Environmental Issues

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ENVIRONMENTAL ISSUES :
“Pollution. Deforestation. Wildlife trade. The aspirations of more than one billion people. These are some of the critical issues that India grapples with every day”
There are many environmental issues in India. Air pollution, water pollution, garbage, and pollution of the natural environment are all challenges for India. The situation was worse between 1947 through 1995. According to data collection and environment assessment studies of World Bank experts, between 1995 through 2010, India has made one of the fastest progress in the world, in addressing its environmental issues and improving its environmental quality. Still, India has a long way to go to reach environmental quality similar to those enjoyed in developed economies. Pollution remains a major challenge and opportunity for India. Some believe economic development is causing the environmental issues. Others believe economic development is key to improving India's environmental management and preventing pollution in India. It is also suggested that India's growing population is the primary cause of India's environmental degradation. Major environmental issues are forest and agricultural degradation of land, resource depletion (water, mineral, forest, sand, rocks etc.), environmental degradation, public health, loss of biodiversity, loss of resilience in ecosystems, livelihood security for the poor. The major sources of pollution in India include the rampant burning of fuelwood and biomass such as dried waste from livestock as the primary source of energy, lack of organized garbage and waste removal services, lack of sewage treatment operations, lack of flood control and monsoon water drainage system, diversion of consumer waste into rivers, cremation practices near major rivers, government mandated protection of highly polluting old public transport, and continued operation by Indian government of government owned, high emission plants built between 1950 to 1980. Environmental issues are one of the primary causes of disease, health issues and long term livelihood impact for India.

Major issues
Air pollution, poor management of waste, growing water scarcity, falling groundwater tables, water pollution, preservation and quality of forests, biodiversity loss, and land/soil degradation are some of the major environmental issues India faces today. India's population growth adds pressure to environmental issues and its resources.

Population growth and environmental quality
There is a long history of study and debate about the interactions between population growth and the environment. According to the British thinkerMalthus, for example, a growing population exerts pressure on agricultural land, causing environmental degradation, and forcing the cultivation of land of poorer and poorer quality. This environmental degradation ultimately reduces agricultural yields and food availability, causes famines and diseases and death, thereby reducing the rate of population growth. Population growth, because it can place increased pressure on the assimilative capacity of the environment, is also seen as a major cause of air, water, and solid-waste pollution. The result, Malthus theorised, is an equilibrium population that enjoys low levels of both income and environmental quality. Malthus suggested positive and preventative forced control of human population, along with abolition of poor laws. Malthus theory, published between 1798 and 1826, has been analysed and criticised ever since. The American thinker Henry George, for example, observed with his characteristic piquancy in dismissing Malthus: "Both the jayhawk and the man eat chickens; but the more jayhawks, the fewer chickens, while the more men, the more chickens." Similarly, the American economist Julian Lincoln Simon criticised Malthus's theory. He noted that the facts of human history have proven the predictions of Malthus and of the Neo-Malthusians to be flawed. Massive geometricpopulation growth in the 20th century did not result in a Malthusian catastrophe. The possible reasons include: increase in human knowledge, rapid increases in productivity, innovation and application of knowledge, general improvements in farming methods (industrial agriculture), mechanisation of work (tractors), the introduction of high-yield varieties of wheat and other plants (Green Revolution), the use of pesticides to control crop pests. More recent scholarly articles concede that while there is no question that population growth may contribute to environmental degradation, its effects can be modified by economic growth and modern technology. Research in environmental economics has uncovered a relationship between environmental quality, measured by ambient concentrations of air pollutants and per capita income. This so-called environmental Kuznets curve shows environmental quality worsening up until about $5,000 of per capita income on purchasing parity basis, and improving thereafter.The key requirement, for this to be true, is continued adoption of technology and scientific management of resources, continued increases in productivity in every economic sector, entrepreneurial innovation and economic expansion. Across India, concern is mounting over an ever growing list of environmental problems. More people means increased pressure on natural resources (from water to forests), while an economy in high-gear is leaving a trail of pollution that’s affecting not only India, but the rest of the world too.

Deforestation :
The cutting down and removal of all or most of the trees in a forested area. Deforestation can erode soils, contribute to desertification and the pollution of waterways, and decrease biodiversity through the destruction of habitat.

India is witnessing a rising demand for forest-based products. This is causing deforestation and encroachment into forest protected areas, which leads to a severe loss of natural resources. It is estimated that total industrial roundwood consumption in India could exceed 70 million m3 per year by the end of the decade (350,000 large shipping containers), while domestic supply would fall short of this figure by an estimated 14 million m3.1 As the nation will have to depend heavily on imports to meet this growing demand, there is fear that this could result in loss of high conservation value forests and biodiversity elsewhere. Forests are cut down for many reasons, but most of them are related to money or to people’s need to provide for their families.The biggest driver of deforestation is agriculture. Farmers cut forests to provide more room for planting crops or grazing livestock. Often many small farmers will each clear a few acres to feed their families by cutting down trees and burning them in a process known as “slash and burn” agriculture.

Logging operations, which provide the world’s wood and paper products, also cut countless trees each year. Loggers, some of them acting illegally, also build roads to access more and more remote forests— which leads to further deforestation. Forests are also cut as a result of growing urban sprawl. Not all deforestation is intentional. Some is caused by a combination of human and natural factors like wildfires and subsequent overgrazing, which may prevent the growth of young trees. Deforestation has many negative effects on the environment. The most dramatic impact is a loss of habitat for millions of species. Seventy percent of Earth’s land animals and plants live in forests, and many cannot survive the deforestation that destroys their homes. Deforestation also drives climate change. Forest soils are moist, but without protection from sunblocking tree cover they quickly dry out. Trees also help perpetuate the water cycle by returning water vapor back into the atmosphere. Without trees to fill these roles, many former forest lands can quickly become barren deserts.

Removing trees deprives the forest of portions of its canopy, which blocks the sun’s rays during the day and holds in heat at night. This disruption leads to more extreme temperatures swings that can be harmful to plants and animals. Reduced biodiversity is another deforestation concern. Rainforests, arguably the biggest victims of deforestation, cover only about 7 percent of the world's surface. However, within this 7 percent live almost half of all plant and animal species on earth. Some of these species only live in small specific areas, which makes them especially vulnerable to extinction. As the landscape changes, some plants and animals are simply unable to survive. Species from the tiniest flower to large orangutans are becoming endangered or even extinct. Biologists believe that the key to curing many diseases resides within the biology of these rare plants and animals, and preservation is crucial

Soil erosion, while a natural process, accelerates with deforestation. Trees and plants act as a natural barrier to slow water as it runs off the land. Roots bind the soil and prevent it from washing away. The absence of vegetation causes the topsoil to erode more quickly. It's difficult for plants to grow in the less nutritious soil that remains. Because trees release water vapor into the atmosphere, fewer trees means less rain, which disrupts thewater table (or groundwater level). A lowered water table can be devastating for farmers who can't keep crops alive in such dry soil. It is one of the primary contributors to modern climate change. It’s estimated that deforestation currently contributes about 20% of the world’s greenhouse gas emissions directly. Indirectly it contributes significantly by causing carbon dioxide to stay in the atmosphere for longer, rather than being taken up by plants. An estimated 1.5 billion tons of carbon is released every year by tropical deforestation. Trees also play a critical role in absorbing the greenhouse gases that fuel global warming. Fewer forests means larger amounts of greenhouse gases entering the atmosphere—and increased speed and severity of global warming. The quickest solution to deforestation would be to simply stop cutting down trees. Though deforestation rates have slowed a bit in recent years, financial realities make this unlikely to occur. A more workable solution is to carefully manage forest resources by eliminating clear-cutting to make sure that forest environments remain intact. The cutting that does occur should be balanced by the planting of enough young trees to replace the older ones felled in any given forest. The number of new tree plantations is growing each year, but their total still equals a tiny fraction of the Earth’s forested land. The reason that logging is so bad for the climate is that when trees are felled they release the carbon they are storing into the atmosphere, where it mingles with greenhouse gases from other sources and contributes to global warming accordingly. The upshot is that we should be doing as much to prevent deforestation as we are to increase fuel efficiency and reduce automobile usage.

Pollution :
Increasing competition for water among various sectors, including agriculture, industry, domestic, drinking, energy generation and others, is causing this precious natural resource to dry up. Increasing pollution is also leading to the destruction of the habitat of wildlife that lives in waterways. Pollution is the introduction of a contaminant into a natural environment, usually by humans. While most people think of pollution as chemical waste dumped into rivers, or factories spewing toxins into the air, it can also include light pollution or sound pollution.

Environmental pollution is the biggest menace to the human race on this planet today. It means adding impurity to environment. The environment consists of earth, water, air, plants and animals. If we pollute them, then the existence of man and nature will be hampered. The health effects of pollution affect more than 100 million people worldwide — more widespread than global pandemics such as AIDS. In some of the world’s worst polluted places, babies are born with birth defects, children have lost 30 to 40 IQ points, and life expectancy may be as low as 45 years because of cancers and other diseases. Industrialization has led to urbanization, which has added to the pollution problem. Air pollution is the most dangerous form of pollution. land and water pollution have worsened the situation. Pollution causes several types of harmful disease. Environmental pollution is a serious problem of the industrialized societies. The industrial development and the Green Revolution have adversely affected the environment. People have converted the life supporting systems of the entire living world into their own resources and have vastly disturbed the natural ecological balance. Serious degradation and depletion have been caused thought overuse, misuse and mismanagement of resources to meet the human greed.

Environmental pollution is defined as the unfavorable alteration of our surroundings. It is by product of man's activities through direct or indirect efforts of changes. These changes could be in the physical, chemical and biological characteristics of land, air or water that harmfully affect human life or any desirable living thing.

Now, some facts on :AIR POLLUTION :
Ozone (O3) is a gas that can form and react under the action of light and that is present in two layers of the atmosphere. High up in the atmosphere, ozone forms a layer that shields the Earth from ultraviolet rays. However, at ground level, ozone is considered a major air pollutant. Ground-level ozone– the focus of this study – is formed from other pollutants and can react with other substances, in both cases under the action of light. Concentrations are often low in busy urban centres and higher in suburban and adjacent rural areas, particularly on sunny days in summer. However, ozone can be transported through air over long distances and across borders. Ozone is known to cause adverse health effects, but more research is needed. Rising temperatures can make smog pollution worse and increase the number of "bad air days" when it's hard to breathe. This puts many of us at risk for irritated eyes, noses, and lungs -- but it is particularly dangerous for people with respiratory diseases like asthma. As the climate changes, unhealthy air pollution will get worse. Here's how: Ozone smog forms when pollution from vehicles, factories, and other sources reacts with sunlight and heat. Increasing temperatures speed this process and result in more smog. Added to the mix are ragweed and other allergens in the air -- which are expected to worsen as rising carbon dioxide levels cause plants to produce more pollen. Also, as dry areas get dryer, wildfire risks go up and smoke from burning landscapes intensifies poor air quality. Modernisation and progress have led to air getting more and more polluted over the years. Industries, vehicles, increase in the population, and urbanization are some of the major factors responsible for air pollution. The following industries are among those that emit a great deal of pollutants into the air: thermal power plants, cement, steel, refineries, petro chemicals, and mines. Air pollution results from a variety of causes, not all of which are within human control. Dust storms in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate pollution of the air. The source of pollution may be in one country but the impact of pollution may be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which aerial transport can carry pollutants from one place to another. Probably the most important natural source of air pollution is volcanic activity, which at times pours great amounts of ash and toxic fumes into the atmosphere.

Listed below are the major air pollutants and their sources :Carbon monoxide (CO) is a colourless, odourless gas that is produced by the incomplete
burning of carbon-based fuels including petrol, diesel, and wood. It is also produced from the combustion of natural and synthetic products such as cigarettes. It lowers the amount of oxygen that enters our blood . It can slow our reflexes and make us confused and sleepy.

Carbon dioxide (CO2) is the principle greenhouse gas emitted as a result of human activities
such as the burning of coal, oil, and natural gases.

Chloroflorocarbons (CFC) are gases that are released mainly from air-conditioning systems
and refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which leads to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun.

Ozone occur naturally in the upper layers of the atmosphere. This important gas shields the earth
from the harmful ultraviolet rays of the sun. However, at the ground level, it is a pollutant with highly toxic effects. Vehicles and industries are the major source of ground-level ozone emissions. Ozone makes our eyes itch, burn, and water. It lowers our resistance to colds and pneumonia.

Nitrogen oxide (Nox) causes smog and acid rain. It is produced from burning fuels including
petrol, diesel, and coal. Nitrogen oxides can make children susceptible to respiratory diseases in winters.

Suspended particulate matter (SPM) consists of solids in the air in the form of smoke,
dust, and vapour that can remain suspended for extended periods and is also the main source of haze which reduces visibility. The finer of these particles, when breathed in can lodge in our lungs and cause lung damage and respiratory problems.

Sulphur Dioxide (SO2) is a gas produced from burning coal, mainly in thermal power plants. Some
industrial processes, such as production of paper and smelting of metals, produce sulphur dioxide. It is a major contributor to smog and acid rain. Sulfur dioxide can lead to lung diseases.

More on Air Pollution :SMOG :
Smog is a combination of various gases with water vapour and dust. A large part of the gases that form smog is produced when fuels are burnt. Smog forms when heat and sunlight react with these gases and fine particles in the air. Smog can affect outlying suburbs and rural areas as well as big cities. Its occurrences are often linked to heavy traffic, high temperatures, and calm winds. During the winter, wind speeds are low and cause the smoke and fog to stagnate; hence pollution levels can increase near ground level. This keeps the pollution close to the ground, right where people are breathing. It hampers visibility and harms the environment. Heavy smog is greatly decreases ultraviolet radiation. Smog causes a misty haze similar to fog, but very different in composition. In fact the word smog has been coined from a combination of the words fog and smoke. Smog refers to hazy air that causes difficult breathing conditions. The most harmful components of smog are ground-level ozone and fine airborne particles. Ground-level ozone forms when pollutants released from gasoline and diesel-powered vehicles and oil-based solvents react with heat and sunlight. It is harmful to humans, animals, and plants.

ACID RAIN :

Another effect of air pollution is acid rain. The phenomenon occurs when sulphur dioxide and nitrogen oxides from the burning of fossil fuels such as, petrol, diesel, and coal combine with water vapour in the atmosphere and fall as rain, snow or fog. These gases can also be emitted from natural sources like volcanoes. Acid rain causes extensive damage to water, forest, soil resources and even human health.

INDOOR AIR POLLUTION :

It refers to the physical, chemical, and biological characteristics of air in the indoor environment within a home, building, or an institution or commercial facility. Indoor air pollution is a concern in the developed countries, where energy efficiency improvements sometimes make houses relatively airtight, reducing ventilation and raising pollutant levels. Indoor air problems can be subtle and do not always produce easily recognized impacts on health. Different conditions are responsible for indoor air pollution in the rural areas and the urban areas.

In the developing countries, it is the rural areas that face the greatest threat from indoor pollution, where some 3.5 billion people continue to rely on traditional fuels such as firewood, charcoal, and cowdung for cooking and heating. Concentrations of indoor pollutants in households that burn traditional fuels are alarming. Burning such fuels produces large amount of smoke and other air pollutants in the confined space of the home, resulting in high exposure. Women and children are the groups most vulnerable as they spend more time indoors and are exposed to the smoke. In urban areas, exposure to indoor air pollution has increased due to a variety of reasons, including the construction of more tightly sealed buildings, reduced ventilation, the use of synthetic materials for building and furnishing and the use of chemical products, pesticides, and household care products. Indoor air pollution can begin within the building or be drawn in from outdoors. Other than nitrogen dioxide, carbon monoxide, and lead, there are a number of other pollutants that affect the air quality in an enclosed space.

Volatile organic compounds originate mainly from solvents and chemicals. The main indoor
sources are perfumes, hair sprays, furniture polish, glues, air fresheners, moth repellents, wood preservatives, and many other products used in the house. The main health effect is the imitation of the eye, nose and throat. In more severe cases there may be headaches, nausea and loss of coordination. In the long term, some of the pollutants are suspected to damage to the liver and other parts of the body.

Tobacco smoke generates a wide range of harmful chemicals and is known to cause cancer. It is well known that passive smoking causes a wide range of problems to the passive smoker (the person who is in the same room with a smoker and is not himself/herself a smoker) ranging from burning eyes, nose, and throat irritation to cancer, bronchitis, severe asthma, and a decrease in lung function.

Biological pollutants include pollen from plants, mite, hair from pets, fungi, parasites, and
some bacteria. Most of them are allergens and can cause asthma, hay fever, and other allergic diseases.

Formaldehyde is a gas that comes mainly from carpets, particle boards, and insulation foam. It
causes irritation to the eyes and nose and may cause allergies in some people.

Asbestos is mainly a concern because it is suspected to cause cancer. Radon is a gas that is emitted naturally by the soil. Due to modern houses having poor ventilation, it is confined inside the house causing harm to the dwellers.

HEALTH IMPACTS :

Since the onset of the industrial revolution, there has been a steady change in the composition of the atmosphere mainly due to the combustion of fossil fuels used for the generation of energy and transportation. Air pollution is a major environmental health problem affecting the developing and the developed countries alike. The effects of air pollution on health are very complex as there are many different sources and their individual effects vary from one to the other. It is not only the ambient air quality in the cities but also the indoor air quality in the rural and the urban areas that are causing concern. In fact in the developing world the highest air pollution exposures occur in the indoor environment. Air pollutants that are inhaled have serious impact on human health affecting the lungs and the respiratory system; they are also taken up by the blood and pumped all round the body. These pollutants are also deposited on soil, plants, and in the water, further contributing to human exposure.

Pollutant emissions per meal are also very high compared to those of other fuels. Household use of fossil fuel is also fairly common in the developing countries, particularly coal—both bituminous and lignite. These are particularly damaging as they burn inefficiently and emit considerable quantities of air pollutants. If emissions are high and ventilation poor, then the exposure levels to the gases emitted are far higher. The most harmful of the gases and agents that are emitted are particulate matter, carbon dioxide, polycyclic organic matter, and formaldehyde. The indoor concentrations of these are far higher than the acceptable levels and is cause for concern in rural areas.

CONTROL MEASURES AND MONITORING :AESPL offers a wide variety of services concerning Air sampling and Monitoring. Our services include Monitoring of Stack Emissions and Ambient Air Quality and workplace monitoring. Depending on the parameters, air monitoring is directly done on site or analysis is carried out in our "State of the Art" laboratory.

AESPL is well equipped with sophisticated and versatile analytical instruments and having updated technology for various analytical applications in the field of environment.

Parameters commonly covered by our stack emissions monitoring:
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Suspended Particulate Matter(PM10μg/m3 & PM2.5μg/m3), SOx, NOx, Lead, Carbon Monoxide, Ozone Carbon Dioxide, Hydro Carbons, Volatile Organic Compounds Benzene, Benzo Pyrene, Arsenic, Nickel Acid Gases, Fluoride, Ammonia , etc.

Particulate scrubbers : Wet scrubber is a form of pollution control technology. The term describes a variety of devices that use pollutants from a furnace flue gas or from other gas streams. In a wet scrubber, the polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the liquid, by forcing it through a pool of liquid, or by some other contact method, so as to remove the pollutants.

Electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.

A negative voltage of several thousand volts is applied between wire and plate. If the applied voltage is high enough, an electric corona discharge ionizes the gas around the electrodes. Negative ions flow to the plates and charge the gas-flow particles. The ionized particles, following the negative electric field created by the power supply, move to the grounded plates. Particles build up on the collection plates and form a layer. The layer does not collapse, thanks to electrostatic pressure (due to layer resistivity, electric field, and current flowing in the collected layer).

WATER POLLUTION :-

Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). Water pollution occurs whenpollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds. Water pollution affects plants and organisms living in these bodies of water. In almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities. Dirty water is the world's biggest health risk, and continues to threaten both quality of life and public health in the United States. When water from rain and melting snow runs off roofs and roads into our rivers, it picks up toxic chemicals, dirt, trash and disease-carrying organisms along the way. Many of our water resources also lack basic protections, making them vulnerable to pollution from factory farms, industrial plants, and activities like fracking. This can lead to drinking water contamination, habitat degradation and beach closures.

H2O is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use, such as drinking water, and/or undergoes a marked shift in its ability to support its constituent biotic communities, such as fish. Natural phenomena such as volcanoes, algae blooms, storms, and earthquakes also cause major changes in water quality and the ecological status of water.

MAJOR SOURCES :There are many causes for water pollution but two general categories exist: direct and indirect contaminant sources. Direct sources include effluent outfalls from factories, refineries, waste treatment plants etc.. that emit fluids of varying quality directly into urban water supplies. In the United States and other countries, these practices are regulated, although this doesn't mean that pollutants can't be found in these waters.

Indirect sources include contaminants that enter the water supply from soils/groundwater systems and from the atmosphere via rain water. Soils and groundwater contain the residue of human agricultural practices (fertilizers, pesticides, etc..) and improperly disposed of industrial wastes. Atmospheric contaminants are also derived from human practices (such as gaseous emissions from automobiles, factories and even bakeries). Contaminants can be broadly classified into organic, inorganic, radioactive and acid/base. Examples from each class and their potential sources are too numerous to discuss here.

SEWAGE AND WASTE WATER : Domestic households, industrial and agricultural practices produce wastewater that can cause pollution of many lakes and rivers. 1) Sewage is the term used for wastewater that often contains faeces, urine and laundry waste. There are billions of people on Earth, so treating sewage is a big priority. 2) Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water. 3) Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhoea. Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.

MARINE DUMPING :Dumping of litter in the sea can cause huge problems. Litter items such as 6-pack ring packaging can get caught in marine animals and may result in death. Different items take different lengths of time to degrade in water:
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Cardboard – Takes 2 weeks to degrade. Newspaper – Takes 6 weeks to degrade. Photodegradable packaging – Takes 6 weeks to degrade. Foam – Takes 50 years to degrade. Styrofoam – Takes 80 years to degrade. Aluminium – Takes 200 years to degrade.

INDUSTRIAL STUFFS :Industry is a huge source of water pollution, it produces pollutants that are extremely harmful to people and the environment.

Many industrial facilities use freshwater to carry away waste from the plant and into rivers, lakes and oceans. Pollutants from industrial sources include: Asbestos – This pollutant is a serious health hazard and carcinogenic. Asbestos fibres can be inhaled and cause illnesses such as asbestosis, mesothelioma, lung cancer, intestinal cancer and liver cancer. Lead – This is a metallic element and can cause health and environmental problems. It is a nonbiodegradable substance so is hard to clean up once the environment is contaminated. Lead is harmful to the health of many animals, including humans, as it can inhibit the action of bodily enzymes. Mercury – This is a metallic element and can cause health and environmental problems. It is a nonbiodegradable substance so is hard to clean up once the environment is contaminated. Mercury is also harmful to animal health as it can cause illness through mercury poisoning. Nitrates – The increased use of fertilisers means that nitrates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments. Phosphates - The increased use of fertilisers means that phosphates are more often being washed from the soil and into rivers and lakes. This can cause eutrophication, which can be very problematic to marine environments. Sulphur – This is a non-metallic substance that is harmful for marine life. Oils – Oil does not dissolve in water, instead it forms a thick layer on the water surface. This can stop marine plants receiving enough light for photosynthesis. It is also harmful for fish and marine birds. Petrochemicals – This is formed from gas or petrol and can be toxic to marine life.

NUCLEAR WASTES :Nuclear waste is produced from industrial, medical and scientific processes that use radioactive material. Nuclear waste can have detrimental effects on marine habitats. Nuclear waste comes from a number of sources: 1) Operations conducted by nuclear power stations produce radioactive waste. Nuclearfuel reprocessing plants in northern Europe are the biggest sources of man-made nuclear waste in the surrounding ocean. Radioactive traces from these plants have been found as far away as Greenland. 2) Mining and refining of uranium and thorium are also causes of marine nuclear waste. 3) Waste is also produced in the nuclear fuel cycle which is used in many industrial, medical and scientific processes.

DOMESTIC SEWAGE :Sewage is a water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains. Classes of sewage include sanitary, commercial, industrial, agricultural and surface runoff. The wastewater from residences and institutions, carrying body wastes, washing water, food preparation wastes, laundry wastes, and other waste products of normal living, are classed as domestic or sanitary sewage. Liquid-carried wastes from stores and service establishments serving the immediate community, termed commercial wastes, are included in the sanitary or domestic sewage category if their characteristics are similar to household flows.

Wastes that result from an industrial process or the production or manufacture of goods are classed as industrial wastewater. Their flows and strengths are usually more varied, intense, and concentrated than those ofsanitary sewage. Surface runoff, also known as storm flow or overland flow, is that portion of precipitation that runs rapidly over the ground surface to a defined channel. Precipitation absorbs gases and particulates from the atmosphere, dissolves and leaches materials from vegetation and soil, suspends matter from the land, washes spills and debris from urban streets and highways, and carries all these pollutants as wastes in its flow to a collection point.

INDUSTRIAL EFFLUENTS AS A SOURCE OF DRINKING WATER CONTAMINATION :

Contamination of drinking water supplies from industrial waste is a result of various types of industrial processes and disposal practices. Industries that use large amounts of water for processing have the potential to pollute waterways through the discharge of their waste into streams and rivers, or by run-off and seepage of stored wastes into nearby water sources. Other disposal practices which cause water contamination include deep well injection and improper disposal of wastes in surface impoundments.

Industrial waste consists of both organic and inorganic substances. Organic wastes include pesticide residues, solvents and cleaning fluids, dissolved residue from fruit and vegetables, and lignin from pulp and paper to name a few. Effluents can also contain inorganic wastes such as brine salts and metals. The Clean Water Act has standards for the permitted release of a limited amount of contaminants into waterways. This is an incentive for industry to pre-treat their water by neutralizing the chemically active components, recycling, dilution or extraction and collection for proper disposal.. More than 200,000 sources of waste water are regulated by the National Pollutant Discharge Elimination System (NPDES) permit program. Industries which use large amounts of water in their processes include chemical manufacturers, steel plants, metal processers, textile manufacturers, and the following :

Agriculture. Run-off from crops contain pesticides, fertilizer, sediment. Run-off from animal production facilities contain bacteria, organic matter, nitrates, and phosphates. Fruit and vegetables processing : Waste water contains high concentrations of dissolved organic matter and may be highly alkaline from the use of lye. Most of this water is now recycled. Petroleum refining: Oil is mixed with water in the refining process to remove salts and other impurities. It is then separated and collected. Most of this water is now recycled. Pulp and Paper : The use of bisulfite and sulfurous acid or sulfur dioxide in the pulping process yields a waste sulfite liquor containing various wood by-products. This can be reduced or recycled into various useful products. There is presently a concern over the release of dioxins into waterways by the pulp and paper industry. The waste disposal practices which presently pose a threat to drinking water supplies include deep well injection of wastes and wastes that are dumped and retained in surface impoundments or evaporation ponds. Deep well injection is used mostly by the chemical industry. These wells range from 1000 to 9000 feet deep and are used for storage and disposal of wastes . Injection of highly toxic waste into aquifers or leakage of contaminants form confined areas cause water contamination.

MORE ON ..
Where does water pollution come from?

Water pollution is usually caused by human activities. Different human sources add to the pollution of water. There are two sorts of sources, point and nonpoint sources. Point sources discharge pollutants at specific locations through pipelines or sewers into the surface water. Nonpoint sources are sources that cannot be traced to a single site of discharge. Examples of point sources are: factories, sewage treatment plants, underground mines, oil wells, oil tankers and agriculture. Examples of nonpoint sources are: acid deposition from the air, traffic, pollutants that are spread through rivers and pollutants that enter the water through groundwater. Nonpoint pollution is hard to control because the perpetrators cannot be traced.
How do we detect water pollution?

Water pollution is detected in laboratories, where small samples of water are analysed for different contaminants. Living organisms such as fish can also be used for the detection of water pollution. Changes in their behaviour or growth show us, that the water they live in is polluted. Specific properties of these organisms can give information on the sort of pollution in their environment. Laboratories also use computer models to determine what dangers there can be in certain waters.

EUTROPHICATION :Eutrophication means natural nutrient enrichment of streams and lakes. The enrichment is often increased by human activities, such as agriculture (manure addition). Over time, lakes then become eutrophic due to an increase in nutrients. Eutrophication is mainly caused by an increase in nitrate and phosphate levels and has a negative influence on water life. This is because, due to the enrichment, water plants such as algae will grow extensively. As a result the water will absorb less light and certain aerobic bacteria will become more active. These bacteria deplete oxygen levels even further, so that only anaerobic bacteria can be active. This makes life in the water impossible for fish and other organisms.

What causes white deposit on showers and bathroom walls?

Water contains many compounds. A few of these compounds are calcium and carbonate. Carbonate works as a buffer in water and is thus a very important component.When calcium reacts with carbonate a solid substance is formed, that is called lime. This lime is what causes the white deposit on showers and bathroom walls and is commonly known as lime deposit.

MICROBIOLOGICAL :In many communities in the world, people drink untreated water (straight from a river or stream). Sometimes there is natural pollution caused by microorganisms like viruses, bacteria and protozoa. This natural pollution can cause fishes and other water life to die. They can also cause serious illness to humans who drink from such waters.

HEALTH IMPACTS :-

The water we drink is a crucial component for healthy living. Clean Water is essential for Health! A sufficient supply of fresh, clean drinking water is a fundamental need for all human, yet it has been observed that billions of people around the world are being deprived of clean drinking water. Possible effects and diseases that can be brought about by water pollution :        Vomiting or diarrhoea A sick stomach Skin rashes Cancer (Some kinds of cancer, like leukemia, can happen after drinking bad water for a long period of time) Reproductive problems (Some kinds of reproductive problems, like infertility, can happen after drinking polluted water for a long period of time). Developmental problems (Some kinds of learning disabilities can happen after drinking dirty water for a long period of time) Cholera – An infection of the small intestine. The transmission of cholera is primarily through consuming contaminated drinking water or food. Typhoid Fever – a common universal illness spread by the ingestion of food or infected water which has been contaminated with feces of an infected person containing Salmonella Enterica and Serovar Typhi Hepatitis – a medical condition characterized by the inflammation of the liver and by the presence of inflamed cells in the tissue of the organ E-Coli Infections – can be caught by coming in contact with the stools of humans and animals. This can happen when a person drinks water that has been contaminated by feces…..to name a few. Fluoride : Excess fluorides can cause yellowing of the teeth and damage to the spinal cord and other crippling diseases.

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 Nitrates : Drinking water that gets contaminated with nitrates can prove fatal especially to infants that drink formula milk as it restricts the amount of oxygen that reaches the brain causing the ‘blue baby’ syndrome. It is also linked to digestive tract cancers. It causes algae to bloom resulting in eutrophication in surface water.  Petrochemicals : Benzene and other petrochemicals can cause cancer even at low exposure levels.  Chlorinated solvents : These are linked to reproduction disorders and to some cancers.  Arsenic : Arsenic poisoning through water can cause liver and nervous system damage, vascular diseases and also skin cancer.  Other heavy metals : Heavy metals cause damage to the nervous system and the kidney, and other metabolic disruptions.  Salts : It makes the fresh water unusable for drinking and irrigation purposes.

Water-borne diseases are infectious diseases spread primarily through contaminated water. Though these diseases are spread either directly or through flies or filth, water is the chief medium for spread of these diseases and hence they are termed as water-borne diseases. Most intestinal (enteric) diseases are infectious and are transmitted through faecal waste. Pathogens – which include virus, bacteria, protozoa, and parasitic worms – are disease-producing agents found in the faeces of infected persons. These diseases are more prevalent in areas with poor sanitary conditions. These pathogens travel through water sources and interfuses directly through persons handling food and water. Since these diseases are highly infectious, extreme care and hygiene should be maintained by people looking after an infected patient. Hepatitis, cholera, dysentery, and typhoid are the more common water-borne diseases that affect large populations in the tropical regions. A large number of chemicals that either exist naturally in the land or are added due to human activity dissolve in the water, thereby contaminating it and leading to various diseases.

PREVENTIVE MEASURES :-

Water-borne epidemics and health hazards in the aquatic environment are mainly due to improper management of water resources. Proper management of water resources has become the need of the hour as this would ultimately lead to a cleaner and healthier environment. In order to prevent the spread of water-borne infectious diseases, people should take adequate precautions. The city water supply should be properly checked and necessary steps taken to disinfect it. Water pipes should be regularly checked for leaks and cracks. At home, the water should be boiled, filtered, or other methods and necessary steps taken to ensure that it is free from infection.

Green Infrastructure / Low Impact Development
Green infrastructure and low impact development approaches and techniques help manage water and water pollutants at the source, preventing or reducing the impact of development on water and water quality.

Impaired Waters and Total Maximum Daily Loads
States, territories, and tribes must protect water bodies and to address water bodies that do not meet water quality standards (i.e., impaired waters).

Polluted Runoff (Nonpoint Source Pollution)
Polluted runoff is caused by rainfall and snowmelt moving over and through the ground that, picks up and carries with it natural and human-made pollutants, depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water.

NOISE POLLUTION :Noise pollution is displeasing or excessive noise that may disrupt the activity or balance of human or animal life. The word noise is cognate with the Latin word nauseas, which means disgust or discomfort. The source of most outdoor noise worldwide is mainly caused by machines and transportation systems, motor vehicles, aircrafts, and trains. Outdoor noise is summarized by the word environmental noise. Poor urban planning may give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential areas. Indoor noise is caused by machines, building activities, music performances, and especially in some workplaces. There is no great difference whether noise-induced hearing loss is brought about by outside (e.g. trains) or inside (e.g. music) noise.

High noise levels can contribute to cardiovascular effects in humans, a rise in blood pressure, and an increase in stress and vasoconstriction, and an increased incidence of coronary artery disease. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfere with reproduction and navigation, and contribute to permanent hearing loss.

Noise intensity is measured in decibel units. The decibel scale is logarithmic; each 10-decibel increase represents a tenfold increase in noise intensity. Human perception of loudness also conforms to a logarithmic scale; a 10-decibel increase is perceived as roughly a doubling of loudness. Thus, 30 decibels is 10 times more intense than 20 decibels and sounds twice as loud; 40 decibels is 100 times more intense than 20 and sounds 4 times as loud; 80 decibels is 1 million times more intense than 20 and sounds 64 times as loud. Distance diminishes the effective decibel level reaching the ear. Thus, moderate auto traffic at a distance of 100 ft (30 m) rates about 50 decibels. To a driver with a car window open or a pedestrian on the sidewalk, the same traffic rates about 70 decibels; that is, it sounds

4 times louder. At a distance of 2,000 ft (600 m), the noise of a jet takeoff reaches about 110 decibels— approximately the same as an automobile horn only 3 ft (1 m) away.

SOURCES :Noise can come from many places. Let us see a few good sources: Household sources: Gadgets like food mixer, grinder, vacuum cleaner, washing machine and dryer, cooler, air conditioners, can be very noisy and injurious to health. Others include loud speakers of sound systems and TVs, ipods and ear phones. Another example may be your neighbor’s dog barking all night everyday at every shadow it sees, disturbing everyone else in the apartment. Social events : Places of worship, discos and gigs, parties and other social events also create a lot of noise for the people living in that area. In many market areas, people sell with loud speakers, others shout out offers and try to get customers to buy their goods. It is important to note that whey these events are not often, they can be called 'Nuisance' rather than noise pollution. Commercial and industrial activities: Printing presses, manufacturing industries, construction sites, contribute to noise pollutions in large cities. In many industries, it is a requirement that people always wear earplugs to minimize their exposure to heavy noise. People who work with lawn mowers, tractors and noisy equipment are also required to wear noise-proof gadgets.

HEALTH IMPACT :-

Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance, and sleep disturbance.

The Harm of Noise Pollution to the Health of Human's body and mind are as follows:

1. Loud noises can cause ear discomfort, such as ear ringing, ear pains and hearing loss, etc. Noises above 115db can even lead to deafness. According to statistics, about 50 percent of those who are exposed to the noise above 80db for a long time lose their hearing. 2. Noises can cause decrease work efficiency . Under the circumstance of noises above 85db,one may feel discomfort and distracted, thus he can not concentrate on his work or study. 3. Harm to blood vessels of human hearts[/b]. Noise is a dangerous factor for heart diseases, speeding up the aging process of hearts, causing high rate of miocardial infarction incidence. Long-term exposure to noises may lead to high blood pressure. Especially in night, noises cause much higher rate of incidence of a disease. 4. Noises can make nervous system disorder, mental disturbance and incretion disorder. 5. Noises disturb rest and sleep. One may feel exausted after one night's exposure in noises. This condition continuing for a long time may lead to Neurasthenia . 6. Harm for women's physiological function. Noises can cause abnormal menstruation, abortion , premature delivery, and even abnormal embryo. 7. Noises are more harmful for children's body and mind health than that of adults ,because their organs are still weak. Noises can easily hurt their hearing organs, causing hearing damage or loss. 8. Noises' harm for eyesight. According to experiments, when the loudness of noises is above 90db,man's visual receptor cells' sensitivity decreases rapidly and the reaction time for faint light is lengthened. When the loudness reaches 95db,about 40% of people get mydriasis and blurred vision. And when exposed to noises of 115db,most people have difficulty to react to lightness.So those who are in the environment of loud noises for a long time can easily get eye strain,eye pain,blurred vision, and tearing. Beside,noise can cause the abnormity in color vision and eyeshot.

PREVENTIVE MEASURES : Noise producing industries, railway stations, aerodrome, etc should be located far away from the residential areas.  We should play various music systems such as stereos, television, etc. at a low volume.  We should not use loud speakers during night. Even during daytime they should be at low volume.  Various machines should be well maintained so that they produce less sound.  It is observed that certain persons blow horns of their vehicles unnecessarily or remove silencers of the exhaust pipes of vehicles. Such practices produce lot of sound and should be avoided.  Laws should be framed so that the persons producing unnecessary noise should be punished.  Plants also help in controlling noise pollution because they absorb high frequency sound waves. Thus, planting trees along the roads help in controlling noise pollution.

MUNICIPAL SOLID WASTE :
Municipal solid waste (MSW), commonly known as trash or garbage , refuse or rubbish is a waste type consisting of everyday items that are discarded by the public.

 Waste can be classified in several ways but the following list represents a typical classification:  Biodegradable waste: food and kitchen waste, green waste, paper (can also be recycled).  Recyclable material: paper, glass, bottles, cans, metals, certain plastics, fabrics, clothes, batteries etc.  Inert waste: construction and demolition waste, dirt, rocks, debris.  Electrical and electronic waste (WEEE) - electrical appliances, TVs, computers, screens, etc.  Composite wastes: waste clothing, Tetra Packs, waste plastics such as toys.  Hazardous waste including most paints, chemicals, light bulbs, fluorescent tubes, spray cans, fertilizer and containers  Toxic waste including pesticide, herbicides, fungicides

Components of solid waste management
The municipal solid waste industry has four components: recycling, composting, landfilling, and wasteto-energy via incineration. The primary steps are generation, collection, sorting and separation, transfer,

and disposal. Activities in which materials are identified as no longer being of value and are either thrown out or gathered together for disposal. Collection The functional element of collection includes not only the gathering of solid waste and recyclable materials, but also the transport of these materials, after collection, to the location where the collection vehicle is emptied. This location may be a materials processing facility, a transfer station or a landfill disposal site. Waste handling and separation, storage and processing at the source Waste handling and separation involves activities associated with waste management until the waste is placed in storage containers for collection. Handling also encompasses the movement of loaded containers to the point of collection. Separating different types of waste components is an important step in the handling and storage of solid waste at the source. Separation and processing and transformation of solid wastes The types of means and facilities that are now used for the recovery of waste materials that have been separated at the source include curbside collection, drop off and buy back centers. The separation and processing of wastes that have been separated at the source and the separation of commingled wastes usually occur at a materials recovery facility, transfer stations, combustion facilities and disposal sites. Transfer and transport

This element involves two main steps. First, the waste is transferred from a smaller collection vehicle to larger transport equipment. The waste is then transported, usually over long distances, to a processing or disposal site.

Disposal

Today, the disposal of wastes by land filling or land spreading is the ultimate fate of all solid wastes, whether they are residential wastes collected and transported directly to a landfill site, residual materials from materials recovery facilities (MRFs), residue from the combustion of solid

waste, compost, or other substances from various solid waste processing facilities. A modern sanitary landfill is not a dump; it is an engineered facility used for disposing of solid wastes on land without creating nuisances or hazards to public health or safety, such as the breeding of insects and the contamination of ground water.

Energy generation Municipal solid waste can be used to generate energy. Several technologies have been developed that make the processing of MSW for energy generation cleaner and more economical than ever before, including landfill gas capture, combustion, pyrolysis, gasification, and plasma arc gasification.[6] While older waste incineration plants emitted high levels of pollutants, recent regulatory changes and new technologies have significantly reduced this concern. United States Environmental Protection Agency (EPA) regulations in 1995 and 2000 under the Clean Air Act have succeeded in reducing emissions of dioxins from waste-to-energy facilities by more than 99 percent below 1990 levels, while mercury emissions have been by over 90 percent. The EPA noted these improvements in 2003, citing waste-to-energy as a power source “with less environmental impact than almost any other source of electricity.

RADIOACTIVE WASTES :
Radioactive wastes are wastes that contain radioactive material. Radioactive wastes are usually byproducts of nuclear power generation and other applications of nuclear fission or nuclear technology, such as research and medicine. Radioactive waste is hazardous to most forms of life and the environment, and is regulated by government agencies in order to protect human health and the environment. Radioactivity diminishes over time, so waste is typically isolated and stored for a period of time until it no longer poses a hazard. The period of time waste must be stored depends on the type of waste. Lowlevel waste with low levels of radioactivity per mass or volume (such as some common medical or industrial radioactive wastes) may need to be stored for only hours or days whilehigh-level wastes (such as spent nuclear fuel or by-products of nuclear reprocessing) the time frames in question range from 10,000 to millions of years. Current major approaches to managing radioactive waste have been segregation and storage for short-lived wastes, near-surface disposal for low and some intermediate level wastes, and deep burial or transmutation for the high-level wastes. Radioactive waste typically comprises a number of radioisotopes: unstable configurations of elements that decay, emitting ionizing radiation which can be harmful to humans and the environment. Those isotopes emit different types and levels of radiation, which last for different periods of time.

Naturally occurring radioactive material (NORM)

Substances containing natural radioactivity are known as NORM. After human processing that exposes or concentrates this natural radioactivity (such as mining bringing coal to the surface or burning it to produce concentrated ash), it becomes technologically-enhanced naturally-occurring radioactive material (TENORM). A lot of this waste is alpha particle-emitting matter from the decay chains of uranium and thorium. The main source of radiation in the human body is potassium-40 (40K), typically 17 milligrams in the body at a time and 0.4 milligrams/day intake.Most rocks, due to their components, have a low level of radioactivity. Usually ranging from 1 milli-Sievert to 13 milliSievert (mSv) annually depending on location, average radiation exposure from natural radioisotopes is 2.0 mSv per person a year worldwide. This makes up the majority of typical total dosage (with mean annual exposure from other sources amounting to 0.4 mSv from cosmic rays, 0.007 mSv from the legacy of past atmospheric nuclear testing along with the Chernobyl disaster, 0.0002 mSv from the nuclear fuel cycle, and, averaged over the whole populace, 0.6 mSv medical tests and 0.005 mSv occupational exposure). TENORM is not regulated as restrictively as nuclear reactor waste, though there are no significant differences in the radiological risks of these materials.

OTHER SOURCES :Coal contains a small amount of radioactive uranium, barium, thorium and potassium, but, in the case of pure coal, this is significantly less than the average concentration of those elements in the Earth's crust. The surrounding strata, if shale or mudstone, often contain slightly more than average and this may also be reflected in the ash content of 'dirty' coals. The more active ash minerals become concentrated in the fly ash precisely because they do not burn well. The radioactivity of fly ash is about the same as black shale and is less than phosphate rocks, but is more of a concern because a small amount of the fly ash ends up in the atmosphere where it can be inhaled.

Oil and gas

Residues from the oil and gas industry often contain radium and its decay products. The sulfate scale from an oil well can be very radium rich, while the water, oil and gas from a well often containradon. The radon decays to form solid radioisotopes which form coatings on the inside of pipework. In an oil processing plant the area of the plant where propane is processed is often one of the more contaminated areas of the plant as radon has a similar boiling point to propane. Low-level waste :

Low level waste (LLW) is generated from hospitals and industry, as well as the nuclear fuel cycle. Lowlevel wastes include paper, rags, tools, clothing, filters, and other materials which contain small amounts of mostly short-lived radioactivity. Materials that originate from any region of an Active Area are commonly designated as LLW as a precautionary measure even if there is only a remote possibility of being contaminated with radioactive materials. Such LLW typically exhibits no higher radioactivity than one would expect from the same material disposed of in a non-active area, such as a normal office block. Some high-activity LLW requires shielding during handling and transport but most LLW is suitable for shallow land burial. High-level waste : High-level waste (HLW) is produced by nuclear reactors. It contains fission products and transuranic elements generated in the reactor core. It is highly radioactive and often hot. HLW accounts for over 95 percent of the total radioactivity produced in the process of nuclear electricity generation. The amount of HLW worldwide is currently increasing by about 12,000 metric tons every year, which is the equivalent to about 100 double-decker buses or a two-story structure with a footprint the size of a basketball court.

Intermediate-level waste :

Intermediate-level waste (ILW) contains higher amounts of radioactivity and in some cases requires shielding. Intermediate-level wastes includes resins,chemical sludge and metal reactor nuclear fuel cladding, as well as contaminated materials from reactor decommissioning. It may be solidified in concreteor bitumen for disposal. As a general rule, short-lived waste (mainly non-fuel materials from reactors) is buried in shallow repositories, while long-lived waste (from fuel and fuel reprocessing) is deposited in geological repository.

PREVENTION :Vitrification :
Long-term storage of radioactive waste requires the stabilization of the waste into a form which will neither react nor degrade for extended periods of time. One way to do this is throughvitrification.[37] Currently at Sellafield the high-level waste (PUREX first cycle raffinate) is mixed with sugar and then calcined. Calcination involves passing the waste through a heated, rotating tube. The purposes of calcination are to evaporate the water from the waste, and de-nitrate the fission products to assist the stability of the glass produced. The 'calcine' generated is fed continuously into an induction heated furnace with fragmented glass. The resulting glass is a new substance in which the waste products are bonded into the glass matrix when it solidifies. This product, as a melt, is poured into stainless steel cylindrical containers ("cylinders") in a batch process. When cooled, the fluid solidifies ("vitrifies") into the glass. Such glass, after being formed, is highly resistant to water. After filling a cylinder, a seal is welded onto the cylinder. The cylinder is then washed. After being inspected for external contamination, the steel cylinder is stored, usually in an underground repository. In this form, the waste products are expected to be immobilized for thousands of years.

GREEN HOUSE EFFECT AND GLOBAL WARMING :-

The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases, and is re-radiated in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. Solar radiation at the frequencies

of visible light largely passes through the atmosphere to warm the planetary surface, which then emits this energy at the lower frequencies of infrared thermal radiation. Infrared radiation is absorbed by greenhouse gases, which in turn re-radiate much of the energy to the surface and lower atmosphere. The mechanism is named after the effect of solar radiation passing through glass and warming a greenhouse, but the way it retains heat is fundamentally different as a greenhouse works by reducing airflow, isolating the warm air inside the structure so that heat is not lost by convection. If an ideal thermally conductive blackbody was the same distance from the Sun as the Earth is, it would have a temperature of about 5.3 °C. However, since the Earth reflects about 30%of the incoming sunlight, this idealized planet's effective temperature (the temperature of a blackbody that would emit the same amount of radiation) would be about −18 °C. The surface temperature of this hypothetical planet is 33 °C below Earth's actual surface temperature of approximately 14 °C. The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect.

Earth’s natural greenhouse effect makes life as we know it possible. However, human activities, primarily the burning of fossil fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.

Greenhouse gases
By their percentage contribution to the greenhouse effect on Earth the four major gases are:     water vapor, 36–70% carbon dioxide, 9–26% methane, 4–9% ozone, 3–7%

The major non-gas contributor to the Earth's greenhouse effect, clouds, also absorb and emit infrared radiation and thus have an effect on radiative properties of the atmosphere.

OZONE DEPLETION :-

The ozone layer protects the Earth from the ultraviolet rays sent down by the sun. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic.

Ozone is present in the stratosphere. The stratosphere reaches 30 miles above the Earth, and at the very top it contains ozone. The suns rays are absorbed by the ozone in the stratosphere and thus do not reach the Earth. Ozone is a bluish gas that is formed by three atoms of oxygen. The form of oxygen that humans breathe in consists of two oxygen atoms, O2. When found on the surface of the planet, ozone is considered a dangerous pollutant and is one substance responsible for producing the greenhouse effect. The highest regions of the stratosphere contain about 90% of all ozone. In recent years, the ozone layer has been the subject of much discussion. And rightly so, because the ozone layer protects both plant and animal life on the planet. The fact that the ozone layer was being depleted was discovered in the mid-1980s. The main cause of this is the release of CFCs, chlorofluorocarbons. Antarctica was an early victim of ozone destruction. A massive hole in the ozone layer right above Antarctica now threatens not only that continent, but many others that could be the victims of Antarctica's melting icecaps. In the future, the ozone problem will have to be solved so that the protective layer can be conserved.

EFFECTS :Every time 1% of the ozone layer is depleted, 2% more UV-B is able to reach the surface of the planet. UV-B increase is one of the most harmful consequences of ozone depletion because it can cause skin cancer. The increased cancer levels caused by exposure to this ultraviolet light could be enormous. The EPA estimates that 60 million Americans born by the year 2075 will get skin cancer because of ozone depletion. About one million of these people will die. In addition to cancer, some research shows that a decreased ozone layer will increase rates of malaria and other infectious diseases. According to the EPA, 17 million more cases of cataracts can also be expected. The environment will also be negatively affected by ozone depletion. The life cycles of plants will change, disrupting the food chain. Effects on animals will also be severe, and are very difficult to foresee. Oceans will be hit hard as well. The most basic microscopic organisms such as plankton may not be able to survive. If that happened, it would mean that all of the other animals that are above plankton in the food chain would also die out. Other ecosystems such as forests and deserts will also be harmed.

CONCLUSION :-

The need to value environment
Until recently environmental issue has been largely ignored in conventional economic analysis and decision-making, whose main objective has generally focused on profit maximization. Chapter 1 explained that the environmental system is a key development factor and that it has a finite capacity to provide for human needs; in economic terms, it is a scarce resource. Though scarcity of environmental resources and services may be very high in certain regions of the world, the economic value generally placed on them is often underestimated and close to zero. In many cases this has led to an unsustainable path of economic growth. It is also stressed that evidence does not provide a clear response to the question of whether economic growth and environment protection and conservation are conflicting or complementary goals. Rather it shows that trade-offs and complementarities depend on various other factors such as: the scale and the structure of the economic and the social systems, technology, efficiency with which natural resources are used.

Economic, environmental and social dimensions of sustainable development
In addition it is pointed out that economic and environmental issues are two important but not absolute conditions for ensuring a sustainable development. A third dimension, the social dimension, has also to be accounted for because humans are integral parts of ecosystems. Humans and ecosphere are partners in ensuring a good quality of life. It follows that protecting natural resources, their composition, structure, and functions, is protecting humans and life on earth. Finally, it is argued that as not all of these objectives can be maximized, it is important that trade-offs among them are analysed and made clear and that any decision-making focusing on one or two of these dimensions may not lead to sustainable development. In the last decades substantial improvements have been achieved in the general knowledge of environment-economy interactions from both the scientific/technical and economic viewpoint, including how future generations can be accounted for in decision-making. Considerable work has also been undertaken to analyse the interactions between some social aspects and natural resources depletion[40], though more investigation is still required in this area. Further investigation is also needed to understand and measure the interactions occurring simultaneously between the three dimensions. As a result of this work, decision-making in development planning activity has also undergone substantial changes in terms of both the general approach to decision-making and the analytical techniques and tools.

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