Ozone

• Ozone (O₃) is a molecule formed by three atoms of oxygen, shields the surface of the earth (in the stratosphere) from ultraviolet (UV) radiation of Sun. (O₃) in the troposphere is a pollutant, as it is harmful for the living organisms.

Ozone layer Depletion:

• Ozone layer is a layer made up of ozone molecules shielding our atmosphere near the stratosphere which prevents the entry of UV rays of sun into earth’s surface.

• UV radiation is of two types A and B out of which UV-B is more harmful and can cause skin cancer, damage to eyes and decrease immunity of an organism. It can also affect global rainfall and cause ecological disturbances.
• Ozone layer prevents the entry of these UV radiations and thus keeps the earth’s surface safe.

Causes for ozone depletion:

• Accumulation of chlorofluorocarbons in the atmosphere is the major cause behind the breaking of ozone molecules.
• CFCs are used in some spray cans to force the contents out of the can.
• They are also used in refrigerators, air conditioning systems and some fire extinguishers. They are used because they are not poisonous and do not catch fire.

Hole in ozone layer:

• It has been observed that since some decades the ozone layer is depleting and is most severe at the poles especially over Antarctica where it appears as a hole. The Antarctic ozone hole was discovered in 1985 by British scientists. It is not technically a “hole” where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic. The thickness is tremendously decreasing and seems to be threat for survival of living organisms.

Ozone Depletion Effects:

Human Health:

• UV rays can damage the DNA resulting in variations. Such variations can suppress the immune system resulting in increase of infectious diseases, skin cancer, eye cataracts etc.

Plants and Trees:

• It can affect the agricultural fields by reducing the crop production, damaging the seeds etc. thus reducing the quality quantity of crops.

Aquatic Ecosystems:

• They can cause damage to plankton, aquatic plants, fish larvae, shrimp, crabs and other aquatic animals. Such damage affects the food chain thus disturbing the entire ecosystem.

Materials:

• It can also damage the non living things like paints, rubber, wood, plastic etc.