HO CHI MINH UNIVERSITY OF INDUSTRY
INSTITUTE FOR ENVIRONMENTAL ENGINEERING & MANAGEMENT
Compiled by VO DINH LONG
ENVIRONMENTAL SCIENCES
(Specialized English course for Environmental Students)
HO CHI MINH CITY, 2010
CONTENTS
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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.
1.1. 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, saw to it that everything needed
for them to live is found in the world which He created. He
provided space, ways and means by with different organisms can
interact with one another and with their environment.
Part of the world where life operates is known as the biosphere.
The biosphere consists of the air (atmosphere), water
(hydrosphere), and earth (lithosphere) where living things interact
with their environment.
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Figure 1.1: The biosphere
When you study the interaction or relationship between organisms
and their environment, you are studying an ecosystem. The term
ecosystem( he sinh thai) refers to all the living things and the
nonliving things in a given area. It includes all the plants and
animals together with their surroundings. The ecosystem of an
aquarium, for example, consists of the hydrilla and others plants,
fish, snails, and other aquatic animals, some of which can only be
seen under a microscope. It also includes sand and pebbles at the
bottom. We can also include the 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 other
plants and animals that live on it. The pond is another example of
an ecosystem.
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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 an
abundance 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 and
nonliving components occur. The branches and leaves of trees help
break the force of the rain. Layers of dead leaves and twins and
branches on the forest floor soak up water and prevent rain from
washing soil away. Little water runs off the land. The roots of trees
hold the soil and water on which they depend. Moreover, when the
leaves(lá) and branches (cành) decay, they become part of the rich
topsoil.
The soil is made up of minerals like silica and clay. They come
from the breakdown of rocks(fong hóa). There are spaces between
the mineral particles which are filled(được lắp) with air and water.
Roots of plants penetrate(xâm nhập) deeper into the soil causing
physical change. They loosen the tightly packed particles(kết cấu
chặt của các hạt). Chemical change also occurs. 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, like
earthworms(con jun đất), that decompose(phân hủy) the dead plants
and animals. Some are too small to be seen, but they all help
maintaini(duy trì) the ecological balance(cân bằng sinh thái) 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.
1.2. COMPONENTS OF AN ECOSYSTEM
In the preceding section you learned what an ecosystem is. The
living component is known as the biotic and the nonliving
component is known as abiotic. The biotic component consists of
plants, animals, and bacteria. The abiotic component includes all
the factors of the nonliving environment such as the substratum,
light, rainfall, nutrients, soil, and others. Both the biotic and abiotic
components are equally important in the ecosystem because
without one of them the ecosystem would not 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 non living factors, such as temperature,
water, and others. The abiotic affect the biotic components and vice
versa.
1.2.1. Green plants
Green plants are known as the producers. They capture the energy
from the sun and together with carbon dioxide (CO2) in the air and
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water (H2O) convert together those into food energy. 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 that can be
used by other organisms as food. These green plants further 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 to
your eyes. These are the microscopic drifting plants which are
greater sources of food than the big plants that you can see. We call
these microscopic plants phytoplankton. When they become too
abundant, they can give a pond or a body of water a green color, it
is called Eutrophication (Eutrophication is an increase in the
concentration of chemical nutrients in an ecosystem to an extent
that increases the primary productivity of the ecosystem).
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 are phytoplanktons?
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1.2.2. Animals
Animals, or the consumers, obtain their food from plants or other
animals. Because of this, they are also known as heterotrophs,
which means that they feed on others and cannot manufacture their
own food, unlike the green plants.
There are three different types of consumers, namely, the
herbivores, 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 the snake that
eats the caterpillar is a carnivore. Omnivores eat both plants and
animals. A human being is a good example of an omnivore.
Through the process of respiration, animals combine the food they
eat with oxygen to produce CO2 and H2O which are used by plants
in the photosynthesis process. Animals also convert the materials of
the plant bodies into the materials that make-up their own bodies.
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All the energy produced and used by animals comes from the
plants.
Guide questions
1. What are consumers?
2. What are the three types of consumers? and give one example
for each type.
1.2.3. Bacteria and fungi as agents of decay
Have you ever observed what happen to leaves that fall on the
ground?
After some time, the leaves wither, break down into smaller pieces,
decay, and finally become part of the soil. What do you think is
responsible for this change?
Have you heard of the word decomposer? What do you think does a
decomposer do?
Decomposers make-up the third biotic component of the ecosystem.
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 they need and release the
minerals and other nutrients back into the environment for use
again by other organisms. Bacteria are among the most abundant
decomposers while fungi are known to be the fast-acting
decomposers.
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Decomposers are found everywhere. In the pond, they are abundant
at the bottom where the remains of the dead organisms (plants and
animals) settle (đọng). On land, they abound on the surface of the
soil where the dead bodies of plants and animals are found.
Each of the three groups of the biotic component of the ecosystem producers (plants), consumers (animals), and decomposers (bacteria
and fungi) - has its own specific function or 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 its ecological
niche, while the place where the organism lives in the ecosystem is
known as its ecological habitat.
Guide questions
1. What are producers?
2. Give examples of producers?
3. What do decomposers perform in the ecosystem?
1.2.4. Nonliving factors
The nonliving factors of the environment make-up abiotic
component 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
affected differently. For example, lichens may not survive when
temperature gets very high but cactus may.
Different organisms thrive in different conditions. There are
animals, like the earthworms, which favor wet condition, while
others, like ants, prefer drier (con kiến) conditions. Some plants,
such as cactus (xương rồng), grow best in sandy soil while
tomatoes grow best in loamy soil (đất mùn).
As a whole, these environmental factors not only provide (cung
cấp) essential (chủ yếu) energy and materials but also determine
(xác định) the kind of organisms that will inhabit the area. Hence
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(do đó), they provide the conditions necessary (cần thiết) for the
survival (sự tồn tại) of the organisms.
Guide questions
1. What are the components of an ecosystem?
2. Give examples for each component of the ecosystem.
3. In general, what are the functions of these components?
4. Can an ecosystem exists without one of its components?
Justify your answer.
Vocabulary
Autotroph(SV tự dưỡng): Organism that is self-nourishing; one that
can produce its own food.
Hetertrop(SV dị dưỡng): Organisms that feeds on others and
cannot manufacture its own food.
Biological magnification( Sự khuếch đại sinh học): Accumulation
(Sự tích lũy) or increase(Sự gia tăng) of chemical substances on
organisms in succeeding(nối tiếp) higher trophic levels.
Biomass(Sinh khối): 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, the amount of energy in fuel available for powering a
motor vehicle.
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Food chain(Chuỗi thức ăn): Energy pathway which proceeds from
the producers to the consumers.
Food web(Lưới thức ăn): Series of interrelated food chains in an
ecosystem.
Pyramid of energy (Tháp năng lượng): 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 (biểu hiện).
Photosynthesis(Quang hợp): Process of manufacturing food by
green plants in the presence(sự hiện diện) of sunlight.
Atmosphere: Layer of air surrounding(bao quanh) the earth.
Hydrosphere: The part of the Earth composed of water including
clouds (mây), oceans, seas, ice caps (băng), glaciers( Sông băng),
lakes, rivers, underground water supplies (Nước ngầm), and
atmospheric water vapor (hơi nước).
Lithosphere: The outer (phía ngoài), rigid shell (vỏ cứng) of the
Earth, situated above the atmosphere and containing the crust,
continents (lục địa) and oceans or the solid part of the earth’s
surface
Grassland biome (Quần xả SV đồng cỏ): Community where grass is
abundant while trees are scarce and where mostly herbivores and
rodents dwell.(ĐV gặm nhấm)
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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 (tái sản xuất) capacity(khả năng) 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 (bên ngoài) forces and conditions
acting on an organism or a community of organisms. (Tổng hợp
các yếu tố và điều kiện bên ngoài tác động lên 1 SV hay 1 cộng
đồng SV)
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CHAPTER 2: MATERIALS AND NUTRIENT CYCLES
The energy that flows (chảy) into an ecosystem cannot be recycled.
Once the energy is used, it is lost. But it much be constantly
repeatedly replenished if the ecosystem is to continuously function.
(Năng lượng không thể tái sử dụng lãi khi nó đi vào 1 hệ sinh thái.
Chúng chỉ được sử dụng một lần, rồi biến mật. Nhưng chúng lại
được bổ sung 1 cách liên tục nếu hệ sinh thái làm đúng nhiệm vụ
vủa nó)
The importance of chemical nutrients, however, are used
repeatedly. They are cycled (chu trình) between the living and
nonliving components of the ecosystem. Generally, they begin in
the abiotic part of the ecosystem (water, land, and air). Then, they
enter to the bodies of plants and animals and return into the abiotic
environment.
(Tầm quan trọng của các hóa chất dinh dưỡng, dù thế nào, chúng
cũng được sử dụng liên tục. Chúng được xem như 1 chu trình giữa
thành phần vô sinh và hữu sinh trong hệ sinh thái. Cho tới khi
chúng đi vào cơ thể động thực vật và trở lại môi trường vô sinh.)
The movement of these materials and nutrients between the living
and nonliving environment clearly shows the interrelatedness of the
abiotic and biotic components in an ecosystem. Among these
recycled materials and nutrients are carbon, oxygen, water,
nitrogen, and phosphorus.
(Quá trình chuyển hóa của các chất khoáng và dinh dưỡng giữa
môi trường vô sinh và hữu sinh cho thấy một cách rõ ràng sự tương
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tác giữa thành phần vô sinh và hữu sinh trong hệ sinh thái. Một vài
các khoáng chất và dinh dưỡng tái tạo được là C, O, H2O, N, P.
After studying this chapter, you should be able to
1. Identify(Nhận biết) different nutrients that can be recycled.
2. Explain the water, carbon and oxygen, nitrogen, and
phosphorus cycles.
3. Discuss(Tranh luận) the importance of each of these cycles.
4. Discuss how people affect these cycles.
5. Differentiate micronutrients from macronutrients (Sự khác
nhau giữa chất vi lượng và đa lượng)
2.1. IMPORTANCE OF THE NUTRIENT CYCLES
The energy from the sun flows to the plant goes to the herbivore
that eats the plant, to the carnivore, and to the last consumer until
the energy is lost into the ecosystem. The energy does not go back
to the source. It cannot be used over and over again.
(Năng lượng từ mặt trời đi vào cây cối rồi tới động vật ăn cỏ khi
chúng ăn cây cối, rồi tới động vật ăn thịt, và cuối cùng là SV tiêu
hủy trước khi năng lượng ra khỏi hệ sinh thái. Năng lượng không
trở lại thành dạng tài nguyên. Nó không thể sử dụng đi sử dụng lại)
In contrast, when the bodies of dead plants and animals decompose,
they are changed into nutrients through the action of bacteria and
fungi. The nutrients are stored in the abiotic environment like the
soil. The nutrients can be used again by the plants. The plants are
eaten by the animals and when the animals die, they decompose
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into nutrients. These nutrients can be used over and over again. In
this way, a cycle of nutrients is formed.
(Trái lại, khi xác chết của động thực vật phân hủy, chúng được biến
đổi thành dinh dưỡng cho vi khuẩn và nấm. Những chất dinh dưỡng
này được tích lũy trong môi trường vô sinh giống như đất. Chúng
có thể được cây sử dụng lại. Cây cối lại bị động vật ăn, và khi
chúng chết đi, chúng phân hủy thành chất dinh dưỡng. Những chất
dinh dưỡng này có thể được sử dụng đi sử dụng lại. Theo cách này
một chu trình dinh dưỡng được thành lập.)
The cycle of nutrients is an important process that takes place in the
ecosystem. Through the cycle of nutrients, the organic compounds
(hợp chất hữu cơ) found in the bodies of organisms are converted
into inorganic 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 abiotic components
interact with one another.
(Chu trình của các chất dinh dưỡng là 1 quá trình quan trọng diễn
ra trong hệ sinh thái. Thông qua các chu trình dinh dưỡng, các hợp
chất hữu cơ được tìm thấy trong cơ thể sinh vật bị biến đổi thành
các hợp chất vô cơ những chất mà được cung cấp cho các sinh vật
khác. Trong cả 2 quá trình dòng năng lượng và chu trình dinh
dưỡng, cây cối có vai trò liên kết mà theo đó các thành phần vô
sunh và hữu sinh tương tác với nhau.)
Insightfulness
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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 consumers. They are
returned to the nonliving environment by decomposers.
Nutrients may be classified into two types, namely, the
macronutrients and the micronutrients. The macronutrients are
those that are required by the organisms in large quantities.
Examples are carbon, hydrogen, oxygen, and nitrogen. Sulfur,
phosphorus, and potassium are also macronutrients but are needed
by organisms in smaller quantities. The micronutrients are needed
in very small amounts. They are also essential to life. Examples are
copper, zinc, iron, and boron.
(Những chất dinh dưỡng được chia làm 2 dạng, tên là Chất dinh
dưỡng đa lượng và vi lượng. Những chất dinh dưỡng đa lượng là
những chất mà sinh vật cần 1 lượng lớn. Ví dụ như Cacbon, hydro,
Oxi và Nito. Lưu huỳnh, photpho và Kali cũng là những chất đa
lượng nhưng sinh vật cần chúng với lượng nhỏ. Các chất vi lượng
cần thiết ở lượng nhỏ. Chúng lại rất cần thiết cho sự sống. Ví dụ
như đồng, kẽm, sắt và Bo.)
The macronutrients are the major components of fats and
carbohydrates. They make-up the cell structures of plants and
animals. The cell walls of plants, for example, are made up of a
very rigid substance called the cellulose. Cellulose is made up of
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these three elements with a ratio of 7.2 carbons, 1 hydrogen and 8
oxygen. This substance makes the cell walls very firm and rigid. It
adds strength to the plant.
(Các chất đa lượng là thành phần chủ yếu của chất béo và
cacbonhydrat. Chúng cấu tạo tế bào của động thực vật. Thành tế
bào của cây là 1 ví dụ, chúng có cấu trúc rất vững chắc được gọi là
Xenlulozo. Xenlulozo cấu tạo bởi 3 nguyên tố với tỉ lệ 7.2 C, 1H,
8O. Những chất này làm thành tế bào trở lên rất vững chắc và
cứng. Chung thêm độ vững chắc cho cây.)
Nitrogen, carbon, hydrogen, and oxygen are the building blocks of
proteins. Phosphorus makes up many nucleic acids and is also
essential for the transformation of energy in the cells.
(N, C, H và O là cấu trúc chính của protein. Photpho chiếm nhiều
trong cấu tạo của axit nuleic và chúng cần thiết cho việc chuyển
đổi năng lượng trong tế bào.)
The micronutrients are as important as the macronutrients.
Magnesium, for example, is necessary in the production of
chlorophyll.
(Các chất vi lượng cũng quan trọng như các chất đa lượng. Ví dụ
như Magie rất cần thiết trong sản sinh diệp lục.)
Guide questions
1. What happens to the energy from the sun when it enters to an
ecosystem?
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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?
2.2 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)
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Figure 2.1: The water cycle
When water in the atmosphere reaches saturation (the highest
amount of moisture that the air can hold), it falls as rain. This falls
directly to the land and bodies of water like the oceans and seas.
Some runs off the surface of the land into rivers. The rain that falls
on the land is absorbed by plants through the roots and drank by
animals. Some penetrates the soil and becomes part of the
underground water, which eventually empties into the oceans. The
processes of condensation and precipitation are responsible for the
return of water from the atmosphere into the land and other bodies
of water.
The water from the land and other bodies of water returns to the
atmosphere through the process of evaporation. Plants return the
water by the process known as transpiration, while animals do this
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through respiration. Water accumulates again in the atmosphere as
clouds and falls as rain.
Guide questions
1. What is saturation?
2. What is evaporation?
3. What is respiration?
4. Trace the pathway of the water cycle.
2.3. 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 use in the
process of photosynthesis. Oxygen is given off during this process.
Animals and other consumers obtain their food as well as their
oxygen needs from plants. In the process of respiration, the food is
broken down into CO2 and water which are returned into the
atmosphere.
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Figure 2.2: The carbon and oxygen cycles
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 dead organisms fail to
decompose quickly. When this happens, the dead bodies change to
coal, oil, and gas which become fossil fuels after a long time. When
burned, fossil fuels release carbon dioxide into the atmosphere.
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 process of
respiration. Decomposers and burning also release CO2 into the
environment.
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Erupting volcanoes emit carbon dioxide. The eruption of the
volcano supplies fresh carbon to the atmosphere from the deeper
part of the interior of the earth.
Carbon dioxide combines with water and forms calcium carbonate
(CaCO3). This compound is used in the production of shells of
animals like clams and oysters. When shelled organisms die, the
calcium carbonate may dissolve or form part of carbonate rocks
serve as an buffer environment and storing carbon 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?
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.
2.4. THE NITROGEN CYCLE
Nitrogen is an element crucial to life. It is an important component
of proteins and nucleic acids. The nitrogen gas constitutes 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.
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You inhale large quantities of nitrogen but it remains in your body
unchanged.
Figure 2.3: The Nitrogen Cycle
Nitrogen in the atmosphere is converted into nitrates in two ways:
(1) by the action of lightning and (2) by action of specialized
organisms. Electrical activity (lightning) during thunderstorms
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converts nitrogen into nitrates but only a small amount. The nitrates
produced by this process fall to the earth with the rain.
The organisms that convert nitrogen are bacteria, algae, and fungi,
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 legumes like beans, peas, and
peanuts. The association between Rhizobium and legumes forms
swollen areas within the roots called nodules. Nitrates are formed
within the nodules. The compounds are then used by the plants to
build proteins, or remain in the soil as fertilizers. Because of this,
legumes are important crop rotation as they help maintain soil
fertility. This explains why farmers plant legumes in soil before
they plant new 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 others cannot.
They have to transform this into nitrates through the nitrogen-fixing
bacteria. This process converting ammonia to nitrates 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 the bacteria
in a process called denitration. Denitration completes the cycle of
nitrogen.
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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? Is this
beneficial to the soil?
If nitrates are not absorbed by plants, they are washed away by
heavy rains. This process is called leaching. Leaching drains the
soil of its nutrients which are ultimately lost into the rivers and
shallow marine sediments. These nitrates enter the marine food
chain and are returned to land by the droppings of seabirds. These
droppings are known as guano, which were once a major world
supply of fertilizer.
Guide questions
1.
2.
3.
4.
What is the important of nitrogen?
What is the useful form of nitrogen?
How is nitrogen converted into nitrates?
What is nitrogen fixation?
27
5. Differentiate between nitrification and denitrification.
6. Explain leaching. What is its role in the nitrogen cycle?
2.5. THE PHOSPHORUS CYCLE
Phosphorus is essential to life. It is a component of the cell
membranes, nucleic acids, and adenosine triphosphate – the energy
currency of the cell.
Figure 2.4: The phosphorus cycle
Phosphorus is found naturally in the environment in the form of
phosphates. Phosphates in the soil come from phosphate rocks.
Though the process of weathering, the phosphates are incorporated
into the soil in soluble or insoluble forms. The plants absorb the
28
phosphate and use it for protein synthesis. The animals obtain
phosphate from the plants they eat. When the plants and animals
die, decomposition brings back the phosphate into the soil.
Phosphate in the soil may be washed away into shallow marine
sediments by means of leaching. It may also reach the deep ocean
sediments. From the shallow marine sediments, the phosphates are
returned to the soil in the form of guano deposits of marine fish and
sediments. Phosphates in the deep ocean sediments are recycled
back to the soil by means of upwelling. If upwelling does not take
place, the phosphate becomes incorporated into the phosphate
rocks.
Phosphate rocks are mined to be used in the manufacture of
phosphate fertilizers. Though leaching, the phosphorus in these
fertilizers is lost from the soil. Human therefore hasten the rate of
loss of available phosphate. This can have serious effects on the
supply of phosphorus for agriculture in the 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 the dead
bodies into phosphates and return them into the soil.
Guano deposits are good sources of phosphates.
-
29
Human activities have altered the cycle of materials in the
environment. When people cut down trees or destroy forest in one
area, rainwater continues to flow until it finally reaches the sea
instead of rising to the atmosphere and falling again on the forests.
The massive destruction of the forests changes the environmental
conditions, so that forests may never recover at all.
Figure 2.5: Eutrophication
Similarly, deforestation also affects the mount of nitrates in the soil
though leaching. This loss of nitrogen limits the growth of plants
and pollutes groundwater.
The phosphorus cycle has also been disrupted by the activities of
humans especially in the water ecosystem. People use a lot of
agricultural fertilizers and detergents of which phosphates are
30
major components. When the phosphates from fertilizers and
detergents run off into lakes, they stimulate the rapid 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?
4. Define algae bloom. How does it lead to eutrophication?
5. What are the effects of eutrophication?
VOCABULARY
Algae bloom: Very rapid growth of algae in surface waters due to
increase in inorganic nutrients, especially phosphorus and
nitrogens.
Conservation: Process of reducing the use of resources through
recycling, decreased demand, and increased efficiency use.
Denitrifying bacteria: Bacteria that convert nitrates into nitrogen
gas.
Denitrification: Process that convert nitrates into nitrogen gas.
31
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 a liquid or
solid to a gas or vapor. Vanishing of 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.
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.
32
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.
3.1. 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 the gravitational pull of
the sun remains constant, the earth will continue to revolve around
the sun in its present speed. There is a delicate balance between the
centrifugal force of the earth as is goes around the sun.
If the sun continue to shine the way it is now, then the earth will
continue to receive radiant energy needed by the living creatures.
Again, there is a delicate balance here. Too much sunshine will
make the earth too hot for most living beings to survive. In short,
the balance of nature is so delicate that any action that might upset
such balance could have catastrophic results.
For millions of years, this balance of nature has been maintained.
The animals that antedated humans for thousands of year did not
33
really disturb the environment. The effect they made on the
environment was minimal and Mother Nature easily recovered.
During the dawn of civilization, humans and the predators lived in
very similar ways. Both hunted for food and dwelt in natural
habitats, like caves. With this kind of life, they did not alter the
environment. But, since humans were more intelligent and more
cunning, plus the fact that they walked erect and made use of their
hands, they were able to invent weapons to help them. Axe from
stones and spears from sharp object made them better hunters than
the animals. And when they learned the use of fire, they cooked
their food with it, warmed their bodies by it, and heated a lot of
things to help them survive. That was when humans proved their
superiority over animals.
When they learned to eat green leafy vegetables and learned how to
cultivate them, they started to alter the environment. They made
clearings in the forests and planted vegetables. When the land was
no longer that fertile, they abandoned the place and cleared 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 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 the environment was able to recover. The
balance of nature remained.
As the population increased and the needs of people became more
complex, they put greater and greater pressure on the environment.
Larger houses were constructed from different materials, strong
34
fences to protect them from enemies, irrigation canals for
agriculture, and large enclosures for animals, all these required
more change in the environment. But even then, there was no
serious damage to the environment from which nature was unable
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 burden on
Mother Earth, especially in the terms of land used for public
buildings, monuments, and, of course, houses. With more lands
used for agriculture and the upkeep of animals, especially those
used 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, when humans 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.
3.2. 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
35
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 were more resistant to
diseases. Some examples will be enumerated to highlight the point.
Better yielding varieties of rice, wheat, and potatoes have resulted
in bumper harvest in many parts of the world. As the direct
consequence, the problem of feeding the growing populations was
partly solves 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, like melons, 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 preserving
producing healthier babies. The end result of all these are a much
faster rate of population increase.
In the field of animal science, researchers were able to improve the
breed of animals used for food. Faster- growing chickens and pigs
and cultured fish are some good examples. Artificial hatching of
eggs was invented. All these resulted in more food for the fastgrowing 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 recent
36
inventions include the bullet train that can run up to 500 kilometers
(km) per hour, airplanes that can carry up to 700 passengers, and
large ships powered by nuclear fuel.
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 gadgets in the kitchen to the
delight of many housewives.
In the field of food technology, we can choose from a very wide
variety of food available in the market, caned goods of all kinds,
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 and new
technology, people are living better food, live in more comfortable
homes, enjoy their vacations more, get better health services, travel
faster, and dress better. In short, they can do a lot better than their
ancestors.
3.3. ADVERSE EFFECTS OF PEOPLE’S ACTIVITIES
Humankind’s intervention with nature has its adverse effects too.
These include the pollution produced by modern technology and its
37
ill effects on the environment (disruption of the atmosphere which
causes greenhouse effect, ozone depletion and acid rain); among
others; pollution of the water system, deforestation, improper
disposal of solid wastes, as well as nuclear wastes; and noise
pollution.
3.3.1. The greenhouse effect
38
Figure 3.1: The greenhouse effect
Too much carbon dioxide and other gases emitted by factories are
accumulating in the atmosphere. These gases allow sunlight 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 average
temperature of the earth could have serious consequences. Among
them is the melting of ice and glaciers in the North and South poles.
This will raise the water level in many areas of the world, resulting
in the submersion of the low-lying coastal towns and cities.
39
3.3.2. Ozone depletion
High above the earth’s atmosphere, between 15 and 59 km above
the earth, is a layer of ozone (O3). It is formed when ultraviolet
radiation (UV) splits a molecule of oxygen (O2), and the free
oxygen atoms (O) combine with other oxygen molecules. Ozone
acts as a filter in the upper atmosphere, preventing the harmful
ultraviolet radiation of the sun from reaching the earth. Scientists
discovered that compounds of carbon such as carbon dioxide (CO2)
and chloroflofuorocarbons (CFCs), nitrogen oxides (NO) and
methane break up ozone molecules, thereby gradually depleting it.
Figure 3.2: Ozone depletion
In fact a large ozone hole was discovered above the tip of South
America. The people directly below it may experience skin
irritations and soreness in their eyes. This may be due to the higher
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,
40
ozone levels dropped by as much as 10 percent in 1987, causing a
20 percent increase in ultraviolet radiation reaching the ground.
3.3.3. Acid rain
Sulfur and nitrogen oxides are released from industrial factories,
electrical power plants, smelting plants, and motor vehicles.
Figure 3.3: Acid rain
When these gases combine with the moisture in the atmosphere,
they return to the ground as sulfuric acids and nitric acids. These
are popularly known as acids rain. Acid rain brings damage to
lakes, the soil, forest, and buildings.
41
Acid rain and limestone
Trees affected by acid rain
Figure 3.4: Effects of acid rain
Many lakes in the Scandinavian countries are seriously affected by
acid rain. Acid rain has brought extensive damage to the trees of
Europe and the eastern part of the United States. Famous buildings
like the Taj Mahal in India are now being damaged by acids from
local oil refineries.
3.3.4. Water pollution
Industrial wastes disposed of in streams and rivers have polluted
these bodies of water, making them unfit for fish and other aquatic
animals to inhabit. When the water from these streams and rivers
flows into lakes and oceans, then these bodies of water also become
polluted. Wastes from industrial factories along 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 into around
rivers make water pollution. The immediate consequence is the
large reduction in fish catch.
42
Drainage water pollution
Solid wastes disposed to
water
Severe water pollution
Oil pollution
Figure 3.5: Water pollution
There are many rivers and lakes in our country suffering from
pollution, perhaps to a lesser extent but nevertheless a serious threat
to the environment. If you add the bodies of water in other
43
countries that are also polluted, then you will feel how serious this
threat is to the earth’s environment.
3.3.5. Deforestation
Deforestation occurs at an alarming rate. Twenty-three percent of
the Earth's land surface is covered by tropical rainforest; however,
these forests disappear at a rate of 4.6 million hectares a year.
Forests are an integral part for the well being of life on Earth.
Figure 3.6: Deforestation
Many environmental problems such as flooding of rivers, the loss
of biodiversity, accelerated soil erosion, resulting in the loss of the
fertility of the land; flooding during heavy rains because 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.
44
3.3.6. Solid waste disposal
Progress produces a large amount of garbage. Much of these are
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 efficient way is landfills. In Vietnam, garbage collection is not
efficient. With an indifferent population, garbage is one of the main
sources of pollution especially in large population centers like Ho
Chi Minh City. When garbage is not collected on time, people tend
to dump them almost everywhere, resulting in very unsanitary
surroundings, clogged waterways, and polluted creeks and rivers.
Improper garbage disposal is known to have triggered the spread of
diseases, epidemics, and other adverse effects on people’s health.
3.3.7. Nuclear waste
45
Nuclear power is among the most efficient and relatively cheap
sources of energy. But the technology is highly sophisticated and
the possibility of nuclear disaster is not remoted.
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 to the
atomic bombings of Hiroshima and Nagasaki during the Second
World war and the hundreds of fatalities in the Chernobyl accident
in the former Soviet Union are grim reminders of what could
happen in the case of nuclear accidents.
46
Figure 3.9: Hiroshima and Nagasaki disasters
Figure 3.10: the Bombing of Hiroshima and Nagasaki
3.3.8. Noise pollution
47
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 the most
unbearable noise from jet engines are some example. Perhaps noise
pollution is the least paid attention to but the ill effects it has one
people are well documented. Psychological effects including
48
irritability, mental stress, and short temperedness are quite
common. Temporary or permanent loss of hearing is a more serious
physical effect of noise pollution.
The impact of the different kinds of pollution on the people and
environment is serious. Permanent and irreparable damages on the
ecosystem could make the earth no longer a pleasant place to live in
and could even make it uninhabitable. That is why pollution and its
effects on the environment should be the concern 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?
3. Do you know of steps taken by the government and/or other
agencies to protect the environment from harmful pollution?
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
49
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.
50
CHAPTER 4: THE POLLUTION PROBLEMS
After studying this chapter, you will be able to:
1. Trace the history of pollution in the world.
(Nguồn gốc lịch sử của ô nhiễm trên thế giới)
2. Identify the major sources of worldwide pollution.(Xác định
nguồn gốc của sự ô nhiễm toàn cầu
3. Distinguish between toxic pollutants and those that are
harmful only to the environment.(Phân biệt những chất ô
nhiễm độc hại và những chất chỉ có hại với môi trường)
4. Describe the main causes of air, water, and land
pollution.(Mô tả nguyên nhân chính của ô nhiễm KK, nước,
đất)
5. Enumerate the efforts exerted by some people to help reduce
pollution.(Liệt kê các biện pháp của con người giúp giảm
thiểu ô nhiễm)
4.1. MEANING OF POLLUTION
When there is a change in the physical, chemical, or biological
condition in the environment which harmfully affects the quality of
life, including effects on other animals and plants, then we say that
there is pollution in environment.
(Khi có sự thay đổi điều kiện vật lý, hóa học hay sinh học trong môi
trường nó gây ảnh hưởng có hại cho chất lượng cuộc sống, bao
gồm các ảnh hưởng lên các động thực vật, khi đó chúng ta nói đó
là sự ô nhiễm môi trường)
The change is generally brought about by introduction of hazardous
substance into the environment. A hazardous substance includes
51
any substance that poses a threat to human health or to the
environment. Substances that are poisonous to human beings and
animals are called toxicants. Those that harm to the environment
may be corrosive, flammable, or explosive. Examples of toxic
materials are carbon monoxide (CO), sulfur dioxide (SO2), and the
oxides of lead and mercury.
(Sự thay đổi xảy tới trước tiên do các chất độc đem tới môi trường.
Các chất độc hại bao gồm những chất mà gây hại cho con người và
động vật được gọi là chất độc.Những chất gây hại cho môi trường
có thể dễ ăn mòn, dễ cháy hoặc nổ. Ví dụ của chất độc hại là khí
Co, SO2 và Oxit Chì, Oxit thủy ngân)
Examples of substances that harm the environment include wastes
disposed of improperly by industries, nonbiodegradable materials,
like plastic, thrown just anywhere; and excessive carbon dioxide
(CO2) introduced into the atmosphere.
(Ví dụ của chất gây hại cho môi trường bao gồm các chất thải xử lý
không đúng bởi các ngành công nghiệp, vật liệu chống phân hủy,
như nhựa, được ném mọi nơi, và khí CO2 được sản sinh quá mức
trong khí quyển.)
Problems caused by hazardous substances are twofold: first, they
cause a wide range of harmful effects on human health such as
cancer, damage to the brain, liver, kidney, bone marrow, embryo,
skin, gastrointestinal organs, and to the central nervous system;
second, these substances can cause long-term or permanent
damages to ecosystem. For instance, toxic substances dumped into
52
the water system can cause long-term damage to most of our rivers
and lakes.
(Nguyên nhân của vấn đề là do các chất độc hại được thể hiện 2
phần: đầu tiên, chúng gây ra hàng loạt các ảnh hưởng có hại cho
con người như ung thư, tổn thương não, gan, thận, tủy xương, phôi
thai, da, các cơ quan tiêu hóa, và đến hệ thống thần kinh trung
ương; thứ 2, các chất này có thể gây ra thiệt hại lâu dài hoặc vĩnh
viễn cho hệ sinh thái. Thì dụ như, chất độc được thải vào hệ thống
nước có thể dẫn tới tác hại lâu dài tới hầu hết các con sông hay hồ
của chúng ta.)
We classify pollution into four types: air pollution, water pollution,
land and soil pollution, and noise pollution.
(Chúng ta phân ô nhiễm thành 4 dạng: ô nhiễm khí, ô nhiễm nước,
ô nhiễm đất, và ô nhiễm tiếng ồn.)
Guide questions
Name some hazardous substances emitted by vehicles that run on
gasoline or diesel fuel. What possible damage can they cause to
humans?
(Tên một số chất độc hại được thải ra từ các phương tiện chạy
bằng khí gas hoặc diesel. Chúng có tác hại gì cho con người?)
4.2. AIR POLLUTION
Substances that pollute the air are generally of two types. The first
types of air pollutants are those that are directly harmful to humans.
53
They include toxic materials emitted by factories and motor
vehicles. The second types of pollutants are those that damage the
environment and possibly alter the earth’s climate.
(Các chất ô nhiễm không khí thông thường có 2 loại. Thứ nhất, là
những khí ô nhiễm gây hại trực tiếp tiếp con người. Chúng bao
gồm các chất độc được thải tử các máy móc và motor. Thứ hai, là
những khí gây hại cho môi trường và làm biến đổi khí hậu trái đất.)
Figure 4.1: Environmental pollution
4.2.1. Toxic air pollutants
Toxic air pollutants include oxides of sulfur and nitrogen, carbon
monoxide, volatile and organic compounds, lead oxide, and
benzene.
(Những chất ô nhiễm không khí độc vao gồm các oxit lưu huỳnh,
nito, Cacbon monoxide, hợp chất hữu cơ và dễ bay hơi, oxit chì, và
benzene.)
54
The main source of toxic pollutants is the burning of fossil fuels
like gasoline, diesel, and petroleum in power plants, factories, and
motor vehicles. Burning of trash also produces toxic pollutants.
(Nguồn chính của các chất ô nhiễm độc hại là do quá trình đốt
cháy các nguyên liệu hóa thạch như gas, diesel và dầu khí tại các
nhà máy điện, động cơ, moto. Đốt rác cũng sản sinh ra các khí độc
hại.)
Figure 4.2: Burning tyres 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 obvious
effects are:
55
(Những chất ô nhiễm được xem là chất độc vì cơ thể con người hấp
thụ các khí này dưới dạng các hạt mịn vào máu, gây ra hiệu ứng
sức khỏe xấu. Những ảnh hưởng rõ ràng nhất là:
1. Breathing difficulties. (khó thơ)
2. Increased susceptibility to respiratory infection.(dễ nhiễm
trùng đường hô hấp)
3. Development of chronic lung disease. (Phát triển các bệnh
phổi mãn tính)
4. Worsening of existing heart and lung diseases. (Trái tim trở
lên yếu đi và bệnh phổi xuất hiện)
5. Fetal defects and various kinds of cancer. (Bào thai dị tật và
các loại ung thư khác)
Figure 4.3: Health effects by environmental pollutants
4.2.2. Contributors of common air pollutants (Thủ phạm của
các chất ô nhiễm không khí thông thường)
The urban and industrialized areas in the world are the greatest
contributors of air pollution. Knowing that pollutants are the causes
56
of many bad effects on human health, these should be main causes
for alarm by the people in general and by the government in
particular. As experienced by the United States, Japan, and the
European countries, emission control costs are high, but still,
control measures must be undertaken.
(Các khu vực đô thị và các vùng công nghiệp hóa trên thế giới là
những vùng gây nên nhiều cho ô nhiễm không khí. Các chất ô
nhiễm được biết đến là nguyên nhân gây ra nhiều hiệu ứng xấu cho
sức khỏe con người, đó có thể là nguồn gốc cho những cảnh báo
cho con người nói chung và chính phủ nói riêng. Theo kinh nghiệm
của Us, Japan, và các nước châu Âu khác, chi phí kiểm soát khí
thải cao, nhưng vẫn còn biện pháp, biện pháp kiểm soát cần được
thực hiện.)
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.
(Mặt khác, chi phí cho giờ công, chăm sóc sức khỏe, không phát
sinh, và ………UNEP and WHO đề suất duy trì SX từng bước một
của các nhà máy và các nhà máy năng lượng.)
Guide questions
1. Explain the two types of air pollution.
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?
57
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.
6. Explain the greenhouse effect.
7. Cite some possible consequences of an increase in global
temperature.
4.3. LAND AND SOIL POLLUTION
There are two principal sources of wastes responsible for the land
and soil pollution. The first one is the solid waste which comes
from mining operations. It includes direct waste from the mining of
minerals and fossil fuels and those associated with the mining and
processing industries. Strip mining not only produces mineral waste
that pollutes the soil and streams but also leaves huge scars on the
land. The loosening of the soil leads to erosion during heavy rains,
causing sediments to settle at the bottom of rivers and lakes.
Erosion also adds to the deterioration of the land, making it unfit
for agriculture. It also makes the water turbid-cloudy, thick, and
dense.
(Có 2 lý do chính của việc bỏ hoang đất thường xuyên do chất thải.
Thứ nhất là chất thải rắn chúng có nguồn gốc từ quá trình khai mỏ.
Nó bao gồm rác thải trực tiếp từ việc khai thác khoáng và nguyên
liệu hóa thạch và những được đồng hành với công nghiệp chế biến
và khai thác. Khai khoáng lộ thiên không chỉ sinh ra thải vào đất và
58
dòng chảy mà còn để lại những hố to trên mặt đất. Sự mất đất dẫn
đến xói mòn trong các trận mưa lớn, dẫn đến các trầm tích lắng
xuống bên dưới song và hồ. Xói mòn cũng làm thay đổi đất làm
cho nó không còn phù hợp cho nông nghiệp. Nó làm cho nước đục
và tăng mật độ ô nhiễm.
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 horses and
from all forms of crop harvesting. These wastes are generally less
polluted because they are spread over wide areas. Also, they are
biodegradable, meaning, they return to the soil as nutrients of
plants. In excessive amounts, they emit bad odor, which is almost
intolerable to human beings.
(Loại ô nhiễm khác là phế phẩm của nông nghiệp. Nó gồm phân
động vật và chất thải từ trang tại và từ các loại hình thu hoạch.
Những rác thải này nói chung ít ô nhiễm so được phân tán dưới
diện tích rộng, chúng cũng có khả năng phân hủy, nghĩa là, chúng
trở lại đất dưới dạng chất dinh dưỡng. Khi vượt quá ngưỡng,
59
chúng giải phóng ra mùi hôi, chúng bắt đầu xâm nhập vào cơ thể
con người.)
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?
2. Do you know of other rivers and lakes affected by soil
erosion? Where does the eroded soil come from?
4.4. RADIATION AND ITS HARMFUL EFFECTS
Radiation is the general term used to refer to a variety of rays to
which life on earth is exposed to. These include visible light,
infrared and ultraviolet rays, X rays, cosmic rays, and rays from
radioactive materials.
(Phóng xạ là khái niệm dùng để chỉ nhiều tia mà ….. Chúng bao
gồm ánh sáng nhìn thấy, tia cực tím, tia X, tia vũ trụ, và những tia
từ vật liệu có tính phóng xạ.)
In a wide sense, any result of radiation energy to a living organism
is a biological effect of radiation. This includes normal effects like
photosynthesis on plants and vision in animals and also the
injurious effect burns, anemia, and cancer on humans and animals.
(Nói rộng ra, bất kì 1 kết quả nào của năng lượng phóng xạ với
sinh vật sống được gọi là ảnh hưởng của phóng xạ. Nó bao gồm
ảnh hưởng thông thường như là quang hợp với thực vật, tầm nhìn
60
với động vật, đó cũng là ảnh hưởng như bỏng, thiếu máu, và ung
thư với con người & động vật.
4.4.1. Historical background
When X rays were discovered by the German physicist Wilhelm
Conrad Roentgen in 1895, the focus of attention was its possible
applications, especially in the field of medicine. The harmful
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.
(Khi tia X được nhà vậy lý tên ….1895, các sự quan tậm tập trung
vào khả năng ứng dụng của nó, đặc biệt trong lĩnh vực y khoa, ảnh
hưởng xấu được phát hiện 1 năm sau đó. Năm 1896, Elihu Thomas
tiếp xúc 1 ngón tay của ông với tia X và quan sát thấy vết bỏng gây
ra bởi nó.)
In the same year, the famous American inventor, Thomas Alva
Edition, observed the effects of X rays exposure on one of his
assistants, Clarence Dally. Dally hair fell out and his scalp became
inflamed. Eight years later, he developed severe ulcers on both
hands and arms. They became cancerous and eventually caused his
death.
(Cùng lúc đó, nhà khám phá nổi tiếng người Mỹ, ….,phát hiện thấy
ảnh hưởng của tia X lên phụ tá của ông, Dally. Tóc của Dally rụng
và da đầu …..Tám năm sau, ông ta bị phát triển nhiều khối u ở cả
tay và cánh tay. Chúng chuyển sang ung thư và dẫn tới ông ta bi tử
vong.)
61
The harmful effects of radioactivity were also observed by Pierre
Curie, a French chemist and one of the great scientists, in 1906.
Burns were produced on the parts of the body exposed to radiation.
In 1925, a number of women exposed to paint containing radium
became ill with anemia and had lesions in the jawbone and mouth.
Some of them developed bone cancer later.
(Ảnh hưởng xấu của phóng xạ cũng được Curie nhận thấy, nhà hóa
học người Pháp và cũng là nhà khoa học lỗi lạc vào năm 1906.
Những vết bỏng được tao ra ở các phần tiếp xúc với phóng xạ. Năm
1925, một lượng phụ nữ tiếp xúc với sơn có chưa RADIUM đã bị
thiếu máu và bị thương tổn. Một vài người trong họ phát triển ung
thư xương sau đó.)
Ernest Lawrence - an American physicist who invented the
cyclotron, a rich source of neutron - exposed rats to this deadly
radiation. He found that fast neutrons are 21/2 times more effective
in killing them then slow neutrons.
(Ernest – nhà khoa học người Mỹ phát hiện ra CYCLOTRON, hạt
làm giàu notron -…. Ông ta phát hiện hạt notron nhanh có ảnh
hưởng hơn 11,5 lần so với hạt notron chậm.
Neutron radiation harmed and killed many people in Hiroshima,
Japan, when an atomic bomb was dropped there in 1945. A study
was conducted on several hundred pregnant women who survived
the Hiroshima and Nagasaki bomb blasts. Their children were
medically observed for more than 20 years. Many of them had
heads smaller than the normal size, and there was a significant
increase in the number of mentally retarded children.
62
(
4.4.2. Specific harmful effects of radiation
There are many sources of radiation that may cause injury to human
beings. The natural sources, like cosmic rays and natural products
like granite and monazite sands (an important source of the element
thorium), give dosage that are very safe to humans.
(Có nnie6u2 nguồn phóng xạ dẫn đến tổn thương với cơ thể người.
Các nguồn tự nhiên như ……..
The artificial sources like medical X rays, high - voltage power
supplies, television sets, and luminous dial watches give significant
dosage but the effects do not show until after many years. These
effects may include lower blood counts, temporary sterility, skin
irritations, and on rare occasions, cancer.
(Nguồn nhân tạo như tia X trong y khoa, nguồn cung cấp điện nâng
với thế áp cao, TV và các thiết bị nghe nhìn kĩ thuật số thì sinh ra
các liều lượng phóng xạ phức tạp, nhưng ảnh hưởng của nó không
được thấy cho đến nhiều năm. Những ảnh hưởng có thể là làm
giảm lượng máu, vô sinh, kích thích da, và đôi khi là ung thư.
63
Figure 4.5: Harmful effect of radiation
The very serious health effects come from very massive dozes of
radiation from nuclear reactor leaks and explosions of nuclear
weapons; such as:
(ảnh hưởng đến sức khỏe nghiêm trọng đến từ việc rò rỉ từ các nhà
máy sản xuất hạt nhân
The effects of the Hiroshima and Nagasaki explosions and lately,
the Chernobyl disaster attested to the veracity of these estimates.
Although less damaging, the effects of the nuclear tests in the
Nevada desert were also well documented.
(Ảnh hưởng của 2 vụ nổ, và sau đó là thảm hoạ CHERNOBYL dẫn
đến những vấn đề
The bomb that was dropped in Hiroshima killed more than 140.000
of its 255.000 inhabitants, and more deaths occurred later from
radioactive radiation. The effects of the Nagasaki blast were similar
to that of Hiroshima.
64
In Chernobyl, Ukraine, four nuclear reactors used in generating
electricity exploded in April of 1986. The explosion released
between 50 and 100 million curies of radioactive material into
environment. Within a few months, 29 people died of radiation
poisoning and 200 other were estimated to develop cancer in later
life. The eventual toll of the nuclear accident has been estimated to
be as high as 135000 cancer cases and 35000 deaths.
From 1951 to 1962, the United States exploded 126 atomic bomb
into the atmosphere at the Nevada test sites. Some civilians (thường
dân) and military personnel (lực lượng quân đội) working at the
test sites developed disorders like cancer, heart disease, thyroid
dysfunction, and diabetes. The same thing happened to people in
southern Utah where winds from the test sites carried radioactive
material that affected a lot of people. Tests were subsequently
underground to minimize radiation effects and recently, 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?
3. What events in the past resulted in many deaths due to
massive exposure to radioactive materials?
4.7. POLLUTION REDUCTION (giảm thiểu ô nhiễm)
65
There is a universal concern for doing something about the
production and disposal of hazardous substances. Leading
industrialized countries and some leading industrial companies
have initiated serious efforts to reduce pollution.
(Đó là mối lo ngại chung cho việc sản xuất và tiêu hủy các chất độc
hại. Các nước có nền công nghiệp hóa và có 1 số công ty công
nghiệp hàng đầu đã bắt đầu nỗ lực để giảm thiểu ô nhiễm nghiêm
trọng.)
4.7.1. Recycling
How to handle society’s toxic chemical waste now ranks among the
top environmental issues in most industrial countries. Without
concerned efforts to reduce, recycle, and reuse more industrial
wastes, the quantities produced will overwhelm even the best
treatment and disposal systems [Thảo Nguyên].
(Làm thế nào để xử lý các chất độc hóa học của xã hội hiện nay xếp
trong số các vấn đề môi trường hàng đầu ở hầu hết các nước công
nghiệp. Nếu không có những nỗ lực liên quan để giảm thiểu, tái chế
và tái sử dụng, công nghệ sử dụng lại chất thải công nghiệp, số
lượng được sản xuất sẽ chôn vùi ngay cả những nghiên cứu tốt nhất
và hệ thống xử lý.)
The process of converting materials into new products that may or
may not resemble the original material is known as recycling.
(Quá trình chuyển đổi vật liệu thành các sản phẩm mới mà có thể
hoặc không thể giống với vật liệu ban đầu được gọi là Recycling.
66
Figure 4.6: The conception of Recycle
For example, old newspapers may be recycled into newsprint paper,
board for packing, and construction materials for roofing and
insulation.
(Ví dụ như, giấy cũ có thể tái chế thành giấy in báo, bàn cũ thành
bao bì, và vật liệu xây dựng để lợp và cách điện.
The benefits (Lợi ích) of recycling include the following:
1. It reduces waste. (Giảm bớt rác thải)
67
2. It lowers energy, water, and primary raw material
requirements. (Nó làm giảm năng lượng, nước và các yêu
cầu nguyên liệu chính.)
3. It reduces both air and water pollution. (Giảm thiểu cả ô
nhiễm khí và nước)
Imagine the number of trees that would be saved by recycling
newspapers. And imagine the amount of trash that would have to be
disposed of if plastics, glass, and cans were not recycled.
(Hình dung lượng gỗ mà có thể tiết kiệm bằng tái chế giấy báo. Và
tưởng tượng lượng bã mía sẽ phải xử lý với nhựa, kính, và lon
không thể tái chế.)
Japan is the leading country that undertakes recycling. The country
recycles or reuses about 50 percent of its solid wastes, compared
with only 11 percent of the United States and 15 percent of
Germany.
(Japan là nước đi đầu trong thực hiện cam kết tái chế. Quốc gia tái
chế hoặc tái sử dụng 50% lượng chất thải rắn, so với chỉ 11% của
US và 15% của Đức.)
Moreover, after burning 23 percent of Japan’s trash in waste-toenergy facilities, only 27 percent remains to be disposed of in
landfills and by other means. In contrast, 83 percent of solid waste
in the United Stated and 55 percent of solid waste in Germany are
disposed of by similar means [Hồng Yến].
(Hơn nữa, sau khi đốt 23% lượng rác của Japan trong các cơ sở
chất thải năng lượng, chỉ 27% vẫn còn phải xử lý ở các bãi chon
68
lấp và các phương thức khác). Ngược lại, 83% chất thải rắng ở US
và 55% chất thải rắn ở Đức được xử lý bằng phương pháp tương
tự.)
Table 4.1: Solid waste management in the United Stated, Japan and
West Germany
Type
United
States
Japan
West
Germany
Recycled or reused
Waste-to-energy
Landfilled or others
11
6
83
50
23
27
15
30
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 and food
cans, and converted much of the remaining trash into fertilizers,
fuel gases, and recycled metals.
(Hơn nữa, thời báo Time, phát hành vào 2.2.1989, đã báo cáo về
Japan, vào 1988, đã tái chế 50% giấy thải, 55% chai lọ thủy tinh,
66% lon thực phẩm và đồ uống, và chuyển đổi số rác còn lại thành
phân bón, khí nhiên liệu và kim loại tái chế.)
Part of the success of Japan’s recycling program is the wholehearted 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.
69
(Một trong những thành công của chương trình tái chế của Japan
là sự hợp tác tận tình của công dân. Người Japan phân rác thành 6
loại để dễ tái chế. Ngược lại, ở US vào 1986 đã thu hồi được 23%
các sản phẩm giấy, 9% thủy tinh, và 25% nhôm)
Several countries have followed the Japanese. Glass recycling 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.
(Nhiều nước đã làm theo người Nhật. Tái chế thủy tinh phát triển
nhanh ở châu Âu. Các thành phố Rome, Vienna, Marid đã dựng lên
các nhà máy sản xuất phục hồi kim loai, thủy tinh, giấy, nhựa, sợi
và các sản phẩm khác.)
Some third world countries, although on a limited scale, have
similarly 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 its waste for
biogas production, fertilizers, and brick and cement manufacture.
The city also reprocesses many materials like metals, rubber,
plastics, paper, glass, and waste oil.
(Ở 1 số nước còn lại, mặc dù ở quy mô hạn chế, cũng thử đi vào tái
chế. Ở Ấn Độ, hơn 1/3 chất thải đô thị dăng được đốt để sản xuất
khí methan, dạng viên nhiên liệu, phân bón, thức ăn chăn nuôi.
Trung quốc, đặc biệt là thành phố Thượng Hải, quy trình và bán
hơn 10% chất thải cho sản xuất sinh học, phân bón, sản xuất gạch
70
và xi măng. Thành phố cũng tái xử lý nhiều vật liệu như kim loại,
cao su, nhựa, giấy, thủy tinh, và dầu thải.)
4.7.2. 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. (Giúp trường của bạn luôn sạch sẽ
từ việc xử lý thích hợp rác không mong muốn)
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
produced by their engines could permanently impair their
sense of hearing. (Trợ giúp của tổ chức hoặc tham gia các
chiến dịch cộng đồng của bạn để tuyên truyền cho công
chúng về mối nguy hiểm gây ra bởi ô nhiễm. Ví dụ, người lái
xe 3 bánh có thể không biết tiếng ồn do động cơ của họ có
thể làm giảm thính giác của họ.)
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. (Giảm thiểu sử dụng thuốc
trừ sâu tại nhà. Nếu bạn sử dụng chúng, cần giảm thiểu các
tiềm năng nguy hiểm tiềm năng bằng cách (a) chắc chắn
rằng người và động vật nằm ngoài vùng thực hiện và (b)
không thực hiện gần suối và ao hồ.)
4. Find out what companies are major contributors to pollution.
Do not patronize their products and convince others to do the
71
same. (Tìm hiểu những công ty đang làm ô nhiễm . Không
bảo trợ sản phẩm của họ và thuyết phục những người khác
cũng làm như thế.)
5. Separate wastes that can be recycled. Sell them to local
dealers or give them to garbage collectors for their extra
income. (Riêng các chất thải có thể tái chế. Bán chúng cho
các đại lý địa phương hoặc đem chúng tới nơi thu gom rác.)
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.
(Trợ giúp giảm thiểu chất thải sản sinh từ gia đình bạn. Ví
dụ, sử dụng ít túi nhựa và bán hoặc cho báo cũ cho người thu
mua để tái chế)
7. Volunteer to help in the information campaign to minimize
pollution through proper waste disposal. (Tình nguyên giúp
chiến dịch thông tin để giảm thiểu ô nhiễm thông qua xử lý
chất thải phù hợp)
8. Generate enthusiasm about programs that would minimize
air, water, land, and noise pollution. (Nhiệt tình tổ chức các
chương trình có thể giảm thiểu không khí nước, đất và ô
nhiễm tiếng ồn.)
9. Eat fewer animal products and consume more grains,
vegetables, and fruits that require less energy to produce and
therefore create less pollution. (Ăn ít các sản phẩm động vật
và dùng nhiều ngũ cốc hoa quả mà ít tốn năng lượng trong
việc sản xuất từ đó giảm ô nhiễm)
10. Urge your parents to buy household items and appliances
that contain no, or less, pollutants. Read the labels carefully
before buying.(Khuyên cha mẹ của bạn mua đồ gia dụng và
72
các thiết bị không chứa, hoặc ít chất gây ô nhiễm. Đọc nhãn
cẩn thận trước khi mua.
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. (Trồng những cây phát triển nhanh đặc biệt là xung
quanh nhà bạn. Chúng cung câp bóng mát trong những ngày
nắng và hấp thụ CO2 trong không khí. Do đó chúng giúp
chống lại hiệu ứng nhà kính.)
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. (Bằng cách giảm tiêu
thụ năng lượng, bạn sẽ giúp làm giảm bớt thiệt hại môi
trường. Năng lượng bạn sử dụng có thể đến từ việc đốt các
nguyên liệu hóa thạch như gas, dầu hoặc than đá. Ít sử dụng
năng lượng nghĩa là ít đốt cháy các nguyên liệu hóa thạch.)
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. (Tiết kiệm trong việc sử dụng vật liệu góp phần
hạn chế sự suy giảm của tài nguyên thiên nhiên. Ví dụ, bằng
cách sử dụng giấy ít hơn, đó là 1 sản phẩm gỗ, bạn sẽ giúp
giảm việc phải cưa cây.)
Guide question
1. Cite government efforts to reduce pollution. (Trích dẫn
những nỗ lực của chính phủ nhằm giảm thiểu ô nhiễm)
73
2. Explain the good side and the bad side of burning dry leaves
under fruit-bearing trees, like mango. (Giải thích mặt tốt và
mặt xấy của việc đốt lá của các cây ăn trái.)
3. What materials are being recycled in Vietnam? (Những vật
liệu được tái chế ỡ VN là gì?)
4. How is garbage (solid waste) disposed of in your
community? Is it the good way? (Rác thải được xử lý như thế
nào trong cộng đồng bạn sống? Đó có phải là cách tốt.
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.
74
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.
(Giải thích tại sao sự cân bằng tự nhiên bị biến đổi trong thời
gian gần đây.)
2. Relate how humans were able to control nature (Con người
có khả năng kiểm soát thiên nhiên thế nào?)
3. Enumerate the consequences of controlling nature. (Liệt kê
hậu quả của việc kiểm soát thiên nhiên)
4. Comprehend the pressure on the environment, resulting from
rapid increase population.(Hiểu những áp lực môi trường, do
dân số tăng nhanh.)
5. Understand the problem of uneven distribution of wealth
(Hiểu vấn đề phân phối không đồng đều của cải)
6. Distinguish the problem of solutions offered to problem
impacts in the world. (Phân biệt các giải pháp đề xuất tới
những tác động trên thế giới)
5.1. THE GLOBAL ENVIRONMENTAL SITUATION (Tình
hình MT toàn cầu)
Scientists have estimated that the Earth is more than four billion
years old, and it will continue to exist for around the same period of
time. Life on Earth as we know it today came into being around
three billion years ago. Based on fossils found around the world,
human beings have inhabited the Earth for more than two million
years. All this time, nature and life on Earth lived in equilibrium.
75
There was no major disturbance which could alter the balance of
nature. This was true up to around 2000 years ago.
(Các nhà khoa học ước tính trái đất đã hơn 4 tỉ năm tuổi, và nó còn
tiếp tục tồn tại khoảng cùng thời gian này. Cuộc sống trên Trái Đất
như chúng ta biết đến ngày nay đã có khoảng 3 tỉ năm trước đây.
Dựa trên các hóa thạch tìm thấy trên khắp thế giới, con người đã
sống hơn 2 triệu năm. Tất cả thời gian này, thiên nhiên và sự sống
trên trái đất trong trạng thái cân bằng. Không có xáo động nào có
thể làm thay đổi cân bằng của thiên nhiên. Điều này đúng đến
khoảng 200 năm trước.)
At around that time, people began to disturb the environment in
such a manner as to effect the global environment.
(Vào khoảng thời gian đó, con người bắt đầu làm xáo trộn môi
trường theo nhiều cách làm ảnh hưởng tới MT toàn cầu)
The rampant and reckless cuttings of trees in virgin forests have
resulted in soil erosion, flooding, expansion of deserts, and
destruction of lakes. Overexploitation of other natural resources,
like fish and other aquatic resources, has resulted in alarming
decrease of catch worldwide.
(Việc cắt phá cây 1 cách quá mức và thiếu kiềm chế trong các rừng
nguyên sinh dẫn tới kết quả là xói mòn đất, lũ lụt, sa mạc tăng lên,
sự biến mất của các hồ. Khai thức quá mức tài nguyên khác, như cá
và các nguồn thủy sản khác, đã dẫn tới mức báo động việc đánh
bắt trên toàn cầu.)
76
Too much use of fossil fuels, like oil and other minerals, has
depleted these natural resources to much an extent that the supply
may not last for another one hundred years. It takes millions of
years to form oil from the fossils of plants.
(Sự dụng quá nhiều nguyên liệu hóa thạch, như dầu và khoáng sản
khác, làm cạn kiệt các nguồn tài nguyên thiên nhiên tới mức mà
không thể cung cấp cho người khác trong vòng 100 năm. Phải mất
hàng triệu năm để tạo dầu từ hóa thạch thực vật.)
The industrial revolution has produced all kinds of hazardous
materials that harmed the environment-pollution of the air, water,
land, and the atmosphere. Many of these hazardous substances are
also toxic to humans as well as to other animals.
To be fair to those concerned, all these were the unwanted effects
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 have in many ways succeeded in
this worthy ambition. People were, to a certain extent, able to
control nature. By applying what they have discovered about the
laws of nature, they were able to conquer darkness though electric
bulbs and fluorescent lamps, hot weather conditions through
electric fans and air conditioners, and cold weather through heaters.
Through modern medicines and sanitation, they were able to
control the spread of diseases; through modern agriculture, they
were able to produce more food containing better nutrients.
77
The overall result of better living conditions, better sanitation, and
better nutrition includes rise in life expectancy and low infant
mortality. The net effect is rapid increase in population.
Insightfulness
The luxurious life-style of the rich and famous contributes to
environmental degradation.
According to the United Nations Statistical Yearbook (1988), the
doubling of the population between 1950 and 1986 was
accompanied by grain consumption of 2.6 times, energy use of 3.7
fold, and quadruple economic output and sevenfold increase in the
production of manufactured goods. All these were accompanied by
more than ninefold increase in water, air, and land pollution.
Insightfulness
Most developed countries have zero or very, very low population
growth rate.
But the irony is, situation differ from region to region and country
to country. Because of the wide gap between the rich and the poor
nations, the benefits of these increases do not apply equally among
people of the world.
For instance, despite overall rise in food production in the world,
nearly a billion people (1/5 of the world’s population) do not
consume enough calories for an active working life. And because of
less scientific agricultural practices combined with a high
78
population growth, the grain production per person is declining in
Africa, India, and Latin America.
In the less-developed countries, it is estimated that only half of the
people have access to safe drinking water. Because of this, around
10 million people worldwide die due to water-borne diseases. In the
industrialized countries, agriculture and industry are rapidly using
up groundwater. Deforestation in many areas aggravates the
situation. It prevents the staring of groundwater.
The main sources of energy in the world are fossil fuels (oil and
charcoal) and natural gas. At the beginning of their use, many
people thought that the supply is practically inexhaustible. But
since Would War II, energy consumption has increased more than
four times. Scientists have since then changed their predictions.
They now predict that oil reserves will be used up in less than 50
years, and natural gas by around 60 years.
Since the introduction of polluting materials by humans, the quality
of air, soil, and water has deteriorated. Humans, animals, and plants
have been affected. Toxic pollutants cause many kinds of 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, especially among the
industrialized countries. Increase in atmospheric carbon dioxide is
casing the so-called greenhouse effect. This is predicted to alter the
earth’s climate and raise ocean levels, with disastrous consequences
to coastal towns and cities.
79
Most of the time, nature is friendly. It seldom shows its fury. When
it does, it is uncontrollable.
80
Table 5.1: Global problem impacts and problem causes
Problem causes
Unsustain
Problem Impacts
-able
populatio
Poverty
Unsustain Unsustain
Unsustain
-able
-able food -able
and
industrial
productio energy
Inequality
productio
n growth
n
use
n
Unmet basic human needs for safe water,
education,
■
■
☼
►
►
Species depletion (extinction of plants and
animals, habitat degradation)
■
■
♣
☼
☼
Land
degradation:
soil
desertification, loss of fertility
■
♣
■
♣
►
♣
►
♣
■
♣
food, shelter, health
employment, etc.
Depletion
minerals
of
care,
erosion,
nonrenewable energy and
81
Depletion of fresh water (groundwater and
surface water)
♣
►
■
►
♣
♣
☼
♣
☼
■
Air pollution: urban air pollution, acid
deposition, ozone layer depletion, greenhouse
gas buildup
♣
☼
☼
■
■
Conflict and war: domestic and international
♣
♣
☼
☼
☼
Water pollution: chemical and bacterial
contamination of groundwater and surface
water
Source: W. Lorson, ed., The Global Ecology handbook, 1990
■: Very important cause
♣: Moderately important cause
☼: Less important but insignificant cause
►: Unimportant or insignificant cause
82
It can be seen from above table that unsustainable population
growth is a very important cause of three problem impacts and a
moderately 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 too rapid
increase in population without straining the environment. And an
unrestrained exploitation of our natural resource results in 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 a direct
consequence.
In order to support an ever - increasing population, more and more
factories must be put up. Industry must be expanded and of course
pollution follows, the consequences of which are already
enumerated above.
The probability of conflict between ethnic groups and nations is
increased with unsustainable population growth. They may fight
over needs resources, like oil and water. Or, they may fight for
territories needed by their increasing number. The resulting misery
and human sufferings brought about by war are too well known.
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.
83
Geographically, the earth is divided into nations with varying
resources and with varying population densities and varying
degrees of industrialization. In short, some countries are wealthier
than others. And even in the same country, the structure of society
varies; there is a very wide gap between the rich and the poor.
Cutting more trees and over fishing in order to survive are likely
examples 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.
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.
5.2. SUISTAINABLE DEVELOPMENT
The past 20 years have seen a growing realisation that the current
model of development is unsustainable. In other words we are
living beyond our means. From the loss of biodiversity with the
felling of rainforests or over fishing to the negative effect our
consumption patterns are having on the environment and the
84
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 for ever.
Especially as the world's population continues to increase and we
already see a world where over a billion people live on less than a
dollar a day, more than 800 million are malnourished, and over two
and a half billion lack access to adequate sanitation.
Some people started realizing the development and environmental
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 (JessicaTuckma Mathews,
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 on environment 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 Western Europe are more
developed than those of Eastern Europe. Similarly, the countries in
85
North America are more developed than those of Central and South
America. Likewise most countries in Africa are less developed.
Some countries in Asia like Japan, Korea, Taiwan, and Singapore
are more developed than others like the Philippines, Malaysia,
Indonesia, Bangladesh, India and Vietnam.
The People’s standard of living also varies from one country to
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, as
measured 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 needs of the present
without compromising the ability of future generations to meet their
own needs”. This means development without permanent damage
to the ecological system.
Sustainable development means using the natural resources only to
a certain extent so that they will be able to recover. It further means
that population should either be help to a minimum or be stopped
altogether. This is the same as saying that 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
86
and by ensuing equitable economic, 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 are controlled by a
few rich families, where the middle class in weak and a great
majority of the people are poor, a restructuring of society might be
needed.
In order that the definition of sustainable development is fully
understood 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
sollutions to the problems of basic human needs and habitat
degradation.
Making agriculture: Making agriculture sustainable requires drastic
reduction in soil erosion, maintenance of arable lands, and a drastic
decrease in harmful farming practices like the use of toxic
chemicals. Systems for reducing soil erosion should be devised.
There should be strict policy in the conversion of arable lands into
roads and subdivisions, and for industrial development.
Maintaining soil fertility though intercropping and the trees and the
87
use of nontoxic fertilizers will go a long way toward solving the
problem of pollution.
Forest protection: Forest protection is not easy for a country where
there are so many poor people. They need the trees and the land for
survival. Government must have a viable program for reforestation.
Success in this degradation will effectively reduce 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 energy
saving measures from the government: regulating speed limits,
requiring the installation of energy saving devices in offices, and
developing more renewable energy source like hydro electronic
power plants. The net effect of the measures would be energy
conservation and less pollution.
Supply of fresh water: The supply of fresh water in the world is
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 has
deteriorated. The need to conserve fresh water is of utmost
importance to support a growing population and to provide
irrigation to agricultural crops.
88
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.
89
Asthma: Lung disorder characterized by the constriction and mucus
production and deposition in the bronchioles.
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.
90
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.
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 solve environmental
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.
91
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.
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 efficiency use.
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.
92
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.
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.
93
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.
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.
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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 organisms after along 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 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.
Groundwater: Water below the earth’s surface.
95
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 heath
and the environment.
Herbivore: Organisms that feeds directly on plants
Hetertrop: 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.
96
Littoral zone: Shallow waters along a lakeshore where rooted
vegetation grows.
Magma: Molten rock beneath the earth’s crust.
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:
decomposition.
Bacterium
of
fungus
that
carries
out
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.
97
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 a new
and large nucleus.
Nuclear power: Energy derived from nuclear fission or fusion.
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.
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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 of 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.
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.
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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 tissue equivalent
to 100 grs/gram of tissue.
Reactor core: That which consists of fuel rods in a reactor vessel.
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.
100
Relative humidity: Amount of moisture in a give 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.
101
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
tress 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.
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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.
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METRIC UNIT CONVERSION TABLES
THE METRIC SYSTEM
Standard metric Units
Units
Standard unit of mass
Gram
g
Standard unit of length
Standard unit of volume
Meter
Liter
m
l
Common
Prefix
Kilo
Centi
Milli
Micro (µ)
Nano (n)
Pico (p)
Unit
Abbreviations
Examples
1,000
A kilogam is 1,000 grams.
0.01
0.001
Onemillionth
One-billionth
A centimeter is 0.01 meter.
A milliter is 0.001 liter.
A micrometer is0.000001
(one- millionth) of a meter.
A nanogram is10-9 (one-
billionth) of a gram.
One-trillionth A pictogram is10-12 (onebillionth) of a gram.
UNITS OF LENGTH
Unit
Meter
Abbreviations
Equivalent
m
Approximately 39 in
104
Centimeter
Millimeter
Micrometer
cm
mm
µm
10-2m
10-3m
10-6m
Nanometer
Angstrom
nm
Ǻ
10-9m
10-10m
Length conversions
1 in = 2.5 cm
1 mm = 0.039 in
1 ft = 30 cm
1 yd = 0.9 cm
1 mi = 1.6 km
1 cm = 0.39 in
1 m = 39 in
1 m = 1.094 yd
1 km = 0.6 mi
To convert
Multiply by
To obtain
Inches
Feet
Centimeters
Millimeter
2.54
30
0.39
0.039
Centimeters
Centimeters
Inches
Inches
UNITS OF VOLUME
Unit
Liter
Milliliter
Abbreviations
Equivalent
l
ml
Approximately 1.06 qt
10-3 (1ml = 1cm3 = 1cc)
105
Miccroliter
10-6l
µl
Volume conversions
Equivalent
1 tsp = 5ml
1 tbsp = 15ml
1 fl oz = 30ml
1ml = 0.3fl oz
1l = 2.1 pt
1l = 1.06 qt
1 cup = 0.24l
1 pt = 0.47l
1l = 0.26 gal
1 pt = 0.95 l
1 gal = 3.8 l
To convert
Multiply by
To obtain
Fluid ounces
Quarts
30
0.95
Milliliters
Liters
Milliliters
Liters
0.03
1.06
Fluid ounces
Quarts
UNITS OF WEIGHT
Unit
Kilogram
Gram
Milligram
Microgram
Abbreviations
Equivalent
kg
g
mg
µg
103g (approximately 2.2 lb)
Approximately 0.035 oz
10-3 g
10-6 g
106
Nanogram
Pico gram
10-9 g
10-12 g
ng
pg
Weight conversions
1oz = 28.3g
1g = 0.035 oz
1lb = 453.6g
1lb = 0.45kg
1kg = 2.2 lb
To convert
Multiply by
To obtain
Ounces
Pounds
Pounces
Grams
Kilograms
28.3
453.6
0.45
0.035
2.2
grams
grams
kilograms
ounces
pounces
Temperature conversions
Some equivalents
( 0F  32) * 5
C=
9
0 0C = 32 0F
o
370C = 98.6 0F
0
0
F=
C *9
+32
5
100 0C = 212 0F
107
108
REFERENCE
1. Barrington, Ernest, and James William. Environmental Biology.
New York, U.S.A.: Wiley Inc., 1980.
2. Chiras, DanielD. Environmental Science: A Framework fo
Decision Making. California, U.S.A.: Benjamin/Cummings
Publication, Co., 1988.
3. Committee For Global Biosphere Program. Global Change and
Our Common Factor. Washington, D.C., U.S.A.: National
Academy Press, 1986.
4. Erickson, Jon. Greenhouse Earth. Tomorrow’s Disaster Today.
Blue Ridge Summit, P.A., U.S.A.: Tab Books, 1990.
5. Nebel, Bernard. Environmental Science. Englewood Cliffs, N.
J., U.S.A.: Prentice Hall, 1990.
109