environmental science : specialized english for environmental courses. part 1, principles of...

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VO DINH LONG

Environmental Science

(Specialized English for Environmental Courses)

PART 1

PRINCIPLES OF ENVIRONMENTAL SCIENCE

Ho Chi Minh University of Industry Publishing House, 2011



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PREFACE

This book is basically the result of six years of teaching in thefield of environmental science. Some of my graduate andundergraduate students using this book have been beingengineers, practitioners, and officers. I am very grateful to themfor their patience and tolerance as it progressed from crudelectures to its present book.This book is divided into 5 chapters:

Chapter 1: Basic units of ecology.Chapter 2: Materials and nutrient cycles.Chapter 3: Humankind’s invention with nature.Chapter 4: The pollution problems.Chapter 5: Sustainable development and the future.Many problems are discussed in the book include: the

ecosystem; materials and nutrient cycles; balance of nature; progress in agriculture, engineering, and medicine; adverseeffects of people’s activities; air, water and soil pollution; pollution reduction; how the global environment faces; and themeaning of sustainable development.

Although this book contributes by one person for the purposeof teaching and reading. I am lucky to have the supports from somany people and without their helps this book would not have been published. While most people did not help directly on mytheme, one of them contributed in some ways towarded helping

me.Many thanks to my colleagues at Ho Chi Minh University of

Industry: Prof. Le Huy Ba for reading my book and offeringvaluable advice; Miss. Nguyen Le Kim Cuong and Mrs. Nguyen



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Thi Thu Thuy for using my crude lectures for their teaching, andMiss. Nguyen Thi Hong Nhung for her reading andcommending.

I would also like to thank all of them for numerous hoursthey have allowed me to spend with them in discussing my book, confirming reading notes, and helping me with this book.

The most importantly of all, my thanks also to the editorialstaff of Ho Chi Minh University publishing house for their patience with me in reading, reviewing, and publishing this book.

Ho Chi Minh City, June 2011Author

VO DINH LONG



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CONTENTS

Chapter 1: Basic units of ecology§1. The ecosystem§2. Components of an ecosystemVocabulary

QuestionsChapter 2: Materials and nutrient cycles§1. Importance of the nutrient cycles§2. the water cycle§3. the carbon and oxygen cycle§4. the nitrogen cycle§5. the phosphorus cycle

Chapter 3: Humankind’s invention with nature§1. Balance of nature

§2. Progress in agriculture, engineering, and medicine§3. Adverse effects of people’s activities

Chapter 4: The pollution problems§1. Meaning of pollution§2. Air pollution§3. Land and soil pollution§4. Radiation and its harmful effects§5. Pollution reduction

Chapter 5: Sustainable development and the future

§1. The global environmental situation§2. Suistainable developmentGlossaryMetric unit conversion tablesReferences



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CHAPTER 1: BASIC UNITS OF ECOLOGY

After studying this chapter, you should be able to:

1. Define environment.

2. Define an ecosystem.

3. Identify the components of the biosphere.

4. Describe the living and nonliving components of the

environment.

5. Explain that bacteria and fungi are agents of decay.

6. Discuss the process of photosynthesis.

7. Enumerate the important factors that affect the growth of

plants and the survival of animals.

§1. THE ECOSYSTEM

When God created the world, He said, “ Let the earth

produces all kinds of plants, those that bear grain and those that

bear fruit ”, and it was done. Then He also created animals,including human beings and provided light. God, therefore, sawto it that everything needed for them to live is found in the worldwhich He created. He provided spaces, ways and means by withdifferent organisms can interact with one another and with their environment.

Part of the world where life operates is known as the biosphere.



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The biosphere consists of the air (atmosphere), water (hydrosphere), and earth (lithosphere) where living thingsinteract with their environment.

When you study the interaction or relationship betweenorganisms and their environment, you are studying anecosystem. The term ecosystem refers to all the living things andthe nonliving things in a given area. It includes all the plants andanimals together with their surroundings.

Figure 1.1: The biosphere

The ecosystem of an aquarium, for example, consists of thehydrilla and others plants, fish, snails, and other aquatic animals,some of which can only be seen under the microscope. It also

includes sand and pebbles at the bottom. We can also includethe owner who takes care of the aquarium.

A grassland, too, is an ecosystem. This ecosystem consists of the grass, earthworms, insects, bacteria, soil, water, sunlight, and



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other plants and animals that live on it. The pond is another example of an ecosystem.

WARM UP

The forest is a more complex ecosystem. Can you identify

some of the components of this ecosystem?

The entire earth can be thought of as an ecosystem. It has anabundance of different kinds of species of living things which,although separate by great distances, still react with one another and with the nonliving world.

In a forest ecosystem, interrelationships among its living andnonliving components occur. The branches and leaves of treeshelp break the force of the rain. Layers of dead leaves and twinsand branches on the forest floor soak up water and prevent rain

from washing soil away. Little water runs off the land. The rootsof trees hold the soil and water on which they depend.Moreover, when the leaves and branches decay, they become part of the rich topsoil.

The soil is made up of minerals like silica and clay. Theycome from the breakdown of rocks. There are spaces betweenthe mineral particles which are filled with air and water. Rootsof plants penetrate deeper into the soil causing physical change.They loosen the tightly packed particles. Chemical change alsooccurs. The roots absorb the minerals present.



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Figure 1.2: Plant-soil relationship

There are thousands of organisms that live in the soil, likeearthworms, that decompose the dead plants and animals. Someare too small to be seen, but they all help maintain the ecological

balance in the soil.

Figure 1.3: Organisms in the soil



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GUIDE QUESTIONS

1. What is an ecosystem?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………………………………………………………………………………

2. How do the living components of an ecosystem affect the

nonliving components? Give example.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

3. Can a fallen log be considered as an ecosystem? Explain

your answer.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

§2. COMPONENTS OF AN ECOSYSTEMIn the preceding section you learned what an ecosystem is.

The living component is known as the biotic and the nonlivingcomponent is known as abiotic. The biotic component consists



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of plants, animals, and bacteria. The abiotic component includesall the factors of the nonliving environment such as thesubstratum, light, rainfall, nutrients, soil, and others. Both the biotic and abiotic components are equally important in theecosystem because without one of them the ecosystem wouldnot function.

INSIGHTFULNESS

The ecosystem consists of the biotic and abiotic components.

The biotic components are the plants, animals, and

decomposers. The abiotic components are the nonliving factors,

such as temperature, water, and others. The abiotic affect the

biotic components and vice versa.

1. Green plants

Green plants are known as the producers. They capture

energy from the sun and together with carbon dioxide (CO2) inthe air and water (H2O) converting together those into foodenergy. Since plants are able to manufacture their own food,they are also known as autotrophs (or self-nourishing). These plants are able to manufacture food though the process of photosynthesis, which will be explained in the next section.

Green plants also take substances, such as nitrogen and sulfur from the environment and convert those into plant materials thatcan be used by other organisms as food. These green plantsfurther provide oxygen which is taken in by humans and animals

in the process of respiration. For these reasons, all life, whether in the pond, forest, or grassland, depend on green plants.

You might think that green plants consist only of the trees or big plants that you see around. The other producers are invisible



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to your eyes. These are the microscopic drifting plants which aregreater sources of food than the big plants that you can see. Wecall these microscopic plants phytoplankton. When they becometoo abundant, they can give a pond or a body of water a greencolor, it is called Eutrophication (Eutrophication is an increasein the concentration of chemical nutrients in an ecosystem to an

extent that increases the primary productivity of the ecosystem).WARM UP

Have you ever seen a pond or a lake with green surface?

GUIDE QUESTIONS

1. What are producers?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What do producers perform in an ecosystem?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

3. What is phytoplankton?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



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2. Animals

Animals, or the consumers, obtain their food from plants or other animals. Because of this, they are also known asheterotrophs, which means that they feed on others and cannotmanufacture their own food, unlike the green plants.

There are three different types of consumers, namely, theherbivores, the carnivores, and the omnivores.

Figure 1.4: There are three different types of consumers

The herbivores are those that eat plants only. For example,the caterpillar that feeds on leaves is an herbivore while thesnake that eats the caterpillar is a carnivore. Omnivores eat both plants and animals. A human being is a good example of anomnivore.

Through the process of respiration, animals combine the foodthey eat with oxygen to produce CO2 and H2O which are used by plants in the photosynthesis process. Animals also convertthe materials of the plant bodies into the materials that make-up



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their own bodies. All the energy produced and used by animalscomes from the plants.

GUIDE QUESTIONS

1. What are consumers?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What are the three types of consumers? And give one

example for each type.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

3. Bacteria and fungi as agents of decay

Have you ever observed what happen to leaves that fall onthe ground?

After some time, the leaves wither, break down into smaller pieces, decay, and finally become part of the soil. What do youthink is responsible for this change?

WARM UP

Have you heard of the word decomposer? What do you think

does a decomposer do?



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Decomposers make-up the third biotic component of theecosystem. They use the bodies of dead animals and plants for their food. The materials contained in these dead bodies are broken down by the decomposers, thus they get the energy theyneed and release the minerals and other nutrients back into theenvironment for use again by other organisms. Bacteria are

among the most abundant decomposers while fungi are knownto be the fast-acting decomposers.

Decomposers are found everywhere. In the pond, they areabundant at the bottom where the remains of the dead organisms(plants and animals) settle. On land, they abound on the surfaceof the soil where the dead bodies of plants and animals arefound.

Each of the three groups of the biotic component of theecosystem - producers (plants), consumers (animals), and

decomposers (bacteria and fungi) - has its own specific functionor task to perform.

Figure 1.5: Relationship among biotic component of the ecosystem



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The work performed by an organism is known as itsecological niche, while the place where the organism lives in theecosystem is known as its ecological habitat.

GUIDE QUESTIONS

1. What are decomposers?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What do decomposers perform in the ecosystem ?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



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4. Nonliving factors

The nonliving factors of the environment make-up abioticcomponent of the ecosystem. These include the chemical and physical factors in the environment, such as light, temperature,water, pH (acidity), wind, chemical nutrients, salinity (saltiness),soil, and others.

Organisms are affected by the biotic factors simultaneously but, of course, different species of organisms are affecteddifferently. For example, lichens may not survive whentemperature gets very high but cactus may.

Different organisms thrive in different conditions. There areanimals, like the earthworms, which favor wet condition, whileothers, like ants, prefer drier conditions. Some plants, such ascactus, grow best in sandy soil while tomatoes grow best inloamy soil.

As a whole, these environmental factors not only provideessential energy and materials but also determine the kind of organisms that will inhabit the area. Hence, they provide theconditions necessary for the survival of the organisms.

GUIDE QUESTIONS

1. What are the components of an ecosystem?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



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2. Give examples for each component of the ecosystem.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………3. What are the functions of these components?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

4. Can an ecosystem exist without one of its components?

Justify your answer.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



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VOCABULARY

Autotrophs: Organism that is self-nourishing; one that can

produce its own food.

Heterotroph: Organisms that feeds on others and cannot

manufacture its own food.

Biological magnification: Accumulation or increase of

chemical substances on organisms in succeeding higher trophic

levels.

Biomass: Amount of organic materials in plants or animals

from which energy can be derived.

Energy: Capacity to do work

Energy content: The amount of energy available for doing

work. For example, amount of energy in fuel available for

powering a motor vehicle.Food chain: Energy pathway which proceeds from the

producers to the consumers.

Food web: Series of interrelated food chains in an ecosystem.

Pyramid of energy: Representation of the organic content in

each trophic level.

Biosphere: Portion of the earth and its environment within

which life in any of its form is manifested.

Photosynthesis: Process of manufacturing food by green

plants in the presence of sunlight.

Atmosphere: Layer of air surrounding the earth.



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Hydrosphere: The part of the Earth composed of water

including clouds, oceans, seas, ice caps, glaciers, lakes, rivers,

underground water supplies, and atmospheric water vapor.

Lithosphere: The outer, rigid shell of the earth, situated

above the atmosphere and containing the crust, continents and

plates or the solid part of the earth’s surface.

Grassland biome: Community where grass is abundant while

trees are scarce and where mostly herbivores and rodents dwell.

Carnivore: Animals that get food from killing and eating

other animals.

Herbivore: Organisms that eat plants only.

Omnivore: Organisms that consume both plants and animals

Biotic factor : Living component of the ecosystem which

includes plants, animals, and bacteria.

Biotic potential: Reproductive capacity of the living

components of the ecosystem.

Producer (autotroph): Green plant or organism that,

performs photosynthesis.

Consumer : Organism that feeds on other organisms.

Decomposer ( also known as microconsumer): Organism

which breaks down nonliving organic material; example are

bacteria and fungi.

Environment: Sum of all external forces and conditions

acting on an organism or a community of organisms.



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CHOOSE THE BEST ANSWER FOR THE FOLLOWING

QUESTIONS

1. The biosphere consists of ………………..

a) atmosphere

b) hydrosphere and atmosphere

c) atmosphere and lithosphere

d) atmosphere, hydrosphere and lithosphere

2. Atmosphere ………………..

a) is the air environment

b) consists of air and water

c) consists of soil and water

d) consists of soil and air

3. Hydrosphere ………………..

a) is the air environment

b) is the soil environment

c) is the water environment

d) is the water and soil environment

4. The biosphere is place where ………………..

a) living things do not interact with their environment

b) living things interact with their environmentc) nonliving things interact each other

d) living things interact each other



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5. Lithosphere is ………………..

a) The air environment

b) The water and air environment

c) The soil environment

d) The organisms and their environment6. Studying an ecosystem concentrates on ………………..

a) the relationship between organisms and organisms

b) the relationship between organisms and their environment

c) the relationship between nonliving things

d) plants and animals

7. The term ecosystem refers to ………………..

a) all the living things in a given area

b) all the living things and the nonliving things in a givenarea

c) all the nonliving things in a given area

d) the relationship between organisms and organisms

8. A grassland is an ecosystem because it consists of ………

a) the grass

b) earthworms, insects and bacteriac) plants and animals

d) plants and animals together with their surroundings



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9. The living components of an ecosystem affect the nonlivingcomponents by …………

a) the consumption

b) the decomposition

c) the production

d) the relationship between organisms and their environment

10. ……………….. are known as the biotic.

a) The nonliving components

b) The living components

c) The nonliving and the living components

d) Water and vapour water

11. The abiotic components consist of ………………..a) plants and animals

b) factors of the nonliving environment

c) factors of the living environment

d) bacteria

12. Both the biotic and abiotic components ………………..

a) are unequally important in the ecosystem

b) are equally important in the ecosystemc) are not important in the ecosystem

d) do not relate in the ecosystem



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13. ……………….. are known as the producers

a) Animals

b) Green plants

c) Both green plants and animals

d) Bacteria14. ……………….. capture the energy from the sun and

together with carbon dioxide in the air and water converttogether those into food energy.

a) Green plants

b) Animals

c) Both green plants and animals

d) Bacteria

15. Plants are known as autotrophs because ………………..a) they are green plants

b) they are producers

c) they are able to manufacture their own food

d) they are consumers

16. ……………….. can take substances from the environmentand covert those into materials that can be used by other organisms as food.

a) Green plants b) Animals

c) Consumers

d) Decomposers



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17. ……………….. can provide oxygen which is taken in byhumans and animals in the process of respiration.

a) Consumers

b) Animals

c) Green plants

d) Decomposers18. We call the microscopic plants phytoplankton because …..

a) they give a pond or a body of water a green color

b) they are invisible to your eyes

c) they are microscopic drifting plants

d) big plants

19. Green plants consist of ………………..

a) trees

b) big plantsc) phytoplankton

d) trees, big plants and phytoplankton

20. Animals are known as heterotrophs because …………

a) they obtain their food from plants or other animals

b) they are producers

c) they are able to manufacture their own food

d) they are unlike the green plants

21. Consumers include ………………..a) herbivores

b) carnivores



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c) omnivores

d) herbivores, carnivores and omnivores

22. Herbivores are those ………………..

a) that eat animals and plants

b) that eat animals

c) that eat plants onlyd) that are the producers

23. Carnivores are those ………………..

a) that eat animals and plants

b) that eat animals only

c) that eat plants

d) that are the consumers

24. Omnivores are those ………………..

a) that eat animals and plants b) that eat animals only

c) that eat plants only

d) that are the decomposers

25. A human being is ………………..

a) a herbivore

b) a carnivore

c) an omnivore

d) a producer

26. All the energy used by animals comes from ……………

a) the sun



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b) the plants

c) other animals

d) the plants and other animals

27. The decomposers ………………..

a) cannot use the bodies of dead animals and plants for

their food b) can capture the energy from the sun

c) can use the bodies of dead animals and plants for their food

d) can use the energy from the sun

28. Biotic components of the ecosystem include ……………

a) producers

b) decomposers

c) consumers

d) producers, decomposers and consumers29. ……………….. is known as its ecological habitat.

a) The work performed by an organism b) The place where the organism lives in the ecosystemc) The energy flowing from the sun to the organismsd) The work performed by an organism and the place

where the organism lives in the ecosystem30. The nonliving factors of the environment make up ………

a) the ecosystem b) the biotic components of the ecosystemc) the abiotic components of the ecosystemd) the ecological habitat



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31. . . . . . . . . . . . . . are the nonliving factors of the environment.

a) light and temperature

b) water and pH

c) wind, chemical nutrients and soil

d) light, temperature, water, pH, wind, chemical nutrients,

soil, etc32. Environmental factors can ………………..

a) provide essential energy and materials to organisms

b) determine the kind of organisms

c) provide the necessary conditions for the survival of theorganisms

d) provide the essential energy, materials, conditions anddetermine the kind of organisms

33. Autotroph is ………………..a) self-nourishing organism

b) organisms that cannot produce its own food

c) organisms that feeds on others

d) consumer

34. Biomass are ………………..

a) Amount of organic materials in plants

b) Amount of organic materials in plants and animals

c) Amount of organic materials in animalsd) Amount of organic materials in producers, consumersand decomposers



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35. Energy pathway which proceeds from the producers to theconsumers is known as ………………..

a) food web

b) food chain

c) food net

d) food cycle36. Photosynthesis is ………………..

a) The process of manufacturing food by green plants

b) The process of manufacturing food by animals

c) The process of manufacturing food by bacteria

d) The process of manufacturing food by fungi

37. Nonliving factors include ………………..

a) Temperature, light and water

b) Chemical nutrients and soilc) The physical factors

d) The chemical and physical factors.

38. Layer of air surrounding the earth is ………………..

a) climate

b) atmosphere

c) hydrosphere

d) stratosphere

39. The rigid shell of the earth that contains the crust andcontinents is ………………..

a) atmosphere

b) lithosphere



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c) biosphere

d) atmosphere, lithosphere and biosphere

40. The representation of the organic contents in each trophiclevel is ………………..

a) energy content

b) food webc) pyramid of energy

d) food chain

41. Organism that ……………….. is called autotroph.

a) can’t produce its own food

b) can feed on the others

c) can be self-nourishing

d) can’t be self-nourishing

42. Bacteria is the ………………..a) decomposer

b) composer

c) producer

d) organism

43. The process of manufacturing food by green plants in the presence of sunlight is called ………………..

a) phytoplankton

b) photosynthesisc) absorption

d) greenhouse effect



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44. The caterpillar is ………………..

a) the carnivore

b) the omnivore

c) the herbivore

d) the organism

45. …………… consists of the biotic and abiotic components.a) The ecological habitat

b) The nonliving factor

c) The living factor

d) The ecosystem

46. ……………. consists of plants, animals and bacteria

a) Biotic component

b) Abiotic component

c) Atmosphered) Hydrosphere

47. Organisms that feed on others and cannot manufacture itsown food are called ………..

a) autotroph

b) heterotroph

c) carnivore

d) herbivore

48. …………….. breaks down the nonliving organic material.a) Consumer

b) Organism



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c) Microconsumer

d) Phytoplankton

49. Underground water is a part of ………………..

a) biosphere

b) atmosphere

c) lithosphered) hydrosphere

50. Vapour water is a part of ………………..

a) hydrosphere

b) biosphere

c) atmosphere

d) lithosphere

51. Wolves are the ………………..

a) autotroph b) carnivores

c) omnivores

d) herbivores

52. …………….. of grassland consists of grass, earthworms,insects, bacteria, soil, water, sunlight and other plants andanimals that live on it.

a) The ecosystem

b) The gardenc) The greenhouse

d) The diversity



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53. There are thousands of …… living in the soil decomposethe dead plants and animals.

a) earthworms

b) underground water

c) organisms

d) bacteria54. The ecosystem consists of two components: biotic and ……

a) hydrosphere

b) lithosphere

c) organism

d) abiotic

55. Plants are able to manufacture their own food, so they areknown as ………………..

a) heterotrophs b) autotrophs

c) protectors

d) decomposers

56. Animals are called the …… because they obtain their foodfrom plants or other animals.

a) producers

b) decomposers

c) consumersd) autotrophs

57. Fungi are known to be the fast-acting ………………..

a) producers



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b) decomposers

c) consumers

d) autotrophs

58. The ………. factors of the environment make up abioticcomponent of the ecosystem.

a) nonliving b) living

c) temperature

d) chemical

59. The part of the world where life operates is known ……...the biosphere.

a) like

b) that

c) asd) is

60. The term ecosystem refers … all the living and nonlivingthings in a given area.

a) to

b) of

c) in

d) at

61. When the leaves and branches decay, they become a part…….. the rich topsoil.

a) to

b) of



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c) in

d) at

62. The place …....... the organism lives in the ecosystem isknown as its ecological habitat.

a) which

b) whenc) whose

d) where

63. These environmental factors not only provide essentialenergy and materials …… determine the kind of organismsthat will inhabit the area.

a) but

b) though

c) but alsod) despite

64. Temperature is ………………..

a) the living factor

b) the nonliving factor

c) the chemical factor

d) the living and nonliving factors

65. Ocean is a part of ………………..

a) biosphere b) atmosphere

c) hydrosphere

d) lithosphere



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66. Lithosphere is a part of ………………..

a) atmosphere

b) hydrosphere

c) biosphere

d) water environment

67. The place where living things interact with their environment is called ………………..

a) biosphere

b) atmosphere

c) hydrosphere

d) lithosphere

68. Living components are called ………………..

a) abiotic

b) bioticc) bacteria

d) bacteria and human

69. Nonliving components are called ………………..

a) abiotic

b) biotic

c) bacteria

d) bacteria and human

70. Green plants are ………………..

a) carnivores

b) decomposers



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c) herbivores

d) producers

71. Autotrophs are ………………..

a) plants

b) herbivores

c) carnivoresd) humans

72. How many layers does the atmosphere have?

a) 3

b) 4

c) 5

d) 6

73. The ocean makes up ……………….. in the hydrosphere.

a) about 97% b) about 87%

c) about 77%

d) about 67%

74.The groundwater makes up ……………….. in the hydrosphere.

a) about 2.6%

b) about 1.6%

c) about 0.6%

d) about 0.06%

75. Identify the error underlined word or phrase of thefollowing sentence: “Decomposer make up the third bioticcomponent of the ecosystem”.



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a) decomposer

b) make up

c) biotic

d) ecosystem

76. Identify the error underlined word or phrase of the

following sentence: “When the body of dead plants andanimals decompose, they are changed into nutrients throughthe action of bacteria and fungi”.

a) body

b) decompose

c) are changed into

d) through

77. Identify the error underlined word or phrase of thefollowing sentence: “Green plants also take substances,such as nitrogen and sulfur from the environment andcoverted those into plant materials that can be used by other organisms as food”.

a) substances

b) from

c) coverted

d) can be used


following sentence: “Animals combine the food they eat tooxygen to produce CO2 and H2O which are used by plantsin the photosynthesis process”.

a) combine



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b) to

c) are used

d) photosynthesis process

79. Identify the error underlined word or phrase of thefollowing sentence: “There are animals, like the

earthworms, which favor wet condition, while others, likeants, prefers dry condition”.

a) earthworm

b) favor

c) others

d) prefers

80. On the earth, the lithosphere includes ………………..

a) The crust

b) The uppermost mantlec) The crust and uppermost mantle

d) Water and air

81. The earth's hydrosphere consists of water in all forms: ….

a) the ocean, underground water

b) inland seas, lakes, rivers, ice and rain

c) atmospheric water vapor

d) the ocean, underground water, inland seas, lakes, rivers,ice, rain and atmospheric water vapor

82. An aquatic ecosystem is an ecosystem located in ………

a) body of water

b) body of soil



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c) body of air

d) urban

83. Urban ecosystems are ………….. constructed by humans.

a) the cities

b) towns

c) urban stripsd) the cities, towns and urban strips



42

CHAPTER 2: MATERIALS AND NUTRIENT

CYCLES

The energy that flows into an ecosystem cannot be recycled.

Once the energy is used, it is lost. But it much be constantlyrepeatedly replenished if the ecosystem is to continuouslyfunction.

The importance of chemical nutrients, however, is usedrepeatedly. They are cycled between the living and nonlivingcomponents of the ecosystem. Generally, they begin in theabiotic part of the ecosystem (water, land, and air). Then, theyenter to the bodies of plants and animals and return into theabiotic environment.

The movement of these materials and nutrients between theliving and nonliving environment clearly shows theinterrelatedness of the abiotic and biotic components in anecosystem. Among these recycled materials and nutrients arecarbon, oxygen, water, nitrogen, and phosphorus.

After studying this chapter, you should be able to

1. Identify different nutrients that can be recycled.

2. Explain the water, carbon and oxygen, nitrogen, and

phosphorus cycles.

3. Discuss the importance of each of these cycles.

4. Discuss how people affect these cycles.

5. Differentiate micronutrients from macronutrients



43

§1. IMPORTANCE OF THE NUTRIENT CYCLES

The energy from the sun flows to the plants goes to theherbivore that eats the plant, to the carnivore, and to the lastconsumers until the energy is lost into the ecosystem. Theenergy does not go back to the source. It cannot be used over and over again.

In contrast, when the bodies of dead plants and animalsdecompose, they are changed into nutrients through the action of bacteria and fungi. The nutrients are stored in the abioticenvironment like the soil. The nutrients can be used again by the plants. The plants are eaten by the animals and when the animalsdie, they decompose into nutrients. These nutrients can be usedover and over again. In this way, a cycle of nutrients is formed.

The cycle of nutrients is an important process that takes placein the ecosystem. Through the cycle of nutrients, the organic

compounds found in the bodies of organisms are converted intoinorganic compounds which serve as nutrients to the other organisms. In both processes of energy flow and nutrient cycles,the plants provide the link by which the biotic and abioticcomponents interact with one another.

INSIGHTFULNESS

Energy cannot be recycled. When using, it is lost into the

ecosystem.

The nutrients in an ecosystem can be used over and over

again. They are cycled beginning from the nonliving

environment: air, water, and soil. Then, these substances are

taken in by the producers and are passed on through several



44

consumers. They are returned to the nonliving environment by

decomposers.

Nutrients can be classified into two categories, namely, themacronutrients and the micronutrients. The macronutrients arethose that are required by the organisms in large quantities.Examples are carbon, hydrogen, oxygen, and nitrogen. Sulfur, phosphorus, and potassium are also macronutrients but areneeded by organisms in smaller quantities. The micronutrientsare needed in very small amounts. They are also essential to life.Examples are copper, zinc, iron, and boron.

The macronutrients are the major components of fats andcarbohydrates. They make-up the cell structures of plants andanimals. The cell walls of plants, for example, are made up of avery rigid substance called the cellulose. Cellulose is made up of these three elements with a ratio of 7.2 carbons, 1 hydrogen and

8 oxygen. This substance makes the cell walls very firm andrigid. It adds strength to the plant.

Nitrogen, carbon, hydrogen, and oxygen are the building blocks of proteins. Phosphorus makes up many nucleic acidsand is also essential for the transformation of energy in the cells.

The micronutrients are as important as the macronutrients.Magnesium, for example, is necessary in the production of chlorophyll.

GUIDE QUESTIONS

1. What happens to the energy from the sun when it enters to

an ecosystem?

………………………………………………………………………



45

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What happens to the dead bodies of plants and animals in

an ecosystem?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

3. Define macronutrients and micronutrients.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

4. Make a listing of micronutrients and macronutrients, and

give their functions?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………5. What are the components of cellulose?

………………………………………………………………………

………………………………………………………………………



46

………………………………………………………………………

………………………………………………………………………

§2. THE WATER CYCLE

As with any cycle, the water cycle has neither beginning nor

end. However, it is useful to choose a starting point. Let us begin with water vapor in the atmosphere.

a)

b)

Figure 2.1: The water cycle



47

When water in the atmosphere reaches saturation (the highestamount of moisture that the air can hold), it falls as rain. Thisfalls directly to the land and bodies of water like the oceans andseas. Some runs off the surface of the land into rivers. The rainthat falls on the land is absorbed by plants through the roots anddrank by animals. Some penetrates the soil and becomes part of

the underground water, which eventually empties into theoceans. The processes of condensation and precipitation areresponsible for the return of water from the atmosphere into theland and other bodies of water.

The water from the land and other bodies of water returns tothe atmosphere through the process of evaporation. Plants returnthe water by the process known as transpiration, while animalsdo this through respiration. Water accumulates again in theatmosphere as clouds and falls as rain.

GUIDE QUESTIONS

1. What is saturation?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What is evaporation?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



48

3. What is respiration?

………………………………………………………………………

……………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

4. Trace the pathway of the water cycle.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

§3. THE CARBON AND OXYGEN CYCLE

Much of the carbon in the environment exists in the form of carbon dioxide. Plants absorb this gas though the leaves and usein the process of photosynthesis. Oxygen is given off during this process. Animals and other consumers obtain their food as wellas their oxygen needs from plants. In the process of respiration,the food is broken down into CO2 and water which are returnedinto the atmosphere.

When the animals and plants die, their bodies and waters are broken down by the decomposers. In this process, CO2 is

produced and returned to the atmosphere. Sometimes deadorganisms fail to decompose quickly. When this happens, thedead bodies change to coal, oil, and gas which become fossilfuels after a long time. When burned, fossil fuels release carbondioxide into the atmosphere.



49

Figure 2.2: The carbon and oxygen cycles

INSIGHTFULNESS

Carbon dioxide is present in the atmosphere from wastes,

dead bodies of organisms, and fossil fuels. Plants use CO2 in the process of photosynthesis. Animals

obtain their food from the plants and release CO2 though the



50

process of respiration. Decomposers and burning also release

CO2 into the environment.

Erupting volcanoes emit carbon dioxide. The eruption of thevolcano supplies fresh carbon to the atmosphere from the deeper part of the interior of the earth.

Carbon dioxide combines with water and forms calciumcarbonate (CaCO3). This compound is used in the production of shells of animals like clams and oysters. When shelledorganisms die, the calcium carbonate may dissolve or form partof carbonate rocks serve as an buffer environment and storingcarbon for many years. During the process of weathering,carbon dioxide is again released into the environment.

GUIDE QUESTIONS

1. What are the sources of carbon dioxide?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What are the sources of oxygen?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………………………………………………………………………………



51

3. How is carbon released from carbonate rocks into the

atmosphere?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

4. How are fossil fuels formed?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

5. What two important processes are involved in the cycle of

carbon and oxygen? Discuss these processes.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

§4. THE NITROGEN CYCLE

Nitrogen is an element crucial to life. It is an importantcomponent of proteins and nucleic acids. The nitrogen gasconstitutes about 78 percent of the air in the atmosphere.However, it cannot be used directly by plants and animals.Plants use it in the form of nitrates.



52

You inhale large quantities of nitrogen but it remains in your body unchanged.

Figure 2.3: The nitrogen cycle



53

Nitrogen in the atmosphere is converted into nitrates in twoways: (1) by the action of lightning and (2) by action of specialized organisms. Electrical activity (lightning) duringthunderstorms converts nitrogen into nitrates but only a smallamount. The nitrates produced by this process fall to the earthwith the rain.

The organisms that convert nitrogen are bacteria, algae, andfungi, of which bacteria is the most important. Nitrogen-fixing bacteria directly convert nitrogen into nitrates though the process called nitrogen fixation. Examples of nitrogen-fixing bacteria are the Rhizobium, which live in the roots of legumeslike beans, peas, and peanuts. The association betweenRhizobium and legumes forms swollen areas within the rootscalled nodules. Nitrates are formed within the nodules. Thecompounds are then used by the plants to build proteins, or remain in the soil as fertilizers. Because of this, legumes areimportant crop rotation as they help maintain soil fertility. Thisexplains why farmers plant legumes in soil before they plantnew crops.

Decomposers break down the protein in the bodies of plants,animals, and their wastes. In this process, ammonia is produced.Ammonia may be used directly by some plants but otherscannot. They have to transform this into nitrates through thenitrogen-fixing bacteria. This process converting ammonia tonitrates is known as nitrification. The plants are then able to

obtain nitrates to synthesize amino acids and proteins.The nitrates produced by the nitrogen-fixing bacteria are

converted into nitrites by another group of bacteria called nitrite bacteria. Nitrites are converted into nitrogen by the denitrifying



54

the bacteria in a process called denitration. Denitrationcompletes the cycle of nitrogen.

INSIGHTFULNESS

The most complex of the nutrient cycles is the nitrogen

cycle. It involves many microorganisms.

Nitrogen cannot be used directly by the plants. It has to

be transformed into nitrates.

Lightning, nitrogen-fixing bacteria, and decomposers

convert nitrogen into nitrates.

Denitrifying bacteria convert nitrites into nitrogen, thus

completing the nitrogen cycle.

Plants use nitrogen for the synthesis of amino acids and

proteins.

What will happen if the nitrates are not absorbed by plants? Isthis beneficial to the soil?

If nitrates are not absorbed by plants, they are washed away by heavy rains. This process is called leaching. Leaching drainsthe soil of its nutrients which are ultimately lost into the riversand shallow marine sediments. These nitrates enter the marinefood chain and are returned to land by the droppings of seabirds.These droppings are known as guano, which is a major worldsupply of fertilizer.

GUIDE QUESTIONS

1. What is the important of nitrogen?

………………………………………………………………………

………………………………………………………………………



55

………………………………………………………………………

………………………………………………………………………

2. What is the useful form of nitrogen?

………………………………………………………………………

………………………………………………………………………………………………………………………………………………

………………………………………………………………………

3. How is nitrogen converted into nitrates?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

4. What is nitrogen fixation?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

5. Differentiate between nitrification and denitrification.

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



56

6. Explain leaching. What is its role in the nitrogen cycle?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

§5. THE PHOSPHORUS CYCLE

Phosphorus is essential to life. It is a component of the cellmembranes, nucleic acids, and adenosine triphosphate (ATP) – the energy currency of the cell.

Figure 2.4: The phosphorus cycle



57

Phosphorus is found naturally in the environment in the formof phosphates. Phosphates in the soil come from phosphaterocks. Though the process of weathering, the phosphates areincorporated into the soil in soluble or insoluble forms. The plants absorb the phosphate and use it for protein synthesis. Theanimals obtain phosphate from the plants they eat. When the

plants and animals die, decomposition brings back the phosphateinto the soil.

Phosphate in the soil may be washed away into shallowmarine sediments by means of leaching. It may also reach thedeep ocean sediments. From the shallow marine sediments, the phosphates are returned to the soil in the form of guano deposits by marine fish and sediments. Phosphates in the deep oceansediments are recycled back to the soil by means of upwelling.If upwelling does not take place, the phosphate becomesincorporated into the phosphate rocks.

Phosphate rocks are mined to be used in the manufacture of phosphate fertilizers. Though leaching, the phosphorus in thesefertilizers is lost from the soil. Human therefore hasten the rateof loss of available phosphate. This can have serious effects onthe supply of phosphorus for agriculture in the near future.

INSIGHTFULNESS

- Phosphorus presents in soil in the form of phosphates.

Though weathering, phosphate rocks contribute to the

amount of phosphate in the soil.- Phosphate is taken in by plants and passed on the food

chain. When plants and animals die, the bacteria convert



58

the dead bodies into phosphates and return them into the

soil.

- Guano deposits are good sources of phosphates.

Human activities have altered the cycle of materials in theenvironment. When people cut down trees or destroy forest in one

area, rainwater continues to flow until it finally reaches the seainstead of rising to the atmosphere and falling again on theforests. The massive destruction of the forests changes theenvironmental conditions, so that forests may never recover at all.

Figure 2.5: EutrophicationSimilarly, deforestation also affects the amount of nitrates in

the soil though leaching. This loss of nitrogen limits the growthof plants and pollutes groundwater.



59

The phosphorus cycle has also been disrupted by theactivities of humans especially in the water ecosystem. Peopleuse a lot of agricultural fertilizers and detergents of which phosphates are major components. When the phosphates fromfertilizers and detergents run off into lakes, they stimulate therapid growth of algae and other aquatic plants causing algae

bloom. This condition is known as eutrophication.As the plants age and die, decomposition takes place and use

up so much oxygen causing the death of fish and other animals.

GUIDE QUESTIONS

1. What is the importance of phosphorus?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

2. What processes are involved in the cycle of phosphorus?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

3. In what ways have people altered the cycle of nutrients in

the environments?

………………………………………………………………………

………………………………………………………………………



60

………………………………………………………………………

………………………………………………………………………

4. Define algae bloom. How does it lead to eutrophication?

………………………………………………………………………

………………………………………………………………………………………………………………………………………………

………………………………………………………………………

5. What are the effects of eutrophication?

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………

………………………………………………………………………



61

VOCABULARY

Algae bloom: Very rapid growth of algae in surface waters

due to increase in inorganic nutrients, especially phosphorus

and nitrogen.

Conservation: Process of reducing the use of resources

through recycling, decreased demand, and increased efficiencyuse.

Denitrifying bacteria: Bacteria that convert nitrates into

nitrogen gas.

Denitrification: Process that convert nitrates into nitrogen

gas.

Eutrophication: Accumulation of nutrients in a lake or pond

due to human intervention or nature causes.

Evaporation: The process of the change in the state of aliquid or solid to a gas or vapor. Vanishing the surface of a

liquid to the atmosphere.

Leaching: The process by which nutrient chemicals or

contaminants are dissolved and carried away by water, or are

moved into a lower layer of soil.

Nitrate: Inorganic anion containing three oxygen atoms and

one nitrogen atom.

Nitrogen fixation: A process whereby nitrogen fixing bacteria

living in mutualistic associations with plants convert atmospheric nitrogen to nitrogen compounds that plants can

utilize directly.



62

Bacteria: Group of single - celled organisms responsible for

functions like that decay of organic materials and nutrient

recycling.

Nutrient: Substance taken by a cell from its environment and

used in catabolic or anabolic reactions.



63


QUESTIONS

1. The cause makes a pond or a lake with green surface is …..

a) polluted water

b) falling leaves

c) abundant in phytoplankton

d) the agrochemical

2. Adenosine triphosphate ………………..

a) is essential to life

b) has a lot of nutrients

c) is the energy currency of the cell

d) has a lot of nutrients and it is essential to life

3. Phosphorus is a component of ………………..

a) cell membranes

b) nucleic acids and adenosine triphosphate

c) cell membranes and adenosine triphosphate

d) cell membranes, nucleic acids and adenosine triphosphate

4. What do the plants use phosphate for?

a) supplying energy

b) protein synthesisc) photosynthesis

d) protein synthesis and photosynthesis



64

5. ……………….. brings back phosphate into the soil.

a) The excretion

b) The protein synthesis

c) The decomposition

d) The respiration6. Phosphates in the soil may be washed away in to the

shallow marine sediments by ………………..

a) means of leaching

b) decomposition

c) excretion

d) human and animals

7. Guano deposits are good sources of ………………..

a) nutrients

b) nitrates

c) nitrogens

d) phosphates

8. The cause of algae bloom is ………………..

a) the rapid growth of algae

b) the eutrophication

c) the increasing phosphorus and nitrogend) the rapid growth of aquatic plants

9. Nitrogen is an important component of ………………..



65

a) nucleic acids

b) proteins

c) nucleic acids and proteins

d) nucleic acids and phosphorus

10. How many percent does the nitrogen gas constitute in theatmosphere?

a) About 58 percent.

b) About 68 percent.

c) About 78 percent.

d) About 88 percent.

11. How do plants and animals use nitrogen?

a) They use nitrogen directly.

b) They use nitrogen in its other form.

c) They can use it not only directly but also indirectly.

d) They don’t use nitrogen for their life.

12. Nitrogen in the atmosphere can be converted into nitrates by ………………..

a) the photosynthesis

b) the action of lightning

c) the action of specialized organismsd) the action of lightning and specialized organisms

13. Which organism is the most important one in theconverting nitrogen?



66

a) Bacteria

b) Algae

c) Fungi

d) Earth worm

14. The organism which converts nitrates into nitrites is …a) rhizobium

b) algae

c) fungi

d) nitrite bacteria

15. What do plants use nitrogen for?

a) for the synthesis of amino acids

b) for the synthesis of proteins

c) for the synthesis of amino acids and proteins

d) for the photosynthesis

16. Carbon dioxide is present in the atmosphere form ……

a) wastes

b) dead bodies of organisms

c) fossil fuels

d) wastes, dead bodies of organisms and fossil fuels

17. Which process do plants use carbon dioxide in?

a) photosynthesis

b) respiration



67

c) protein synthesis

d) amino acid synthesis

18. What is the saturation?

a) It is the process of releasing carbon dioxide.

b) It is the process of combining carbon dioxide with water.c) It is the highest amount of moisture that the air can hold.

d) It is the process of releasing carbon dioxide andcombining carbon dioxide with water.

19. What is the difference between energy that flows into anecosystem and chemical nutrients?

a) Energy that flows into an ecosystem can be recycled andchemical nutrients are used repeatedly.

b) Energy that flows into an ecosystem cannot be recycled but chemical nutrients are used repeatedly.

c) Energy that flows into an ecosystem cannot be recycledand chemical nutrients are not used repeatedly.

d) Energy that flows into an ecosystem is energy butchemical nutrients are materials.

20. The movement of the materials and nutrients between theliving and nonliving environment is known as …………

a) the energy flows

b) the energy cycles

c) the nutrients cycles

d) the nutrients flows



68

21. The energy from the sun first flows to ………………..

a) the herbivore

b) the plants

c) the carnivore

d) omnivore22. Choose the right sentence

a) The energy from the sun flows to the carnivore and tothe last consumer until the energy is lost into theecosystem.

b) The energy from the sun flows to the herbivore that eatsthe plant, goes to the carnivore, and to the last consumer until the energy is lost into the ecosystem.

c) The energy from the sun flows to the plants goes to the

herbivore that eats the plant, to the carnivore, and to thelast consumer until the energy is lost into the ecosystem.

d) The energy from the sun flows to the animals goes to theherbivore that eats the plant, to the carnivore, and to thelast consumer until the energy is lost into the ecosystem.

23. The energy ………………..

a) cannot go back to the source

b) can be used over and over again

c) can go back to the sourced) can be stored in biomass only

24. Bacteria and fungi are known as ………………..



69

a) consumers

b) decomposers

c) producers

d) consumers and decomposers

25. The nutrients ………………..a) are stored in the abiotic environment

b) are stored in the biotic environment

c) are stored in the abiotic and the biotic environment

d) cannot stored at all

26. The nutrients can be used ………………..

a) over and over by plants

b) over and over by animals

c) over and over by decomposers

d) by producers, consumers and decomposers

27. Through the cycle of nutrients ………………..

a) the organic compounds found in the bodies of organismsaren’t converted into inorganic compounds

b) the organic compounds found in the bodies of organismsare converted into other organic compounds

c) the organic compounds found in the bodies of organismsare converted into inorganic compounds

d) the inorganic compounds found in the bodies of organisms are converted into other inorganic compounds



70

28. Nutrients may be classified into ………………..

a) one type

b) two types

c) three types

d) four types29. What are the macronutrients?

a) They are carbon, hydrogen, oxygen and nitrogen.

b) They are copper and zinc.

c) They are iron and boron.

d) They are magnesium.

30. Choose the right sentence

a) Macronutrients are those that are required by theorganisms in large quantities.

b) Macronutrients are those that are required by theorganisms in small quantities.

c) Macronutrients aren’t the major components of fats andcarbohydrates.

d) Macronutrients are necessary in the production of chlorophyll.

31. The highest amount of moisture that the air can hold is

called ……………a) evaporation

b) saturation



71

c) respiration

d) condensation

32. The processes of ….. are responsible for the return of water from the atmosphere into the land and other bodiesof water.

a) evaporation and saturation b) saturation and precipitation

c) condensation and precipitation

d) evaporation and precipitation

33. The water from the land and other bodies of water returns to the atmosphere through the process of ………

a) evaporation

b) saturationc) condensation and precipitation

d) evaporation, saturation, condensation and precipitation

34. Returning of water from the atmosphere into the land andother bodies of water through ………………..

a) the process of evaporation

b) the processes of condensation and precipitation

c) the process of condensation

d) the process of precipitation



72

35. Much of the carbon in the environment exists in the formof …..

a) coal, oil and gas

b) carbon dioxide

c) hydrogen carbonate (H2CO3)

d) calcium carbonate

36. Carbon dioxide mainly releases through ……..

a) the process of photosynthesis

b) the process of respiration

c) burning

d) the process of respiration and burning

37. Plants use CO2 in the process of ………………..

a) photosynthesis

b) respiration

c) burning

d) condensation

38. Though the process of respiration, animals ……………

a) obtain their food from the plants

b) release CO2

c) obtain there food from other animalsd) obtain their food from the plants and release CO2

39. Plants use nitrogen in the form of ………………..



73

a) nitrites

b) nitrates

c) nitrites and nitrates

d) nitrogen

40. Nitrogen is ………………..a) macronutrient

b) micronutrient

c) intermediate-nutrient

d) micronutrient and intermediate-nutrient

41. Nitrogen in the atmosphere is converted into nitrates in….. ways.

a) one way

b) two ways

c) three ways

d) many ways

42. The organisms that convert nitrogen are ………………..

a) bacteria

b) algae

c) fungi and algae

d) bacteria, algae, and fungi43. The converting nitrites into nitrogen is called …………

a) nitrification



74

b) denitrification

c) nitrogen-fixing

d) nitrogen cycle

44. The most complex of the nutrient cycles is ……………

a) carbon cycle b) phosphorus cycle

c) water cycle

d) nitrogen cycle

45. The water from the land and other bodies of water returns to the atmosphere through ………………..

a) the process of evaporation

b) the processes of condensation and precipitation

c) the process of condensation

d) the process of precipitation

46. Algae bloom is ………………..

a) very rapid growth of algae in surface waters due toincrease in inorganic nutrients

b) very rapid growth of algae in surface waters due toincrease in organic nutrients

c) very rapid growth of algae in deep waters due to increasein inorganic nutrients

d) Very rapid growth of algae in deep waters due toincrease in organic nutrients



75

47. Eutrophication is ………………..

a) Accumulation of nutrients in a lake or pond due tohuman intervention

b) Accumulation of nutrients in a lake or pond due tohuman intervention or nature causes

c) Accumulation of nutrients in a lake or pond due to naturecauses

d) Accumulation of organism in a lake or pond

48. Humans and animals produce carbon dioxide through …

a) the photosynthesis

b) protein synthesis

c) the process of respiration

d) decomposition49. The process of manufacturing by green plants is called ….

a) protein synthesis

b) decomposition

c) the process of respiration

d) the photosynthesis

50. The energy currency of the cell is ………………..

a) adenosine triphosphate

b) cell membranes

c) nucleic acids

d) nutrients



76

51. Plants use ……………….. for the protein synthesis.

a) carbon dioxide

b) water

c) phosphate

d) carbon dioxide and water 52. Plants use ……………….. for the synthesis of proteins

and amino acids.

a) phosphate

b) nitrogen

c) phosphate and nitrogen

d) carbon dioxide and water

53. Plants use……………….. for the photosynthesis.

a) water

b) carbon dioxide

c) sunlight

d) water, carbon dioxide and sunlight

54. The organic compounds are converted into the inorganiccompounds through …………

a) the cycle of nutrients

b) the cycle of water c) the cycle of phosphorus

d) the cycle of carbon



77

55. Carbon, hydrogen, oxygen and nitrogen are called ……

a) magnesium

b) macronutrients

c) magnesium and macronutrients

d) nutrients56. The process of burning releases mainly ………………..

a) phosphorus

b) nitrogen

c) carbon dioxide

d) hydro carbonate

57. Nitrogen is the form that ………………..

a) plants can use

b) plants can’t use

c) the bacteria can’t convert

d) the fungi can’t convert

58. Denitrification is the process that ………………..

a) nitrogen convert into nitrites

b) nitrites convert into nitrates

c) nitrates convert into nitrites

d) nitrites convert into nitrogen



78

59. The change in the physical, chemical or biologicalcondition in the environment which harmfully effects thequality of life, animals and plants is called ……………..

a) environmental pollution

b) deforestation

c) developmentd) revolution

60. The energy that flows …... an ecosystem can’t berecycled.

a) in

b) into

c) over

d) through61. When the bodies of dead plants and animals decompose,

they are changed ………….. nutrients.

a) in

b) into

c) over

d) through

62. The nutrients are stored in the abiotic environment ……..

the soil.a) that

b) in



79

c) like

d) of

63. The cycle of nutrients is an important process that takes place …………… the ecosystem.

a) in

b) on

c) of

d) over

64. Nutrients may be classified into two types, namely, themacronutrients and …………..

a) The autotrophs

b) The nutrients

c) The biotic componentsd) The micronutrients

65. ……………….. are the major components of fats andcarbonhydrates.

a) The nutrients

b) The macronutrients

c) The micronutrients

d) The macronutrients and micronutrients

66. ……………….. makes up many nucleic acids and is alsoessential for the transformation of energy in the cells.

a) Amino acid



80

b) Protein

c) Nutrient

d) Phosphorus

67. Plants return the water by the process known as ………

a) transpiration b) saturation

c) evaporation

d) respiration

68. Animals return the water by the process known as ……

a) transpiration

b) saturation

c) evaporation

d) respiration

69. Plants absorb carbon dioxide though the leaves and use……………….. the process of photosynthesis.

a) to

b) of

c) in

d) at

70. When the animals and plants die, their bodies and watersare broken down ……………….. the decomposers.

a) as

b) like



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c) in

d) by

71. When burned, fossil fuels release carbon dioxide………… the atmosphere.

a) in

b) into

c) on

d) at

72. Carbon dioxide combines ……………….. water andforms calcium carbonate.

a) with

b) by

c) tod) and

73. Nitrogen-fixing bacteria are the Rhizobium, which livein the roots of legumes ………….. beans, peas, and peanuts.

a) that

b) such as

c) by

d) and74. This process converting ammonia to nitrates is known as …

a) nitrites cycle



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b) nitrogen cycle

c) denitration

d) nitrification

75. Phosphates in the soil come ……………phosphaterocks.

a) to

b) from

c) in

d) at

76. The phosphorus cycle has also been disrupted ……….the activities of humans especially in the water ecosystem.

a) by b) to

c) caused

d) due to

77. Identify the error underlined word or phrase of thefollowing sentence: “The water from the land and other bodies returns to the atmosphere through the processes of evaporation”.

a) returns

b) through

c) processes

d) evaporation



83

78. Identify the error underlined word or phrase of thefollowing sentence: “The nitrates produced by thenitrogen-fixing bacteria are converted into nitrites byanother group of bacteria call nitrite bacteria”.

a) produced

b) convertedc) by another group

d) call

79. Identify the error underlined word or phrase of thefollowing sentence: “When the phosphates fromfertilizers and detergents run off into lakes, theystimulate the rapid grow of algae and other aquatic plantscausing algae bloom”.

a) run off

b) stimulate

c) grow

d) causing

80. Identify the error underlined word or phrase of thefollowing sentence: “Plants absorb carbon dioxides andused them in the process of photosynthesis”.

a) absorb

b) carbon dioxidesc) used

d) in



84

81. Identify the error underlined word or phrase of thefollowing sentence: “Leaching drain the soil of itsnutrients which are ultimately lost into the rivers andshallow marine sediments”.

a) drain

b) itsc) ultimately

d) into

82. Carbon exists in the earth’s atmosphere primarily as thegas ………………..

a) CO

b) CO2

c) H2CO3

d) CH4

83. Fungi and bacteria break down the carbon compounds indead animals and plants and convert the carbon to……… if oxygen is not present.

a) CH4

b) CO

c) CO2

d) H2CO

384. Phosphorus normally occurs in nature as part of a ……

ion.

a) PO43-



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b) HPO42-

c) H2PO4-

d) H3PO4

85. The main driving factor of the oxygen cycle is……………

a) nitrogen cycle

b) photosynthesis

c) evaporation

d) deforestation

86. Eutrophication means an increase in …………., typicallycompounds containing nitrogen or phosphorus, in anecosystem.

a) chemical toxicants b) agrochemicals

c) chemical nutrients

d) chemical toxicants and nutrients

87. Eutrophication may occur ………………..

a) on land

b) in water

c) on land and in water

d) in the atmosphere

88. Nitrogen cycle is a ……………….. cycle.

a) gas



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b) gaseity

c) gasification

d) gaseous

89. Some nitrogen fixing bacteria, such as Rhizobium, livein ……….. of legumes such as peas or beans.

a) the root nodules

b) the root borers

c) the roof leaves

d) the root stocks

90. Some bacteria have the nitrogenase enzyme thatcombines gaseous nitrogen with hydrogen to produce …

a) NO

b) NO2

c) HNO3

d) NH3

91. During anaerobic conditions, ………… by bacteria occurs.

a) nitrification

b) denitrification

c) ammonification

d) nitrogen fixation92. Following is the most widely discussed impact of climate

change:

a) increase in average sea level



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b) deforestation

c) soil erosion

d) deforestation and soil erosion

93. Climate change may have an impact on the following:……

a) agriculture, natural terrestrial ecosystems and water resources

b) air quality, oceans and coastal zones

c) energy and human health

d) agriculture, natural terrestrial ecosystems, water resources air quality, oceans and coastal zones, energyand human health



88

CHAPTER 3: HUMANKIND’S INVENTION WITH

NATURE

After studying this chapter, you should be able to

1. Discuss how ancient people affected the environment.

2. Explain the progress made in the field of agriculture.

3. Identify the advances in the area of medicine.

4. Enumerate the new technologies brought about by

advances in engineering.

5. Get a glimpse of the bad side of human beings impact on

the environment.

6. Enumerate some bad effects of modern technologies.

§1. BALANCE OF NATURE

Scientists estimated that the earth is already around three billion years old, and it will exists for another three billion years.The life of the earth depends mainly on the sun. If thegravitational pull of the sun remains constant, the earth willcontinue to revolve around the sun in its present speed. There isa delicate balance between the centrifugal force of the earth as isgoes around the sun.

If the sun continues to shine as the way it is now, then the earthwill continue to receive radiant energy needed by the livingcreatures. Again, there is a delicate balance here. Too muchsunshine will make the earth too hot for most living beings tosurvive. In short, the balance of nature is so delicate that any actionthat might upset such balance could have catastrophic results.



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For millions of years, this balance of nature has beenmaintained. The animals that antedated humans for thousands of year did not really disturb the environment. The effect theymade on the environment was minimal and Mother Natureeasily recovered.

During the dawn of civilization, humans and the predatorslived in very similar ways. Both hunted for food and dwelt innatural habitats, like caves. With this kind of life, they did notalter the environment. But, since humans were more intelligentand more cunning, plus the fact that they walked erect and madeuse of their hands, they were able to invent weapons to helpthem. Axe from stones and spears from sharp object made them better hunters than the animals. And when they learned the useof fire, they cooked their food with it, warmed their bodies by it,and heated a lot of things to help them survive. That was whenhumans proved their superiority over animals.

When they learned to eat green leafy vegetables and learnedhow to cultivate them, they started to alter the environment. Theymade clearings in the forests and planted vegetables. When theland was no longer that fertile, they abandoned the place andcleared other lands. That was the beginning of forest destruction.Then they learned how to domesticate animals and lived in a permanent dwelling which was made of (from) the products of the environment, like wood for the structure and leaves for roofing. They had to change the environment some more.

Fortunately, there were not so many people at that time, so theenvironment was able to recover. The balance of nature remained.

As the population increased and the needs of people becamemore complex, they put greater and greater pressure on the



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environment. Larger houses were constructed from differentmaterials, strong fences to protect them from enemies, irrigationcanals for agriculture, and large enclosures for animals, all theserequired more change in the environment. But even then, therewas no serious damage to the environment from which nature wasunable to recover. It could be said then that by and large, humans

lives for many, many years in harmony with the environment.The rise in civilization of the Sumerians, the Babylonians, the

Egyptians, the Greeks, and the Romans placed additional burdenon Mother Earth, especially in the terms of land used for public buildings, monuments, and, of course, houses. With more landsused for agriculture and the upkeep of animals, especially thoseused in war, changes in the environment became more permanent. But even then, they were not causes for worry.

It was only during the rapid progress in knowledge about the

world, followed by the so-called industrial revolution, whenhumans made greater impact on the environment.

GUIDE QUESTIONS

1. Explain in details the meaning of balance of nature

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

2. Name some ways by which humans upset the balance of

nature.

……………………………………………………………………………



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……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§2. PROGRESS IN AGRICULTURE, ENGINEERING,AND MEDICINE

Because of their superior intelligence, aided by the virtues of curiosity, imagination, and creativity, humans were able to discover the many laws of nature, and they used this knowledge to control parts of nature mostly for the benefit of humankind, in general.

In the field of agriculture, the knowledge of genetics produced larger and better varieties of fruits and vegetables.These varieties gave better yields per area planted and weremore resistant to diseases. Some examples will be enumerated tohighlight the point.

Better yielding varieties of rice, wheat, and potatoes haveresulted in bumper harvest in many parts of the world. As thedirect consequence, the problem of feeding the growing populations was partly solved by these discoveries.

Scientists were able to breed seedless grapes and seedless papayas. Mangoes are now harvested all year round. And perhaps, the other fruits may soon be grown seedless, likemelons, and watermelons. Large varieties of guavas and Santo

are now in abundance.In the field of medicine, doctor and the scientists were able to

discover the cure for many diseases, thus prolonging and



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preserving producing healthier babies. The end result of all theseare a much faster rate of population increase.

In the field of animal science, researchers were able toimprove the breed of animals used for food. Faster-growingchickens and pigs and cultured fish are some good examples.Artificial hatching of eggs was invented. All these resulted inmore food for the fast-growing population of the world.

In the field of engineering, scientists invented better means of transportation on land, at sea, and in the air. The more recentinventions include the bullet train that can run up to 500kilometers (km) per hour, airplanes that can carry up to 700 passengers, and large ships powered by nuclear fuels.

Landscapes have been altered to improve services to the people. For instance, dams were built to produce electricity for homes and factories. Oil, coal, and other fossil fuels were mined

to power these new inventions.For more comfort at home, scientists invented artificial

lighting, air-conditioning systems, refrigerator to preserve food better, radio and television for faster and better dissemination of information and for entertainment, and all those electric gadgetsin the kitchen to the delight of many housewives.

In the field of food technology, we can choose from a verywide variety of food available in the market, canned goods of allkinds, powered milk, packed lunches, preserved fruits and

vegetables, and many others.All there may be considered as the good impact humans have

made on the environment. As a result of these inventions andnew technology, people are living better food, live in more



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comfortable homes, enjoy their vacations more, get better healthservices, travel faster, and dress better. In short, they can do a lot better than their ancestors.

§3. ADVERSE EFFECTS OF PEOPLE’S ACTIVITIES

Humankind’s intervention with nature has its adverse effectstoo. These include the pollution produced by modern technologyand its ill effects on the environment (disruption of theatmosphere which causes greenhouse effect, ozone depletionand acid rain); among others; pollution of the water system,deforestation, improper disposal of solid wastes, as well asnuclear wastes; and noise pollution.

1. The greenhouse effect

The greenhouse effect is the rise in temperature that the Earth

experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example)trap energy from the sun. Without these gases, heat wouldescape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our world,these gases are referred to as greenhouse gases.

The greenhouse effect is important. Without the greenhouseeffect, the Earth would not be warm enough for humans to live.But if the greenhouse effect becomes stronger, it could make theEarth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.



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Figure 3.1: The greenhouse effect



95

Too much carbon dioxide and other gases emitted byfactories are accumulating in the atmosphere. These gases allowsunlight to penetrate the earth’s atmosphere but unfortunately,they also trap radiant heat and revert its escape into outer space.

The immediate consequence is global warming, which is better known as the green-house effect. The rise in the averagetemperature of the earth could have serious consequences.Among them is the melting of ice and glaciers in the North andSouth poles. This will raise the water level in many areas of theworld, resulting in the submersion of the low-lying coastaltowns and cities.

2. Ozone depletion

High above the earth’s atmosphere, between 15 and 59 kmabove the earth, is a layer of ozone (O3). It is formed whenultraviolet radiation (UV) splits a molecule of oxygen (O2), and

the free oxygen atoms (O) combines with other oxygenmolecules. When found on the surface of the planet, ozone isconsidered a dangerous pollutant and is one substanceresponsible for producing the greenhouse effect.

Ozone acts as a filter in the upper atmosphere, preventing theharmful ultraviolet radiation of the sun from reaching the earth.Scientists discovered that compounds of carbon such as carbondioxide (CO2) and chlorofluorocarbons (CFCs), nitrogen oxides(NO) and methane break up ozone molecules, thereby gradually

depleting it.The fact that the ozone layer was being depleted wasdiscovered in the mid-1980s. The main cause of this is therelease of CFCs, chlorofluorocarbons.



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Figure 3.2: Ozone depletion

Large ozone hole was discovered above the tip of SouthAmerica. The people directly below it may experience skinirritations and soreness in their eyes. This may be due to thehigher intensity of harmful ultraviolet radiations hitting them.

Ozone levels, on the average, have declined by around 2 percent between 1969 and 1988. But in some parts of the world,the decrease in much higher. For example, in Melbourne of Australia, ozone levels dropped by as much as 10 percent in1987, causing a 20 percent increase in ultraviolet radiationreaching the ground.

Antarctica (Nam cực) was an early victim of ozonedestruction. A massive hole in the ozone layer right above theAntarctica now threatens not only that continent, but many

others that could be the victims of Antarctica's melting icecaps.In the future, the ozone problem will have to be solved so thatthe protective ozone layer.



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3. Acid rain

The term acid rain refers to what scientists call acid

deposition.

Sulfur and nitrogen oxides are released from industrialfactories, electrical power plants, smelting plants, and motor

vehicles. When these gases combine with the moisture in theatmosphere, they return to the ground as sulfuric acids and nitricacids. These are popularly known as acids rain.

Figure 3.3: Acid rain

Acid rain, one of the most important environmental problems of all, cannot be seen. Acid rain is having harmful effects both on

people and on the natural ecosystems of the world. Scientists todayare convinced that acid rain is severe in many areas, and that it ishaving an adverse effect on the environments of those locations.



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The problem of acid rain is rapidly spreading. Because it ismainly caused by industrial processes, automobiles, and power plants, those countries that are developed have the most severeacid rain problems. However, as the undeveloped nations beginto industrialize, acid rain will increase greatly.

Determining just how much the planet is being hurt by acidrain is very difficult because the ecosystems that it affects are sodiverse and complex.

Many ecosystems are affected by acid rain. Bodies of water,such as lakes and rivers, see many of their inhabitants die off due to rising acidity levels.

Acidic water also ruins (làm hỏng) plant nutrients, hurting plants' ability to survive and to give negative effects to other organisms.

Human-made products are also experiencing degradationfrom acid rain. Cars can lose their finishes, and outdoor statuesare beginning to rust (gỉ).

Acid rain's effects are destructive and long lasting. Thoughscientists have studied lakes, streams, and many other naturalecosystems to prove its negative effects, acid rain continues to be produced and is increasing in many parts of the world.



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Acid rain and limestone Trees affected by acid rain

Figure 3.4: Effects of acid rain

Many lakes in the Scandinavian countries are seriouslyaffected by acid rain. Acid rain has brought extensive damage tothe trees of Europe and the Eastern part of the United States.Famous buildings like the Taj Mahal in India are now beingdamaged by acids from local oil refineries.

4. Water pollution

Industrial wastes disposed of in streams and rivers have polluted these bodies of water, making them unfit for fish andother aquatic animals to inhabit. When the water from thesestreams and rivers flows into lakes and oceans, then these bodiesof water also become polluted. Wastes from industrial factoriesalong the riverbanks polluted the river so much that for all practical purposes, the river is dead.

Most of the industrial factories that dump their wastes intoaround rivers make water pollution. The immediate consequenceis the large reduction in fish catch.



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Attention for water pollution exploded in the 1980s. The oilspill of the Exxon Valdez showed many around the world justhow horrible the effects of water pollution could be.

Drainage water pollution Solid wastes disposed to water

Severe water pollution Oil pollutionFigure 3.5: Water pollution



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There are many rivers and lakes in our country are sufferingfrom pollution, perhaps to a lesser extent but nevertheless aserious threat to the environment. If you add the bodies of water in other countries that are also polluted, then you will feel howserious this threat is to the earth’s environment.

The effects of water pollution are varied and depend on whatchemicals are dumped and in what locations.

Boston Harbor is a strong example of how badly pollutioncan damage bodies of water. The water is filled with toxic wasteand sewage, and routinely receives more waste when rainfall pushes it into the harbor.

Many bodies of water near urban areas are highly polluted.This is the result of both garbage dumped by individuals anddangerous chemicals legally or illegally dumped by industries.

The main problem caused by water pollution is that it killslife that inhabits water-based ecosystems. Dead fish, birds,dolphins, and many other animals often wind up on beaches,killed by pollutants in their habitat.

Pollution disrupts the natural food chain as well. Pollutantssuch as lead and cadmium are eaten by tiny animals. Later, theseanimals are consumed by fish and shellfish, and the food chaincontinues to be disrupted at all higher levels.

Eventually, humans are affected by this process as well. People canget diseases such as hepatitis by eating seafood that has been poisoned.

Ecosystems can be severely changed or destroyed by water pollution. Many areas are now being affected by careless human pollution, and this pollution is coming back to hurt humans.



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5. Deforestation

Forests cover around a quarter to a third of the total land surfaceof the earth. The reduction in area of this valuable environmental,social and economic resource through deforestation has the potentialto cause problems on a global scale. Climate models havedemonstrated a clear link between deforestation and climate change.

Deforestation occurs at an alarming rate. Twenty-three percentof the earth's land surface is covered by tropical rainforest;however, these forests disappear at a rate of 4.6 million hectares ayear. Forests are an integral part for the well-being of life onearth.

Figure 3.6: Deforestation

Many environmental problems such as flooding of rivers, theloss of biodiversity, accelerated soil erosion, resulting in the lossof the fertility of the land; flooding during heavy rains because



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there are no more trees to hold and store the water; silting of rivers and lakes with soil and rocks carried by the floods; loss of habitat to many animal and plant species. Resulting in their extinction; and deforested areas becoming barren and useless.

6. Solid waste disposal

Progress produces a large amount of garbage. Much of theseare nonbiodegradable (do not decay into useful fertilizer) or hazardous materials.

Figure 3.7: Solid waste disposal

How to dispose of them is a big problem in many countries.The most popular way is landfills. In Vietnam, garbage collectionis not efficient. With an indifferent population, garbage is one of the main sources of pollution especially in large populationcenters like Ho Chi Minh City. When garbage is not collected on

time, people tend to dump them almost everywhere, resulting invery unsanitary surroundings, clogged waterways, and pollutedcreeks and rivers. Improper garbage disposal is known to havetriggered the spread of diseases, epidemics, and other adverseeffects on people’s health.



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7. Nuclear waste

Nuclear power is among the most efficient and relativelycheap sources of energy. But the technology is highlysophisticated and the possibility of nuclear disaster is notremoted.

Figure 3.8: Nuclear waste

The resulting nuclear radiations are very harmful to human beings and heavy dozes are fatal. The thousands of deaths due tothe atomic bombings of Hiroshima and Nagasaki during theSecond World war and the hundreds of fatalities in the



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Chernobyl accident in the former Soviet Union are grimreminders of what could happen in the case of nuclear accidents.

Figure 3.9: Hiroshima and Nagasaki disasters

Figure 3.10: The bombing of Hiroshima and Nagasaki



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8. Noise pollution

Figure 3.11: Noise pollution from speaking-trumpet

Figure 3.12: Air and noise pollution Noise pollution is a direct result of industrial revolution.

Noisy engines in factories, the noise produced by motor vehicles, the irritating noise produced by the jackhammer, and



107

the most unbearable noise from jet engines are some example.Perhaps noise pollution is the least paid attention to but the illeffects it has one people are well documented. Psychologicaleffects including irritability, mental stress, and shorttemperedness are quite common. Temporary or permanent lossof hearing is a more serious physical effect of noise pollution.

The impact of the different kinds of pollution on the peopleand environment is serious. Permanent and irreparable damageson the ecosystem could make the earth no longer a pleasant place to live in and could even make it uninhabitable. That iswhy pollution and its effects on the environment should be theconcern of everybody.

GUIDE QUESTIONS

1. Which of the types of pollution briefly described above is

the most dangerous?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

2. As a student, how can you help in the proper disposal of

garbage?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



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3. Do you know of steps taken by the government and/or

other agencies to protect the environment from harmful

pollution?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



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VOCABULARY

Acid precipitation: Rain or snow that has lower pH than

precipitation from unpolluted skies.

Acid rain: Moisture in the atmosphere which has been

contaminated by oxides of sulfur and nitrogen.

Deforestation: Destruction of forest

Greenhouse effect: Rising of the average global temperature

caused by the accumulation of the carbon dioxide and other

gases in the atmosphere. These gases trap radiant heat and

prevent its escape into space.

Nuclear fission: Splitting of an atomic nucleus when struck by

neutrons.

Nuclear fusion: Joining of two small atomic nuclei to form a

new and large nucleus. Nuclear power: Energy derived from nuclear fission or

fusion.

Ozone: Molecule that contains three molecules of oxygen

found in the atmosphere and which screens ultraviolet rays.

Ozone layer ( or the ozonosphere): Thin layer of ozone in the

upper atmosphere which absorbs ultraviolet light and converts

it into infrared radiation.

Pollution: That which occurs when there is a change in the

physical, chemical, or biological conditions in the environment which harmfully effects the quality of life, including effects on

other animals and plants.



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QUESTIONS

1. Rising of the average global temperature due to theaccumulation of the carbon dioxide and other gases in the

atmosphere causes of ………………..a) acid rain

b) greenhouse effect

c) air pollution

d) ozone depletion

2. Greenhouse effect is known as ………………..

a) The global warming

b) The red tiec) The cool weather

d) The normal weather phenomenon

3. One of the consequences of greenhouse effect is …………

a) the lowering sea level

b) the appearance of many low-lying coastal cities

c) the melting of ice and glaciers in the Poles

d) the arising epidemic diseases

4. The consequence of raising sea level in many places of theworld is ………………..

a) the submersion of the low-lying coastal towns and cities



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b) the melting of ice and glaciers in the North and South poles

c) the global warming

d) the water pollution

5. How high does the ozone layer distribute above the earth?

a) 15 – 29 km

b) 15 – 39 km

c) 15 – 49 km

d) 15 – 59 km

6. The layer that distributes between 15 and 59 km above theearth is ………………..

a) the ionosphere

b) the stratospherec) the ozone layer

d) the troposphere

7. The free oxygen atoms combines with the other oxygenmolecules will form ……………

a) the ozone

b) the acid

c) the ultraviolet radiation

d) the base



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8. The functions of ozone layer are ………………..

a) filtering in the upper atmosphere and destroying theatmosphere

b) preventing the harmful UV of the sun from reach theearth and destroying the atmosphere

c) filtering in the upper atmosphere and preventing theharmful UV of the sun from reach the earth

d) filtering in the upper atmosphere, preventing the harmful UVof the sun from reach the earth and destroying the atmosphere

9. CFCs can ………………..

a) deplete the ozone layer

b) break up ozone molecules

c) make air polluted

d) deplete the ozone layer, break up ozone molecules andmake air polluted

10. Which compounds can deplete the ozone layer?

a) Carbon dioxide, chlorofluorocarbons, nitrogen oxide andmethane

b) Chlorofluorocarbons, carbon dioxide and methane

c) Chlorofluorocarbons, carbon dioxide and nitrogen oxide

d) Chlorofluorocarbons, carbon dioxide

11. The moisture in the atmosphere which has been contaminated by oxides of sulfur and nitrogen is called ……

a) greenhouse effect



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d) the waste that can be reused.

16. The most efficient way to dispose waste is ………………..

a) recycling

b) incineration

c) energy recoveryd) landfilling

17. Deforestation is ………………..

a) the prevention of forest

b) the destruction of forest

c) the planting

d) the delivery of forest

18. Most of the industrial factories that dump their wastes intoaround rivers makes …………

a) air pollution

b) soil pollution

c) water pollution

d) air, soil and water pollution

19. How many percent did the tropical rainforest cover theearth’s land surface?

a) About 20 – 25 percent b) About 25 – 30 percent

c) About 30 – 35 percent

d) About 35 – 40 percent



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20. Lost of forest can cause ………………..

a) flooding of rivers

b) loss of bio-diversity

c) soil degradation

d) flooding of rivers, loss of bio-diversity and soildegradation

21. Nuclear power is not used widely because ………………..

a) the nuclear power production need a high andsophisticated technology

b) the nuclear power is not safe

c) the possibility of nuclear disaster is not remote

d) the nuclear power is not safe, its production need a high

technology and the possibility of nuclear disaster is not remote22. Forest trees can hold and store the water, therefore ………

a) many regions have been deforested for firewood.

b) fooding during heavy rains can be minimized.

c) deforestation occurs at an alarming rate

d) forests are an integral part for the well-being of life onearth.

23. What are the non-biodegradable wastes?

a) They are the industrial wastes b) They are the municipal solid waste

c) They can’t be decayed into useful fertilizer



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d) They are the hazardous wastes.

24. Nuclear power is one of the most ………………..

a) expensive sources of energy

b) inefficient sources of energy

c) expensive and inefficient sources of energyd) cheap and efficient sources of energy

25. Noise pollution is a direct result of ………………..

a) industrial revolution

b) agricultural revolution

c) industrial and agricultural revolution

d) natural phenomenon

26. Noise pollution is the cause of ………………..

a) temporary or permanent loss of hearing

b) irritability

c) stress

d) temporary or permanent loss of hearing, irritability andstress

27. Nuclear fission is ………………..

a) the combination of two small atomic nucleic to form a

new and large nucleus. b) the splitting of an atomic nucleus.

c) energy derived from nuclear

d) energy derived from nuclear fusion



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28. Nuclear fusion is ………………..

a) the combination of two small atomic nucleic to form anew and large nucleus.

b) the splitting of an atomic nucleus.

c) energy derived from nuclear

d) energy derived from nuclear fusion

29. Rain or snow that has lower pH than precipitation fromunpolluted skies is called ………………..

a) pollution

b) hail

c) acid precipitation

d) acid

30. Scientists estimated that the earth is already around ………a) three billion years old, and it will exists for another three

billion years

b) two billion years old, and it will exists for another two billion years

c) one billion years old, and it will exists for another one billion years

d) four billion years old, and it will exists for another four billion years

31. The life of the earth depends mainly on ………………..

a) the earth

b) the air



118

c) the sun

d) the water

32. Too much sunshine will ………………..

a) make the earth too cold for most living beings to survive

b) create balance of naturec) make the earth too hot for most living beings to survive

d) upset the balance of nature

33. During the dawn of civilization ………………..

a) humans and the predator animals lived in very similar ways

b) humans and the predator animals lived in very differentways

c) humans and the autotrophs lived in very similar waysd) humans and the autotrophs lived in very different ways

34. During the dawn of civilization, both humans and animals …

a) hunted for foods

b) dwelt in natural habitats

c) hunted for foods and dwelt in natural habitats

d) alter the environment

35. Humans proved their superiority over animals by ………a) more intelligent and more cunning

b) learning the use of fire

c) making use of their hands



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d) more intelligent, learning the use of fire and making useof their hands

36. Yielding varieties of …………….. have resulted in bumper harvest in many parts of the world.

a) potatoes

b) wheatc) rice

d) rice, wheat, and potatoes

37. Humans started to alter the environment ………………..

a) during the dawn of civilization

b) when they learned to eat green leafy vegetables andlearned how to cultivate them

c) when they ate green leafy vegetablesd) as the population increased and the needs of people became more complex

38. Faster rate of population increase depends on ……………

a) medicine improvement

b) agriculture improvement

c) food engineering improvement

d) medicine, agriculture and food engineering improvement

39. The disruption of the atmosphere will causes ……………a) greenhouse effect

b) ozone depletion



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c) acid rain

d) greenhouse effect, ozone depletion and acid rain

40. The pollution produced by modern technology depends on …

a) improper disposal of solid wastes, nuclear wastes andnoise pollution

b) nuclear wastes

c) improper disposal of solid wastes

d) noise pollution

41. Green-house effect is the result of ………………..

a) carbon dioxide emitted by factories in the atmosphere

b) gases emitted by factories in the atmosphere

c) too much carbon dioxide and other gases emitted by

factories in the atmosphered) noise pollution

42. The consequence of global warming is known as …………

a) greenhouse effect

b) ozone depletion

c) acid rain

d) greenhouse effect, acid rain and ozone depletion

43. Rising in the average temperature of the earth is impacted by ………………..

a) too much carbon dioxide accumulates in the atmosphere

b) too much methane accumulates in the atmosphere



122

47. Ozone depletion will ………………..

a) raise the water level in many part of the world

b) revert radiant heat’s escape into outer space

c) increase in ultraviolet radiation reaching the ground

d) decrease in ultraviolet radiation reaching the ground48. Acid rain dues to ………………..

a) sulfur oxides are released from industrial factories

b) nitrogen oxides are released from industrial factories

c) motor vehicles

d) sulfur and nitrogen oxides are released from industrialfactories, electrical power plants, smelting plants, andmotor vehicles

49. Famous buildings are now being damaged by ……………a) ozone depletion


c) acid rain

d) ozone depletion, acid rain and greenhouse effect

50. Water pollution dues to ………………..

a) industrial solid wastes

b) industrial water wastec) domestic wastes

d) industrial and domestic wastes



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51. Water pollution will result in ………………..

a) oxygen exhaust

b) reduction in fish catch

c) unfit for all practical purposes

d) oxygen exhaust, reduction in fish catch and unfit for all practical purposes

52. Many environmental problems such as ……………….. arecaused by deforestation

a) flooding

b) the loss of biodiversity

c) accelerated soil erosion

d) flooding, the loss of biodiversity, accelerated soil

erosion, etc53. Which type of pollution described below is the most

danger?

a) Greenhouse effect

b) Water pollution

c) Nuclear waste

d) Solid waste

54. Thousands of deaths due to the atomic bombings of

Hiroshima and Nagasaki during the second World war andthe hundreds of fatalities in the Chernobyl accident in theformer Soviet Union are cases of ………………..

a) photochemistry



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c) nuclear accidents

d) acid rain

55. Acid rain is caused by ………………..

a) contaminating of oxides of sulfur and nitrogen inatmosphere

b) water pollution

c) higher pH than the precipitation from unpolluted skies

d) deforestation

56. Greenhouse effect makes ………………..

a) rise of the average global temperature

b) accumulation of the carbon dioxide

c) rise in other gases in the atmosphere

d) rise of the average global temperature cause by theaccumulation of the carbon dioxide and other gases inthe atmosphere

57. Nuclear power is ………………..

a) the energy derived from nuclear fission or fusion

b) the energy derived from nuclear fission

c) the energy derived from nuclear fusion

d) the energy derived from nuclear



125

58. Pollution occurs when ………………..

a) there is a change in the physical conditions in theenvironment

b) there is a change in the chemical conditions in theenvironment

c) there is a change in the biological conditions in theenvironment

d) there is a change in the physical, chemical or biologicalconditions in the environment

59. As the population increased, humans put greater andgreater pressure ……………….. the environment.

a) in

b) on

c) atd) off

60. The rise in the average temperature of the earth could haveserious ………………..

a) consequences

b) results

c) advantage

d) disadvantage

61. Greenhouse effect will raise the water level ……… manyareas of the world.

a) at



126

b) on

c) in

d) of

62. Carbon dioxide, chlorofluorocarbons, nitrogen oxides andmethane can ……………….. ozone layer.

a) break down

b) push off

c) destroy

d) deplete

63. Acid rain brings damage …… lakes, the soil, forest and buildings.

a) to

b) in

c) up

d) on

64. Most of the industrial factories ……….. dump their wastesinto around rivers make water pollution.

a) who

b) whom

c) that

d) such as65. Deforestation occurs ……………….. an alarming rate.

a) at

b) on



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c) in

d) of

66. Human’s activities produce a large amount …… garbage.

a) at

b) onc) in

d) of

67. The nuclear radiations ……very harmful to human beings.

a) is

b) are

c) was

d) were

68. Noise pollution is a direct result of …………revolution.

a) industry

b) industrial

c) industrialize

d) industrially

69. Deforested areas are becoming barren …… useless.

a) but

b) or

c) and

d) of



128

70. Nuclear power is one of efficient and cheap sources ……energy.

a) at

b) on

c) in

d) of 71. Who discovered the greenhouse effect?

a) Joseph Fourier

b) Elihu Thomas

c) Wilhelm Conrad Roentgen

d) Thomas Alva Edition

72. When was greenhouse effect discovered?

a) 1624

b) 1724

c) 1824

d) 1924

73. Acid rain is mostly caused by………………..

a) human emissions of sulfur compounds

b) human emissions of nitrogen compounds

c) human emissions of sulfur and nitrogen compounds

d) human emissions of water and vapour water

74. Acid rain was first found in ………………..

a) United States



129

b) Sweden

c) Vietnam

d) Singapore

75. The process in which the emission of infrared radiation bythe atmosphere warms a planet’s surface is called ………

a) photosynthesis


c) acid rain

d) ozone depletion

76. Which country is the leading country that undertakesrecycling?

a) United States

b) Germanyc) England

d) Japan

77. How many percent can Japan can recycle or reuse their solid wastes?

a) about 11%

b) about 15%

c) about 27%

d) about 50%

78. A site for the disposal of waste material by burial is called ………

a) storehouse



130

b) graveyard

c) landfill

d) a) and b) are correct

79. The oldest form of waste treatment is ………………..

a) landfilling b) incinerating

c) composting

d) recycling

80. …………… has the greatest role in the greenhouse effect.

a) CO2

b) CFC

c) CH4

d) NO2

81. ……………….. has the least role in the greenhouse effect.

a) CO2

b) CFC

c) CH4

d) NO2


following sentence: “Sulfur and nitrogen oxide are releasedfrom industry factories, electrical power plants, smelting plants and motor vehicles”.

a) are released



131

b) industry

c) electrical

d) smelting

83. Identify the error underlined word or phrase of thefollowing sentence: “When humans learned to eat

vegetables and learned how to cultivate them, they startedto altered the environment”.

a) humans

b) eat

c) how to

d) altered

84. Identify the error underlined word or phrase of thefollowing sentence: “In the field of agricultural, the

knowledge of genetics produced larger and better varietiesof fruits and vegetables”.

a) in

b) agricultural

c) genetics

d) larger and better

85. Identify the error underlined word or phrase of thefollowing sentence: “This will raise the water level in

many area of the world, resulting in the submersion of thelow-lying coastal towns and cities”.

a) water level



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b) area

c) resulting

d) low-lying

86. Identify the error underlined word or phrase of thefollowing sentence: “Ozone acts as a filters in the upper

atmosphere, preventing the harmful ultraviolet radiation of the sun from reaching the earth”.

a) filters

b) preventing

c) harmful

d) from

87. Identify the error underlined word or phrase of thefollowing sentence: “Improper garbage disposal is known

to have triggered the spread of diseases, epidemics andother adverse effects at people’s health”.

a) disposal

b) known

c) spread of

d) at

88. The destruction of significant areas of forest cover hasresulted in a degraded environment with reduced …………

a) pollution

b) population

c) biodiversity



133

d) animals

89. Deforestation results from removal of trees without sufficient ……

a) reforestation

b) forest

c) forester d) forestation

90. Deforestation affects the amount of water in the soil andgroundwater and the moisture in the atmosphere.

a) amount of water in soil

b) amount of water in groundwater

c) the moisture in the atmosphere

d) the moisture in the atmosphere and amount of water in

soil and in groundwater 91. Garbage generated in households can be ……… to prevent

creation of waste at source and reducing amount of waste.

a) recycled

b) reused

c) recycled and reused

d) thrown away

92. Household waste is generally classified as ………………..

a) hazardous waste

b) municipal waste

c) biomedical waste



134

d) solid waste

93. There are various municipal waste disposal methods. Oneof the following methods solves the problem of leaching tosome extent.

a) open dumps

b) landfillsc) sanitary landfills

d) open dumps, landfills and sanitary landfills

94. Which is potentially the safest means of disposing of the mosttoxic wastes: organic solvents, chlorinated hydrocarbons, PCBsand dioxins?

a) municipal incineration

b) industrial high temperature incineration

c) landfills

d) municipal incineration and landfills

95. Municipal waste is disposed in the open dumps, landfills,sanitary landfills, and is also burnt in large furnaces. Thismethod is known as ………………..

a) incineration

b) blast furnace

c) waste furnace

d) incineration, blast furnace and waste furnace



135

CHAPTER 4: THE POLLUTION PROBLEMS

After studying this chapter, you will be able to:

1. Trace the history of pollution in the world.

2. Identify the major sources of worldwide pollution.

3. Distinguish between toxic pollutants and those that are

harmful only to the environment.

4. Describe the main causes of air, water, and land

pollution.

5. Enumerate the efforts exerted by some people to help

reduce pollution.

§1. MEANING OF POLLUTION

When there is a change in the physical, chemical, or biological conditions in the environment which harmfullyaffects the quality of life, including effects on other animals and plants, then we say that there is pollution in the environment.

The change is generally brought about by introduction of hazardous substance into the environment. A hazardous substanceincludes any substance that poses a threat to human health or to theenvironment. Substances that are poisonous to human beings and

animals are called toxicants. Those that harm to the environmentmay be corrosive, flammable, or explosive. Examples of toxicmaterials are carbon monoxide (CO), sulfur dioxide (SO2), and theoxides of lead and mercury.



136

Examples of substances that harm the environment includewastes disposed of improperly by industries, non-biodegradablematerials, like plastic, thrown just anywhere; and excessivecarbon dioxide (CO2) introduced into the atmosphere.

Problems caused by hazardous substances are twofold: first,they cause a wide range of harmful effects on human health suchas cancer, damage to the brain, liver, kidney, bone marrow,embryo, skin, gastrointestinal organs, and to the central nervoussystem; second, these substances can cause long-term or permanent damages to ecosystem. For instance, toxic substancesdumped into the water system can cause long-term damage tomost of our rivers and lakes.

We classify pollution into four types: air pollution, water pollution, land and soil pollution, and noise pollution.

GUIDE QUESTIONS

Name some hazardous substances emitted by vehicles that

run on gasoline or diesel fuel. What possible damage can they

cause to humans?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§2. AIR POLLUTION

Substances that pollute the air are generally of two types. Thefirst types of air pollutants are those that are directly harmful to



137

humans. They include toxic materials emitted by factories andmotor vehicles. The second types of pollutants are those thatdamage the environment and possibly alter the earth’s climate.

Figure 4.1: Environmental pollution1. Toxic air pollutants

Toxic air pollutants include oxides of sulfur and nitrogen,carbon monoxide, volatile organic compounds (VOC), leadoxide, and benzene.

The main source of toxic pollutants is the burning of fossilfuels like gasoline, diesel, and petroleum in power plants,factories, and motor vehicles. Burning of trash also producestoxic pollutants.



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Figure 4.2: Burning tires harm to air environment

These pollutants are considered toxicants because the human

body absorbs these gases together with fine particles into the bloodstream, causing adverse health effects. The most obviouseffects are:

1. Breathing difficulties.

2. Increased susceptibility to respiratory infection.

3. Development of chronic lung disease.

4. Worsening of existing heart and lung diseases.

5. Fetal defects and various kinds of cancer.



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Figure 4.3: Health effects by environmental pollutants

2. Contributors of common air pollutants

The urban and industrialized areas in the world are thegreatest contributors of air pollution. Knowing that pollutants

are the causes of many bad effects on human health, theseshould be main causes for alarm by the people in general and bythe government in particular. As experienced by the UnitedStates, Japan, and the European countries, emission control costsare high, but still, control measures must be undertaken.

Otherwise, the cost of man-hours, health care,unproductively, and shorter life span will be more staggering.UNEP and WHO suggested a gradual introduction, and proper maintenance of factories and power plants.

GUIDE QUESTIONS 1. Explain the two types of air pollution.

……………………………………………………………………………

……………………………………………………………………………



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……………………………………………………………………………

……………………………………………………………………………

2. Is air pollution in your area serious? If it is, do you known

if you or some of your neighbors have suffered from of it? What

suggestions can you give?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

3. Do you know of some steps that the government has taken

to reduce air pollution, especially in the Ho Chi Minh City?

How effective are they?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

4. What are the forms of air pollution that can easily be

avoided?

5. Enumerate some general effects of acid rain on the

environment.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



141

6. Explain the greenhouse effect.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………7. Cite some possible consequences of an increase in global

temperature.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§3. LAND AND SOIL POLLUTION

There are two principal sources of wastes responsible for theland and soil pollution. The first one is the solid waste whichcomes from mining operations. It includes direct waste from themining of minerals and fossil fuels and those associated with themining and processing industries. Strip mining not only produces mineral waste that pollutes the soil and streams butalso leaves huge scars on the land. The loosening of the soilleads to erosion during heavy rains, causing sediments to settle

at the bottom of rivers and lakes. Erosion also adds to thedeterioration of the land, making it unfit for agriculture. It alsomakes the water turbid-cloudy, thick, and dense.



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Figure 4.4: Pollutants harm to the environment

Another type of solid waste is the by-products of agriculture.It includes animal manure and wastes from slaughtered horsesand from all forms of crop harvesting. These wastes aregenerally less polluted because they are spread over wide areas.

Also, they are biodegradable, meaning, they return to the soil asnutrients of plants. In excessive amounts, they emit bad odor,which is almost intolerable to human beings.

GUIDE QUESTION

1. What are the major sources of water pollution in Ho Chi

Minh City? Do you know if something is being done to reduce it?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



143

2. Do you know of other rivers and lakes affected by soil

erosion? Where does the eroded soil come from?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§4. RADIATION AND ITS HARMFUL EFFECTS

Radiation is the general term used to refer to a variety of raysto which life on earth is exposed to. These include visible light,infrared and ultraviolet rays, X rays, cosmic rays, and rays fromradioactive materials.

In a wide sense, any result of radiation energy to a living

organism is a biological effect of radiation. This includes normaleffects like photosynthesis on plants and vision in animals andalso the injurious effect burns, anemia, and cancer on humansand animals.

1. Historical background

When X rays were discovered by the German physicistWilhelm Conrad Roentgen in 1895, the focus of attention wasits possible applications, especially in the field of medicine. Theharmful effects were observed one year later. In 1896, Elihu

Thomas exposed one of his fingers to X rays and observed the burns caused by these.

In the same year, the famous American inventor, ThomasAlva Edition, observed the effects of X rays exposure on one of



145

The artificial sources like medical X rays, high - voltage power supplies, television sets, and luminous dial watches givesignificant dosage but the effects do not show until after manyyears. These effects may include lower blood counts, temporarysterility, skin irritations, and on rare occasions, cancer.

Figure 4.5: Harmful effect of radiation

The very serious health effects come from very massivedozen of radiation from nuclear reactor leaks and explosions of nuclear weapons; such as:

The effects of the Hiroshima and Nagasaki explosions andlately, the Chernobyl disaster attested to the veracity of theseestimates. Although less damaging, the effects of the nuclear tests in the Nevada desert were also well documented.

The bomb that was dropped in Hiroshima killed more than140.000 of its 255.000 inhabitants, and more deaths occurredlater from radioactive radiation. The effects of the Nagasaki blast were similar to that of Hiroshima.

In Chernobyl, Ukraine, four nuclear reactors used ingenerating electricity exploded in April of 1986. The explosion



146

released between 50 and 100 million curies of radioactivematerial into environment. Within a few months, 29 people diedof radiation poisoning and 200 other were estimated to developcancer in later life. The eventual toll of the nuclear accident has been estimated to be as high as 135000 cancer cases and 35000deaths.

From 1951 to 1962, the United States exploded 126 atomic bombs into the atmosphere at the Nevada test sites. Somecivilians and military personnel working at the test sitesdeveloped disorders like cancer, heart disease, thyroiddysfunction, and diabetes. The same thing happened to people insouthern Utah where winds from the test sites carriedradioactive material that affected a lot of people. Tests weresubsequently underground to minimize radiation effects andrecently, testing of atomic weapons was altogether halter.

GUIDE QUESTION

1. What types of radiation are useful to human? What types

are harmful?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

2. What type of radiation may be useful and harmful at the same

time?

……………………………………………………………………………

……………………………………………………………………………



147

……………………………………………………………………………

……………………………………………………………………………

3. What events in the past resulted in many deaths due to

massive exposure to radioactive materials?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§5. POLLUTION REDUCTION

There is a universal concern for doing something about the production and disposal of hazardous substances. Leading

industrialized countries and some leading industrial companieshave initiated serious efforts to reduce pollution.

1. Recycling

How to handle society’s toxic chemical waste now ranksamong the top environmental issues in most industrial countries.Without concerned efforts to reduce, recycle, and reuse moreindustrial wastes, the quantities produced will overwhelm eventhe best treatment and disposal systems.

The process of converting materials into new products that

may or may not resemble the original material is known asrecycling .



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Figure 4.6: The conception of recycle

For example, old newspapers may be recycled into newsprint paper, board for packing, and constructional materials for roofing and insulation.

The benefits of recycling include the following:

1. It reduces waste.2. It lowers energy, water, and primary raw material

requirements.

3. It reduces both air and water pollution.



149

Imagine the number of trees that would be saved by recyclingnewspapers. And imagine the amount of trash that would haveto be disposed of if plastics, glass, and cans were not recycled.

Japan is the leading country that undertakes recycling. Thecountry recycles or reuses about 50 percent of its solid wastes,compared with only 11 percent of the United States and 15 percent of Germany.

Moreover, after burning 23 percent of Japan’s trash in waste-to-energy facilities, only 27 percent remains to be disposed of inlandfills and by other means. In contrast, 83 percent of solidwaste in the United Stated and 55 percent of solid waste inGermany are disposed of by similar means.

Table 4.1: Solid waste management in the United Stated,

Japan and Germany

Type UnitedStates

Japan Germany

Recycled or reused 11 50 15

Waste-to-energy 6 23 30

Landfilled or others 83 27 55

Total 100 100 100

Furthermore, Time magazine, in its January 2, 1989, issue,reported that Japan, in 1988, recycled 50 percent of its waste paper, 55 percent of its glass bottles, 66 percent of its beverage



150

and food cans, and converted much of the remaining trash intofertilizers, fuel gases, and recycled metals.

Part of the success of Japan’s recycling program is the whole-hearted cooperation of the citizens. The Japanese separate their trash into six classifications to simplify recycling. In contrast,the United Stated in 1986 recovered only 23 percent of its paper products, 9 percent of its glass, and 25 percent of its aluminum.

Several countries have followed the Japanese. Glassrecycling is fast growing in Europe. The cities of Rome, Vienna,and Madrid have put up recovery plants producing metals, glass, paper, plastics, fibers, and other products.

Some third world countries, although on a limited scale, havesimilarly ventured into recycling. In India, more than a third of urban waste is being composted to produce methane gas, fuel pellets, fertilizers, and animal feeds. China, specifically the city

of Shanghai, processes and sells more than 10 percent of itswaste for biogas production, fertilizers, and brick and cementmanufacture. The city also reprocesses many materials likemetals, rubber, plastics, paper, glass, and waste oil.

2. What you can do

The following are things that you can do at home, in school,or in the community to help in the reduction of pollution:

1. Help keeping your school free from unwanted garbage

through proper disposal.

2. Help organize or join campaigns in your community to

inform the public of the hazards posed by pollution. For

example, tricycle drivers may not know that the noise



151

produced by their engines could permanently impair their

sense of hearing.

3. Minimize the use of pesticides at home. If you must use

them, minimize the potential hazards by (a) making sure

people and pets are out of the area during the application

and (b) not applying near streams and ponds.

4. Find out what companies are major contributors to

pollution. Do not patronize their products and convince

others to do the same.

5. Separate wastes that can be recycled. Sell them to local

dealers or give them to garbage collectors for their extra

income.

6. Help minimize the amount of waste produced in your

home. For example, use less plastic wrappers and sell or

give old newspapers to dealers who in turn sell them for recycling.

7. Volunteer to help in the information campaign to

minimize pollution through proper waste disposal.

8. Generate enthusiasm about programs that would

minimize air, water, land, and noise pollution.

9. Eat fewer animal products and consume more grains,

vegetables, and fruits that require less energy to produce

and therefore create less pollution.

10. Urge your parents to buy household items and appliancesthat contain no, or less, pollutants. Read the labels

carefully before buying.



152

11. Plant fast-growing trees especially around your house.

They provide shade during sunny days and absorb carbon

dioxide in the air. They therefore help counteract the

greenhouse effect.

12. By reducing energy consumption, you will help lessen

environmental damage. The energy you use may come

from burning fossil fuels like gas, oil, or, coal. Less

energy used means less burning of these fossil fuels.

13. Economize in the use of materials that contribute to the

depletion of natural resources. For example, by using less

paper, which is a wood product, you help reduce the need

for cutting trees.

GUIDE QUESTIONS

1. Cite government efforts to reduce pollution.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

2. Explain the good side and the bad side of burning dry

leaves under fruit-bearing trees, like mango.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



153

3. What materials are being recycled in Vietnam?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………4. How is garbage (solid waste) disposed of in your

community? Is it the good way?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



154

VOCABULARY

Recycling: Processing of material into new products that

may or may not resemble the original material.

Toxic substance: Substance poisonous to human beings and

animals.


QUESTIONS

1. How many types of pollution do people classify?

a) 3

b) 4

c) 5d) 6

2. Toxic substances can cause ……………….. to ecosystem.

a) short-term damages

b) long-term damages

c) permanent damages

d) short-term, long-term and permanent damages

3. Substances that pollute the air can ………………..

a) directly harmful to human b) damage the environment

c) directly harmful to human and damage theenvironment



155

d) not directly harmful to human and not damage theenvironment

4. Which toxic materials are directly harmful to human?

a) The toxic materials are emitted by the photosynthesis

b) The toxic materials are emitted by factories andmotor vehicles

c) The toxic materials are emitted by the process of respiration

d) The toxic materials are emitted by the algae bloom

5. Toxic air pollutants include ………………..

a) oxides of sulfur and nitrogen

b) carbon monoxide and lead oxide

c) volatile and organic compounds

d) sulfur oxide, nitrogen oxide, carbon monoxide, leadoxide, volatile and organic compounds

6. The main source of air pollution is ………………..

a) burning of fossil fuel

b) burning of trash

c) insanitary

d) acid rain

7. Health effects by environmental pollutants are ……………

a) Breathing difficulties and increasing susceptibility torespiratory infection.

b) Developing of chronic lung disease and fetal defectsand various kinds of cancer.



156

c) Decreasing susceptibility to respiratory infection.

d) Decreasing the serious diseases

8. The principal sources of wastes which are responsible for the land and soil pollution are ………………..

a) the solid wastes which come from mining operations

b) the municipal solid wastes and the solid wasteswhich come from mining operations

c) the solid wastes which come from mining operationsand the by-product of agriculture

d) the municipal solid wastes and the by-product of agriculture

9. Which wastes from the mining operations can make theland and soil pollution?

a) wastes from the mining of minerals

b) wastes from the mining of fossil fuelsc) wastes that associated with the mining and

processing industries

d) wastes that associated with the mining and processing industries and the wastes from the miningof minerals and fossil fuels

10. Some effects of erosion are ………………..

a) making the soil become deteriorative and waterless

b) making the soil become fertile and deteriorativec) making the soil become waterless and fertile

d) making the soil become fertile and erodent



157

11. Which wastes is the by-product of agriculture?

a) animal manure

b) wastes from slaughtered horses

c) wastes from all forms of crop harvesting

d) animal manure, wastes from slaughtered horses and

wastes from all forms of crop harvesting12. When was X-ray discovered?

a) 1885

b) 1890

c) 1895

d) 1900

13. Who invented the cyclotron?

a) Ernest Lawrence

b) Elihu Thomasc) Wilhelm Conrad Roentgen

d) Thomas Alva Edition

14. Problems caused by hazardous substances are ……………

a) harmful effects on human health

b) short-term damages to ecosystem

c) long-term or permanent damages to ecosystem

d) harmful effects on human health, short-term, long-

term or permanent damages to ecosystem15. Pollution can be classified into ……………..

a) two types

b) three types



158

c) four types

d) five types

16. Substances that pollute the air can be classified into ……...

a) two types

b) three types

c) four typesd) five types

17. Burning of fossil fuels like gasoline, diesel, and petroleummostly ………………..

a) pollutes to water environment

b) pollutes to air environment

c) pollutes to soil environment

d) pollutes to land

18. Pollutants are considered toxic because ………………….a) the human body absorbs these gases

b) the human body absorbs fine particles into the bloodstream

c) they are causing adverse health effects

d) because the human body absorbs these gasestogether with fine particles into the bloodstream,causing adverse health effects

19. What are the greatest contributors of air pollution?

a) the urban and industrialized areas in the world

b) deforestation and greenhouse effect

c) acid rain and deforestation



159

d) greenhouse effect and acid rain

20. What is the form of air pollutants that can easily be avoided?

a) sulfur oxide

b) carbon monoxide

c) organic compounds

d) nitrogen oxide21. There are ……………. of wastes responsible for the land

and soil pollution.

a) two principal sources

b) three principal sources

c) four principal sources

d) five principal sources

22. Animal manure and wastes from slaughtered horses and

from all forms of crop harvesting are ………………..a) by-product of industry

b) by-product of agriculture

c) by-product of domestic

d) by-product of agriculture, industry and domestic

23. By-products of agriculture are less polluting because …….

a) they are biodegradable

b) they are able to return to the soil as nutrients of

plantsc) they are spread over wide areas

d) they are biodegradable, spread over wide areas andable to return to the soil as nutrients of plants



160

24. X rays were discovered by

a) Elihu Thomas

b) Wilhelm Conrad Roentgen

c) Thomas Alva Edition

d) Clarence Dally

25. There are ..…………….. of radiation that may cause injuryto human beings

a) two source

b) three sources

c) four sources

d) five sources

26. What are the natural sources of radiation?

a) cosmic rays, granite and monazite sands

b) medical X raysc) high - voltage power

d) luminous dial watches

27. The effects of the Hiroshima and Nagasaki explosions due to …

a) nuclear tests

b) nuclear weapons

c) nuclear reactor used in generating electricity

d) nuclear accident

28. Which type of radiation may be useful and harmful at thesame time?

a) nuclear tests

b) nuclear weapons



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c) nuclear reactor used in generating electricity

d) nuclear accident

29. Which event dues to massive exposure to radioactivematerials?

a) The bombs were dropped in Hiroshima and

Nagasaki. b) Nuclear reactor used in generating electricity

exploded in Chernobyl.

c) 126 atomic bombs into the atmosphere at the Nevada testsites.

d) The bombs in Nevada test sites, in Hiroshima and Nagasaki and nuclear reactor used in generatingelectricity exploded in Chernobyl.

30. The process of converting material into new products that

may or may not resemble the original material is called …..a) recycling

b) reducing

c) reusing

d) recycling, reducing and reusing

31. The substance that is poisonous to human beings andanimals is called …….

a) toxic substance

b) solid wastec) waste water

d) hazardous waste



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32. Recycling is beneficial because ……………..

a) it reduces wastes

b) it lowers energy, water and primary raw materialrequirements

c) it reduces both air and water pollution

d) it lowers energy, water and primary raw materialrequirements, therefore, it reduces wastes, air andwater pollution

33. Which gases contribute to greenhouse effect?

a) carbon dioxide and methane

b) methane and nitro dioxide

c) nitro oxide and nitro dioxide

d) carbon dioxide, methane, nitro oxide and nitrodioxide

34. Many famous buildings have been deteriorated by ………..

a) acid rain

b) ozone depletion

c) greenhouse effect

d) acid rain, ozone depletion and greenhouse effect

35. Which activity makes a great contribution to air pollution?

a) Deforestation

b) Acid rain

c) Industry

d) Greenhouse effect



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36. Gases produced by the decay of organic matter, especiallymanure and crop residues are ………………

a) greenhouse gases

b) biogas

c) natural gases

d) artificial gases37. Biological control is ……………..

a) the use of natural parasites and bacteria to control pests

b) the use of predators to control pests

c) the use of predators, natural parasites and bacteria tocontrol pests

d) the use agrochemicals to control pests

38. Amount of organic materials that is available at eachtrophic level is ………….

a) food chain

b) energy content

c) energy pyramid

d) biomass pyramid

39. Biome is ……………..

a) a large geographical area with characteristic lifeforms

b) amount of organic materials in plants or animalsc) the object that can be acted upon by micro-

organisms



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d) organism that is self-nourishing

40. The process of decaying plants, animals and other organicmatter in the presence of air to obtain humus is called ………

a) landfilling

b) recycling

c) incineratingd) composting

41. The main sources of energy in the world are …………….

a) oil and charcoal

b) oil and natural gas

c) fossil fuels and natural gas

d) charcoal and natural gas

42. Choose the correct sentence:

a) Humans and animals release toxic pollutants. b) Toxic pollutants cause many kinds of diseases for

humans and animals.

c) Toxic pollutants causes air pollution.

d) The photosynthesis makes the air polluted.

43. The urban and industrialized areas in the world are the………… contributors of air pollution.

a) great

b) greatestc) greater

d) greatly



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44. There are many sources of ……………….. that may causeinjury to human beings.

a) radar

b) radiate

c) radiative

d) radiation45. The old newspapers may be recycled …... newsprint paper,

board for packing and construction materials for roofingand insulation.

a) to

b) in

c) into

d) on

46. The harmful effects of radioactivity …….. observed byPierre Curie, a French chemist, in 1906.

a) is

b) are

c) was

d) were

47. Some ….. of X rays may include lower blood counts,temporary sterility, skin irritations and cancer.

a) effect

b) effectsc) result

d) results



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48. The by-product ….. agriculture includes animal manure and thewastes from slaughtered horses and from the crop harvesting.

a) of

b) from

c) to

d) in49. The strip mining not only produces ….. waste that pollutes

the soil and streams but also leaves huge scars on the land.

a) mine

b) miner

c) mineral

d) mineralogical

50. Nitrogen is the ……….. because the human body absorbs

it together with fine particles into the bloodstream, causingadverse health effects.

a) toxic

b) toxicity

c) toxicant

d) toxication

51. The pollutants that are ………. harmful to humans includetoxic materials from the factories and motor vehicles.

a) direct

b) directlyc) indirect

d) indirectly



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52. Substances that are poisonous to human beings andanimals are called ………………..

a) toxic

b) toxicity

c) toxicant

d) toxication53. The main source of toxic pollutants is the burning of fossil

fuels like gasoline, diesel and petroleum ….. power plants,factories and motor vehicles.

a) in

b) on

c) of

d) at

54. Which causes make the land degradation?a) soil erosion

b) desertification

c) loss of fertility

d) soil erosion, desertification and loss of fertility

55. The main causes make air pollution are ………………..

a) acid deposition and greenhouse gas build-up

b) greenhouse gas build-up and ozone layer depletion

c) acid deposition, greenhouse gas build-up and ozonelayer depletion

d) respiration and photosynthesis



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56. Identify the error underlined word or phrase of thefollowing sentence: “These pollutants considered toxic because the human body absorbs these gases together withfine particles into the bloodstream, causing adverse healtheffects”.

a) considered

b) absorbs

c) into

d) causing

57. Identify the error underlined word or phrase of thefollowing sentence: “Radiation is the general term use torefer to a variety of rays to which life on the earth isexposed”.

a) general

b) use toc) to which

d) is exposed

58. Identify the error underlined word or phrase of thefollowing sentence: “The process of converting materialsinto new products that may or may not resemble theoriginal material is know as recycling”.

a) into

b) resemble

c) knowd) recycling



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59. Identify the error underlined word or phrase of thefollowing sentence: “The loosening of the soil lead toerosion during heavy rains, causing sediments to settle atthe bottom of rivers and lakes”.

a) loosening

b) leadc) during

d) causing

60. Identify the error underlined word or phrase of thefollowing sentence: “A hazard substance includes anysubstance that poses a threat to human health or theenvironment”.

a) hazard

b) includes

c) posesd) human health

61. The following pollutant is not contained in the vehicular exhaust emissions:

a) lead

b) ammonia

c) carbon monoxide

d) particulate matter

62. Health problems related to air pollution include:a) coughing

b) asthma

c) bronchitis



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d) coughing, asthma and bronchitis

63. Water has an adverse effect on both the environment and health.What are the main sources of water pollution in Vietnam?

a) municipal waste

b) bathing

c) industrial discharged) municipal waste and industrial discharge

64. Which are highly responsible for eutrophication of water bodies?

a) phosphorus and carbon

b) nitrogen and phosphorus

c) iron and arsenic

d) arsenic and phosphorus

65. Of the following indications of the health of water body,which is the most widely accepted means of measuringhow polluting an effluent is?

a) BOD

b) COD

c) Chloroform content

d) pH



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CHAPTER 5: SUSTAINABLE

DEVELOPMENT AND THE FUTURE

After studying this chapter, you should be able to:

1. Explain why the balance of nature was altered only

recently

2. Relate how humans were able to control nature

3. Enumerate the consequences of controlling nature

4. Comprehend the pressure on the environment, resulting

from rapid increase population

5. Understand the problem of uneven distribution of wealth

6. Distinguish the problem of solutions offered to problem

impacts in the world.

§1. THE GLOBAL ENVIRONMENTAL SITUATION

Scientists have estimated that the earth is more than four billion years old, and it will continue to exist for around thesame period of time. Life on earth as we know it today cameinto being around three billion years ago. Based on fossils foundaround the world, human beings have inhabited the earth for more than two million years. All this time, nature and life onearth lived in equilibrium. There was no major disturbancewhich could alter the balance of nature. This was true up toaround 2000 years ago.

At around that time, people began to disturb the environmentin such a manner as to effect the global environment.



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The rampant and reckless cuttings of trees in virgin forestshave resulted in soil erosion, flooding, expansion of deserts, anddestruction of lakes. Overexploitation of other natural resources,like fish and other aquatic resources, has resulted in alarmingdecrease of catch worldwide.

Too much use of fossil fuels, like oil and other minerals, hasdepleted these natural resources to much an extent that thesupply may not last for another one hundred years. It takesmillions of years to form oil from the fossils of plants.

The industrial revolution has produced all kinds of hazardousmaterials that harmed the environment-pollution of the air,water, land, and the atmosphere. Many of these hazardoussubstances are also toxic to humans as well as to other animals.

To be fair to those concerned, all these were the unwantedeffects of a desire to improve the quality of life - a very noble

intention. In fact, as direct consequences of scientific breakthroughs in many fields of human endeavor, people havein many ways succeeded in this worthy ambition. People were,to a certain extent, able to control nature. By applying what theyhave discovered about the laws of nature, they were able toconquer darkness though electric bulbs and fluorescent lamps,hot weather conditions through electric fans and air conditioners, and cold weather through heaters. Through modernmedicines and sanitation, they were able to control the spread of diseases; through modern agriculture, they were able to produce

more food containing better nutrients.The overall result of better living conditions, better

sanitation, and better nutrition includes rise in life expectancy



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this, around 10 million people worldwide die due to water-bornediseases. In the industrialized countries, agriculture and industryare rapidly using up groundwater. Deforestation in many areasaggravates the situation. It prevents the staring of groundwater.

The main sources of energy in the world are fossil fuels (oiland charcoal) and natural gas. At the beginning of their use,many people thought that the supply is practically inexhaustible.But since World War II, energy consumption has increasedmore than four times. Scientists have since then changed their predictions. They now predict that oil reserves will be used up inless than 50 years, and natural gas by around 60 years.

Since the introduction of polluting materials by humans, thequality of air, soil, and water has deteriorated. Humans, animals,and plants have been affected. Toxic pollutants cause many kindsof illnesses in humans and animals. Oxides of nitrogen and sulfur,

the ozone, and other pollutants are causing acid rain that lower crop yield and damage millions of hectares of forests, especiallyamong the industrialized countries. Increase in atmosphericcarbon dioxide is casing the so-called greenhouse effect. This is predicted to alter the earth’s climate and raise ocean levels, withdisastrous consequences to coastal towns and cities.

WARM UP

Most of the time, nature is friendly. It seldom shows its fury.

When it does, it is uncontrollable.



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Table 5.1: Global problem impacts and problem causes

Problem Impacts

Problem causes

Unsustain-able

population

growth

Poverty and

Inequality

Unsustain-able food

production

Unsustain-able

energy use

Unsustain-able

industrial

production

Unmet basic human needs for safe water, food,shelter, health care, education, employment, etc.

■ ■ ☼ ► ►

Species depletion (extinction of plants andanimals, habitat degradation)

■ ■ ♣ ☼ ☼

Land degradation: soil erosion, desertification,loss of fertility

■ ♣ ■ ♣ ►

Depletion of nonrenewable energy and minerals ♣ ► ♣ ■ ♣

Depletion of fresh water (groundwater and surfacewater)

♣ ► ■ ► ♣

Water pollution: chemical and bacterialcontamination of groundwater and surface water

♣ ☼ ♣ ☼ ■

Air pollution: urban air pollution, acid deposition,ozone layer depletion, greenhouse gas buildup

♣ ☼ ☼ ■ ■

Conflict and war: domestic and international ♣ ♣ ☼ ☼ ☼

Source: W. Lorson, ed., The Global Ecology handbook, 1990

■: V ery important cause ♣: Moderately important cause

☼: Less important but insignificant cause ►: Unimportant or insignificant cause

1 7 2



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It can be seen from above table that unsustainable populationgrowth is a very important cause of three problem impacts and amoderately important cause for the five other problem impacts.

It is very difficult to meet the basic human needs for food,safe water, shelter, health care, education, and others by toorapid increase in population without straining the environment.And an unrestrained exploitation of our natural resource resultsin the loss of virgin forests and soil fertility, soil erosion of deserts. These in turn deprive many animals and plants of their natural habitat. Extinction of many animal and plant species is adirect consequence.

In order to support an ever-increasing population, more andmore factories must be put up. Industry must be expanded and of course pollution follows, the consequences of which are alreadyenumerated above.

The probability of conflict between ethnic groups and nationsis increased with unsustainable population growth. They mayfight over needs resources, like oil and water. Or, they may fightfor territories needed by their increasing number. The resultingmisery and human sufferings brought about by war are too wellknown.

The possibility of poverty and unequal distribution of wealth becomes greater with unsustained population growth. Food production may not be able to keep up with the increase in the

number of consumers.Geographically, the earth is divided into nations with varyingresources and with varying population densities and varyingdegrees of industrialization. In short, some countries are wealthier



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than others. And even in the same country, the structure of societyvaries; there is a very wide gap between the rich and the poor.Cutting more trees and over fishing in order to survive are likelyexamples of this.

GUIDE QUESTIONS

1. Explain the main reasons why humans drastically alter the global environment.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

2. Explain some of the consequences of altering the balance

of nature.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

3. Enumerate more beneficial effects of humankind’s being

able to control nature.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………



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4. Why is the increase in food consumption, energy use, and

economic output much greater than the increase in population?

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

5. Cite policies by some governments around the world to

address the problem of inequality of life among peoples of the

world.

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

……………………………………………………………………………

§2. SUISTAINABLE DEVELOPMENT

The past 20 years have seen a growing realization that thecurrent model of development is unsustainable. In other wordswe are living beyond our means. From the loss of biodiversitywith the felling of rainforests or over fishing to the negativeeffect our consumption patterns are having on the environmentand the climate. Our way of life is placing an increasing burden

on the planet - this cannot be sustained.The increasing stress we put on resources and environmental

systems such as water, land and air cannot go on forever.Especially as the world's population continues to increase and



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we already see a world where over a billion people live on lessthan a dollar a day, more than 800 million are malnourished, andover two and a half billion lack access to adequate sanitation.

Some people started realizing the development andenvironmental protection are inequality; such as:

Successful economic development and environmental protection go hand in You cannot have one without the

other. (Former U. S President George Bush)

Achieving sustainable economic growth will require the

remodeling of agriculture, energy use, and industrial

production after nature’s example. (Jessica TuckmaMathews - World Resource Institute)

Our global future depends upon sustainable development.

It depends upon our willingness and ability to duplicate

our intelligence, ingenuity, and adaptability - and our energy - to our common future. This is a choice we can

make. (the Report of the world commission onenvironment and development)

Some countries are more developed than others in terms of agriculture, industry, education, health services, and other aspects of development. Most of the countries in WesternEurope are more developed than those of Eastern Europe.Similarly, the countries in North America are more developedthan those of Central and South America. Likewise most

countries in Africa are less developed. Some countries in Asialike Japan, Korea, Taiwan, and Singapore are more developedthan others like the Philippines, Malaysia, Indonesia,Bangladesh, India and Vietnam.



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The People’s standard of living also varies from one countryto another. Needless to say, those from the developed countries,on the average, have higher standard of living.

Some researches show that the less developed countries, asmeasured by their per capita income, have higher birth rates,lower life expectancy, poorer dwellings, lower birth weights,lower literacy, less number of doctor and nurses per unit population, and consume less energy and fewer calories.

A widely-used and accepted international definition of sustainable development is “development which meets the needsof the present without compromising the ability of futuregenerations to meet their own needs”. This means developmentwithout permanent damage to the ecological system.

Sustainable development means using the natural resourcesonly to a certain extent so that they will be able to recover. It

further means that population should either be help to aminimum or be stopped altogether. This is the same as sayingthat sustainable development must not endanger the atmosphere,water, soil, and ecosystem that support life on earth. Moreover,sustainable development requires societies to meet human needs by increasing productive potential and by ensuing equitableeconomic, social, and political opportunities for all.

To accomplish such an objective might curtail some kind of upheaval in some societies around the world. Instance, in a

country where the economy and the means of production arecontrolled by a few rich families, where the middle class inweak and a great majority of the people are poor, a restructuringof society might be needed.



181

In order that the definition of sustainable development is fullyunderstood and the proposed solutions to the problem impacts,as mentioned earlier, be adequately addressed.

Some solutions for achieving sustainable development as

Reducing poverty: Reducing poverty implies better health,

better nutrition, longer life expectancy, and improved literacy.Reducing inequalities suggests better employment prospects and broadening of opportunities for those who have less in life.These are important solutions to the problems of basic humanneeds and habitat degradation.

Making agriculture: Making agriculture sustainable requiresdrastic reduction in soil erosion, maintenance of arable lands,and a drastic decrease in harmful farming practices like the useof toxic chemicals. Systems for reducing soil erosion should bedevised. There should be strict policy in the conversion of arable

lands into roads and subdivisions, and for industrialdevelopment. Maintaining soil fertility though intercropping andthe trees and the use of nontoxic fertilizers will go a long waytoward solving the problem of pollution.

Forest protection: Forest protection is not easy for a countrywhere there are so many poor people. They need the trees andthe land for survival. Government must have a viable programfor reforestation. Success in this degradation will effectivelyreduce freshwater depletion, slow down land degradation, and

prevent periodic flooding.Wise use of energy: Wise use of energy includes changing the

life style of well-to-do people like using smaller car, less use of air conditioners, and less light in the homes. It also includes



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energy saving measures from the government: regulating speedlimits, requiring the installation of energy saving devices inoffices, and developing more renewable energy source likehydro electronic power plants. The net effect of the measureswould be energy conservation and less pollution.

Supply of fresh water : The supply of fresh water in the worldis critical. With very high demand from industry and people,aggravated by deforestation, the supply has greatly diminished.In addition, because of pollution, the quality of the water hasdeteriorated. The need to conserve fresh water is of utmostimportance to support a growing population and to provideirrigation to agricultural crops.


QUESTIONS

1. ……………….. means using the natural resources only toa certain extent so that they will be able to recover.

a) Unsustainable population growth

b) Problems

c) Globalization

d) Sustainable development

2. Sustainable development ……………… the atmosphere,water, soil and ecosystem.

a) must not endanger

b) is dangerous



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c) can develop

d) can’t develop

3. Forest protection is one of the solutions of ………………..

a) environment protection

b) sustainable development

c) environment protection and sustainable developmentd) industrial revolution

4. Some of solutions for achieving sustainable developmentare …….

a) reducing poverty and making agriculture

b) protecting forest

c) wising use of energy and supplying of fresh water

d) reducing poverty and making agriculture, protecting

forest and wising use of energy and supplying of fresh water

5. Reducing poverty implies ………………..

a) better health and nutrition

b) longer life expectancy

c) better health, nutrition and longer life expectancy

d) soil degradation

6. What does making agriculture sustainable require?

a) reduction in soil erosion b) maintenance of arable lands

c) decreasing the use of toxic agro-chemicals



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d) reduction in soil erosion, maintenance of arablelands and decreasing the use of toxic agro-chemicals

7. Deforestation means ………………..

a) cutting down forest trees for firewood andagriculture development

b) planting forest treesc) afforesting

d) sell firewood for life

8. The benefit of reforestation is ………………..

a) reducing freshwater depletion

b) reducing land degradation

c) preventing periodic flooding

d) preventing periodic flooding and reducing

freshwater depletion and land degradation9. Use of hydro electronic power is a way of ………………..

a) saving money

b) wise use of energy

c) development

d) using energy

10. Wise use of energy includes ………………..

a) less use of air conditioners and less light in the home

b) less use of cars and developing renewable energysource

c) less use of air conditioners and cars and less light inthe home and developing renewable energy sources



185

d) use unsustainably the energy sources.

11. Which cause makes the supply of fresh water diminished?

a) deforestation

b) high demand from industry and deforestation

c) water protection

d) greenhouse effect12. The quality of the water has deteriorated by ………………

a) pollution

b) sustainable development

c) less use of air conditioners

d) afforesting

13. The components of atmosphere include ………………..

a) nitrogen, oxygen, hydrogen and steam

b) carbon oxide, ozone and methanec) inert gas, carbon oxide, ozone and methane

d) nitrogen, oxygen, hydrogen, steam, carbon oxide,ozone, methane and inert gas

14. Choose the correct sentence:

a) Carbon dioxide is a source of water pollution.

b) El-Nino makes the Earth’s temperature decrease.

c) The effusive volcano causes the air pollution.

d) Deforestation is a best way to protect the forest.15. One of the principles of sustainable development is ………

a) protecting the diversity of the Earth



186

b) changing the personal habit.

c) Managing the natural resources

d) protecting the diversity of the Earth, changing the personal habit and managing the natural resources

16. People began to disturb the environment in such a manner

……….. to effect the global environment many years ago.a) like

b) as

c) by

d) from

17. Most developed countries have zero or very, very low population …..

a) people

b) ratingc) growing

d) growth rate

18. In the less-developed countries, it is estimated that onlyhalf …….. the people have safe drinking water.

a) in

b) on

c) of

d) at

19. …………. in many areas aggravates the environmentaldegradation.

a) afforestation



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b) deforestation

c) forest

d) forester

20. Oxides of nitrogen, sulfur, carbon dioxide and other pollutants are …….. acid rain that lower crop yield and

damage millions of hectares of forests.a) due to

b) dued to

c) resulting

d) causing

21. The probability of conflict between ethnic groups andnations is increased with ……………….. populationgrowth.

a) unsustainable

b) unsustained

c) sustainable

d) sustained

22. Achieving sustainable economic growth will require theremodeling ……………….. agriculture, use of energy andindustrial production after nature’s example.

a) in

b) on

c) of d) at



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23. Sustainable development …………….. using the naturalresources only to a certain extent so that they will be ableto recover.

a) mean

b) means

c) is meantd) is meaning

24. Sustainable development requires societies to meet humanneeds ……………….. increasing productive potential and by ensuing equitable economic, social and politicalopportunities for all.

a) by

b) to

c) caused

d) due to25. ……………….. inequalities suggests better employment

prospects and broadening of opportunities for those whohave less in life.

a) reduce

b) reducing

c) reducible

d) reduction

26. Making agriculture sustainable requires drastic reduction…… soil erosion, maintenance of arable lands, and adrastic decrease in harmful farming practices like the useof toxic chemicals



189

a) of

b) at

c) on

d) in

27. Forest protection is not easy for a country …….. there are

so many poor people.a) when

b) where

c) which

d) what

28. ….. the wide gap between the rich and the poor nations, the benefits of these increases do not apply equally among people of the world.

a) Although b) Despite

c) Because

d) Because of

29. The luxurious life-style of the rich …………….. famouscontributes to environmental degradation.

a) and

b) or

c) between

d) with



190

30. The main sources …………….. energy in the world arefossil fuels and natural gas.

a) at

b) on

c) in

d) of 31. Identify the error underlined word or phrase of the

following sentence: “The industrial revolution have produced all kinds of hazardous materials that polluted theenvironment”.

a) industrial

b) have produced

c) hazardous

d) polluted

32. Identify the error underlined word or phrase of thefollowing sentence: “Oxides of nitrogen and sulfur, ozoneand other pollutants are causing acid rain that lower cropyield and damages millions of hectares of forests,especially among the industrial countries”.

a) oxides

b) lower

c) damages

d) of



191

33. Identify the error underlined word or phrase of thefollowing sentence: “The possible of poverty and unequaldistribution of wealth becomes greater with unsustained population growth”.

a) possible

b) wealthc) with

d) population

34. Identify the error underlined word or phrase of thefollowing sentence: “Sustainable development means usingthe natural resources only to a certain extent so that they beable to recover”.

a) means

b) using

c) extentd) be able to

35. Identify the error underlined word or phrase of thefollowing sentence: “It is very difficulty to meet the basichuman needs for food, safe water, shelter, health care,education and others by too rapid increase in populationwithout straining the environment”.

a) difficulty

b) needs

c) increased) straining



192

36. Which among the following is most energy efficient?

a) incandescent bulb

b) florescent tube light

c) compact fluorescent lamp

d) incandescent bulb and florescent tube light

37. In rural areas, this gas can be generated and used for cooking and lighting.

a) biogas

b) oxygen

c) ammonia

d) biogas, oxygen and ammonia

38. Wind energy is the kinetic energy associated withatmospheric air. It has been used for centuries for the

following operation.a) grinding grain

b) generating electricity

c) running cars

d) grinding grain and running cars



193

GLOSSARY

Abiotic factor: Nonliving components of the ecosystem

including physical and chemical factors such as pH of soil,

temperature, and relative humidity.

Acid precipitation: Rain or snow that has lower pH than

precipitation from unpolluted skies.

Acid rain: Moisture in the atmosphere which has been

contaminated by oxides of sulfur and nitrogen.

Active solar: Process of capturing and storing energy from

the sun though solar panels.

Adaptation: Ability of an organism to adjust to the constantly

changing conditions of the environment.

Advanced industrial society: Post - World War II industrial

society characterized by great rise in production and consumption and increase energy demand.

Agricultural period: Period when people that lived in towns

or villages rely on domestic animals and fields.

Algae bloom: Very rapid growth of algae in surface waters

due to increase in inorganic nutrients, especially phosphorus

and nitrogen.

Alien species (also called foreign species): Species

introduced in new habitats.

Aquifer: Groundwater for human use.

Asthma: Lung disorder characterized by the constriction and

mucus production and deposition in the bronchioles.



194

Atmosphere of the earth: Layer of air surrounding the earth.

Autotroph: Organism that is self-nourishing; one that can

produce its own food.

Bacteria: Group of single-celled organisms responsible for

functions like that decay of organic materials and nutrient

recycling.

Biodegradable: Object that can be acted upon by

microorganisms, like bacteria and fungi.

Biogas: Gas produced by the decay of organic matter,

especially manure and crop residues.

Biological control: Use of natural parasites, predators,

bacteria, and others to control pests.

Biological magnification: Accumulation or increase of chemical

substances on organisms in succeeding higher trophic levels.

Biological oxygen demand (BOD): Measure of the depletion

of oxygen in water due to bacteria decay.

Biomass: Amount of organic materials in plants or animals

from which energy can be derived.

Biomass pyramid: Amount of organic materials available at each

trophic level.

Biome: Large geographical area with characteristic life

forms; a stable community.

Biosphere: Portion of the earth and its environment within

which life in any of its form is manifested.

Biotic factor: Living component of the ecosystem which

includes plants, animals, and bacteria.



195

Biotic potential: Reproductive capacity of the living

components of the ecosystem.

Birthrate: Average number of living births per year per 1000

inhabitants in the certain place.

Bottom-up approach: Change in attitudes and values which

can influence a change in life-style in order to solveenvironmental problems.

Cancer: Uncontrolled growth of body cells.

Canopy: Uppermost leafy covering of the forest.

Carbon cycle: Cycling of carbon between organisms and the

environment.

Carcinogen: Chemical that causes cancer.

Catalyst: Substance that accelerates reaction of chemicals.

Cell: Basic unit of life.

Chlorophyll: Green pigment in plants involved in the process

of photosynthesis.

Clear cutting: Removal of all trees in an area like a forest.

Climate: Average weather condition.

Climax community: Mature and stable community.

Cogeneration: Production of two and more forms of useful

energy from one process.

Community: Population of plants, animal, and

microorganisms living and interacting in a given locality.



196

Composting: Process of decaying plants and animals, and

other organic matter in the presence of air to obtain humus.

Coniferous biome: Forest abundant in cone - bearing trees,

called conifers, which have needlelike leaves.

Conservation: Process of reducing the use of resources

through recycling, decreased demand, and increased efficiencyuse.

Consumer: Organism that feeds on other organisms.

Crop rotation: Alternating crops in the fields.

Curie: Unit of radioactivity equivalent to 3.70×1010

disintegration per second of any radioactive nuclides.

DDT: Organochlorine insecticide used to control pets. It is

now banned due to its harmful effects in the environment.

Death rate: Average number of deaths per year 1000 population in the certain place.

Deciduous forest: Forest consisting of plants that shed off

their leaves annually.

Decomposer (also known as microconsumer ): Organism

which breaks down nonliving organic material; example are

bacteria and fungi.

Deforestation: Destruction of forest.

Denitrifying bacteria: Bacteria that convert nitrates into

nitrogen gas.

Desert: Type of biome characterized by low humidity, high

temperature, and plants, and animals adapted to lack of water.



197

Desertification: Formation of deserts in arid and semi - arid

regions due to change in climate and overgrazing.

Detritus: Any organic waste from plants and animals.

Dinoflagellate: Small organism floating near the surface of

the ocean that cause red tides.

Diversity: Number of different species in an ecosystem.

Dominants: Most numerous organisms in a community; they

are usually the plants.

Ecological habitat: Place where the organisms live in the

ecosystem.

Ecological niche: Specific function performed by an

organism.

Ecology: Division of biology that treats the relation between

organisms and their environment.

Ecosystem: Interaction between an organism and its

environment.

Ecosystem stability: State of balance or equilibrium in an

ecosystem.

Ecotone: Community of transition zone between two adjacent

communities.

Endangered species: Organism that is in danger of becoming

extinct.

Energy: Capacity to do work

Environment: Sun of all external forces and conditions acting

on an organism or a community of organisms.



198

Eutrophication: Accumulation of nutrients in a lake or pond

due to human intervention or nature causes.

Exclusion principle: Idea that no two species can occupy

exactly the same niche.

Fecundity: Ability of the population to bear children.

Fission: Splitting of heavy nuclei when struck by neutrons or

other subatomic particles.

Fluorocarbon: Organic molecule consisting of chlorine and

fluorine covalently bonded to carbon.

Food chain: Energy pathway which proceeds from the producer to

the consumer.

Food web: Series of interrelated food chains in an ecosystem.

Fossil fuel: that which is composed of coal, gas, and soil

which are derived from the decomposition of dead organismsafter a long time.

Frontier mentality: Kind of attitude among people to effects

that the environment can be abused and misused.

Fusion: See nuclear fusion.

Geothermal energy: Energy derived from magma.

Grassland biome: Community where grass is abundant while

trees are scarce and where mostly herbivores and rodents dwell.

Greenhouse effect: Rising of the average global temperaturecaused by the accumulation of the carbon dioxide and other gases

in the atmosphere. These gases trap radiant heat and prevent its

escape into space.



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Groundwater: Water below the earth’s surface.

Habitat: Place where the organism lives.

Halophyte: Plant that grows in saline or salty environment,

like seaweeds and algae.

Hazardous substance: Substance that poses a threat to human

health and the environment.

Herbivore: Organisms that feeds directly on plants

Heterotroph: Organisms that feeds on others and cannot

manufacture its own food.

Humus: Material which consist of decaying matter and

inorganic substances that result from the decomposition of dead

plants and animal.

Hydroelectric power: Power produced in turbines powered by

running water.

Hydrophytes: Plant that grows in water and permanently water -

logged soil.

Insecticide: From of pesticide used to control insect

population.

Life expectancy: Average age at which a person is calculated

to live.

Limnetic zone: Open water zone of lakes through which

sunlight penetrates.

Littoral zone: Shallow waters along a lakeshore where rooted

vegetation grows.

Magma: Molten rock beneath the earth’s crust.



200

Maximum temperature: Highest limit of temperature by

which an organism can still function.

Mesophyte: Plant of grows in moderate conditions between

the environmental extremes.

Microconsumer: Bacterium of fungus that carries out

decomposition.

Minimum temperature: Lower limit of temperature by which

an organism can still function or survive.

Mutation: Any damage done to the DNA or chromosomes.

Natural gas: Fuel containing about 50 to 90 percent methane.

Niche: Place where organisms live.

Nitrate: Inorganic anion containing three oxygen atoms and one

nitrogen atom.

Nitrite: Inorganic anion containing two oxygen atoms and one

nitrogen atom.

Nitrogen cycle: Cycling of nitrogen between the organisms and the

environment.

Noise pollution: Unwanted sound that have harmful effects

on the body.

Nuclear fission: Splitting of an atomic nucleus when struck by

neutrons.

Nuclear fusion: Joining of two small atomic nuclei to from anew and large nucleus.

Nuclear power: Energy derived from nuclear fission or

fusion.



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Oil: See petroleum.

Oil shale: Sedimentary rock which is finely grained and

contains an inorganic substance called kerogen.

Omnivore: Organism that consumes both plants animals.

Optimum temperature: Temperature at which the organism can

function best.

Ozone: Molecule that contains three molecules of oxygen

found in the atmosphere and which screens ultraviolet rays.

Ozone layer (or the ozonosphere): Thin layer of ozone in the upper

atmosphere which absorbs ultraviolet light and converts it to infrared

radiation.

Paralytic shellfish poisoning: Effect to red tide poisoning.

Particulate radiation: That which consists of parts of atoms

that are radiated either by natural radioactive disintegration or by artificial means like the explosion of atomic bombs.

Passive solar: Capture and retention of the sun’s energy

within a building though windows and some from the heat

storage in the building.

pH: Measure of the acidity on a scale of 0 to 14.

Photosynthesis: Process of manufacturing food by green

plants in the presence of sunlight.

Physiological drought: The result when the roots of plants

become les permeable at low temperatures.

Pioneer community: First group of organisms that becomes

established in an environment that was not previously occupied

by any life form.



202

Pollution: That which occurs when there is a change in the

physical, chemical, or biological conditions in the environment

which harmfully effects the quality of life, including effects on

other animals and plants.

Population: Group of organisms that belong to the same

species and can interbreed freely.

Population growth rate: Natural increase in population

represented by the different between birth and death rates.

Predator: Organism that kills and eats another organism.

Prey: Organism that is killed and eaten by a predator.

Primary consumer: First organisms that eats the plants in the

tropic level

Primary succession: Development of communities where no

organisms previously existed.

Principle of least effort: phenomenon when the population of

the herbivores increases.

Producer (autotroph): Green plant or organism that, performs

photosynthesis.

Profundal zone: Deeper part of the lake water into which

sunlight does not penetrate.

Pyramid of energy: Representation of the organic content in each

trophic level.

Radiation dose absorbed in the human or animal tissueequivalent to 100 grs/gram of tissue.

Reactor core: That which consists of fuel rods in a reactor

vessel.



203

Recycling: Processing of material into new products that

may or may not resemble the original material.

Red tide: Phenomenon that occurs when the population of the

dinoflagellates increases tremendously.

Relative humidity: Amount of moisture in a given quantity of

air divided by the amount the air could hold at that temperature.Rem (or roentgen equivalent man): dose from any radiation

that produces biological effects in man equivalent to one rad or

X ray.

Resilience: Ability of an organism to return to its normal

state after a disturbance.

Roentgen unit (R): Quantity of radiation (gamma or X ray)

that will produce electrostatic unit of positive or negative

electricity in 1cm3

of air at normal temperature and pressure.

Secondary consumer: Organism that belongs to the third trophic level in a food chain.

Secondary succession: Sequential development of biotic

communities occurring after the complete or partial destruction of

an existing community.

Sediment: Soil particles, sand, and other mineral mater

eroded from land and carried to surface waters.

Shale oil: Thick heavy oil formed when shale is heated.

Slash-and-burn agriculture: Practice in farming in which the

forests are cleared by cutting and burning.Sludge: Solid organic material produced during sewage

treatment.

Solar aqua cell: Waste water treatment, using solar heat.



204

Solar collector: Derived from the sun and natural phenomena

driven by the sun.

Species: Kind of organism.

Species diversity: Different kinds of plants and animals in a

community.

Succession: Natural replacement of one community by another community.

Sustainable ethics: Set of views in which man and nature are

one and that the earth’s resources are limited.

Taiga: Biome found south of North America, Asia, and

Europe and characterized by coniferous forests.

Temperate deciduous forest: Biome characterized by

deciduous trees and abundant rainfall.

Teratogen: Agent or chemical that causes birth defects.

Top-down approach: Approach in solving environmental problems which involves the creation of laws and regulations

that will regulate behavior.

Toxic substance: Substance poisonous to human beings and

animals.

Transpiration: Evaporation of water from the leaves.

Trophic level: Position occupied by lack of trees and low

temperature.

Weathering: Process of breaking down rocks into small

particles.

Wetland: Land area along freshwater and salt water.

Xerophytes: Plant that grows in dry or arid conditions.



205

METRIC UNIT CONVERSION TABLES

THE METRIC SYSTEM

Standard metric Units Units Abbreviations

Standard unit of mass gram g

Standard unit of length meter m

Standard unit of volume liter l

Common

Prefix

Unit Examples

kilo 1,000 A kilogram is 1,000 grams.

centi 0.01 A centimeter is 0.01 meter.

milli 0.001 A milliliter is 0.001 liter.

micro (µ) one-millionth A micrometer is 0.000001 (one-millionth) of a meter.

nano (n) one-billionth A nanogram is 10-9 (one- billionth) of a gram.

pico (p) one-trillionth A pictogram is 10-12 (one- billionth) of a gram.

UNITS OF LENGTH

Unit Abbreviations Equivalent

meter m Approximately 39 incentimeter cm 10-2m

millimeter mm 10-3m



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micrometer µm 10-6m

nanometer nm 10-9m

angstrom Ǻ 10-10m

Length conversions

1 in = 2.5 cm 1 mm = 0.039 in

1 ft = 30 cm 1 cm = 0.39 in

1 yd = 0.9 cm 1 m = 39 in

1 mi = 1.6 km 1 m = 1.094 yd

1 km = 0.6 mi

To convert Multiply by To obtaininches 2.54 centimeters

feet 30 centimeters

centimeters 0.39 inches

millimeter 0.039 inches

UNITS OF VOLUME


liter l Approximately 1.06 qtmilliliter ml 10-3 (1ml = 1cm3 = 1cc)

miccroliter µl 10-6 l



207

Volume conversions Equivalent

1 tsp = 5ml 1ml = 0.3fl oz

1 tbsp = 15ml 1l = 2.1 pt

1 fl oz = 30ml 1l = 1.06 qt

1 cup = 0.24l 1l = 0.26 gal

1 pt = 0.47l

1 pt = 0.95 l

1 gal = 3.8 l

To convert Multiply by To obtain

fluid ounces 30 milliliters

quarts 0.95 liters

milliliters 0.03 fluid ouncesliters 1.06 quarts

UNITS OF WEIGHT


kilogram kg 103g (approximately 2.2 lb)

gram g Approximately 0.035 oz

milligram mg 10-3 g

microgram µg 10-6

gnanogram ng 10-9 g

pico gram pg 10-12 g



208

Weight conversions

1 oz = 28.3g 1g = 0.035 oz

1 lb = 453.6g 1kg = 2.2 lb

1 lb = 0.45kg

To convert Multiply by To obtain

ounces 28.3 grams

pounds 453.6 grams

pounces 0.45 kilograms

grams 0.035 ounces

kilograms 2.2 pounces

Temperature conversions Some equivalents

oC =9

5*)32( o F

oF =5

9*C o

+ 32

0oC = 32oF37oC = 98.6oF100oC = 212oF



REFERENCES

1. Barrington, Ernest, and James William, Environmental

Biology, Wiley Inc., New York, U.S.A., 1980.2. Chiras Daniel D., Environmental Science: A Framework for

Decision Making , Benjamin/Cummings Publication Co.,California, U.S.A., 1988.3. Committee for Global Biosphere Program, Global

Change and Our Common Factor , National Academy Press,Washington, D.C., U.S.A., 1986.

4. Erickson Jon, Greenhouse Earth - Tomorrow’s Disaster

Today. Blue Ridge Summit, Tab Books, P.A., U.S.A., 1990.5. Nebel Bernard, Environmental Science. Englewood Cliffs,

Prentice Hall, N.J., U.S.A., 1990.

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