals. However, skin cancer and sunburn is also founded in some animals.

Ozone depletion also causes forest fire, thus destroying habitat of thousands of animals.

3: Effect on plants:    

The UV radiations when fall on leaves of plants, it mainly causes destruction of chloroplast (present in plant cell), and affects the process of photosynthesis.

4: Effect on crops:

Several worlds’ major crop sources are sensitive to UV radiations. When UV radiations fall on crops like rice, wheat, barley, oats, corn, soybeans, etc.  these radiations slow down the process of its growth, photosynthesis and reproduction. It is estimated that 1% increase in UV radiations decreases 1% production of soybean crops. Thus UV radiations are dangerous for all.

Effect on marine life:

UV radiations when fall on lake, river, seas or oceans, they estimate themselves over 20m, thus when UV radiations fall on unicellular (prokaryotes) or immature multicellular organisms (like tortoise larvae) kills them. If these radiations fall on fish eggs, it may kill the under developing embryo in the egg.

Effect on materials:

UV radiations causes rubber to harden and crack, thus reducing life of tires. Besides plastics, fabrics, wood and many other construction materials are degraded by UV radiations.

These all causes led to the “global warming” or “greenhouse effect”  

What we should do to prevent Ozone depletion:

1: We should not use CFC’s in refrigerator, freezers or air conditioned.

2: We should not use nitrous oxide (also known as NOS) in cars or bikes, etc.

3: To prevent global warming, we should prevent environmental pollution

Protect yourself from UV radiations:

1: Use sunblock frequently in summer.

2: Use sunglasses when going into sunlight.

3: Use sunblock before swimming.