Environmental Education for Class XI PDF

ENVIRONMENTAL EDUCATION For Class XI Assam Higher Secondary Education Council Bamunimaidam, Guwahati-21 First published : 2012 Fourth published : 2016 (Enlarged Edition) Copyright : Fifth published : 2017 © Secretary, AHSEC No part Sixth published : 2018 of this book can be printed in Seventh published : 2019 any form either separately or Eight published : 2020 as extra pages in any book Nineth published : 2021 without the permission of the Secretary, AHSEC otherwise it will be treated as a violation Assam Higher Secondary of the Copyright Act, and Education Council necessary action will be taken Bamunimaidam, accordingly. Guwahati-21 Price : Rs. 63.00 Cover Design : Khairul Basar Printed at : Saraighat Photo Types Pvt. Ltd. Bamunimaidam, Guwahati-21 Published by : Assam Book Hive on behalf of Assam Higher Secondary Education Council Bamunimaidam, Guwahati-21 PREFACE As per guidelines of honourable Supreme Court, Assam Higher Secondary Education Council has introduced a new subject i.e. Environmental Studies for higher secondary First Year from the session 2012-13 with the aim of creating awareness and interest among the students. Again as per indication of honourable Supreme Court "Road Safety" issue and as per indication of government of Assam, "Disaster Management". These two new units are incorported in Environmental Studies book in view of the importance and significance of the two topics as per decision of Assam Higher Secondary Education Council. These two new chapters are included in the Environmental Studies to bring a fresh look. Any undesired mistake pointed out by respected teachers and experts related to the subject, will be corrected in the subsequent editions. At last, all are requested to take part and put forward a helping hand to make the subject full fledged. Secretary Assam Higher Secondary Education Council Bamunimaidam, Guwahati-21 THE AUTHORS Environmental Education : Unit-I Dr. Hari Prasad Sarma Rector, Gauhati University Ex. Professor & Head of the Department, Dept. of Environmental Science Gauhati University. Disaster Management : Unit-II Sri Hiren Nath, IPS Inspector General of Police (Special Branch) (Experienced with various training, workshop in Disaster Management and writer of books in the subject Disaster Management) Road Safety : Unit-III Sri Dwijen Das Retd. District Transport Officer, Govt of Assam. (Experienced with various training, workshop in Road Safety and writer of books in this subject) Co-ordinator Anurupa Choudhury Deputy Secretary (Academic) Assam Higher Secondary Education Council. CONTENT Unit - 1 : Environmental Education Chapter-1: Basic Concept of Environment 1-7 Components of Environment Environmental Segments Environmental Education Multidisciplinary nature  Need for environmental awareness Chapter-2 : Ecological Concept 8-16 Meaning of ecology and ecosystem  Typesof Ecosystem  Structure of ecosystem Function of an ecosystem Food chain, food web and trophic levels Chapter-3: Biodiversity and its conservation 17-25 The term Biodiversity Value of biodiversity Threats to biodiversity Conservation of biodiversity National Conservation Strategies: Chapter-4: Natural Resources 26-31  Natural Resources  Different types of natural resources  Forest resources Conservation of natural resources  Water resource  Land Resource  Mineral Resources Chapter-5: Environmental Pollution 32-54 Introduction The term pollution Different types of pollution Classification of pollutants Causes of environmental Pollution Air pollution  Deforestation Vehicular emissions Burning of fossil fuels Rapid industrialization Classification of air pollutantsWater Pollution  Water borne diseases Soil Pollution Noise Pollution Environmental effects of solid wastes Chapter-6: Social Issues and Environment 55-64 Concept of Sustainable Development  Sources of energy Energy Conservation Environment and Health  Greenhouse Effect Global warming Climate change Depletion of ozone layer Acid rain Unit - 2 : Disaster Management : 65-75 Responsibilities and Precautions Introduction  Natural Disasters  Man-made Disasters  Disaster Management Role of Students in Disaster Management  Steps to be taken during Search and Rescue Operation What ‘Not to DO’ during Disaster Disaster Management Initiatives in India Unit-3 : Road Safety 76-95  What does road safety mean  Causes of road accidents  Issues of road safety Some Statistics of Road Accidents Rules of the Road Must obey While traveling by bus Helmet Vehicular emission pollution Seat belt Driving licence International Driving Permit Major Motor Vehicle Laws Traffic Light Road signs Syllabus on Environmental Education (For Class XI) Marks Distribution Full Marks : 50 Total Marks in Theory (Written Examination) : 40 Unit-I : Environmental Education Mark : 20 Unit-II : Disaster Management Mark : 10 Unit-III : Road Safety Mark : 10 Marks in Project : 10 PROJECT (Total Marks - 10) Each student should carry out and submit a project under the supervision of a teacher. Ten marks alloted for the project is to be credited in the final examination of Environmental Studies. Students may perform their projects on anyone of the following topics. Besides students may also perform their projects under the guidance of teacher on topics related to the subject matter. (a) To collect data by visiting a local environmental resource like– River / Forest / Grassland / Agriculture land / Hill. (b) To prepare a note by visiting some polluted areas like– city, village, industrial area etc. (c) To prepare a list on daily basis by observing a nearby plant / insect / bird / animal for three months enlisting their changes, movements and impacts on environment. (d) Submit a report by visiting a particular place during summer vacation and note down its natural environment, natural resources, environment dependent economy, social issues related to conservation of environment. (e) Prepare a first-aid-box to be used during a disaster. (f) Prepare a list of emergency service related phone numbers and addresses like – Police Station, Fire Station, Hospital, Disaster Management divisional office, Municipal office, Deputy Commissioner's office, Block Development office etc. (g) Prepare a report by visiting disaster affected neighbouring area with details of causes, results, measures for rescue operations and steps to neutralize future probabilities. (h) Prepare a pictorial table on mandatory / alarming road symbols as per traffic rules. (i) Prepare a pictorial note on movement of traffic, around your school and rules to be followed to make the institution pollution free and maintain a healthy environment. (j) To form eco club in the school and celebrate various environment related programmes / World Environment Day / Road Safety Week / National Disaster Management Day (29 October) etc. UNIT -1 BASIC CONCEPT OF ENVIRONMENT Environment. The term environment means surroundings. It comes from the French word environner ( to encircle or to surround ). It is a composite term for the conditions in which organisms live and thus consists of air, water, soil and sunlight which are the basic needs of all living beings and plant life to carry on their life functions. The environment also includes temperature, wind, energy etc. Thus it consists of both biotic and abiotic components. Environment creates favourable conditions for the existence and development of living things. Environment may be defined in a number of ways –  It can be defined as the circumstances or conditions that surround an organism or a group of organisms.  Environment is the sum of all social, economical, biological, physical or chemical factors which constitute the surroundings of man, who is both the creator and moulder of his environment. Components of Environment : Environment consists of the following three components 1. Abiotic component or non-living component 2. Biotic component or living component 3. Energy component The abiotic or physical environment is subdivided into three categories i. Lithosphere (solid) ii. Hydrosphere (liquid) iii. Atmosphere (gas) The biotic component consists of flora and fauna including man. The energy component includes solar energy, geothermal energy, hydroelectrical energy, atomic energy etc. 2 Environmental Education Environmental Segments : There are four segments of the environment. 1. Atmosphere 2. Hydrosphere 3. Lithosphere 4. Biosphere 1. Atmosphere : The earth is the only planet in the solar system capable of supporting life. The supporting property of our planet is due to its unique atmosphere. It is the protective blanket of gases surrounding the earth which sustains life on earth and saves it from the hostile environment of the outer space. It absorbs most of the cosmic rays from the outer space and a major portion of the electromagnetic radiation from the sun. It filters out tissue damaging ultra violet radiations. The atmosphere plays a key role in maintaining the heat balance of the earth through absorption of infra red radiation emitted by the sun and reemitted from the earth. Composition of the atmosphere : Major components Nitrogen, N2 ( 78.09 % ) Oxygen, O2 ( 20.94 % ) Minor components Argon, Ar ( 9.34 x 10-1 % ) Carbon dioxide, CO2 (3.25 x 10-2 % ) Trace gases Neon, helium, methane, water vapour, krypton, nitrous oxide, xenon, hydrogen, sulphurdioxide, ozone, ammonia, carbon monoxide, nitrogen dioxide etc. The atmosphere is the source of oxygen, essential for life on earth. The atmosphere is the source of carbon dioxide, essential for Basic Concept of Environment 3 plant photosynthesis. The atmosphere also supplies nitrogen to yield chemically bound nitrogen ( protein ) essential for life. The atmosphere may be broadly classified into four regions. Region Altitude Temp. Important range (Km) range (0C ) chemical species Troposphere 0 – 11 15 to –56 N2,O2,CO2,H2O Stratosphere 11 – 50 –56 to –2 O3 Mesosphere 50 – 85 –2 to –92 O2+, NO+ Thermosphere 85 – 500 –92 to 1200 O2+, O+, NO+ The ozone (O3) present in the stratosphere plays an important role for us. It acts as a protective shield for life on earth from the injurious effects of the sun’s ultra violet radiations. 2. Hydrosphere : The hydrosphere includes all types of water resources – oceans, seas, rivers, lakes, reservoirs, glaciers, polar icecaps and ground water (water below the earth’s surface ). Earth is flooded with water, a total volume of about 1400 million cubic kilometres cover 71% of earth’s surface. Yet, in many locations, it is still difficult to obtain desired amount of water of suitable quality. About 97% of the earth’s water supply is in the ocean, which is unfit for human consumption and other uses because of its salinity. Only 3% is fresh water. 79% of this 3% is locked in the polar icecaps and glaciers, 20% is locked as underground water and only 1% is readily available water (found in rivers, lakes, streams, reservoirs) for direct human use. 3. Lithosphere : This is the outer mantle of the solid earth consisting of minerals and soil. Soil comprises a complex mixture of minerals, organic matters, air and water. The soil is the most important part of the lithosphere. The soil is a storehouse of minerals, reservoir of water, 4 Environmental Education conserver of soil fertility, producer of crops, home of wildlife and livestock. 4. Biosphere : Biosphere is the layer on the earth in which life can exist. The layer extends about 6 - 8 km up into the atmosphere and as much as 8 - 10 km below into the depth of the sea. Thus it denotes the realm of living organisms and their interactions with the environment i.e. atmosphere, hydrosphere and lithosphere. The biosphere and the environment are influenced considerably by each other. Environmental Education : There was a time when everything around us was pure and safe. The air, water and soil were in balanced condition. The nature itself was very much enjoyable. In primitive days, the limited needs of man did not disturb the harmony with nature. Because population was less. But in subsequent years, the population has increased manifold. Science and technological advancement accelerated and the environmental degradation started. With the increase in population, the attempts to make life more and more comfortable, man destroys the forests thoughtlessly, pollutes air and water recklessly, spoils the nature ruthlessly. Environmental problems have attracted the attention of a wide section of people all over the world during the last few decades. People are becoming increasingly conscious of the variety of environmental problems today. Nature’s precious resources are getting depleted because of indiscriminate and unplanned activities of man. World educators and the environmental specialists have repeatedly pointed out that any solution to the environmental crisis will require environmental awareness and clear understanding of the problem and hence the answer of all these is the Environmental Education. Education always plays a vital role for creating healthy attitude, skills and dissemination of knowledge. That is why the Stockholm Basic Concept of Environment 5 conference on human environment in 1972 emphasized the need for environmentally oriented education. It is not a new discipline and should not be treated as new discipline rather a new dimension in education system. In short, it can be said that environmental education is education through environment, about environment and for the environment. Environmental education is the educational process dealing with man’s relationship with his natural and man-made surroundings and includes the relation of population, pollution, resource allocation and depletion, conservation, transportation technology and urban and rural planning to the total human environment. Environmental education is the process of recognizing values and clarifying concepts in order to develop skills and attitudes necessary to understand and appreciate the interrelatedness among man, his culture and his biophysical surroundings. The report of the first intergovernmental conference of environmental education held at Tbilisi ( USSR,1977 ) is the single most important document which provides broad guidelines for environmental education. The declaration decreed that environmental education should :  be interdisciplinary in its approach  consider the holistic environment  be continuous, beginning at preschool level and continuing through all the formal and non formal stages  examine the major environmental issues critically from the local, regional, national and international points of view  dwell on the current and future environmental trends and scenario  help learners discover the symptoms and real causes of environmental problems and plan accordingly  finally strive to promote the value and necessity of local, national and international cooperation in solving environmental problems. 6 Environmental Education The objectives and the guiding principles for environmental education are - 1. Awareness and sensitivity to the environment and environmental challenges 2. Knowledge and understanding of the environment and environmental challenges 3. Attitude of concern for the environment and motivation to improve or maintain environmental quality 4. Skills to identify and help resolve environmental challenges 5. Participation in activities that lead to the resolution of environmental challenges. Multidisciplinary nature : Environmental education is a multidisciplinary subject. In order to know the environment and its different complex phenomena, one requires knowledge from various disciplines. Subjects like botany, zoology, biotechnology, bioengineering, microbiology, genetics, biochemistry etc. help in understanding biotic components and their interactions. The basic knowledge of physics, chemistry, mathematics, statistics help in understanding the different phenomena in the environment. Computer science and information technology is a part and parcel of environmental education. Similarly, for control of pollution, environmental engineering is essential. Other branches of engineering e.g. chemical, civil, mechanical including new innovative technologies have been involved in protecting the environment. Green chemistry finds its distinct and well specific role in protecting the degraded environment. Subjects like sociology, economics, education, philosophy are involved in a number of ways. Environmental laws are always enacted for the protection of the environment. So environmental education carries the multidisciplinary nature where different aspects are dealt with holistic approach. Basic Concept of Environment 7 Need for environmental awareness : The world today is confronted with the great problem of environmental degradation and pollution. Different types of pollution, fast depleting forest resources, rapid population explosion, expanding industrialization, unplanned urbanization, mining, soil erosion etc have created ecological imbalances in recent years. Man’s quest for economic development has been mainly responsible for the ruthless exploitation of natural resources. Moreover highly materialistic, greedy and luxurious life style attitude of human race indiscriminately exploited or imprudently destroyed the natural resources. All these activities have become a threat to the very existence of a number of living organisms So creation of public awareness is must to protect the environment from further deterioration. Environmental problems can be best addressed if the people become environmentally aware. No Government can solve these problems by simply implementing certain environmental protection rules if people are not co-operating. People are to be environmentally educated. They should be able to learn that if we degrade our environment today, we will have to suffer tomorrow and our future generation will be in great danger. We are a part of the environment and it is our duty to protect it. Questions 1. What is environment ? 2. What are the different components of the environment ? 3. What are the different segments of the environment ? 4. Mention the major components of the atmosphere. 5. What is the role of ozone present in the stratosphere ? 6. What do you mean by environmental education ? 7. What are the broad guidelines of environmental education ? 8. Mention the basic principles of environmental education. 9. Discuss the multidisciplinary nature of environmental education. 10. How do environmental awareness help to protect our environment ? 8 Unit 2 Ecological Concept Meaning of ecology and ecosystem The word ‘ecology’ is derived from the Greek words oikos (means- home) and logos ( means – study). So ecology deals with the study of organisms in their natural homes interacting with their surroundings or environment. In other words, ecology is the study of the interconnections and interdependence of plants, animals and their environment. The essence of ecology lies in the study of togetherness of everything – plants, animals, micro-organisms and their environment. There are intricate connections between the various components of nature. For instance, green plants take nutrients and water from the soil. Their leaves, fruits and other parts may then be eaten by a bird or a deer. When these die, a part of their dead remains are eaten up by bacteria, fungi, etc., while the remainder is broken down into smaller elements like nitrogen, carbon, sulphur, etc., and goes back to the soil, thus connecting them all. The best way to understand ecology is to look at it from the levels (hierarchy) of organization that ecology focuses on. These levels are : organisms, species, population, communities and ecosystems. Interactions with the physical environment (energy and matter) at each level produces characteristic functional systems. Organisms An organism is any form of life. A wide range and variety of organisms are present on the earth –from the single-celled amoeba to huge sharks, from microscopic blue green algae to massive banyan trees. Ecological Concept 9 Species Groups of organisms that resemble one another in appearance, behaviour, chemistry and genetic structure form a species. Organism of the same species can breed with one another and produce fertile offspring under natural conditions. For instance, all human beings (Homo sapiens) resemble one another in their body structure, body systems, and they all have similar genetic structure. They are thus grouped together under the species sapiens. Population A population is a group of individuals of the same species occupying a given area at a given time. For example, the Rhinoceros unicornis in the Kaziranga National Park, Assam, make a population. Communities Populations of various species occupying a particular area and interacting with each other make a community. For example, when we say ‘ the community of the Kaziranga National park’, we refer to the rhino population, the elephant population, the cattle population, the grass population and populations of all kinds of life forms present there. Thus a community comprises several species interacting with each other. Ecosystem An ecosystem is a community of organisms involved in a dynamic network of biological, chemical and physical interactions between themselves and with the non-living components. Such interactions sustain the system and allow it to respond in changing conditions. Thus, an ecosystem includes the biological components , the non-living components (physical environment ) and their interactions. The Kaziranga ecosystem will thus include the various life forms found in the park (the community) and also the non-living components of the park, like the soil, rocks, water, etc., and even the solar energy that is captured by the plants and the interactions. 10 Environmental Education According to Odum ( 1963 ), ecosystem is the main active unit of ecology. Types of Ecosystem Ecosystem is of two major types a) Natural ecosystem : b) Artificial or man-made ecosystem a) Natural ecosystem is again divided into i) Terrestrial ecosystem ( for example - forest ecosystem, grassland ecosystem, desert ecosystem ) and ii) Aquatic ecosystem can be fresh water ecosystem and marine ecosystem. Fresh water ecosystem may be lotic (free flowing type, e.g. rivers) or lentic (standing type, e.g. ponds, lakes ). b) Man-made ecosystem : These ecosystems are created by man. For example – cropland ecosystem, fisheries etc. a) Natural ecosystem This is an ecosystem that is found in nature, where there is no interaction with humans. It is a system where everything is in balance and if one component is removed, the system will fall apart. Natural ecosystems are defined by their habitat. The two major categories are terrestrial and aquatic. Deserts, forests, meadows, prairies and jungles are terrestrial ecosystems, while aquatic ecosystems include all marine and freshwater systems. b) Artificial ecosystem Artificial ecosystems are constructed in some fashion by humans. For example, a pond is built, plants are physically planted surrounding the pond and varieties of fish species are released into the pond. To keep the constructed wetland in balance, human intervention is needed to maintain the ecosystem. Ponds must be kept filled with water so that plants and fish will thrive, invading weeds must be controlled and predators need to be controlled. So it Ecological Concept 11 is not a natural ecosystem. Other artificial ecosystems are orchards, large or small gardens and farms. Structure of ecosystem Composition and organization of biotic and abiotic components constitute the structure of an ecosystem. Biotic structure The plants, animals and the micro-organisms present in an ecosystem form the biotic component. Depending upon the different nutritional behaviour , biotic components may be divided into a) Autotrophs and b) Heterotrophs a) Autotrophs : They are known as producers. They can produce their food themselves by making use of carbon dioxide present in air and water in presence of sunlight by involving chlorophyll, the green pigment present in leaves of plants, through the process of photosynthesis. There are some micro-organisms which can produce organic matter through oxidation of certain chemicals in absence of sunlight. b) Heterotrophs : Organisms of this class can not produce their food by themselves. They get their organic food from the producers. So they are called consumers. The consumers are of two types – macro consumers and micro consumers. Macro consumers : The animals that consume the producers either directly or indirectly are called macro consumers. These can be divided into four types- i) Herbivores: Animals that directly consume producers are called herbivores or primary consumers. Examples – cows, deer, goat etc. ii) Carnivores: They feed on other consumers. If they feed on herbivores, they are called secondary consumers. Examples 12 Environmental Education – frog. If they feed on other carnivores, then they are known as tertiary consumers. Example – snake, big fish. iii) Omnivores: They feed on both plants and animals. Example – man, fox, rat etc. iv) Detrivores : They generally feed on the dead animals, partially decomposed matter, wastes of other living organisms. Examples –beetle, ants, earthworms etc. Micro consumers : There are certain living organisms that derive their nutrients by decomposing or breaking down dead plants and biotic compounds in the environment. They are called decomposers or micro consumers. Examples – bacteria, fungus. Abiotic Structure The physical and chemical components of an ecosystem constitute the abiotic structure. It includes all kinds of physical factors like sunlight, latitude and longitudes, average temperature, rainfall pattern, wind velocity etc. as well as edaphic ( soil ) factors. Under chemical components, major nutrients like carbon, nitrogen, phosphorous, oxygen, potassium etc, compounds like carbohydrates, proteins, nucleic acid, various other organic matters present in soil and water influence the functioning of the ecosystem. Function of an ecosystem The ecosystems perform their functional attributes in a systematic way under natural conditions. It receives energy from the sun and passes it into the different components at different levels. The function of an ecosystem can only be considered as a whole, as every part of the ecosystem has a functional effect on another. The major functional characteristics of an ecosystem may be described in terms of food chain, food webs and trophic levels, energy flow, nutrient cycles etc. Ecological Concept 13 Food chain, food web and trophic levels Food chain In an ecosystem, the sequential chain of eating and being eaten is called a food chain. The common examples of food chain are– Grasses –cattle – tiger ( the chain consists of three links ) Grasses – grasshopper – birds – hawks ( the chain consists of four links ) Phytoplankton – water fleas – small fish – tuna Two types of food chain can be found in natural ecosystem. One type starts from green plants ( autotrophs ) constituting the first trophic level, the herbivores form the second trophic level and predators form the third trophic level. They are referred to as grazing food chain. The other type starts with debris detritus produced by green plants is termed as detritus food chain. Food chain is always unidirectional. Food web A number of food chains interwoven with one another give rise to a structure similar to the web of a spider. These interlocking patterns formed by several food chains that are linked together are called food webs. So food web is a network of food chains where different Food web are :  nterconnected food chains  They show the feeding relatio- nships in an ecosystem 14 Environmental Education types of organisms are connected at different trophic levels, so that there are a number of options of eating and being eaten at each trophic level. The two most important functions of the ecosystem i.e. energy flow and nutrient cycling take place through them. Trophic level Every organism in an ecosystem can be assigned a feeding level, referred to as the trophic level. The living organisms which derive energy from the same source are said to belong to the same trophic level. Thus the green plants would be grouped in the first trophic level (producers), herbivores in the second trophic level(primary consumers), carnivores in the third (secondary consumers), and so on. Top Carnivores/Teritary Consumers Carnivores/Secondary Consumers Herbivores/Primary Consumers Photosynthesis/Primary Producers Solid Decomposers Ecological Pyramids The graphical representation of the trophic structure and functions of an ecosystem with producers at the base and successive trophic levels of consumers forming the higher layers (apex ) is known as ecological pyramids. Ecological pyramids are of three basic types: Ecological Concept 15 The pyramid of numbers : Here the numbers of individual organisms are depicted; The pyramid of biomass : based on the total dry weight or other measures of the total amount of living matter; 16 Environmental Education The pyramid of energy : in which the energy assimilated and/ or productivity at successive trophic levels is shown. Ecological pyramids are used for comparing biomass and energy flow between trophic levels. Such comparisons can be used for identifying / comparing which ecosystems and communities are more efficient in terms of energy transfer. Questions 1. Define the term ecology. 2. What do you mean by ecosystem? 3. Classify the ecosystems. 4. What are lotic and lentic ecosystems ? Give examples. 5. What are producers, consumers and decomposers ? 6. Write briefly on structure and functions of an ecosystem. 7. What are food chain and food web ? 8. What is trophic level. 9. What do you mean by ecological pyramids? Name the different types of ecological pyramids. 10. Mention the main characteristics of food chain and food web. 17 Unit 3 Biodiversity and its conservation The term Biodiversity The term ‘biological diversity’ commonly shortened to biodiversity refers to the number, variety, and variability of all life forms on earth. These include millions of plants, animals and micro- organisms, the genes they contain, and the intricate ecosystems of which they are a part. Biodiversity is usually described at three levels: genetic, species and ecosystem diversity. Genetic biodiversity This is the diversity of genes within a species, which are passed down the generations. It is this type of diversity that gives rise to the varieties of species. For example, basmati rice is distinct from joha rice. Some variations are easy to see, such as, size or colour. Taste or flavor can be perceived by other senses. Species biodiversity Species is the unit used to classify the millions of life forms on earth. Each species is distinct from every other species. Horses and donkeys are distinct species, as are lions and tigers. What unites members of a species is the fact that they are genetically so similar that they can produce fertile offspring. Species diversity is usually measured in terms of the total number of species within a defined area. Ecosystem biodiversity An ecosystem is a set of life forms (plants, animals micro- organisms) interacting with one another and with non-living elements (soil, air, water minerals, etc). Ecosystem diversity is, therefore, the diversity of habitats which include the different life forms within 18 Environmental Education Species Diversity itself. It is also used to refer to the variety of ecosystems found within a biogeographical or political boundary. Value of biodiversity Biodiversity may sound like an abstract concept, but in reality it touches almost every aspect of our life. The earth has an enormous variety of plants and animals, both domesticated and wild, as also a Biodiversity and its conservation 19 wide array of habitats and ecosystems. This diversity meets the food, medicinal, clothing, shelter, spiritual as well as the recreational needs of millions of people around the world. It also ensures that ecological functions such as the supply of clean water, nutrient cycling and soil protection are maintained. In fact, biodiversity loss would mean a threat to the survival of the human race itself. Consumptive use We have noticed that the biodiversity products like fuel, food, drugs, fibres etc. have been used by man from time immemorial. About 90 per cent of the world’s food comes from plant species. Genetic diversity is important in breeding crops and livestock. Crop breeders need a diversity of crop varieties in order to breed new varieties that resist evolving pests and disease. The loss of diversity in crop species has severe implications for global food security. A single pest invasion or disease could wipe out all standing crop or a particular livestock. About 80 per cent of the people in developing countries depend for primary healthcare on traditional medicine, most of which is derived from plants, and some from animal and mineral sources. We get penicillin used as antibiotic from a fungus called penicillium. Similarly we get tetracycline from a bacterum, aspirin from the plant Filipendulaulmaria, and quinine from the bark of cinchona tree. The fuel wood, fossil fuels (like coal, petroleum) natural gas, minerals etc have been used by all of us. Productive use These are the commercial products manufactured or prepared from the different resources of biodiversity. Even today a large number of traditional communities depend wholly or partially, on the surrounding natural resources for their daily needs of food, shelter, clothing, household goods, medicines, fertilizers and entertainment. The tusks of elephants, silk from silk worm, wool from sheep, lac from lac insect are obtained from the animal diversity. Many industries 20 Environmental Education depend largely on plant materials e.g. paper and pulp industry, sugar industry, plywood industry, railway sleeper etc. Social use In India, many plants and animals have ritual significance and are associated with religious, spiritual and other cultural uses. Among the auspicious flowers offered in temples are hibiscus, offered to the goddess Kali, and datura flowers offered to Shiva. Similarly different parts of mango, tulsi, lotus, bel tree etc are in use for different purposes. Various animal species like cow, goat, buffalo are considered sacred on account of their association with different deities. Some animal species are believed to be the vahanas or vehicles of the deities and are hence venerated. In India and several other countries, pockets of forests have traditionally been set aside because they are believed to be the abode of a particular god. Over the ages, local communities have protected these areas which are called sacred groves. As a result of the protection, these areas are preserved as pockets of rich biodiversity. Ethical use Each species is unique and has a right to exist. Humans do not have the right to eliminate any species. Ethics provide the basis for deciding what is right or wrong, good or bad. The world charter for nature, adopted by the United Nations in 1982, states that ‘every form of life is unique warranting respect regardless of its worth to man, and to accord other organisms such recognition, man must be guided by a moral code of action.’ Aesthetic use Each species and ecosystem adds to the richness and beauty of life on earth. Perhaps no artificial medium can match the sheer joy of watching a sunset over an ocean, the sight of leaping deer, the sound Biodiversity and its conservation 21 of a singing bird, or the smell of wet earth after the first rains. A natural ecosystem, once destroyed, is impossible to recreate. The number of people who visit a natural site is an indication of its aesthetic value. No one of us want to visit a barren land but we generally try to enjoy the natural beauty by visiting national parks, wildlife sanctuaries or even the forest area. Threats to biodiversity Extinction or elimination of species is a natural process of evolution. But in recent past, the elimination of innumerable species have been talked about in different national and international forums. The changing attitude of human society to the environment in general and biodiversity in particular has reached such a level that the conservation of biodiversity has become a great challenge. There have been threats to biodiversity from different angles such as a) Habitat destruction b) Overgrazing c) Poaching d) Natural calamities e) Climate change and global warming f) Biopiracy a) Habitat destruction Destruction of natural habitats through commercial felling of trees, encroachment of forests for settlement and agriculture, jhum cultivation in the hill slopes and various other developmental activities have put serious threat to biodiversity. Construction of roads and railways, construction of industries, construction of mega dams etc have immense impact on biodiversity. 22 Environmental Education b) Overgrazing Uncontrolled grazing by livestock is also a major problem specially on the grasslands. Since most of the grasslands are confined to a small area, so the pressure on it is not negligible. It also accelerates top soil erosion and thereby destroys the biodiversity. c) Poaching After loss of habitat, poaching is another major threat to biodiversity. Species such as elephants, rhinos, tigers are poached regularly for international trades. A large number of rhinoceros in Assam have been killed for its horn. Despite ban on trade in products from endangered species, smuggling of wildlife items like fur, hides, horn, tusks are going in full swing. d) Natural calamities Natural calamities like floods, earthquakes, tsunamis, storm etc cause irreparable loss to biodiversity. Photograph : A rhinoceros with its calf at Flood effected Kaziranga. Biodiversity and its conservation 23 e) Climate change and global warming Climate change is often cited as a serious threat to biodiversity. Due to change in climatic pattern, many species can not tolerate it and hence die. There are different views regarding the effect of climate change and global warming on agriculture. Tropical and sub tropical regions will be more affected since the average temperature in these regions is on the warmer side. Soil moisture will decrease and evapotranspiration will increase which may have affect on production of certain agro products. The effects of global warming adds a catastrophic threat toward mass extinction of global biological diversity. The extinction threat is estimated to range from 15 to 30 per cent of all species over the next 50 - 60 years. f ) Biopiracy Biopiracy is a kind of procurement of biological resources from a country or a place and the subsequent patentisation of their products. The indigenous people of some countries are the treasure house of knowledge and beliefs. Agents of some companies or other middle persons collect their knowledge and valuable living materials and subsequently proceed for patentisation on their own. Thus through unethical means they acquire rights of marketing these products. A number of such cases are found to occur in different countries. Biopiracy of certain high valued bioresources has been a major threat to biodiversity. Conservation of biodiversity Biodiversity is recognized as a global wealth to which no value can be put. Conservation of biodiversity means the proper protection and management of biological wealth with its ecosystems for the benefit of all kinds of living organisms including man. Measures have been taken at an international as well as national level to tackle this issue. Conservation of biodiversity is of two types 24 Environmental Education a) In-situ Conservation b) Ex-situ Conservation a ) In-situ Conservation: In-situ conservation is conservation of wild species of flora and fauna in their natural habitat i.e. on site preservation. e.g. biosphere reserves, national parks, wildlife sanctuaries, reserve forests etc. India has a long tradition of such conservation. It has continued this through the establishment of a network of protected areas throughout the country. Today, India has over 533 national parks and sanctuaries. These protected areas cover about 4.5 per cent of the country’s territory and have helped in conserving habitats and their biodiversity. Several special projects have also been launched to save certain animal species which have been identified as needing concerted protection effort. Assam has now 5 national parks and 22 wildlife sanctuaries. Kaziranga National Park and Pobitora wildlife sanctuary are involved in the protection of Asiatic Rhino. Kaziranga is also the home of swamp deer, hog deer and elephants. The biosphere reserve, Manas National Park is the home of golden langur and pigmy hog. b) Ex-situ Conservation: Ex- situ conservation is the conservation of plants and animals away from their natural habitat. This could be in zoological parks and botanical gardens or through the forestry institutions and agricultural research centres. A lot of effort is under way to collect and preserve the genetic material of crops, animal, bird, and fish species. This work is being done by institutions such as the National Bureau of Plant Genetic Resources, New Delhi, the National Bureau of Animal Genetic Resources, Karnal, etc. National Conservation Strategies: India has several Acts in force which have a bearing on the conservation of biodiversity. Some of these Acts are: Biodiversity and its conservation 25 Environment Protection Act, 1986: This act relates to general measures to protect the environment, such as restriction on industrial and other processes or activities in specified areas. It also deals with prevention of and control over the manufacture, use, release and movement of hazardous substances. Forest (Conservation) Act , 1980: This act primarily focuses on prohibiting or regulating non forest use of forest lands. Wildlife (Protection) Act, 1972, and Wildlife (Protection) Amendment Act, 1991: These deal with restriction and prohibition of hunting of animals, and with the protection of specified plants. They also deal with the setting up and management of sanctuaries and national parks, setting up of the central zoo authority, control of zoos and captive breeding. They also control trade and commerce in wild animals, animal articles and trophies. Questions 1. Define the term biodiversity. 2. Explain with suitable examples – genetic diversity, species diversity and ecosystem diversity. 3. What are value of biodiversity ? 4. What is consumptive value ? 5. What is productive value ? 6. What are major threats to biodiversity ? 7. What are Ex-situ and In-situ conservation of biodiversity ? Give examples of each. 8. What is biopiracy ? 9. Mention two conservation strategies in our country. 10. In which year the Earth Summit was held ? 26 UNIT 4 NATURAL RESOURCES Natural Resources The world we live in is full of variety of resources. The welfare and development of human civilization largely depend upon these resources. Since these resources are obtained from nature, so they are called natural resources. It is possible to obtain valuable goods from any resource. Thus land, water, air, minerals, coal, forest, wildlife etc are natural resources. The natural resources are of two kinds: a) Renewable resources b) Non-renewable resources a) Renewable resources: Renewable resources are resources that are in-exhaustive and can be regenerated within a given span of time e.g. solar energy, forest, wildlife etc. Though many renewable resources do not have a rapid recovery rate, these resources are susceptible to depletion by over-use e.g. forest, groundwater etc b) Non-renewable resources: Non renewable resources are resources that are available only in finite quantities e.g. fossil fuel like coal, petroleum, minerals etc. Once we exhaust these resources, the same can not be replenished. Different types of natural resources The different types of natural resources are - 1) Forest resources 2) Water resources 3) Land resources 4) Mineral resources 5) Food resources 6) Energy resources Natural Resources 27 1) Forest resources About 1/3rd of the world’s land area is covered by forests. The green forest not only provides us all sorts of essential commodities but gives us a number of ecological services. Forests provide us with commercial goods like timber, wood, food items, fuel, fodder, medicines, drugs and many more. But we have to acknowledge the non commercial services offered by the green forests.  The green forests produce oxygen by photosynthesis which is very vital for life on earth.  During photosynthesis, green plants absorb carbon dioxide from the atmosphere and thus reduce the global warming problem.  The forests give shelter to millions of life forms starting from the insects to the huge wild animals.  It retards soil erosion.  It regulates local climatic condition and hydrological cycle.  There are certain plants which can absorb many toxic gases and act as pollution indicators. Major causes of deforestation in NE India 1) Timber industry 2) Conversion from forest to agricultural land 3) Infrastructure development like roads, bridges, industries etc 4) Encroachment by illegal immigrants 5) Illegal extraction of forest products 6) Poaching of wild animals in the forest. 2) Water resource Water can be regarded as the most important resource on earth because life is impossible without water. The earth has a reserve of 28 Environmental Education 75% water of which 97% is of saline nature and only 3% is fresh water. Of this small fraction, most of this fresh water is locked in the polar ice caps and only 0.003% is readily available to us in the form of groundwater and surface water. Water resource of North east India North east India is relatively rich in fresh water resource. Average annual surface water potential of 585.6 km3 has been assessed in this region, which is highest among all the river systems in India and fifth in the world. Out of this, 24.0 km3 is utilizable water and is merely 4.1% of annual surface water potential. North-East India receives high rainfall of an average of 2000 mm a year with a maximum of 11000 mm in Cherrapunjee, Meghalaya. Although monsoon rainfall is heavy, the people of the northeast also suffer from acute water shortages in dry season every year. The geological formations often do not retain water, runoff is rapid, and springs and small streams soon dry up when there is no rain. Ground water resource is high only in the plains. Ground water of both shallow and deeper aquifers is suitable for irrigational and industrial purposes. It has low content of dissolved minerals. Assam has the highest groundwater potential among the northeastern states. All the perennial rivers of NE India originates from the Himalayan glaciers including the mighty Brahmaputra. These rivers with its hundreds of tributaries are a major source of fresh water in the hilly terrains of the NE. NE India also has large amount of wetlands. More than 3,500 wetlands cover 101,232 hectares in the Brahmaputra valley. In Manipur, there are about 155 wetlands covering an area of 52,959 hectares, of which Loktak Lake (6,475 hectares) is one of the largest freshwater lakes in India. The Barak valley has a number of floodplain wetlands harbouring a great variety of aquatic macrophytes. There are more than 10 natural lakes in Sikkim. Natural Resources 29 Conservation of water Water being the one of the most precious and indispensable natural resources, appropriate techniques should be adopted for its conservation. The following steps may be taken in this regard - 1. Rainwater harvesting 2. Decreasing runoff losses 3. Reducing evaporation losses 4. Reuse of water 5. Preventing wastage of water 6. Controlling water pollution 7. Implementation of strict laws 8. Organization of awareness programmes 3) Land Resource Land is a finite and valuable resource upon which we depend for our food, fibre and fuel wood, the basic amenities of life. About 200-1000 years are needed for the formation of one inch or 2.5 cm of soil. Causes of degradation of soil 1) Soil erosion: Loss of top soil 2) Waterlogging: Accumulation of excess water under the ground 3) Salinization: It is the accumulation of soluble salts of sodium, magnesium and calcium in soil to the extent that soil fertility is severely affected. 4) Contamination of soil with industrial waste like heavy metals, pesticides, fertilizers etc Conservation of land resources 1) Soil erosion can be minimized by afforestation in the hilly slopes 30 Environmental Education 2) Use of pesticides and fertilizers should be banned and organic fertilizers should be encouraged 3) Proper disposal of industrial waste is a must 4) Cultivation of traditional crops variety in a region should be encouraged 4) Mineral Resources Minerals are naturally occurring inorganic, crystalline solids having definite chemical composition and characteristic physical properties. The most common minerals of our daily use are iron, coal, zinc etc. It is used in several purposes like industrial plants and machineries, generation of energy (coal, uranium), construction purposes, jewellery etc. Minerals can be of three types 1) Metallic minerals: e.g. bauxite, copper pyrites, haematite, galena, zinc blende etc 2) Non metallic minerals:e.g. graphite, diamond, quartz, feldspar etc. 3) Energy generating minerals: Coal, petroleum and uranium. India’s mineral resource is sufficiently rich and can provide the country with strong industrial base. India is rich in metallic minerals of the ferrous group such as iron-ore, manganese, chromite and titanium. But the reserves of petroleum and some other non ferrous metallic minerals e.g. copper, lead, tin, graphite, zinc are inadequate. Mineral resources of NE India North eastern region of India is a treasure home of valuable mineral resources. Meghalaya is famous for uranium, coal and limestone. Assam is widely known for its mineral resources. The exploration of minerals in the state comprises mainly petroleum Natural Resources 31 (crude), natural gas, coal and limestone. Oil and Natural Gas Commission (ONGC) is the most profitable public sector organization in the State. Assam is endowed with varieties of other minerals such as sillimanite, base-metals, beryl, building and road metals, asbestos, fire clay, kaolin, fuller’s earth, mica, quartz, dolomite etc. But the extraction of most of these minerals is not economically viable at present. The gold extraction from the river Subansiri dates back to earlier than eighteenth century. Conservation of natural resources Continuous increase in population causes an increased demand for resources. This creates a situation where the valuable resources may come to an end after some decades. Conservation means the use of natural resources frugally and without wastage. It is the use of resources prudently avoiding overuse, misuse and untimely use. Questions 1. What do you mean by natural resources ? 2. What are the different types of natural resources ? 3. What are renewable and non-renewable natural resources ? Give examples. 4. Mention the ecological services of the green plants. 5. Name the national parks of Assam. 6. Give 5 names of wildlife sanctuaries of Assam. 7. Name the great wetland of Manipur. 8. Mention two conservation measures for land resources. 9. Mention the mineral resources of NE India. 10. Mention a few water conservation measures. 32 UNIT - 5 ENVIRONMENTAL POLLUTION Introduction The world today is confronted with the great problem of environmental degradation and pollution. Different types of pollution, fast depleting forest resources, rapid population explosion, expanding industrialization, unplanned urbanization, mining, soil erosion etc have created ecological imbalances in recent years. Man’s quest for economic development has been mainly responsible for the ruthless exploitation of natural resources. The environmental pollution, in fact, started with the increase of human population and considering the mythological suggestion that the process of Adam and Eve who ate an apple and threw away the peels, which led to the beginning of environmental pollution. Subsequently it accelerated with the development of socioeconomic activities such as industrialization, urbanization, transportation, modern agricultural practices etc. With growing population, requirement of foodgrains and other consumer items increased greatly leading to vast environmental degradation. As long as the assimilation capacity of receiving water system, land, air etc was more than the population load, the importance of environmental pollution was not really appreciated. But today, the situation has been completely reversed. The rapid strides in technology and unprecedented population growth have depleted the earth’s natural resources with respect to quality and quantity. The unchecked population growth and increasing demands consequently taxing more and more the finite or limited resources of the earth. This also leads to environmental pollution. Moreover highly materialistic, greedy and luxurious life style attitude of human race indiscriminately exploited or imprudently destroyed the natural resources. Environmental Pollution 33 The term pollution: The word pollution derived from the Latin word pollutionem (meaning to make dirty) is the unfavourable alteration of our environment largely because of the anthropogenic or human activities. More precisely, pollution is an undesirable change in physical, chemical and biological characteristics of air, water and soil that may harmfully affect man, animal, other living organisms or property. Different types of pollution: 1. According to environment – When different segments of the environment are affected by pollution, they may be categorized as a. Air pollution b. Water pollution c. Soil pollution 2. According to pollutant – Pollution caused by pollutants may be of different types such as a. Thermal pollution b. Noise pollution c. Radioactive pollution d. Solid waste pollution e. Oil pollution f. Industrial pollution g. Marine pollution Pollutant and contaminant Pollutant : A substance present in nature, in greater than natural abundance due to human activities, which ultimately has a detrimental effect on the environment. Examples – Carbon monoxide, sulphur di oxide, arsenic, fluorides, lead, cadmium etc Classification of pollutants Pollutants may be of two types – primary and secondary on the basis of their forms they exist in environment after their release. 34 Environmental Education Primary pollutants : These pollutants are released directly from an identifiable source and exist as such in the environment. Examples - oxides of sulphur, oxides of nitrogen, hydrocarbons etc Secondary pollutants - These pollutants are derived from the primary pollutants by chemical reactions or by natural causes. Example – hydrocarbons and nitrogen oxides react in presence of sunlight to form peroxy acetyl nitrate (PAN) as secondary pollutant. Contaminant : A substance which does not occur in nature, but is introduced by human activities into the environment. Contaminant is also a pollutant. Example - Fluorine from chlorofluorocarbons, food additives, paints etc. Causes of environmental Pollution Both natural and anthropogenic activities are responsible for environmental pollution, but the impact of the latter is severe and sometimes irreversible. Sometimes the natural causes may also be more dangerous. Natural Earthquake, volcanoes, eruption, excessive rainfall (flood), landslides, storms, weathering of rocks etc. Anthropogenic or Man made Population increase, deforestation, industrial and automobile exhausts, burning of fossil fuel, war, construction works Air pollution Air pollution may be defined as the presence of one or more pollutants/contaminants like dust, smoke, mist, odour, suspended particulate matter (SPM) etc in the atmosphere which are injurious to human being, plants and other animals or which unreasonably obstruct the comfortable enjoyment of life and property. Environmental Pollution 35 Air pollution may be described as “ the imbalance in quality of air so as to cause adverse effects on the living organisms existing on earth ” The presence of one or more contaminants in the atmosphere in such quantity and for such duration as is injurious or tends to be injurious to human health or welfare, affect other animal or plant life may be called air pollution. Sources of air pollution : Air is never found absolutely clean in nature. Pollution of air started from the very moment when the primitive men knew how to make fire. Major sources of air pollution can be of two types- 1. Natural sources a. Volcanic eruption : releasing poisonous gases like SO2, H2S, CO etc b. Forest fires: In the areas of tropical region throughout the year forest fire is a common feature. Very large quantities of smoke and particulate matter are liberated during their breakout. c. Decomposition of organic and inorganic substances: Methane gas , carbon dioxide are released into the air d. Dust : Dust is always present in the atmosphere in varying amount. e. Pollen grains of flowers : The pollution is also caused by the production of pollens in the spring season. Pollens or aeroallergens enter the atmosphere from weeds, grasses and trees. They are mainly responsible for causing allergy. 36 Environmental Education f. Fungal spores: Micro-organisms such as algae, fungi, bacteria, yeasts, rusts, spores etc are present as variable particles in the atmosphere. g. Radioactive materials : The radioactive minerals present in the earth crust and action of cosmic rays from outer space on gaseous constituents of the atmosphere are mainly responsible for radioactivity of the atmosphere In the lower atmosphere the natural chemical reactions lead to the conversion of gases or vapours into solid and liquid products by oxidation, reduction, combination, combustion, condensation or polymerization processes etc. In the upper atmosphere the photochemical reactions may undergo breakdown to the more complex molecules by absorption of high energy UV solar radiation. 2. Man made sources- a. Deforestation b. Burning of fossil fuels c. Emission from vehicles d. Rapid industrialization e. Modern agricultural practices Deforestation : Forests are one of the most important natural resources on this earth. Covering the earth like a green blanket, these forests not only produce innumerable material goods but also provide several environmental services which are essential for life. Environmental Pollution 37 But it is a matter of concern that almost everywhere the forest cover has declined to a great extent. Deforestation is going on in full swing due to population increase, shifting cultivation, fuel requirements, raw materials for industries, developmental projects, growing food needs, overgrazing etc.which has far reaching consequences such as global warming and climate change, loss of soil fertility, loss of biodiversity etc. Vehicular emissions : It is the most dangerous form of air pollution. Inspite of introducing stringent laws, adopting new standards, changing the fuel characteristics, modifying the design of vehicles etc studies reveal that vehicular pollution is increasing day by day. The principal pollutants emitted by vehicles are – Carbon monoxide ( CO ) Hydrocarbons ( HC ) Oxides of nitrogen ( NOx ) and Suspended particulate matter ( SPM ) Petroleum based vehicles also emit polynuclear aromatic hydrocarbons and aldehydes in trace amounts. Depending upon the sulphur content of the fuel, varying amount of sulphur dioxide (SO2) may also be emitted. In addition the exhaust gases from petrol based fuel vehicles also contain lead particles and sometimes lead compounds because of the addition of tetraethyl lead. Diesel vehicles contribute more NOx and particulate matter. 38 Environmental Education The pollution load from vehicular exhausts depends on  characteristics of the fuel  efficiency of combustion  types of engine used  age of the vehicle  congested traffic  poor road condition  outdated automotive technology etc Prevention & Control of Vehicular Pollution :  Upgrading the fuel quality and use of cleaner fuel  Reduction of lead content in motor fuel  Enforcement of emission standards for vehicles  Public transport facilities  Improvement of roads and traffic systems  Modification of internal combustion engines (high technology) Burning of fossil fuels : The industries need fossil fuels like coal, wood and petroleum for energy which is used to drive machines and for many other purposes. The imperfect burning of these fuel produces smoke which contains  Fine particles less than 100 ì in diameter : These are carbon particles, metallic dust particles, resins, tars, aerosols, solid oxides, sulphates, nitrates etc.  Coarse particles which are over 200 ì in diameter  Nitrogen oxides Environmental Pollution 39  Halogens  Radioactive substances. Major fuel burning sources are automobiles, thermal power plants, industrial processes etc. Burning of fossil fuels such as coal, petrol, diesel in thermal power plants produce about 2/3 rd of sulphur dioxide present in air. Rapid industrialization : Industrial processes like chemical plants, metallurgical plants, smelters, pulp and paper mills, cotton and textile mills, petroleum refineries, synthetic rubber manufacturing plants etc produce about 20 % of air pollution. In factories and mines around the world hundreds of thousands of workers are daily exposed to a large variety of toxic or poisonous substances that lead to deadly diseases as silicosis, foetal disorders, paralysis, skin allergies, pneumoconiosis etc. In textile industries workers constantly inhale cotton dust. Similarly in a flour mill, workers constantly inhale flour dust, asbestos dust in asbestos manufacturing mills, silica dust in factories making bangles and glass wares etc. 40 Environmental Education Sinks of atmospheric gases: Oceans as well as vegetation are the most important sinks for most atmospheric gases. Sink is a medium which is capable of retaining and interacting with a long lived pollutant, though not necessarily indefinitely. The gases widely dispersed in the troposphere, find oceans as the ready sinks. The gases diffuse to the surface of the oceans cross the gas liquid interface and finally go into the bulk of the oceans. Plants ( vegetation ) are also capable of taking up the atmospheric gases without active metabolism. Some plants have the capacity to metabolise the gas resulting in creating an optimum concentration gradient for further absorption. In addition, there are a number of other sinks also. For example, limestone acts as the sink for atmospheric acids. Major carbon monoxide (CO) sinks are some soil micro-organisms. Classification of air pollutants: Air pollutants are generally classified into the following categories – Pollutants Sub classes Examples 1. Gases (inorganic) Oxides of nitrogen Nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2 ) Oxides of Sulphur Sulphur dioxide (SO2), sulphur trioxide (SO3 ) Oxides of Carbon Carbon dioxide (CO2 ), carbon monoxide (CO) Environmental Pollution 41 Other inorganic Hydrogen sulphide, compounds ammonia, chlorine etc. Gases (organic) Hydrocarbons methane, ethane, ethene, ethyne, benzene etc Aldehydes & formaldehyde, Ketones acetone etc Other organic Chlorinated compounds hydrocarbons, alcohols etc 2. Particulates Solid Dust, smoke, fumes, flyash Gases Mist, spray Outdoor air pollutants :  Vehicles are the sources of the highest amount of pollutants  Immoderate chemical subtances  Particulates  Sulphur-di-oxide  Carbon monoxide and carbon-di-oxide  Ozone  Lead Indoor air pollutants : Indoor air pollution, a major health problem in industries, has now been recognized as significant pollution at homes and offices in urban areas. Pollution from air conditioners, gas stove smoke, building materials, 42 Environmental Education furnishing, photocopies are increasingly found to cause allergy, asthma, diseases of the skin, lungs and respiratory tract. Prolonged exposure to oxides of nitrogen from gas stoves may damage the lungs and increase susceptibility to respiratory infections. Volatile Organic Compounds ( VOC ) like formaldehyde from paper products, carpets, floor coverings, adhesives and resins may cause irritation in mucous membranes, headache, fatigue etc. Air pollutants, their sources and effect on man Air pollutant Sources of Effects on man production 1. Sulphur-dioxide Coal & oil Causes chest combustion constriction, headache, vomiting, death from respiratory ailments 2. Nitrogen oxides Soft coal & Headache, automobile drowsiness, exhausts, unvented irritated lungs, gas stove, kerosene childrens colds heaters, wood Inhibits cilia stoves action so that soot and dust penetrate far into the lungs 3. Carbon monoxide Burning of coal, Causes nausea, gasoline, motor reduces oxygen exhausts, faulty carrying capacity furnaces, unvented of blood, gas stove, kerosene Headache, heaters, wood drowsiness, burning irregular heartbeat Environmental Pollution 43 4. SPM ash, soot Incinerators & Causes eye smoke etc. every irritation, manufacturing emphysema, processes cancer 5. Hydrogen Refineries, Causes nausea, sulphide chemical irritation of eyes industries, and throat bituminous fuels 6. Ammonia Explosives, dye Inflames upper making, fertilizer respiratory plants passages 7. Phosgene or Chemical and dye Induce coughing carbonyl chloride making irritation and fatal pulmonary edema 8. Aldehydes Thermal Irritate nasal and decomposition of respiratory tracts oils, fats or glycerol 9. Suspended Incinerators and Cause particles almost every emphysema, eye manufacturing irritation, cancer process 10. Asbestos Pipe insulation, Lung diseases, vinyl ceiling floor lung cancer tiles 44 Environmental Education Prevention and control of air pollution Chemists always have to play a key role in protecting the environment from the adverse affects of the chemicals. The chemists have to think of the following points while involved in manufacturing different chemicals or design some new pathways for synthesis of chemicals.  Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final products.  Wherever practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment.  It is better to prevent waste than to treat or clean up waste after it is formed.  The use of auxiliary substances ( eg. solvents, separation agents etc ) can be avoided wherever possible  Energy requirements should be minimized.  A raw material for feedstock should be renewable rather than depleting.  They should encourage plantation programme in the industrial site in particular.  Less polluting fuels should be used.  Use of non conventional sources of energy should be encouraged.  Proper Environmental Impact Assessment for any developmental work must be done.  Strict rules and regulations can help in controlling air pollution. Water Pollution : Water pollution may be defined in a number of ways – Alteration in physical, chemical and biological characteristics of water that may cause harmful effects on man and other aquatic biota. Environmental Pollution 45 Addition of excess of undesirable substances to water that make it harmful to man, animal and aquatic life or otherwise cause significant departure from the normal activities of various living organisms in or around water. Sources of water pollution The following sources have been identified as the sources of water pollution a. Domestic wastes b. Industrial effluents c. Agricultural wastes d. Run off from urban areas e. Soluble effluents f. Oil spills g. Seepage pits h. Refuse dumps i. Solid wastes Fig. Water polution due to j. Thermal pollutants industrial effluents k. Radioactive nuclides l. Particulates and atmospheric gases m. Infectious agents etc Problems associated with drinking water Man needs water for drinking, cooking, washing, bathing, gardening, irrigation, industry and for a lot of other purposes. The quality of water used by man for various purposes varies widely and what is satisfactory for one purpose may not be so for another. Water for human consumption must be free from pathogenic micro- organisms and other substances which are hazardous to health. A water sample is normally rejected for drinking purposes if it is highly turbid, highly coloured or has an objectionable taste, but the absence of these adverse sensory effects does not guarantee the safety of water for drinking. The enormous pressure exerted by rapidly increasing population, massive industrial activities, modern agricultural practices have resulted in discharge of a very large amount of pollutants to the 46 Environmental Education water bodies. The problem is particularly manifested as the fresh water suitable for drinking purposes is in very short supply. Contamination of drinking water, either directly or indirectly by sewage and other wastes or by human or animal excrement is the most common and widespread danger associated with water quality problem particularly in the underdeveloped world. Faecal pollution leads to introduction of a variety of intestinal pathogens – bacteria, virus and parasites – causing diseases starting from mild gastroenteritis to severe and fatal dysentery, cholera or typhoid. When drinking water is contaminated with sewage, gastroenteritis and infectious hepatitis may occur in epidemic proportion. Other diseases like rashes, fever, myocarditis, meningitis, respiratory diseases etc. are also likely. Protozoic diseases like amoebiasis, giardiasis may also occur through sewage contamination of water sources. The chemical contamination do not cause immediate, acute health problems unless they are present in massive quantities through some accident. However, these are important in this respect that after prolonged period of exposure to them, they can do considerable harm by being cumulative poison and carcinogens. It is generally thought that undesirable constituents in water will affect the appearance, smell or the taste of the water and a person can evaluate the acceptability of the water sample with his senses. This is no longer true. No water sample can be termed as safe if it is not subjected to rigorous test. Such tests particularly for drinking water are still in the infant stage in Assam. Access to safe drinking water is vital for healthy life, also basic human right and accordingly considered as component of all holistic plans through out the globe for health protection. The importance of water, sanitation and hygiene for health and development has been reflected in the outcomes of a series of international policy forums and environment related protocols. Water contamination The most common and widespread health risk associated with drinking water is microbial contamination, the consequences of which mean that its control must always be of paramount importance, Environmental Pollution 47 because microbial contamination of major urban systems has the potential to cause large outbreaks of water borne diseases. Discharge of untreated sewage and agricultural waste waters, effluents from the industries, dumping of solid wastes, oil spills from giant oil tankers, mining operations etc are responsible for the contamination of the drinking water sources. Water borne diseases Diseases caused by ingestion of water contaminated by human activities or animal excreta, which contain pathogenic micro- organisms. Contaminated surface water sources and poorly maintained municipal water distribution systems contribute to transmission of water borne bacterial diseases. Brewery, dairy and distillery organic load, dyeing, leather tanning, textile colour, organic load, heavy metals etc can also affect water quality. Common water borne diseases a. Typhoid – salmonella typhi b. Cholera - vibrio cholerae c. Dysentery – shigella d. Diarrhoea – cryptosporidium e. Giardiasis - giardia lamblia f. Diarrhoea – e coli g. Gastroenteritis – viruses h. Polio – polioviruses Safe Water : Any kind of water is not safe for drinking unless chemical test is carried out. Safe water is suitable for household activities along with personal cleanliness. Packaged water should be used for drinking. In some special activities like dialysis (medical sector), cleaning contact lens or food processing and manufacturing medicines, highly sophisticated water is essential. Which water is unfit for drinking? Untreated water is not safe for drinking. If water samples collected from hand pumps, ring wells and tapes are found highly coloured with objectionable taste, highly turbid, high iron content, 48 Environmental Education normally these are not fit for drinking. If the ranges of the water quality parameters are above the permissible level, then also it is not fit for drinking. What we can do ? The following suggestions can be made to improve the quality of drinking water at the community as well as at the individual level. Since cost is less so these are quite acceptable even to family with lower income. (a) Common filtration process using sand, stone and charcoal should be carried out as the first treatment. (b) High turbidity and iron can be removed by alum treatment and improved filtration technique at least in rainy season. (c) Hardness can be softened by boiling. This process also kills bacteria. (d) Disinfection with chlorine should be done to minimize bacteriological contamination. (e) Defluoridation technique using low cost bio absorbent can be encouraged. (f) Boiling of drinking water is highly essential. Protective measures To keep drinking water sources clean and safe the following measures should be adopted: (a) Location: Water sources should be on a higher location at least 10m to 15 m away from polluting sources like latrine, soak pit, garbage etc. (b) Plateform: A cement concrete plateform around the tube wells and ring wells extending 1m in all directions having gentle slope outwards towards a drain should be built. These plateforms should be free from cracks and damages. (c) Drain: Water sources should have sound drainage systems to check stagnancy. Waste water should not be allowed to accumulate in these areas. Environmental Pollution 49 (d) Covering: The mouth of a ring well should always be covered at all times to prevent foreign materials from entering it. (e ) Lining: The lining of a ring well should be built of stones set in cement upto a depth of at least 6m so that water enters from the bottom and not from the sides. Soil Pollution : Soil is the upper most part of the earth crust and is a mixture of organic as well as weathered rock and materials necessary for the plant growth. Soil system is indeed very complex and dynamic. It is formed as a result of long term process of complex interactions, disintegration and decomposition of rocks due to weathering leading to the production of mineral matrix in close association with interstitial organic matter. Dumping of various types of specially domestic and industrial wastes, application of pesticides in the agricultural fields etc make the soil polluted. Even the fertility of soil decreases due to addition of a number of different types of toxic materials. Sources of soil pollution : The following sources have been found to be responsible for soil pollution a. Industrial wastes b. Urban wastes c. Agricultural practices/wastes d. Municipal wastes e. Radioactive pollutants f. Biological agents Effects of soil pollution a. Industrial wastes consist of a variety of chemicals whice are extremely toxic. Chemicals like acids, alkalis, pesticides (weedicides, fungicides, insecticides, rodenticides ), heavy metals etc affect soil fertility and ultimately affect human health. b. Some of the persistent toxic organic chemicals inhibit the non-target organisms, soil flora and fauna and reduce soil productivity. These chemicals accumulate in food chain and ultimately affect man and other animals. 50 Environmental Education c. Sewage sludge has many types of pathogenic micro- organisms which may cause various diseases. Varieties of soil transmitting diseases like giardiasis, tetanus etc are caused by soil pollution. d. Nitrogen and phosphorus from the fertilizers in soil reach nearby waterbodies with agricultural run off and cause eutrophication. e. The problem of radioactive wastes dumped into the soil is more complicated. This is so because every radioactive element like radium, uranium, thorium, plutonium etc can remain active in soil for thousands of years. Since radioactive wastes are produced in huge quantities and have higher activation energy, they create an extremely difficult public health problem. Control of soil pollution a. Industrial effluents should be properly treated before discharging them on the soil. b. Solid wastes should be properly segregated as biodegradable and non biodegradable wastes at source and then disposed off by adopting effective scientific methods. c. Use of bio-fertilizers should be encouraged instead of chemical fertilizers. d. Application of pesticides should be controlled. e. Bioremediation can be adopted for degradation of toxic chemicals present in soil. f. Necessary enactment of laws should be made for panel action against those who are involved in polluting soil. g. Awareness should be created among the people. Noise Pollution : We hear various types of sounds every day. Crowded cities, various means of transportation systems, new mechanisms of recreation and entertainment etc are dumping different types of sounds to the environment and people have to talk about the ill affects of these sounds. A particular sound may be musical to one but noise for another. A sound may be pleasant when soft, but noise when loud. Environmental Pollution 51 So noise pollution has become an important matter of concern specially in the urban environment. Noise pollution may be defined in a number of ways - Any unwanted electromagnetic signal that produces a displeasing effect and which interferes with human communication, comfort and health is termed as noise pollution. Noise pollution is the unwanted sound dumped into the environment without regard to the adverse effect it may have. Sources of noise pollution The sources of noise pollution may be a) Natural b) Man-made a) Natural : The natural source of noise pollution is thunder. b) Man-made : Noise pollution is mainly caused by the different activities of man. The automobiles such as trucks, buses, scooters, fire extinguisher vehicles, police vans, ambulances etc, the trains, the aeroplanes, industries, factories, loud speakers, musical instruments, sirens, blast of explosions etc produce unwanted sounds. During dewali, people of all ages enjoy with firecrackers. The noise produced by the crackers exceeds the permissible level. During the other festivals people use different forms of noise producers. Effect of noise pollution The effects of noise pollution may be auditory effects or non- auditory effects. a) Auditory effects: The most acute and immediate effect of noise pollution is the impairing of hearing which may cause auditory fatigue and finally lead to deafness. b) Non-auditory effects: The non-auditory effects are also equally serious. It includes interference with speech communication, annoyance leading to ill temper, mental anxieties, mental stress, bickering and violent behaviour. Noise pollution affects human health, disrupts comforts 52 Environmental Education and working efficiency. Excessive noise pollution causes psychological disorder. Pollution from Solid Wastes Solid wastes are all the wastes produced by household, commercial, institutional, agricultural, mining and industrial activities and are discarded as useless or unwanted. An apt definition of solid waste is “ materials in the wrong place”, implying that a material becomes waste only when a specific owner ceases to have a use for it. With rapid urbanization, industrialization, population growth and increasing economic standard, the solid waste has become a serious threat in recent years and the situation is going to be worse in coming years if appropriate measures are not taken immediately. Dumping the wastes as a waste has two-fold negative implications. On the one hand, it pollutes the air, water and land resulting in diseases and Fig. Impact of Solid waste on environment destruction of human habitat, while on the other hand, it deprives us of a powerful resource material for producing energy, electricity, manure etc. A commercially viable technology suited to deal with they content of the waste material can put this double-edged weapon in the service of human race and natural habitat. The problem of solid waste management encompasses both the urban and rural spheres. This malaise needs to be looked into and considered urgently, lest it should become an uncontrolled proportion Environmental Pollution 53 in the near future, threatening the generations to come. The day-to- day management of municipal solid waste is a complex and a costly task. Direct activities that must be considered and coordinated on a daily basis include the generation rates, collection, storage, transfer and transport, processing and disposal of wastes. These activities are associated directly with the management programme which include – financing, operations, equipment and personnel, cost involved and budgeting, contact administration, ordinates and guidelines, public communications and public awareness. In short, the solid waste management imbibe in itself the (a ) effective refuse of the solid wastes (b) determining a substitute technology toward recycling of solid wastes, with due consideration given to the economic constraints and environmental aspects. Environmental effects of solid wastes : Solid waste has the potential to degrade the air, water and the soil. There are potential risk to health and to the environment from improper handling of solid wastes. Direct risks concern mainly the workers in the field, who need to be protected , as far as possible, from the skin contact with the waste. There are also specific risk in handling wastes from hospitals and clinics. For the general public, the main risk to health are indirect and arise from the breeding of disease vectors, primarily flies and rats. Improper storage and disposal provide the condition under which these risks arise. It also helps in inducing health hazards like plague, dengue, cholera etc. Garbage burning contributes significantly to urban air pollution. Using water polluted by solid waste for bathing, irrigation and drinking can also cause diseases like skin infections. The other environmental damage caused by solid wastes is aesthetic – ugliness of street litter and the destruction of the beauty of countryside by uncontrolled dumping of city wastes. More serious and often unrecognized is the transfer of pollution to water bodies which occurs when the leachate from a refuse dump enters surface water or ground water. Air pollution may be caused from the inefficient burning of waste. Industrialization introduces the dangers of hazardous wastes. Improper disposal of such wastes results in the death of humans and other animals. The present practice of solid waste disposal in different cities and towns is highly unscientific and poses a lot of environmental problems such as 54 Environmental Education  open dumps are malodorous places in which disease carrying vermins such as rats and flies proliferate  methane gas is released into the surrounding air due to decomposition of solid wastes by the micro-organisms.  liquid that oozes and seeps through solid waste heap ultimately find its way into the soil, surface water and ground water.  hazardous materials dissolved in this liquid contaminate underground water and soil strata  the solid waste is highly heterogeneous and is not being segregated at any stage. It includes wastes from industries, hospitals and nursing homes, domestic waste etc.  the leachate consisting of a variety of chemical constituents seeps and pollute the ground water.  absence of landfill liners aggravate the problem furthermore.  health hazards faced by the residents living in the nearby areas of dumping sites can not be ignored.  the present practice of collecting solid waste from the individual houses results in wastage of time and thereby increases the cost of collection.  transportation of collected solid wastes openly by the tractors or trucks is unhygienic and the aesthetic look of the city is also affected. Questions 1. What do you mean by environmental pollution? Name the different types of pollution. 2. What is air pollution ? Identify the sources of air pollution. 3. Mention few effects of air pollution on human health. 4. What is water pollution ? What are the effects of water pollution on human health ? 5. What is soil pollution ? How can it be controlled ? 6. What are solid wastes ? How are they classified ? Give examples. 7. Discuss the environmental effects of solid wastes. 8. Mention two methods of solid waste management. 9. What is noise pollution? Write two probable effects of it on human health. 10. What measures can be taken to keep drinking water sources clean and safe? 55 UNIT 6 SOCIAL ISSUES AND ENVIRONMENT Concept of Sustainable Development : The bourgeoning population, rapid urbanization and accelerated rates of industrialization in recent times have brought about tremendous pressure on land, water and other natural resources leading to deterioration of environmental quality, loss of life forms and depletion of vast natural resources. Deterioration of the environmental quality and economic growth and development are inextricably linked. Towards the later part of 20th century, there emerged a new concept called sustainable development where the issue of environmental safety are taken care of in the development plan itself. Today, the need for maintaining balance in nature or environmental quality through the concept of sustainable development is emphasized by conservationists, environmentalists, planners and decision makers alike. The concept of sustainable development has gained much importance since the publication of Brundtland Report, Our Common Future, in 1987 under the auspices of the World Commission on Environment and Development ( WCED, 1987 ). According to Brundtland, sustainable development is “development that meets the need of the present without compromising the ability of the future generations to meet their own needs”. G.H.Brundtland was the Norwegian Prime Minister as well as the Director of World Health Organization (WHO). WECD maintains that sustainable development is a process of change in which exploration of resources, the direction of investment, the orientation of technological advancement and institutional changes are made consistent with future as well as present needs. It also includes social and economic development in one hand, and the maintenance of the environment on the other. It is based on improving the quality of life for all. The concept got further boost and greater attention since the United Nations Conference on Environment and Development 56 Environmental Education (UNCED), popularly known as the ‘Earth Summit” held in Rio de Janeiro in June, 1992. The UNCED came up with several documents including Rio Declaration on Environment and Development that listed 27 principles of sustainable development, the agenda 21 which is a detailed action plan for sustainable development in the 21st century and the convention on Biological Diversity. Energy Utilization and Conservation : The capacity to do work is called energy. Energy can not be destroyed, it can be transformed from one form to other. Energy consumption of a country is usually considered as an index of its development. Economic development depends on per capita use of energy in a country. This is because all developmental activities are directly related to energy. Our industries, transportation systems, lighting, cooling, heating need enormous amount of energy. With the increase in population and the fast changing of lifestyle, the demand for energy also increases manifold. So let us first look at the various sources of energy wherefrom these demands can be met. Sources of energy: A source of energy is one that

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