Environmental Science Notes PDF

INTRODUCTION The four major components of environment are Atmosphere, Lithosphere, Hydrosphere and Biosphere. BIOSPHERE The outer layer of the planet Earth can be divided into several compartments: the hydrosphere (or sphere of water), the lithosphere (or s...

INTRODUCTION The four major components of environment are Atmosphere, Lithosphere, Hydrosphere and Biosphere. BIOSPHERE The outer layer of the planet Earth can be divided into several compartments: the hydrosphere (or sphere of water), the lithosphere (or sphere of soils and rocks), and the atmosphere (or sphere of the air). The biosphere (or sphere of life), sometimes described as "the fourth envelope", is all living matter on the planet or that portion of the planet occupied by life. The biosphere is the part of the earth, including air, land, surface rocks, and water, within which life occurs, and which biotic processes in turn alter or transform. Biosphere, a thin shell of organic matter on surface of earth comprising of all living things; is a subsystem responsible for recycling and occupies least volume of all 3 spheres. In hydrosphere oceans take responsibility of sinks while rivers play the role of conveyors. Atmosphere has the least storage capacity for matter while it supports transportation the most. Atmosphere in conjunction with hydrosphere form effective transporters of matter. HYDROSPHERE The Earth's hydrosphere consists of water in all forms: the ocean (which is the bulk of the hydrosphere), other surface waters including inland seas, lakes, and rivers; rain; underground water; ice (as in glaciers and snow); and atmospheric water vapor (as in clouds). The average depth of the oceans is 3,794 m (12,447 ft), more than five times the average height of the continents. The abundance of water on Earth is a unique feature that distinguishes our "Blue Planet" from others in the solar system. Approximately 70.8 percent (97% of it being sea water and 3% fresh water) of the Earth is covered by water and only 29.2 percent is landmass. The water cycle describes the methods of transport for water in the hydrosphere. This cycle includes water beneath the Earth's surface and in rocks (lithosphere), the water in plants and animals (biosphere), the water covering the surface of the planet in liquid and solid forms, and the water in the atmosphere in the form of water vapor, clouds, and precipitation. The water in the oceans moves as it is of different temperature and salinity on different locations. Surface waters are also moved by winds, giving rise to surface ocean currents. Warm water is lighter or less dense than cold water which is more dense or heavier and salty water is also denser than fresh water. The combination of the water's temperature and salinity determines whether it rises to the surface, sinks to the bottom, or stays at some intermediate depth. 2  ATMOSPHERE The atmosphere is a complex, dynamic natural gaseous system that is essential to support life on planet Earth. The gases are attracted by the gravity of the body, and are retained for a longer duration if gravity is high. The sky appears blue during daytime and blazing red-orange at sunset due to the phenomenon of scattering. Blue color has shorter wavelength and hence is scattered more than other colors during sunrise as sun is high on horizon and blue encounters very less molecules. During sunset, sun is low on the horizon; sunlight passes through more of the atmosphere and hence encounters more molecules. This is because red has longer wavelength while blue scatters off our line of sight. The pressure of an atmosphere decreases with altitude due to the diminishing mass of gas above each location. However, atmospheres are not uniform in temperature, so the exact determination of the atmospheric pressure at any particular altitude is more complex. Atmospheric gases scatter blue light more than other wavelengths, giving the Earth a blue halo when seen from space. The Earth's atmosphere consists, from the ground up, of the troposphere aslowest layer, stratosphere, mesosphere, ionosphere (or thermosphere) and the exosphere. The ozone layer, which absorbs ultraviolet energy from the Sun, is located primarily in the stratosphere, at altitudes of 15 to 35 km. The Kármán line, located within the thermosphere at an altitude of 100 km, is commonly used to define the boundary between the Earth's atmosphere and outer space. Troposphere is the lowest layer of the atmosphere that begins at the surface and extends to between 7 km at the poles and 17 km at the equator. The troposphere has a great deal of vertical mixing due to solar heating at the surface. Hence most weather activities take place here. Stratosphere from the troposphere's 7-17 km range to about 30 km, here temperature increases with height. Global warming, ozone depletion originate here. Mesosphere starts about from 50 km to the range of 80- 85 km, here temperature decreasing with height. Thermosphere starts from 80–85 km to 640+ km, temperature increasing with height. Ionosphere is the part of the atmosphere that is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. It is located in the thermosphere. Exosphere begins from 500-1000 km up to 10,000 km, free-moving particles that may migrate into and out of the magnetosphere or the solar wind. The boundaries between these regions are named the tropopause, stratopause, mesopause, thermopause and exobase. Commercial airliners [subsonic] fly in lower stratosphere, jet airliners [supersonic] fly in the troposphere. Spy satellites orbit in exosphere at about 434 miles [700 km], where in while meteorites burn up in thermosphere. 3  COMPOSITION OF AIR [by volume] 75.523% nitrogen 23.133% oxygen 1.288% argon 0.035% carbon dioxide 0.001267% neon 0.00029% methane 0.00033% krypton 0.000724% helium 0.0000038 % hydrogen LITHOSPHERE The lithosphere is the solid outermost shell of a rocky planet. The lithosphere is about 100 km thick. If you could slice the Earth in half, you would see four layers: the crust, the mantle, the inner core, and the outer core. Each layer is made of different materials, has a different density, and has a different thickness. The Crust The crust is Earth's outermost layer. The crust varies from 5 to 70 kilometers in thickness. The crust includes rocks, minerals, and soil. There are two kinds of crust: continental and oceanic. Yes, there is even crust under the ocean! The crust is constantly moving, which is why continents move and earthquakes happen. The science that studies how the parts of the crust move is called "Plate Tectonics." Earth's oceanic crust is a thin layer of dense rock about 5 kilometers thick. The continental crust is less dense, with lighter-colored rock that varies from 30 to 70 kilometers thick. The continental crust is older and thicker than the oceanic crust. The crust is made of many types of rocks and hundreds of minerals. These rocks and minerals are made from just 8 elements: Oxygen (46.6%), Silicon (27.72%), Aluminum (8.13%), Iron (5.00%), Calcium (3.63%), Sodium (2.83%), Potassium (2.70%), and Magnesium (2.09%). The oceanic crust has more Silicon, Oxygen, and Magnesium. The continental crust has more Silicon and Aluminum. The Mantle Directly below the crust is the mantle. The mantle makes up the largest volume of the Earth's interior. It is almost 2900 kilometers thick and comprises about 83 % of the Earth's volume. It has two parts, an upper layer and a lower layer. The upper mantle is about 670 kilometers in depth. It is brittle and less dense. It is thought to be made of peridotite, a rock made from the minerals olivine and pyroxene. The rocks in the upper mantle are more rigid and brittle because of cooler temperatures and lower pressures. The Lower Mantle is much thicker and denser. It is 670 to 2900 kilometers below the Earth's surface. This layer is hot and plastic. The higher pressure in this layer causes the formation of minerals that are different from those of the upper mantle. 4 The Outer and Inner Core The region beneath the mantle is called the core, and is made of two parts, a liquid outer core that is about 2250 km thick and a solid inner core which is 1220 km thick. The core is mostly made of iron, with a little bit of nickel. The outer core is at 1,800 - 3,200 miles (2,890-5,150 km) below the earth's surface. The temperature in the outer core is about 7200 - 9032 ºF (4000-5000ºC). The molten, liquid iron in the outer core is important because it helps create Earth's magnetic field. The inner core is 3,200 - 3,960 miles (5,150-6,370 km) below the earth's surface and mainly consists of iron, nickel and some lighter elements (probably Sulphur, carbon, oxygen, silicon and potassium). The temperature in the inner core is about 9032 - 10832 ºF (5000-6000 ºC). Because of the high pressure, the inner core is solid. Earthquake is an outcome of pressure buildup in lithospheric plates called tectonic plates that move about each other, generating friction and resulting in pressure built up. But when pressure exceeds sustenance, huge amount of force is released destroying tectonic plates resulting in phenomenon called earthquake. ECOSYSTEM An ecosystem can be defined as any situation where there is interaction between organisms and their environment. The ecosystem is composed of two entities, the entirety of life and the medium that life exists in. They can be classified as AQUATIC and TERRESTRIAL. A BALANCED ECOSYSTEM is one in which there is a Population balance existing between Prey-Predators, Producers-Consumers relationship and as well its ensured that there is constant and optimum recycling of matter. Plants constitute 99 percent of earths living species and the rest 1 per cent include animals and man who depend on the plant world for their food. If this ratio (99:1) is disturbed by elimination of plants (i.e., deforestation), then the natural balance will be lost and the entire living world will suffer most. The dynamic balance is among plants (producers), bacteria and micro-organisms (decomposers who decompose mineral salts in soil into elements which are cycled back into the plants) and animals plus man (consumers). Once this dynamic balance is upset, there would be ecological crisis and the entire biosphere would be in danger. Soil (edaphic factors) includes soil texture, soil air, soil temperature, soil water, soil solution and pH, together with soil organisms and decaying matter. Winds carry water vapor which may condense and fall in the form of rain, snow or hail. Wind plays a role in pollination and seed dispersal of some plants, as well as the dispersal of some animals, such as insects. Wind erosion can remove and redistribute topsoil, especially where vegetation has been reduced. 5 Physiographic factors are those associated with the physical nature of the area, such as altitude, slope of land and the position of the area in relation to the sun or rain-bearing winds. Altitude plays a role in vegetations zones. Slopes are important when considering the temperature of the soil surface on land with a northern slope, on level and on land with south facing slopes. The most important gases used by plants and animals are oxygen, carbon dioxide and nitrogen. Oxygen is used by all living organisms during respiration. Carbon dioxide is used by green plants during photosynthesis. Nitrogen is made available to plants by certain bacteria and through the action of lightning. Plant and animal habitats vary from entirely aquatic environments to very dry deserts. Water is essential for life and all organisms depend on it to survive in especially desert areas. Plants can be classified into 3 groups according to their water requirements. Hydrophytes are plants which grow in water e.g. water-lilies and rushes. Mesophytes are plants with average water requirements e.g. roses, sweet peas. Xerophytes are plants which grow in dry environments where they often experience a shortage of water e.g. cacti and often succulents. The distribution of plants and animals is greatly influenced by extremes in temperature for instance the warm season. The occurrence or non-occurrence of frost is a particularly important determinant of plant distribution since many plants cannot prevent their tissues from freezing or survive the freezing and thawing processes. Light energy (sunlight) is the primary source of energy in nearly all ecosystems. It is the energy that is used by green plants (which contain chlorophyll) during the process of photosynthesis; a process during which plants manufacture organic substances by combining inorganic substances. Visible light is of the greatest importance to plants because it is necessary for photosynthesis. Factors such as quality of light, intensity of light and the length of the light period (day length) play an important part in an ecosystem. Macronutrients are those elements, which generally occur in 1000 ppm or higher in plants. They include nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and sulfur (S), whereas the micronutrients are generally found in plants at levels of 500 ppm or less. Group of minerals that plants use in very small amounts are commonly referred as "trace or micro" nutrients and include iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), molybdenum (Mo), boron (B), chlorine (Cl) and nickel (Ni). The classical approach to assessing micronutrient limitations is based on the law of limiting factors, sometimes also referred to as Liebig’s law of the minimum. Biotic factors include INTRASPECIFIC AND INTERSPECIFIC relations. Interspecific relations are interactions between different species, usually described according to their beneficial, detrimental or neutral effect. Intraspecific relations are those that are established between individuals of the same species, forming a population. 6 Positive Interactions: [a] Mutualism: Populations help each other through mode ofsymbiosis. [E.g. Pollination, lichens] [b] Commensalism: Only one species is befitted while neither is harmed or Benefited. [E.g. Epiphytes] [c] Proto-co-operation: Non-obligatory symbiotic relationship. [E.g., Sea Anemone attached to molluscan shell harboring hermit crab]. Negative Interactions: [a] Competition: [i] Resource competition: Battle for resources in scarcity [ii] Interference competition: Battle for resources in non-scarcity [b] Parasitism: Receiving benefit at cost of other’s survival or well-being. The most significant relation is the relation of predation (to eat or to be eaten), which leads to the essential concepts in ecology of food chain. HYDROLOGICAL CYCLE The movement of water around, over and through the Earth is called the water cycle. The water cycle has no starting point. However, we'll begin in the oceans, since that is where most of Earth's water exists. The sun, which drives the water cycle, heats water in the oceans. Some of it evaporates as vapor into the air. Ice and snow can sublimate directly into water vapor. Organisms play an important role in the water cycle. As you know, most organisms contain a significant amount of water (up to 90% of their body weight). This water is not held for any length of time and moves out of the organism rather quickly in most cases. Animals and plants lose water through evaporation from the body surfaces and through evaporation from the gas exchange structures (such as lungs). In plants, water is drawn in at the roots and moves to the gas exchange organs, the leaves, where it evaporates quickly. This special case is called transpiration because it is responsible for so much of the water that enters the atmosphere. Rising air currents take the vapor up into the atmosphere, along with water from evapotranspiration, which is water transpired from plants and evaporated from the soil. Guttation is the process of loss of water form roots. The vapor rises into the air where cooler temperatures cause it to condense into clouds. Air currents move clouds around the globe; cloud particles collide, grow and fall out of the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, which can store frozen water for thousands of years. Most precipitation falls back into the oceans or onto land, where, due to gravity, the precipitation flows over the ground as surface runoff. A portion of runoff enters rivers in valleys in the 7 landscape, with stream flow moving water towards the oceans. Runoff, and ground-water seepage, accumulate and are stored as freshwater in lakes. Snowmelt refers to the runoff produced by melting snow. Runoff includes the variety of ways by which water moves across the land. This includes both surface runoff and channel runoff. As it flows, the water may infiltrate into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses. Once water condenses, gravity takes over and the water is pulled to the ground. Gravity continues to operate, either pulling the water underground (groundwater) or across the surface (runoff). In either event, gravity continues to pull water lower and lower until it reaches the oceans. Infiltration is the flow of water from the ground surface into the ground. Once infiltrated, the water becomes soil moisture or groundwater. Not all runoff flows into rivers, though. Much of it soaks into the ground as infiltration. Some water infiltrates deep into the ground and replenishes aquifers (saturated subsurface rock), which store huge amounts of freshwater for long periods of time. Some infiltration finds openings in the land surface and emerges as freshwater springs. Subsurface Flow is the flow of water underground, in the vadose zone and aquifers. Subsurface water may return to the surface as a spring or by being pumped) or eventually seep into the oceans. Groundwater tends to move slowly, and is replenished slowly, so it can remain in aquifers for thousands of years. FOOD CHAIN A food chain is the flow of energy from one organism to the next. Organisms in a food chain are grouped into trophic levels. Trophic levels may consist of either a single species or a group of species that are presumed to share both predators and prey. They usually start with a primary producer and end with a carnivore. Below a food chain has been depicted beginning from grass extending to hawk in a single linear chain. GRASS ---> GRASSHOPPER --> MOUSE ---> SNAKE ---> HAWK FOOD WEB 8 A food web extends from a food chain concept from a simple linear pathway to a complex network of interactions. Food chains, food webs graphically represent the transfer of material and energy from one species to another within an ecosystem. Below a food web has been depicted showing the complex nature of interactions between each trophic level influencing directly and indirectly. ORGANISMS REPRESENTED IN FOOD CHAINS Producers/Autotrophs -- An organism that produces complex organic compounds from simple inorganic molecules and an external source of energy, such as light or chemical reactions of inorganic compounds. Autotrophs are considered producers in a food chain. Plants and other organisms that carry out photosynthesis are phototrophs (or photoautotrophs). Bacteria that utilize the oxidation of inorganic compounds such as hydrogen sulfide, ammonium or ferrous iron as an energy source are chemoautotrophs They take energy from the environment (sunlight or inorganic sources) and use it to process carbon-based and other organic molecules that are used to carry out various biological functions such as cell growth. Other organisms, called heterotrophs, utilize autotrophs as food to carry out these same functions. Consumers/Heterotrophs -- animals, which can be primary consumers (herbivorous), secondary or tertiary consumers (carnivorous) and Tertiary consumers (omnivores). There are some species of organisms that require organic compounds as a source of carbon, but are able to use light or inorganic compounds as a source of energy. Such organisms are not defined as autotrophic, but rather as heterotrophic. An organism that obtains carbon from organic compounds but obtains energy from light is called a photo heterotroph, while an organism that obtains carbon from organic compounds but obtains energy from the oxidation of inorganic compounds is termed a chemo heterotroph. Decomposers --organisms that consume dead plants and animals, and, in doing so, carry out the natural process of decomposition. The primary decomposers are bacteria and fungi. When a plant or animal dies, it leaves behind nutrients and energy in the organic material that comprised its body. Scavenger and detrivores may feed on the carcasses or litter, but they will inevitably leave behind a considerable amount of unused energy and nutrients. Decomposers complete decomposition by breaking down this remaining organic matter. Although decomposers are generally located on the bottom of ecosystem diagrams such as food chains, food webs, and energy pyramids, decomposers in the biosphere are crucial to the environment. ECOLOGICAL PYRAMIDS Pyramid of Numbers: Developed by Charles Elton, it depicts the number of organisms at each trophic level. The general representation shows maximum numbers at the base [producers] and least at the top usually Homo sapiens. 9 Pyramid of Biomass: The biomass of the members of the food chain present at any time forms the pyramid of bio-mass. The pyramid depicts decrease in bio-mass as one move from base to apex. Pyramid of Energy: when production is considered in terms of energy that i.e., chemical energy, the scenario is same displaying energy losses as the movement is towards the apex ENERGY FLOW All ecosystems must have a source of energy (usually the sun) because all organism functions such as growth and reproduction require energy. Energy moves through the ecosystem by a series of events that link organism’s together.Plants and photosynthetic microorganisms convert light into chemical energy by the process of photosynthesis, which creates glucose (a simple sugar) and releases free oxygen. Glucose; thus, becomes the secondary energy source which drives the ecosystem. Photosynthesis Carbon dioxide + Water + Sunlight (Energy) = Glucose + Oxygen Some sugars produced during photosynthesis are broken down during respiration to release energy needed by the plant for growth and reproduction. Others are used to make "building blocks" that are combined to make plant cells, hence plant parts. Respiration Glucose + Oxygen = Carbon dioxide + Water + Energy (Heat) Animals that eat plants (herbivores) use them to make animal parts or burn them to produce energy for their cell functions. Any compounds not used immediately are combined and stored as fats. Tissues of animals eaten by other animals (predators/carnivores) are broken down and re- combined into new parts for that animal and so on. Thus, all animals depend on plants for food. In any food network, the energy contained in the level of the producers is not completely transferred to the consumers, the higher one[n] goes up the chain, the more energy and resources is lost and consumed. It is often the case that biomass of each trophic level decreases from the base of the chain to the top. This is because energy is lost to the environment with each transfer. On average, only 10% of the organism's energy is passed on to its predator. The other 90% is used for the organisms life processes or is lost as heat to the environment. Anthroposystem In an ecosystem most of the materials are transferred from the producers (plants) to the recyclers (bacteria), and only a small fraction is passed through the consumers to the recyclers. The decomposers (recyclers) return most of the materials to the producers from reuse. In the Anthroposystem the flow from the producers to the recyclers is small or even nonexistent since it would be pointless to produce (mobilize) materials and immediately recycle them without a consumer in the loop. In the Anthroposystem much of the mobilized materials are transferred to the rest of the material environment, to the producer and to the consumer. Hence, it is mostly an open system, where recycling accounts for only a small fraction of the mobilized matter. 10 In the Anthroposystem, there is usually a significant physical displacement between the producer and the consumer. Balanced Ecosystem A Balanced Ecosystem occurs when there is a Population balance existing between Prey- Predators and Producers-Consumers relationships. It ensures that there is constant and optimum recycling of matter. Plants constitute 99 percent of earth’s living species and the rest one percent include animals and homo-sapiens. If this ratio (99:1) is disturbed by elimination of plants (i.e., deforestation), then the natural balance will be lost and the entire system will collapse. There is a dynamic balance among green plants (producers), bacteria and micro-organisms (i.e., decomposers who decompose mineral salts in soil into elements which are cycled back into the plants) and animals (consumers). Once this dynamic balance is upset, there would be ecological crisis and the entire biosphere would be in danger. To avoid this, there must exist equilibrium between the biotic (living) and abiotic (non-living). To overcome imbalances and for survival, organisms sometime undertake in Ecological succession, a process in which ecological communities respond to changes in their environment. Classification of Ecosystem Aquatic Ecosystems Marine Ecosystems: These cover approximately 71% of the Earth's surface and form approximately 97% of the planet's water. Marine ecosystems generate 32% of the world's net primary production. They are distinguished from freshwater ecosystems by the presence of dissolved compounds, especially salts, in the water. Marine ecosystems can be divided into oceanic shelf, salt marshes, coral reefs and hydrothermal vents. Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks. Freshwater Ecosystems: These cover 0.8% of the Earth's surface and contain 0.009% of its total water. They generate nearly 3% of its net primary production. There are 2 basic types of freshwater ecosystems.  Lentic: Slow-moving water, including pools, ponds, and lakes.  Lotic: Rapidly-moving water, for example streams and rivers. Organisms in marine ecosystems tolerate salinity, while many freshwater organisms are intolerant of salt. Estuaries are special ecosystems formed where sea water mixes with fresh water and nutrients from rivers, streams, and runoff. The pond is the simplest aquatic ecosystem. During rainy seasons, when a pond begins to fill, its life forms such as the algae and microscopic animals, aquatic insects, snails, and worms come out of the floor of the pond where they remained dormant in the dry phase. The vegetation in the pond consists of floating weeds and rooted vegetation on the periphery which grows on the muddy floor under water and emerges out of the surface of the water. As the pond fills during the monsoon, a large number of food chains are formed. Algae are eaten by microscopic animals, which are in turn eaten by small fish. 11 The temporary ponds dry after the rains and surrounding grasses and terrestrial plants spread into the exposed moist mud. Frogs, snails and worms remain dormant in the mud, anticipating next monsoon. Lake Ecosystem Lakes are large natural bodies of standing-water, which is formed when precipitation, runoff, or groundwater seepage fills depressions on the Earth’s surface”. The parts of a lake also can be classified by temperature:  The epilimnion [the upper layer of warm water].  The hypolimnion [the lower layer of colder, denser water].  The thermocline [the area in between in which water temperature decreases rapidly with depth]. Lakes and ponds are divided into 4 different “zones” usually determined by depth and distance from the shoreline. The four zones of a lake from top to bottom are the littoral zone, the limnetic zone, the profundal zone and the bathyal zone.  Littoral zone encompasses the area near the shore at the top of the lake that receives sunlight, extending down to the depth where rooted plants stop growing. This zone has high biodiversity. This zone is the warmest since it is shallow and can absorb more of the Sun’s heat. It sustains a fairly diverse community, which can include several species of algae (like diatoms), rooted and floating aquatic plants, grazing snails, clams, insects, crustaceans, fishes, and amphibians. As further depth increases, dissolved oxygen levels 12  decreases, so the epilimnion has the highest amount of oxygen and the hypolimnion the lowest amount.  Limnetic zone the near-surface open water surrounded by the littoral zone. The limnetic zone is essentially the open area away from the shore. Most photosynthesis occurs in this part of the lake itself. The zone is well-lighted just like the littoral zone and is dominated by plankton, both phytoplankton and zooplankton.  Profundal zone the deep open water where it is tough for photosynthesis to happen and the planktons here have short life spans. This zone is much colder and denser than the other 2 as little light penetrates. The fauna are heterotrophs, meaning that they eat dead organisms and use oxygen for cellular respiration.\  Benthic zone is the very bottommost layer of the lake. Organisms here tend to tolerate cooler temperatures much better. Low levels of photosynthesis result in low levels of DO in this level. Terrestrial Ecosystems Terrestrial ecosystems include Forests, Grasslands, Semi-arid areas and Deserts. Forest Ecosystem A forest is a highly complex, constantly changing environment encompassing variety of living and non-living things. The word forest is derived from the Latin word Foris. Forest cover approximately occupies 9.4% geographical portion of the earth. Forests Ecosystem sub- Classification includes Tropical Rainforests, Sub-Tropical Forests, Mediterranean Forests, Temperate Forests, Coniferous Forests, Montane Forests, Plantation Forests, Deciduous Forest and Evergreen Forest. Functions of Forest Ecosystem Regulatory functions  It helps regulate water cycle.  The ecological benefit apart from cleansing of air, water includes carbon sequestration, and reducing Global warming.  It helps regular global ambient air temperature.  It provides raw material for paper and pulp industries. Habitat functions  Provides a reproduction habitat to wild plants and animals  Contributes to in-situ conservation of biological and genetic diversity and the evolutionary process. 13 Production functions  Through the process of photosynthesis and nutrient uptake by autotrophs converts energy, carbon dioxide, water and nutrients into a wide variety of carbohydrate structures which are then used by secondary producers to create an even larger variety of living biomass. Information functions  Provides an essential 'reference function‘  Contribute to the maintenance of human health by providing opportunities for reflection, spiritual enrichment, cognitive development, recreation and aesthetic experience.  Trees also help in absorbing noise and creating an aesthetic environment free of stress and peace.  It serves for tourism attraction and provides recreational activities like hunting, camping, hiking, fishing, watching wildlife, off road biking, horseback riding and plantcollecting. Desert Ecosystem Deserts are terrestrial ecosystems found around the tropic of Cancer and tropic of Capricorn in Northern and Southern Hemispheres. They have mega-thermal climate, as per Koppen climate classification. The desert is the hottest biome on Earth and occupies about one fifth of the Earth's land surface. Sahara Desert, Arabian Desert, Gobi Desert, Kalahari Desert and Thar Desert are few of famous deserts around the world. Hot deserts  Temperature is very warm entire year, with summers being extremely hot.  More flora and fauna can be found here compared to cold desert.  Water is very scarce.  Temperature is very high during day and very low at night.  Xerophytes have modifications like pulpy stem to store water and wax covered thorny leaves to reduce transpiration. The roots are very long to reach the water table.  Animals such as reptiles, rodents, wolves display nocturnal behaviour. Cold deserts  This type of desert has short and warm summers, and Long, cold winters  Found in places near the north and south poles  Less flora and fauna can be found compared to hot desert. Functions of Desert Ecosystem  Deserts contain valuable mineral deposits like silica, gypsum, borates are found here.  Due to consistent dryness, deserts are ideal places for natural preservation of artifacts and fossils. 14 Structure of Desert Ecosystem  The abiotic factors include sunlight, oxygen, carbon-di-oxide, ground water, temperature, humidity, pH.  The producers mainly include shrubs, bushes, some grasses and few trees Abiotic Factors of Desert Ecosystem  The thin soils frequently attacked by sand storm and wind with lack of humus makes them infertile.  The moisture lost through evaporation is much greater than that gained during rainfall.  The rainfall is extremely irregular.  The drought period is usually longer than a year. Biotic Factors of Desert Ecosystem – Fauna  Hundreds of different animals thrive in deserts.  Most of these are found only at dawn or dusk, when climate is much cooler.  The fauna include snakes, owls, mice, armadillo lizards, fennec foxes, bats, vultures and camels. Biotic Factors of Desert Ecosystem – Flora  There are several varieties of plants that are able to survive in the desert.  Most plants survive due to their tap roots that are able to reach underground water.  The vegetation of the Desert Biome is mostly characterized by dominance of annual plants, often annual grasses.  These plants have special parts and adaptations that help them save water. BIODIVERSITY & ITS VALUES Biodiversity can be defined as the richness of the diversification of all the species living in a particular area. The values of biodiversity are classified as Ecosystem service value, Ethical Values, Aesthetic Values, Ecosystem service value, Option value, Social value and Productive use values. Ethical Value is also sometimes called as existence value. It incorporates the ethical issues that all life must be preserved. This is based on the concept of Live and Let Live. Biodiversity is valuable in all facets and If we want our human race to survive, then we must protect all biodiversity. The ethical aspect means that we may or may not use a species, but knowing the very fact that this species exists in nature gives us pleasure. We are not deriving anything directly animals from Kangaroo, Zebra or Giraffe, but the strong urge must be that these species should co-exist in nature. Hence it means, there is an ethical value or existence value attached to every species on earth. 15 Option values include the potential of biodiversity that are presently unknown and needs to be explored from their realms for their true function. There is a hint that we might have potential cure for diseases such as AIDS or cancer existing within the depths of a marine ecosystem, or a tropical rainforest. Option value is hence knowing that there are biological resources existing on this biosphere that may one day prove to be an effective option for the future. The option value of biodiversity therefore suggests that any species may prove to be a useful someday. The biodiversity is a precious gift of nature and we should not commit the folly of losing these gifts even before unwrapping them. Social values are associated with the social life, customs, religion and psycho-spiritual aspects of the humans. Many plants are considered holy and sacred in our country such as Tulsi, Peepal, Lotus, Bael. The leaves, fruits or flowers of these plants are used in worship of deities or the plant itself is sometimes worshipped. The tribal people are very closely linked with social values of the forests. The social life, songs, dances and customs of tribes are closely woven around the forest and its wildlife. Many animals like Cow, Snake, Bull, Peacock, Owl have significant place in our psycho-spiritual arena and hence gains social importance. Ecosystem service values refers to the services provided by ecosystems in preventing soil erosion and floods, fixation of nitrogen, cycling of water, their role as carbon sinks, pollutant absorption and mitigating the threat of global warming. Ecosystem services those are often not readily visible. It plays a part in regulating the chemistry of our atmosphere. Biodiversity is directly involved in recycling nutrients and providing fertile soils. Experiments with controlled environments have revealed that humans cannot easily build ecosystems to support human needs. Example: Insect pollination cannot be mimicked by human-made construction. Productive use values are the commercially viable values where the product is marketed and sold for profitable ventures. This includes lumber or wild gene resources that can be traded by scientists for introducing desirable traits in the crops and domesticated animals. This may include the animal products like silk from silk-worm, wool from sheep, fir of many animals, lac from lac insects. Many industries are dependent upon productive use values of biodiversity such as paper and pulp industry, plywood industry, Silk industry, textile industry. Developing nations of Asia, Africa and Latin America are the richest biodiversity centers. Consumptive use value includes direct use values where the biodiversity product can be harvested and consumed directly. Levels of Biodiversity Biodiversity can be explained at three levels, namely Genetic Diversity, Species Diversity and Ecosystem Diversity.  Genetic biodiversity reflects at the variation of genes within a species. Diversity of genes within a species increases its potential ability to adapt to disease, pollution and the other changes in habitat or environment. When a variety of particular specie is destroyed, the genetic diversity gets diminished; hence increase in genetic diversity is essential for a species to evolve. 16   Species Diversity is portrayed as the variability found within the population of a species or between different species of a community. It indicates broadly the species richness and their abundance of community. Species biodiversity indicates variability of species within a region. Species diversity can be measured on the basis of species in a region. Greater species biodiversity reflects at more biological wealth.  Ecosystem diversity is defined as ‘the aggregation of various habitats, community types and abiotic environments of a given area’. This is essentially the diversity of ecological complexity showing variations in ecological niches, tropic structure, food-webs and nutrient cycling. This diversity reflects on the variations with respect to physical parameters like moisture, temperature, altitude precipitation. The ecosystem diversity is of great value that must be kept intact as its destruction would disrupt the ecological balance. This diversity refers to diversity at habitat level. For example in a forest ecosystem, the ecosystem diversity is reflected by tropical rainforest, deciduous forest, temperate deciduous forest and boreal forest. Human knowledge of the world’s biodiversity is still inadequate. There are three levels of biodiversity, global, national and local levels. All the three global, national and local levels are linked and constitute a gene pool. India is a signatory to Convention on Biological Diversity by ratifying it in 1993. There are 34 world biodiversity hot spots. Overall 6% of the global species are found in India itself. Biodiversity Hot-Spots Threats to Biodiversity As human population expands and natural habitats shrink, they constantly and increasingly come into conflict over living space and other resources. Humans unlike other animals prefer tochange the environment around them instead of adjusting himself according to the environment. 17 Animals often end crossing paths without humans for reasons such as loss of habitat, loss of food and natural pathway of migration and movement. Environmental pollution and global warming also causes certain animals especially those who cannot regulate body temperature and under stress to lock horns with humans. The other major threats are:  Loss of habitat  Poaching and Over hunting  Man-wildlife conflicts  Deforestation  Dams  Urbanisation  Agriculture  Deforestation  Forest fires  Introduction of new species  Natural disasters  Mining  Desertification Control measures to conserve and protect Biodiversity  Proper Land-use planning  Community Based Management  Ensuring forests are free of human interference.  Controlling rate of deforestation.  Strict adherence to forest laws.  Strict implementation of law, punishments and penalties for violators and poachers.  Regular monitoring by foot patrol and GIS tracking.  Strict control on the issuance of license of firearms around important protected areas.  Spread awareness amidst general public about conservation and preservation of wildlife and their habitat.  Protection of the habitats permanently through formation and conservation of national parks, nature reserves and wilderness areas will help preserve biodiversity. In-situ & Ex-situ conservation of Biodiversity The enormous value of biodiversity in the form of their genetic, commercial, medical, aesthetic and ecological importance emphasizes the need to conserve biodiversity. There are two approaches to biodiversity conservation: In-situ conservation and Ex-situ conservation. In situ conservation (within habitat) is achieved by protection of wild flora and fauna by creating environment similar to nature such as national parks, forest reserves, and Sanctuaries. Ex-situ conservation (outside habitats) is done by establishing gene banks, seed banks, zoos, and botanical gardens. Genes are the basic units of hereditary information transmitted from one generation to the other. The genes found in organisms can form enormous combinations each of which gives rise to some variability. When the genes within the same species show different versions due to new combinations, it is called genetic variability. 18  NATURAL RESOURCES Nature provides life support materials or resources for sustenance of life on earth for plants, animals and man. These are known as Natural Resources. Examples are water, air, soil, forests, minerals, crops etc. There are 2 categories of natural resources: 1. Renewable resources: These can be recycled and regenerated within a given span of time. E.g., Forests, wind energy, solar energy, biomass energy, hydropower etc. 2. Non-Renewable Resources: These cannot be regenerated e.g., fossil fuels such as coal, petroleum, minerals etc. The major natural resources are: 1. Forest resources 2. Water resources 3. Mineral resources 4. Food resources 5. Energy resources 6. Land resources FOREST WEALTH Forest resources play a vital role in the economy of India, the following section deal with the forest resources, its utility and emerging threats COMPONENTS OF FOREST A forest is a highly complex, constantly changing environment made up of a variety of living [wildlife, trees, shrubs, wildflowers, ferns, mosses, lichens, fungi and microscopic soil organism] and non-living [water, nutrients, rocks, sunlight and air] things. Trees are the most dominant component of this environment BENEFITS OF FOREST Forests cover much of the planets land area. They are extremely important to humans and the natural world. For humans, they have many aesthetic, recreational, economic, historical, cultural and religious values. Timber and other products of forests are important economically both locally and as exports. Forest provides wood for fuel as a significant for those who harvest the wood or products of the living forest. Other non-wood products come in the form of medicinal compounds, dyes and fabrics. One-third of the world’s population depends on wood for fuel as a significant energy source. Some indigenous people [tribal] depend completely on forest as their home and for many it’s a source of their livelihood. 19 Key benefits of forest are: Provides clean water by intercepting water from rain and slowing it down and hence aids soil absorption for gradual release into streams at a slow and even rate. Cleansing action is done by root system. Provides clean air by mode of photosynthesis wherein they release oxygen and take in carbon-di- oxide. Trees filter air off harmful pollutants and moderate the air temperature. Provides home/shelter to a wide array of species of flora and fauna. There is a possibility that many herbs of potential medical treatments, cures and vaccines may lie undiscovered within forests. As source of economic growth by providing timber and playing important role in wood based industries and paper and pulp industries. Also it serves for tourism attraction And finally it also provide fruits, nuts, flowers and many other products of economic value. Provides recreational activities like hunting, camping, hiking, fishing, watching wildlife, off road biking, horseback riding and plant collecting. The ecological benefit apart from cleansing of air, water includes carbon sequestration i.e., taking carbon-di-oxide of out of the earth atmosphere to produce wood and leaf matter. Trees as well help in absorbing noise, creating an aesthetic environment free of stress and peace. Trees protect topsoil from erosion and reduce risk of failure of slopes and hence prevent landslides and avalanches. Water from roots is drawn up to the leaves where it evaporates. The conversion from water to gas absorbs huge amounts of heat cooling hot city air. Trees help to offset the heat island effect resulting from too much glass and concrete in city environments. DEFORESTATION It refers to the loss of forest cover; land that is permanently converted from forest to agricultural land, golf courses, cattle pastures, homes, lakes or desert. It is sometimes referred as change of forest with depletion of tree crown cover more than 90%. UNCED 1992 defined deforestation as land degradation in arid, semi-arid and sub humid areas resulting from various factors including climatic variations and human activities. Causes: Agriculture – most of the forest clearing around the world is done for agricultural purposes [grazing cattle, planting crops etc.] poor farmers cut down small areas [few acres] and burn down the trees and proceed with agriculture. Intensive an extensive agriculture destroys forest on a larger scale. 20 Commercial logging – cutting trees for timber or pulp. Logging can occur selectively [only the economically valuable species are cut]or by clear cutting [all tree are cut]. Commercial logging employs heavy machinery. The cash crop economy – this is an integral part of the Third World Development and a major cause of deforestation. The best land is taken to earn export income, which is very often used to pay the foreign debt. Farmers are forced onto marginal land. Mining and Dams – mining, hydro-electric schemes and industrial development are also significant causes of deforestation, both in terms of land they occupy and displacement of forest people. Effects: Fewer trees result in insecure work for forest workers Heavy rainfall and high sunlight damage the topsoil in absence of trees. Erosion of soil, landslide frequented Loss of future markets for eco-tourism Indigenous people loss livelihood Loss of rare/endangered wildlife species Loss of habitat and migration of wild animals to rural and urban zones Cutting or burning o tees give a lot of carbon-di-oxide into atmosphere Reduction in rainfall Desertification No recycling of water Less carbon-di-oxide and nitrogen exchange Desiccation of soil Remedies Reduce the consumption of forest and related products Avoid harmful products by consumer boycotts; such has tropical rainforest wood, old growth wood from the tropical rainforest. Boycott products of companies involved in deforestation Compel govt. and industries to make changes in forest policies Increase public awareness 21 MODULE 2 22  ENERGY Energy is the capacity to do work. A plenty of energy is needed to sustain industrial growth and agricultural production. CLASSIFICATION OF ENERGY 1. Conventional energy: is in practice for long duration of time and well established technology is available to tap and use them. e.g. Coal, oil, natural gas, hydro power, nuclear power etc. 2. Non-conventional energy: source can be used with advantage for power generation as well as other applications in a large number of locations and situations. These energy sources cannot be easily stored and used conveniently. e.g. Solar, wind, tidal and geothermal etc. Based upon nature, energy sources are classified as 1. Renewable energy sources are inexhaustible and are renewed by nature itself. Solar, wind, tidal, hydro and biomass are few examples. 2. Non-renewable energy sources are exhaustible within a definite period of time depending upon its usage. Fossil fuels (coal, oil, gas) and nuclear fuels are few examples. Renewable Nonrenewable 1. sun 1. coal 2. water 2. natural gas 3. wood 3. petroleum 4. wind 4. nuclear fission 5. biomass 6. geothermal 7. ocean tides SOLAR ENERGY The surface of the earth receives about 1014 kW from sun in the form of solar energy which is approximately five orders of magnitude greater than that currently being consumed from all resources. There are two obvious obstacles to harnessing solar energy. Firstly it is not constantly available on earth. Thus some form of storage is needed to sustain solar energy through the night and during rainy season. Secondly the solar energy is diffused. Although the total amount of energy is enormous, the collection and conservation of solar energy into useful forms must be carried out over a large area which entails large capital investments. By using solar radiation, water or any fluid can be heated by using a solar collector. Such systems can provide hot water for different applications in industries directly or as boiler feed and also in hostels, hotels and canteens. There are two types of solar collectors in use: 23 Flat plate collector: The absorber plate is metallic. It is usually coated black to absorb more heat energy. Tubes, passages or channels integral with the collector carry water or other working fluid. Insulation should be provided at the back and at the sides to minimize the heat losses. Usually glass wool is used as insulation material. A transparent cover (glass) will be provided at the top to permit the radiation from the sun to the metal plate. Parabolic or concentrating collector Highly polished metallic surfaces are used as the reflector. The reflector will have a parabolic shape so that the sun rays striking the profile will be reflected on its focal point. If a tube carrying a fluid is kept along the focal line, the fluid will be heated to a very high temperature. Advantages 1. Renewable source of energy 2. Pollution free 3. After the capital cost, the cost of power generation is quite low 4. Wide range of applications, powering street lights to satellites Disadvantages 1. Capital cost is very high 2. Large area of land is required 3. Large number of solar panels are required 4. Affected by seasons. 24  WIND ENERGY The electrical energy can be generated by wind energy by utilizing the kinetic energy of wind. The wind energy which is an indirect source of energy can be used to run a wind mill which in turn drives a generator to produce electricity. Wind mills are classified into two types. Horizontal Axis Wind Turbine Horizontal axis wind turbines have the main rotor shaft running horizontally. Fig shows a schematic arrangement of a horizontal axis machine. This system consists of a tower mounted two bladed or multi bladed rotor facing the wind, rotating around a horizontal axis and turning an electrical generator. The Blades are generally made of composite material, usually fibre reinforced plastic (FRP) because of its high strength and light weight. Wind mills are manufactured with a capacity from a few kilowatts to several megawatts in Europe, the USA, and other parts of the world including India. Vertical Axis Wind Turbine Vertical axis wind turbines have the main rotor shaft running vertically. The tower construction is simple here because the generator and gear box can be placed at the bottom, near the ground. Advantages 1. Wind is Renewable and free of cost 2. Pollution free 3. Can be installed in remote villages, thus reducing costly transmission lines Disadvantages 1. Capital cost is very high 2. Large area of land is required 3. Maintenance cost is very high 25  TIDAL ENERGY The periodic rise and fall of water level of sea which are carried by the action of the sun and moon on water of the earth is called “tide”. The large scale up and down movement of sea water represents an unlimited source of energy. The main feature of the tidal cycle is the difference in water surface elevations at the high tide and at the low tide. If the differential head could be utilized in operating a hydraulic turbine, the tidal energy could be converted into electrical energy by means of an attached generator. Tidal Power Plant A Tidal power plant mainly consists of the following: 1. A barrage with gates and sluices 2. One or more basins 3. A power house A barrage is a barrier constructed across the sea to create a basin for storing water. The barrage has to withstand the pressure exerted by the water head and also should resist the shock of the waves. A basin is the area where water is retained by the barrage. Low head reversible water turbines are installed in the barrage separating the sea from the basin. During high tide, water will flow from sea to tidal basin through turbine, thus producing electricity. During low tide, water will flow from tidal basin to sea through turbine producing electricity. Advantages 1. It is inexhaustible source of energy 2. No problem of pollution 3. The cost of power generation is quite low 4. High output can be obtained compared to solar or wind energy Disadvantages 26  1. Capital cost is very high 2. As the head is not constant, variable output is obtained 3. As the head is low, large amount of water is necessary for the turbine 4. It will not operate when the available head is less than 0.5m GEOTHERMAL ENERGY Geothermal power plants derive energy from the heat of the earth’s interior. The average increase in temperature with depth of the earth is 10C for every 30-40m. At a depth of 10-15km, the earth’s interior is as hot as 1000-12000C. In certain areas of our planet, the underground heat has raised the temperature of water to over 2000C which bursts out as hot steam through the cracks in the earth’s crust. These are called thermal springs. This steam can be utilized for power production. Geothermal Sources 1. Hydrothermal convective systems (i) Vapor dominated or dry steam fields (ii) Liquid dominated or wet steam fields (iii) Hot water fields 2. Geo-pressure resources 3. Petrothermal or hot dry rocks 4. Magma resources 5. Volcanoes Geothermal Power Plants Geothermal wells are drilled at suitable locations. Water vaporized into steam comes out of the earth’s surface in a dry condition at around 200C and 8 bar. The moisture is removed by a centrifugal separator and this steam will run the turbine coupled with a generator. Steam is condensed in a condenser and re injected back into the ground by a rejection well. 27 Advantages 1. Geothermal energy is cheaper 2. Used as space heating for buildings 3. Used as industrial process heat 4. Geothermal energy is inexhaustible Disadvantages 1. Low overall power production efficiency (about 15%) 2. Large areas are needed foe exploitation of geothermal energy OCEAN THERMAL ENERGY CONVERSION OTEC uses the temperature difference of the sea water at different depths to generate electricity. OTEC utilizes the temperature difference that exists between the surface waters heated by the sun and the colder deep (up to 1000m) waters to run a heat engine. This source and sink provides a temperature difference of 20C in ocean areas within 20 of the equator. These conditions exist in tropical coastal areas, roughly between the tropic of Capricorn and the tropic of cancer. Such a small temperature difference makes energy extraction difficult and expensive. Hence, typically OTEC systems have an overall efficiency of only 1 to 3%. The OTEC is shown in fig. Advantages OTEC uses clean, renewable, natural resources. Warm surface seawater and cold water from the ocean depths replace fossil fuels to produce electricity. Suitably designed OTEC plants will produce little or no carbon dioxide or other polluting chemicals. 28 There is enough solar energy received and stored in the warm tropical ocean surface layer to provide most, if not all, of present human energy needs. The use of OTEC as a source of electricity will help reduce the state's almost complete dependence on imported fossil fuels. Disadvantages OTEC-produced electricity at present would cost more than electricity generated from fossil fuels at their current costs. OTEC plants must be located where a difference of about 20º C occurs year round. Ocean depths must be available fairly close to shore-based facilities for economic operation. Floating plant ships could provide more flexibility. Construction of OTEC plants and lying of pipes in coastal waters may cause localised damage to reefs and near-shore marine ecosystems. BIOGAS Biogas is generated when bacteria degrade biological material in the absence of oxygen, in a process known as anaerobic digestion. Since biogas is a mixture of methane (also known as marsh gas or natural gas, CH4) and carbon dioxide (CO2) it is a renewable fuel produced from waste treatment. Anaerobic digestion is basically a simple process carried out in a number of steps by many different bacteria that can use almost any organic material as a substrate. Anaerobic digestion breaks down readily degradable organic matter in a series of steps, where the product of one step becomes the substrate for the next step. The initial step is usually considered to be “hydrolysis” – where extra cellular enzymes break complex organic molecules like fats and starches into simpler molecules like glucose. These simpler molecules are then utilised by “acetogenic” bacteria to produce acetic acid, with carbon dioxide as another product of the breakdown. “Methanogens” are then able to use the acetic acid and produce methane. There is also another group of “methanogens” that convert carbon dioxide to methane. As a result of these steps “biogas” is mainly methane (typically 60%, but less if the digester is not operating properly and sometimes up to about 80%) and carbon dioxide with traces of hydrogen sulphide, ammonia, water vapour, other organic volatiles and possibly some nitrogen gas. ……………………… ……........ 33 Advantages Produces a renewable fuel that is flexible and can be used to produce heat, power, domestic gas use or as a vehicle fuel; Generates methane that can be captured and used to produce energy that might otherwise leak into the atmosphere and increase the greenhouse effect; The process fixes nitrogen in the digestate and reduces emissions of nitrous oxide (a strong greenhouse gas) compared to composting or landfill. Disadvantages Biogas contains contaminant gases which can be corrosive to gas engines and boilers; Will only produce a limited quantity of energy demand and is dependent upon location in proximity to feedstock and energy users; There is little or no control on the rate of gas production, although the gas can, to some extent be stored and used as required. HYDRO ELECTRIC POWER Advantages 1. Once a dam is constructed, electricity can be produced at a constant rate. 2. If electricity is not needed, the sluice gates can be shut, stopping electricity generation. 3. Dams are designed to last many decades and so can contribute to the generation of electricity. 34 4. The lake that forms behind the dam can be used for water sports and leisure / pleasure activities. 5. The lake's water can be used for irrigation purposes. 6. The buildup of water in the lake means that energy can be stored until needed. 7. When in use, electricity produced by dam systems does not produce greenhouse gases. Disadvantages 1. Dams are extremely expensive to build and must be built to a very high standard. 2. The high cost of dam construction means they must operate for many decades to become profitable. 3. The flooding of large areas of land means that the natural environment is destroyed. 4. People living in villages and towns that are in the valley to be flooded, must move out. 5. The building of large dams can cause serious geological damage. 6. Dams built blocking the progress of a river in one country. 7. Building a large dam alters the natural water table level. MINING Mining is the extraction of valuable minerals or other geological materials from the earth. Materials recovered by mining include bauxite, coal, copper, gold, silver, diamonds, iron, precious metals, lead, limestone, nickel, phosphate, oil shale, rock salt, tin, uranium, and molybdenum. Any material that cannot be grown from agricultural processes, or created artificially in a laboratory or factory, is usually mined. Mining in a wider sense can also include extraction of petroleum, natural gas, and even water. On an industrial scale can produce environmental damages resulting from exploration and development, even long after the mine is closed. The exploratory phase generally causes the least impact, although drilling holes to determine the existence of deposits may involve transporting heavy equipment’s and building roads. Environmental effects include erosion, formation of sinkholes, loss of stability, subsidence of land, weakening of lithospheric plates, dust generation, removal of green belt, desertification, loss of top soil, noise generation, loss of biodiversity, and contamination of groundwater and surface water by chemicals from the mining process and products. Mining can have adverse effects on surrounding surface and ground water if protection measures are not exercised. The result can be unnaturally high concentrations of some chemical elements, notably arsenic and sulfuric acid, over a significantly large area of surface or subsurface. Old mines are often dangerous and can contain deadly gases, snakes, and other dangerous animals. The entrance to an old mine in particular can be very dangerous, as weather may have eroded the earth/rock surrounding the entrance. Old mine workings, caves, etc. are commonly hazardous simply due to the lack of oxygen in the air (a condition in mines known as blackdamp) and this is a deadly killer which provides no warning to those entering such an environment. 35 Acid mine drainage (AMD), or acid rock drainage (ARD), refers to the outflow of acidic water from (usually) abandoned metal mines or coal mines. Open pit mining, generates enormous quantities of waste compared to any other natural resource extraction activity. Water interacts with these wastes to generate contaminated fluids that can pollute soils, rivers and ground water. These fluids can be highly acidic and metal laden or highly alkaline and they often contain various forms of cyanide and sulfides. SO2 + H2O -> H2SO4 CLOUD SEEDING Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical processes within the cloud. The usual intent is to increase precipitation (rain or snow), but hail and fog suppression are also widely practiced in airports where harsh weather conditions are experienced. Cloud seeding also occurs due to ice nucleators in nature, most of which are bacterial in origin. The most common chemicals used for cloud seeding include silver iodide, potassium iodide and dry ice (solid carbon dioxide). Liquid propane, which expands into a gas, has also been used. This can produce ice crystals at higher temperatures than silver iodide. After promising research, the use of hygroscopic materials, such as table salt, is becoming more popular. When cloud seeding, increased snowfall takes place when temperatures within the clouds are between −4 and 19 °F (−20 and −7 °C). Introduction of a substance such as silver iodide, which has a crystalline structure similar to that of ice, will induce freezing nucleation. There are three cloud seeding methods: static, dynamic and hygroscopic. Static cloud seeding involves spreading a chemical like silver iodide into clouds. The silver iodide provides a crystal around which moisture can condense. The moisture is already present in the clouds, but silver iodide essentially makes rain clouds more effective at dispensing their water. Dynamic cloud seeding aims to boost vertical air currents, which encourages more water to pass through the clouds, translating into more rain. Up to 100 times more ice crystals are used in dynamic cloud seeding than in the static method. The process is considered more complex than static clouding seeding because it depends on a sequence of events working properly. Hygroscopic cloud seeding disperses salts through flares or explosives in the lower portions of clouds. The salts grow in size as water joins with them. With an NFPA 704 health hazard rating of 2, silver iodide can cause temporary incapacitation or possible residual injury to humans and other mammals with intense or chronic exposure. However, there have been several detailed ecological studies that showed negligible environmental and health impacts. 36 Carbon Trading Carbon trading is an exchange of credits between nations designed to reduce emissions of carbon dioxide. It is also referred to as carbon emissions trading. Carbon emissions trading accounts for most emissions trading. When countries use fossil fuels and produce carbon dioxide, they do not pay for the implications of burning those fossil fuels directly. There are some costs that they incur, like the price of the fuel itself, but there are other costs not included in the price of the fuel. These are known as externalities. In the case of fossil fuel usage, often these externalities are negative externalities, meaning that the consumption of the good has negative effects on third parties. These externalities include health costs, (like the contribution that burning fossil fuels makes to heart disease, cancer, stroke, and lung diseases) and environmental costs, (like environmental degradation, pollution, climate change, and global warming). Interestingly, research has found that, often, the burdens of climate change most directly affect countries with the lowest greenhouse emissions. So, if a country is going to burn fossil fuels, and produces these negative externalities, the thinking is that they should pay for them. The carbon trade originated with the 1997 Kyoto Protocol, with the objective of reducing carbon emissions and mitigating climate change and future global warming. At the time, the measure devised was intended to reduce overall carbon dioxide emissions to roughly 5% below 1990 levels by between 2008 and 2012. Basically, each country has a cap on the amount of carbon they are allowed to release. Carbon emissions trading then allow countries that have higher carbon emissions to purchase the right to release more carbon dioxide into the atmosphere from countries that have lower carbon emissions. The carbon trade also refers to the ability of individual companies to trade polluting rights through a regulatory system known as cap and trade. Companies that pollute less can sell their unused pollution rights to companies that pollute more. The goal is to ensure that companies in the aggregate do not exceed a baseline level of pollution and to provide a financial incentive for companies to pollute less. 37 MODULE 3 38  ENVIRONMENTAL POLLUTION Pollution is the introduction of pollutants (chemical substances noise, heat, light, energy and others) into the environment which results in deleterious effects of such a nature as to endanger human health, harm living resources and ecosystems, and impair or interfere with amenities and other legitimate uses of the environment. Major forms of pollution The major forms of pollution are listed below along with the particular pollutants relevant to each of them:  Air pollution, the release of chemicals and particulates into the atmosphere. Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight.  Water pollution via surface runoff, leaching to groundwater, liquid spills, wastewater discharges, Eutrophication and littering.  Soil contamination occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, herbicides, pesticides and chlorinated hydrocarbons.  Radioactive contamination, added in the wake of 20th-century discoveries in atomic physics.  Noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.  Light pollution, includes light trespass, over-illumination and astronomical interference.  Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.  Thermal Pollution is a temperature change in natural water bodies caused by human influence. AIR POLLUTION Definition: the presence in the air of substances generally originating from manmade/natural activities in concentrations that interfere with the health, comfort, and safety of living beings. It can be indoor as well outdoor Air pollution. However our discussion will be restricted to Outdoors type. 39  CLASSIFICATION OF AIR POLLUTANTS [a] Origin of pollutants Primary pollutants: emitted directly from source, say, release of SO2 from burning of coal. Secondary Pollutants: Formed due to interaction of 2 or more primary and secondary pollutants, say for instance Acid rain, Ozone, PAN, Smog etc. [b] States of Matter Particulates: composed of solid-liquid --- inert/reactive particles sized 2x10-4 – 500 microns. e.g., dust/smoke Gaseous: SO2, CO, H2S, CH4, CO2 and O3 [c] Chemical composition Organic: Aldehydes, Esters, ethers, and amines Inorganic: NOx, SO2, NH3, H2S and O3 [d] Characteristics Physical: Dust, fly ash, spray, pollen, smoke, mist and fumes Chemical: Organic – Inorganic Biological: Protozoa, Bacteria, Fungi and Virus. Chernobyl Nuclear disaster April, 27, 1986, a major accident had occurred at an atomic reactor at Chernobyl in the Ukraine area of the erstwhile Soviet Union. This had resulted in clouds of radioactive smoke over a large area in Scandinavian countries about 2000 km away, and in the Russian region itself. 1st explosion occurred at reactor number 4 at the Chernobyl complex occurred on April 26, 1986 and resulted in a massive and uncontrollable fire. The explosion was followed by a second explosion on May 5th. Majority of radiation [about 10.19 Bq. of radio nuclides] escaped was released in span of 10 days between 2 explosions. The explosion and fire was caused by failure of emergency cooling system in the light water graphite reactor, due to human error. 40 The explosion and subsequent hot fire (about 2500 0C) blew large amounts of radionuclides high into the atmosphere. Four main radionuclides released include I-131 [half-life 8.5 years], Cesium- 137 [half-life 30 years], C-14 [half-life 5730 years] and Sr-90 [half-life 28 years]. During the first 10 days over 400 million people were exposed to the radiation. In the immediate vicinity 30 soviet citizens died from radiation poisoning. Over 1,50,000 were evacuated from an area of radius 30km. The chronic health impacts include blood abnormalities, hemorrhagic diseases, thyroid changes, mutagenic and somatic alterations, bone necrosis, skin cancer, failure of reproductive organs etc. Bhopal Gas Tragedy On the fateful night of December 02, 1984 and the early hours of December 03, 1984, more than one million residents of Bhopal, capital of Madhya Pradesh, India, reported irritation of eyes that quickly lead to macabre death dancing. A cloud of poisonous gas was released from the union carbide factory, a pesticide manufacturing plant owned by UNION CARBIDE INDIA Ltd., a subsidiary of union carbide, USA. The factory was licensed to produce Methyl Iso Cynate, CH3NCO, an extremely hazardous chemical, which is used in the manufacture of several pesticides like Sevin Carbaryl and Temik 10-G.Carbon monoxide, obtained by partial oxidation of coal is combined with chlorine gas in presence of activated carbon to produce phosgene, COCl2. Phosgene gas and methyl amene combine to form MIC. The product is stored in tanks for further production carbomite insecticides. COCl2 + CH3NH2 → CH3NCO +2HCl Bhopal gas tragedy was as well associated with thick winter fog and thermal inversion, which did not allow the pollutants to disperse and dilute. It was alleged that MIC is stored up to a purity of 99.5% and 0.1% phosgene is permitted as impurity. MIC shall not be stored more than 1 month, but due to sheer negligence and ignorance, it was stored for more than 3 months, as a result of which there was pressure built-up, and the tank couldn’t resist the extreme pressure generated and exploded releasing as into atmosphere. About 40 tons of MIC AND 40 kg of phosgene was vaporized and released. In such a scenario, there is a provision of burning up the gas, by control equipment called flare tower, on whose failure the gas can be neutralized by caustic soda using vent scrubber. Unfortunately both control devices failed to work as they were maintained. This was sheer case of human negligence. MIC is a toxic gas that is denser than air and even at low concentrations is fatal causing death due to anoxia. MIC is a very reactive chemical that can react with itself unless maintained at a specific temperature [150C]. Liquid nitrogen was used to maintain this, but device circulating it had failed to operate and situation worsened. The next day entire Bhopal railway station was filled with corpses of people who tried to fled the place, had it not been for presence of 2 lakes that came in way of escaping gas, the disaster would have been multifold. 41 Impacts of Air Pollution Health issues, Soiling of clothes, buildings and plants, Lack of appetite, rapid loss of weight, lameness, death and Masking of human performance. In plants causes collapse of tissues [necrosis], reduction in chlorophyll [chlorosis] and dropping of leaves [abscission]. CONTROL MEASURES AND PREVENTITION MEANS Control techniques:- At Source: Modification of process / equipment / exhaust / products. At Receiver: Proper zoning / planning of industrial area. At Transmission: Operation/maintenance of vehicles / forest belt. Alternative Fuel resources: bio fuel/ eco-friendly fuel/ low Sulphur % coals Norms & Regulations: Emission tests, Penalties, Stringent enforcements & monitoring Dilution of pollutants concentration at source by use of tall stacks and control equipment’s. Some of the control equipment’s used are settling chamber, cyclonic separator, filter, electrostatic precipitator and wet collector, the choice depends on characteristics of airpollutant. NOISE POLLUTION Noise can be defined as the wrong sound at wrong place at wrong time. It is derived from the Latin word Nausea. Noise is any sound independent of loudness producing undesirable effects on individual. Amplitude [loudness] and frequency [intensity] are its two properties. Sources of noise  Indoor – Outdoor  Industrial - Residential/Traffic  Natural - Manmade  Indoor source: baby crying, door banging, audio systems  Outdoor source: loud speakers, brawling  Natural sources: birds, thunder, earthquake, volcanic eruptions  Man-made sources: automobiles  Industrial sources: drilling, rotary machinery, mining,  Traffic: aircrafts, railways 42 Time of exposure, Frequency, intensity are certain factors under which effect of noise is biased. Noise can affect auditory, circulatory and nervous system of human body. Speech interference, masking, effect on human performance acoustic trauma [sudden permanent aural damage due to short exposure], temporary and permanent threshold shift are effects on auditory system observed in humans. Human hearing mechanism comprise ear drum, cochlea and hair cells. Shrinking of blood vessels, low blood flow to organs, blood pressure, cardio-vascular death, heart attack and digestive spasms are effects on circulatory system while ear drum rupture, aggressiveness, fatigue, insanity are symptoms of effects on nervous system. Noises can seriously damage and effect physiological and psychological health. Noise also make species communicate louder (which is called Lombard Vocal Response). Noise Standards CLASS ZONE 7 AM - 10 PM 10 PM - 7AM A INDUSTRIAL 75 70 B COMMERCIAL 65 55 C RESIDENTIAL 55 45 D SILENT 50 40 Noise pollution limits at residential area 55 dB, Industrial area 65 dB, Commercial area 60 dB and Silent zone is 45 dB. Tolerant noise level in city levels is 65 dB, while normal permissible is 45 dB. Control of noise is to be achieved not only at the source but also at receiver end, via transmission route, via application of rules and regulations, maintenance of vehicular condition, utilization of silencers, ban on shrill horns, eco-friendly zoning, green belt development and proper town planning. WATER POLLUTION UTILISATION OF WATER Precipitation is the primary resource of irrigation water, in the form of rainfall and snow. These give rise to secondary sources of irrigation broadly classified as; 1. Surface Water 2. Ground Water 3. Auxiliary Water 43  Storage Component Total water (%) Oceans 97.6 Ice caps & Glaciers 1.9 Ground water & soil moisture 0.5 Fresh water lakes 0.009 Saline lakes 0.008 Rivers 0.0001 Atmosphere 0.001 TOTAL 100.00 Figure: Total available water in world Distribution % Evaporation loss 18 Surface run of 29 Soil infiltration 53 Figure: Distribution of precipitation About 97% of earth’s water supply is in the oceans which is unfit for human consumption and the other uses due to salinity. Of the remaining, 2.3% is locked in the polar ice caps and hence out of bounds. The balance 0.7% is available as fresh water but the bulk of it 0.67 exist as ground water, and the rest 0.03% is available to us as fresh water, rivers, lakes and streams. The breakup of this 0.03% freshwater is 0.01% as lakes & rivers, 0.01 as water vapor, 0.0003 as streams and the remaining0.0187 confined in plants and animal tissues. Mass balance of annual rainfall shows about 70 % loss by evapo-transpiration, while reminder is stream flow. USES OF WATER Productive use: water is primarily used for irrigation of food crops, fodder crops, medicinal herbs, etc. Consumptive use: water is consumed in exhaustive quantities for domestic purposes such as drinking, cooking, washing etc. water find its application in almost all the processes in industries, starting from the manufacturing processes to housekeeping activities. Commercial use: Water consumed for carrying out commercial and recreational activities. Many uses of water include agricultural, industrial, household, recreational and environmental activities. Virtually all of these human uses require fresh water. The framework for allocating water resources to water users (where such a framework exists) is known as water rights. Agricultural 44 It is estimated that 69% of world-wide water use is for irrigation. In some areas of the world irrigation is necessary to grow any crop at all, in other areas it permits more profitable crops to be grown or enhances crop yield. Industrial It is estimated that 15% of world-wide water use is industrial. Major industrial users include power plants, which use water for cooling or as a power source (i.e. hydroelectric plants), ore and oil refineries, which use water in chemical processes, and manufacturing plants, which use water as a solvent. The portion of industrial water usage that is consumptive varies widely, but as a whole is lower than agricultural use. Household Drinking water It is estimated that 15% of world-wide water use is for household purposes. These include drinking water, bathing, cooking, sanitation, and gardening. Basic household water requirements have been estimated at around 50 liters per person per day, excluding water for gardens. Recreation Recreational water use is usually a very small but growing percentage of total water use. Recreational water use is mostly tied to reservoirs. If a reservoir is kept fuller than it would otherwise be for recreation, then the water retained could be categorized as recreational usage. Other examples are anglers, water skiers, nature enthusiasts and swimmers. WATER BORNE DISEASES Waterborne diseases are caused by pathogenic microorganisms which are directly transmitted when contaminated drinking water is consumed. Contaminated drinking water used in the preparation of food can be the source of food borne disease through consumption of the same microorganisms. Waterborne disease can be caused by protozoa, viruses, bacteria, and intestinal parasites. Bacterial Infections Cholera - Vibrio cholerae bacteria - gastro-intestinal often waterborne Diarrhoeal diseases - caused by the water contamination of Cryptosporidium parvum [E.Coli]. Dysentery - Shigella/Salmonella bacteria - gastro-intestinal food/water Typhoid - Salmonella typhi bacteria - gastro-intestinal water/food borne Viral Infections Adenovirus infection - its serotypes are typically waterborne. 45 Hepatitis A - Hepatitis A virus - gastro-intestinal water/food borne Polio - polioviruses - gastro-intestinal exposure to untreated WATER INDUCED DISEASES On the other hand Water Induced Diseases are those which are not transmitted directly by water but facilitate its propagation such as Malaria that for instance support as breeding grounds for mosquitoes. Vivax & Plasmodium Falciparum are the 2 major strains of the 4 which affect humans globally, carried by female anopheles mosquitoes. Incidentally Malaria means Bad Air in Italy [ Mal-aria], Salaria means healthy air. WATER QUALITY STANDARDS BIS: Bureau of Indian Standards IS 10500-2003 [for drinking water] Turbidity 5 NTU [Nephelo Turbidity Units] pH 6.5-8.5 [ U S studs 6-9] Total hardness 300 ppm as CaCO3 Iron 0.3 ppm Lead 0.05 ppm Fluoride 1.0 ppm Arsenic 0.05 ppm Nitrates 45 ppm Pesticides NIL Total Coliform 1 MPN/100 ml [Most probable number] Hexavalent Chromium 0.05 ppm Trivalent chromium 0.1 ppm Water pollution is the introduction into fresh or ocean waters of chemical, physical, or biological material that degrades the quality of the water and affects the organisms living in it. This process ranges from simple addition of dissolved or suspended solids to discharge of the most insidious and persistent toxic pollutants (such as pesticides, heavy metals, and non-degradable, bio accumulative, chemical compounds). 46 Ground water pollution.i.e., highly prolific arsenic contamination is widely due to leaching of ,minerals below the earth surface. This happens as a result of excessive pumping of ground water by shallow tube wells. In this process air [Oxygen] is injected into ground water bed which leaches the overlying mineral, iron pyrites [Fe, As etc.,] oxidizes it and releases arsenic into ground water. Sources of water pollution  Geology of aquifers from which groundwater is abstracted  Industrial discharge of chemical wastes and byproducts  Discharge of poorly-treated or untreated sewage  Surface runoff containing pesticides or fertilizers  Slash and burn farming practice, which is often an element within shifting cultivation agricultural systems  Surface runoff containing spilled petroleum products  Surface runoff from construction sites, farms, or paved and other impervious surfaces e.g. silt  Discharge of contaminated and/or heated water used for industrial processes  Acid rain caused by industrial discharge of Sulphur dioxide (by burning high-Sulphur fossil fuels)  Excess nutrients are added (Eutrophication) by runoff containing detergents or fertilizers  Underground storage tank leakage, leading to soil contamination, and henceaquifer contamination  Inappropriate disposal of various solid wastes and, on a localized scale, littering Types of pollutants 1] Physical : turbidity, color, odor [Fe] 2] Chemical: 2.1] Organic pollutants: domestic sewage, pesticides, and plant nutrients. 2.2] Inorganic pollutants: mineral acids, detergents, and trace element. 2.3] Radioactive materials: mineral wastes, debris of medicinal R&D, industrial facilities. 3] Thermal/heat; thermal pollution from coal fired/nuclear fuel fired thermal power plants. 4] Sediments/suspended matter: soil erosion, runoff. 5] Disease causative agents: Pathogens, total coliform group. Contaminants may include organic and inorganic substances Some organic water pollutants are: 1. Insecticides and herbicides, a huge range of organ halide and other chemicals 2. Bacteria, often is from sewage or livestock operations; Food processing waste, including pathogens  Tree and brush debris from logging operations  VOCs (Volatile organic compounds), such as industrial solvents, from improper storage Some inorganic water pollutants include: 47   Heavy metals including acid mine drainage  Acidity caused by industrial discharges (especially sulfur dioxide from power plants)  Chemical waste as industrial by products  Fertilizers, in runoff from agriculture including nitrates and phosphates  Silt in surface runoff from construction sites, logging, slash and burn practices or land clearing sites Sources of water pollution 1] industrial effluent 2] domestic sewage 3] fertilizers/pesticides from agricultural land as runoff 4] leachate from solid waste disposal sites. Water pollution caused by domestic sewage amounts to 84% while industrial sewage contributes 16%. The previous exerts oxygen demand while latter is toxic and hazardous despite that the load is less. Industrial effluents contribute color [textile firms], heavy metals [electroplating], microbes [pharmacy-distillery] and organic load [paper and pulp industry]. Types of sources 1] Point sources: sources, which discharge pollutants at specific locations through pipelines, sewers into water bodies. E.g., factory outlets, STP [sewage treatment plant] because they are at specific places hence they are fairly easy to identify, monitor and regulate. 2] Non-point sources: sources, which include run off from urban, sub urban , agricultural farms, livestock, animal husbandry, crop lands etc. Difficulty is in controlling non-point source as it is almost impossible in identifying and controlling discharges from so many diffuse sources. Basic Terminologies 1] Sewer: pipeline/conduit carrying sewage. 2] Sewage: the wastewater flowing in sewers, comprises > 99% water, < 1% solids. Generally referred as domestic sewage when water arises from both kitchen & toilets. 3] Sullage: wastewater arising only from kitchen areas. 4] Storm drainage; water entering a sewer due to rainfall. This increases load on treatment plant as well dilutes the waste quality. 5] Sewerage: art of collection, treatment and disposal of sewage. 6] Dry weather flow: in summer season, quantity of sewage in sewers is less as due to scanty rainfall. Types of treatment offered 1] separate treatment: here individual and specific treatment is followed for industrial and domestic sewage separately. This treatment saves space and is process specific w.r.t. pollutant removal. 48 2] Joint treatment: here domestic sewage is mixed with industrial sewage. This helps in diluting the toxicity of industrial wastes but also increases the load on STP. 3] Partial treatment: only a portion of domestic sewage is mixed with industrial waste. This is design specific based on characteristic of wastewaters. Characteristic of Sewage DO [dissolved oxygen] is the amount of free oxygen available to aquatic species necessary for their existence. Situations can arise where in presence of organic matter in waters body necessitates situations where in presence of organic matter utilizes DO as oxidizing element. Organic matter is food for microbes. Fresh sewage is grey in color, as time progresses DO depletes, and color turns black, and its termed Septic. COD i.e., chemical oxygen demand can be defined as the amount of dissolved oxygen required by chemical compounds for oxidation process. Effects of Water Pollution Eutrophication, destruction of aquatic species, threats to coral reefs and endangered species, depletion of dissolved oxygen, spread of water borne, carrying diseases, ecological imbalance, recreational and tourism impacts, loss of water bodies LAND POLLUTION Land pollution is the degradation of the Earth's land surface through misuse of the soil by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban wastes. It includes visible waste and litter as well as pollution of the soil itself. Land pollution is often a consequence of increasing urbanization and industrialization. Man’s increasing demands on the environment and the resources it holds are putting countries under pressure. Soil Pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests). Litter is waste material dumped in public places such as streets, parks, and picnic areas, at bus stops and near shops. Waste Disposal: The accumulation of waste threatens the health of people in residential areas. Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in. Some of the more common soil contaminants are chlorinated hydrocarbons (CFH), heavy metals (such as chromium, cadmium--found in rechargeable batteries, and lead--found in lead paint, aviation fuel and still in some countries, gasoline), MTBE, zinc, arsenic and benzene. 49 Ordinary municipal landfills are the source of many chemical substances entering the soil environment (and often groundwater), emanating from the wide variety of refuse accepted, especially substances illegally discarded there. Soil pollution due to solid waste disposal was brought to the forefront of public attention by the notorious “Love Canal” case in 1978. Toxic chemicals was leached from oozing storage drums into the soil underneath causing an unusually large number of birth defects, cancers and respiratory, nervous and kidney diseases. Control Measures  Anti-litter campaigns can educate people against littering;  Organic waste can be dumped in places far from residential areas;  Inorganic materials such as metals, glass and plastic, but also paper, can be reclaimed and recycled.  In – situ - Bioremediation, phyto remediation, bio-augmentation etc. LANDFILL Sanitary landfill is the cheapest satisfactory means of disposal, but only if suitable land is within economic range of the source of the wastes; typically, collection and transportation account for 75 percent of the total cost of solid waste management. In a modern landfill, refuse is spread in thin layers, each of which is compacted by a bulldozer before the next is spread. When about 3 m (about 10 ft) of refuse has been laid down, it is covered by a thin layer of clean earth, which also is compacted. Gases are generated in landfills through anaerobic decomposition of organic solid waste. If a significant amount of methane is present, it may be explosive; proper venting eliminates this problem. INCINERATION Incineration is a waste treatment technology that involves the combus