STUDY OF ENVIRONMENTAL DEGRADATION

Environmental degradation is an undesirable change in physical, chemical and biological characteristics of air, land and water that may or will affect human life or other species. In other words it is defined as unfavorable alternation of our environment, largely as a result of human activities. Before modern human civilization started on earth basic life supporting components like air, soil and water were pure, undisturbed, uncontaminated, hence earth was most hospitable for all living organisms. with the growth of human population problems started due to industrialization, urbanization, so leading to maximum destruction of natural resources. Pollutants which cause pollution are probably all man made and these are deposited matters (sewage, solids wastes, soot, dust and grit ), gases, chemical compounds, metals, pesticides and fungicides, fertilizers, radioactive substances noise and heat etc. some others associate the human population explosion with the pollution problem. They point out that with more people there are more sewage, more solid wastes, more fuel being burned, more fertilizers and insecticides being used to produced more food. some modern ecologists such as odum sought many factors such as human population explosion, urbanization and deforestation, profit oriented capitalism and technological advancement which may have originated. Non degradable pollutants: plastics materials, aluminium materials, mercury salts and other persistent pesticides are non degradable pollutants. b) bio degradable pollutants: household wastes, sewage, plant and animal materials etc. are bio degradable pollutants that can be rapidly decomposed by natural processes. The various principal pollutants which pollute our air, water, land are as follows Deposited matter: soot, smoke, tar, dust, grit etc. Gases: Oxides of nitrogen, sulphur, carbon monoxide, halogens. Acid droplets: sulphuric acid, nitric acid. Fluorides. Metals: mercury, lead, zinc, nickel, tin, chromium etc. Agrochemicals: biocides ( pesticides, herbicides, fungicides, bactericide etc. Complex organic substances: benzene, ether, acetic acid, benzopyrene etc. Background Nepal lies between the latitudes 26°20’ and 30°10’N and longitudes 80°15’ and 88°10’E. Nepal somewhat rectangular in shape, comprising mostly the mountains and hilly regions with small part of flat terrain land. The altitude varies from 60m above the sea level at the south to 88848m at the north. Okhreni Village Development Committee which is situated at the mid - southern side of Ramechhap District has a total of 9 wards. Total population of Okhreni VDC is 5200 (Recording to Ramechhap District profile) . Different caste group lives in the VDC like Newar, Kshetri, Tamang, Hayu, Dalits and Magars. There are a total of 736 household community in Okhreni VDC . Almost People have no knowledge and skill of environment. Due to the lack of education, awareness, and social discrimination their health status, economical status, Political status and social status are backwarded Most of the people work in agriculture. Their main sources of income are physical work and following traditional occupations. Only a few people are working in Government sectors and now a days only a few people have been working in foreign countries. Most of the people are labourer, humorous, virtuous and strong. But their economical, social, educational and health conditional are back warded. Most people live continue live in extreme poverty, without opportunity and better education. They have lack of knowledge and social status and psychological aspect etc. They are not much serious about their environment and sanitation condition. Limited studies have been taken regarding the sociological and anthropological aspects of this community. Okreni VDC is sloppy shaped, hence poorly environmental condition by deforestation. the VDC comprises sloppy land which is dusty and large number of improperly planned housing. Theirfore air pollution due to auto exhaust fumes different types of dusts. Air pollution- Rapidly increasing growth population and unplanned housing and deforestation are the main cause of pollution. pollution is accelerated by man can solve this problem. Environmental pollution is man's most serious expanding problem. pollution in our atmosphere is in such a great degree that clean air is now becoming a dream in the environment. pollutants act like poison to our breathing air and drinking water. pollutants enter into food chain of our through different means and causes diseases. Most of the plants are sensitive to air pollution which affects the photosynthetic capacity, regards growth; decreases yield etc. Accumulation of toxic substances on the biosphere is causing serious changes in the structure and function of natural ecosystem. In the forest areas, trees are damaged first by low doses of pollutants into the atmosphere, as duration of exposure increases tall shrubs are destroyed followed in order by lower shrubs, herbs, mosses and lichens. There are various sources of air pollution, viz, auto exhausts, industrial effluent, dusts from various sources, fuel burning etc. pollutants are emitted unto the atmosphere as suspended matters like smoke, sulphur dioxide, carbon monoxides, oxides of nitrogen, hydrocarbons, fluorides, leads, foul odour and dusts, solid and liquid aerosols suspended in the atmospheric air pollution, and are referred as particulate matters, likes fumes, gasses, mist, whereas is referred as solid dispersion aerosol. There are various sources of dust particles likes construction works, industrial processes, vehicular traffic, etc. Dust particles greater than 10 micron in size is called settable dust, and smaller particles suspended in the air is called suspended dusts. Sulphuric oxide is considered one of the principal air pollutants. combustion of fuels, chemical processing are the main sources of sulphur dioxide. Major portion of sulphur is emitted as sulphur dioxide from a combustion source. Several ocides of sulphur in the presence of moisture forms sulphuric acid, which causes acid precipitation. Actually only about one third of sulphur dioxide in the atmosphere is believed to be produced by man's activities. Some occur naturally by the processes such as volcanoes. Sulphur dioxide is capable of causing a wide variety of harmful effects both on plants and animals. Sulphur dioxide and sulphuric acid are both capable of irritating the respiratory system of animals and man. sulphur dioxide also affects on vegetation. The two carbon compounds - carbon dioxide and carbon monoxide are the important pollutants of air. A major amount of carbon dioxide is released in the atmosphere from the burning of fossil fuels (coal, oil etc.) for domestic cooking, heating etc. From fossil fuels alone mire than 18×10 tones of carbon dioxide is being released into the atmosphere each year. Since carbon dioxide and other green house gases absorb infrared radiation, increases in its concentration which may cause a global warming of the earth. The chief source of carbon monoxide are automobiles and other sources involve the combustion process such as stoves, furnaces, open fires, forests and bush fires, burning coal mines, factories, etc. carbon monoxide comprises for as much as 80% of all automobile emissions and for more than 60% of all major pollutants added to the atmosphere. Carbon monoxide causes difficulty in breathing, causes headache and irritation of mucous membrane. It combines with haemoglobin of blood reducing its oxygen carrying capacity. Among hydrocarbons, the chief air pollutants are benzene, benzopyrene and methane. Their chief sources are the motor vehicles. Thy have carcinogenic effects on lung. They combine with Knox under UV component of light to form other pollutants like PAN and ozone (photochemical smog) which causes irritation of eye, nose and throat and respiratory diseases. Methane is a gaseous pollutants, which is produced in nature during decay of garbage, aquatic vegetation etc. this is also releases due to burning of natural gas and from factories. The three oxide of nitrogen which are important pollutants of the atmosphere are nitrous oxide, nitric oxide and nitrogen oxide. Most of the gaseous oxides are introduced in considerable amount by burning of fossil fuels, organic matter as will as by microbial action on nitrogenous organic matter and on chemical fertilizers applied in agricultural fields. Nitrous oxide has been accumulating in the atmosphere at a rate of 0.3% per year. Although not harmful to lives, it gives rise to nitric oxide and nitrogen dioxide which are much more injurious. Nitric oxide is responsible for depletion of the stratospheric ozone layer while nitrogen dioxide is an important constituent of the photochemical smog of air pollution and is also at least partially responsible for causing acid rains. Nitrogen oxide also irritates lungs and is capable if causing oedema and pulmonary emphysema. The major source of man made emission of nitrogen oxides into the atmosphere is the combustion of fossil fuels. Indoor sources include tobacco smoking and the use of gas fuel appliances and oil stoves. The term suspended particulate matter covers a wide range of finely divided solids and liquids dispersed into the air in the size range under about 10 micron centimetres. Most of the particulate material in the environment is contributed by dust particles from various sources, fibrous material of plant and animal origin, fly ash derived from combustion of coal, oil and organic matter or from mining and processing operations. Particulate matter may include living organisms like bacteria, virus, molds, pollen etc. the non viable particulate in atmosphere are mists, smokes, fumes, dusts etc. In a polluted environment as many as 100000 of these particles may be found in a single cubic millimetre. The particulate matter directly affects on the respiratory system or it may enter the blood system or lymph system. Solid waste pollution-The solid waste includes glass containers as bottle, plastic containers, polythene and other packing materials that are used and then thrown away as garbage. These pile up at public places and cause obstruction in daily life. Besides these there are also other used things like automobile spars, machines, cycle etc. that are thrown as junk. The waste from building material, sludge, dead animal skeleton , heap of crop residue also contribute to solid waste. solid waste are causing much problem in all world especially in the developed countries. There is problem of disposal of these wastes especially in developed countries where labour is very expensive. To solve these problems technologies have been developed to recycle most of the solid waste items. Thus paper cans, newspapers and others waste paper may be easily recycled. Metallic components of vehicle spares may bi- recycled by cheap methods. However, there is problem of recycle of heavy metals, plastics, nylon, polythene etc. Noise pollution- Noise is the "sound without value" and usually defined as unwanted or unpleasant sound that causes discomfort. Noise is defined as wrong sound in the wrong place at the wrong time. Noise pollution means the unwanted sound dumped into the atmosphere leading to he health hazards. The main contributions to noise pollution are factories and industries, transportation and community and religious activities. The chief man made sources are automobiles, factories, industries, trains, planes. Noise makers are horns, sirens, lawn mover, musical instruments, TV, radio, loud speakers, vaccum cleaner, food mixtures, pressure cookers, etc. Noise causes disturbance in the atmosphere which in turn interfere with the systems if communications. It affects our peace of mind, health and behaviour, Sudden loud noise can cause acute damage to the ear drum and the tiny hair cells in the internal ear. The different effect of noise pollution are categorized as: auditory effects, non auditory effects..