Environment

Every organism is a specialized unit. It Invariably depends upon the environment and other organisms for its existence. It either eats other organisms or is eaten up by others and competes with others for the necessities of life such as food, shelter and mate.

Survival requires group association. such association and inter-relationships of organisms and environment in general constitute the Science of Ecology. The word was coined by Ernst Haeckel in 1869 and is derived from two Greek words "oikos" meaning 'house, habitation or place of living' and "logos" meaning 'study'. The field of ecology deals with the influence of environmental factors on all the aspects of life such morphology, physiology, growth, distribution, behaviour and survival of the organisms.

All the external conditions that affect the life of organisms i their natural habitats aggregate to form the environment i.e. 'the surroundings' of an organism.

The environment has been classified into :

(a) Physical or Abiotic Environment : It is composed of external physical factors like temperature, humidity, water, minerals and gases etc..

(b) Living or Biotic Environment : It is composed of all the living components-plants, animals and micro-organisms.

All these constituents of environment are referred to as the environmental factors or ecological factors or simply as factors. A factor is defines as an ecological condition which directly or indirectly affects the growth and development and hence the life of an organism.

"Environmental Studies" is the scientific of the environmental system and the status of its inherent or induced changes on organism. It includes not only the study of physical and biological characters of the environment but also the social and cultural factors and the impact of man on the environment

Objectives and Guiding Principles of Environmental Studies

According to UNESCO (1971), the objectives of environmental studies are:
(a) creating the awareness about environmental problems among people.
(b) imparting basic knowledge about the environment and its allied problems.
(c) developing an attitude of concern for the environment.
motivating public to participate in environment protection and environment improvement.

Case Study

Ozone Hole over Antarctica

There is so much of hue and cry over ozone hole which has got created over Antarctica. We can explain this phenomenon as follows:

In the stratospheric region , the chloro-fluoro-carbon (CFCs) got broken down by ultraviolet radiation of the sun and as such they release chlorine atom. This chlorine atom reacts with ozone and the subsequent product when its react with NO2, it forms chlorine nitrate. Since chlorine nitrate is an inert compound it cannot cause any harm to ozone. But in the case of Antarctica, a phenomenon of atmospheric circulation called polar vertex or circumpolar forms. This blocks the Warmer air from mixing with the air above the pole. The results is that the polar air gets trapped and it has no connection. with the outside warmer air. The results in cooling of air in the stratosphere. The temperature goes down upto - 90 degree C and ice crystals get formed which provide reaction surfaces for chlorine nitrate to react with water. This results in formation of HOCL and HNO3. This reaction continues to take place as long as circumpolar exists in winter season. But as the Antartic spring comes in August or September the HOCL forms CI and the hydroxyperoxye radical. This destroys the ozone. The cycle repeats itself creating a big ozone hole.

Hyderabad Water Supply and Sanitation Project

By 1989 Government of India had completed work on the Singur Dam in Andhra Pradesh. Te dam later became part of the World Bank supported Hyderabad Water Supply and Sanitation Project. The reservoir created by the dam provided much-needed irrigation water, electric power, and drinking water However, because of the dam construction, thousands of people had to relocate, and therefore, lost their livelihoods. The Hyderabad Water Supply and Sanitation Project extended its coverage to the resettlement and rehabilitation of people displaced by the rising water. The project helped relocate 3,600 households and identified 4,600 families that required assistance to re-establish their economic productivity.

A local non-governmental organization assisting with the economic rehabilitation helped determine the needs of villagers, and identified potential economic resources in each village. This resulted in the identification of a range of employment options. Entrepreneurs who had moved to the area were offered support in exchange for hiring villagers.

Project benefits were supplemented with ongoing district-level development resources. The district Administration helped integrate residents who had not been directly affected by the dam's construction. This inclusionary measure helped narrow the differences between those who did and did not receive benefits. When presented with a base grant (equivalent to a year's income) and a choice of options, many of the villagers, who were headers and weavers before resettlement, opted to use subsidized ban loans to invest in intensified agriculture, housing improvement, and better livestock development.

Deterioration of Taj Mahal

Mathuran Oil Refinery lies only 40 km away from Taj Mahal- one of the eight wonders of the world.

The Oil Refinery emits 25-30 tonnes of SO2 daily inspite of using low sulphur fuels. Air pollution sureys y Indian and International** firms have estimated that any increases in SO2 concentration above the present 1.75 kg/m3 wouls result in acidic precipiatation under condition of low wind speeds combined with humidity. This would results in the conservation of SO2 into sulphuric acid-which is the main cause of "Stone-Cancer".

The sulphuric acid could react with Calcium Carbonate (CaCO3) in the marle to form Calcium Sulphate (CaSO4)-which would cause pitting in the Taj.