Speech on the Effects of Ozone Layer Depletion on Human, Biotic Community and Plants!
The ozone layer in the stratosphere protects us from the harmful UV radiations coming from the sun. The change in stratospheric structure could influence the world climate whereas increased UV radiation at the surface would affect biological system.
1. Effect on Human Beings:
(a) UV radiations cause immunological effect. The irradiated skin develops red patches.
(b) The three forms of skin cancer are caused by prolonged cumulative exposure to UV rays.
(c) UV radiation cause blood vessels near the skin surface to carry more blood causing sun burns and skin aging.
(d) UV radiation is also absorbed by cornea and lens in the eye leading to photo keratitis and cataracts.
(e) Ozone at ground level enters the body through inhalation and exerts its toxic effects.
(f) Any increased concentration of ozone brings about changes in the nucleic acid, DNA and RNA. So increased UV absorption will have drastic results.
2. Effect on Biotic community:
(a) The marked reduction in the productivity of Phytoplankton’s adversely affects zooplanktons.
(b) Ozone is reported to be highly toxic to fish in the concentration ranging from 0.1 to 1.0 ppm.
3. Effects on Plants:
1. Plants are sensitive to UV rays below 300 nm.
2. Expose to air containing zone results in the lesions to plants. Usually confined to the upper surfaces of leaves.
3. Plants proteins are also susceptible to UV injury because they absorb strongly around 280 nm. About 20-50% chlorophyll reduction and harmful mutation have also been reported.