Environmental studies.
1.
Goals of Environmental studies.
Environmental
Management can be defined as “the management of
the interaction and impact
of human activities
on the natural environment”
Environmental
management, which integrates, policy making, planning and social development.
• The
prevention and resolution of environmental problems
• Establishing
limits
• Establishing institutions that effectively support environmental research, monitoring and management
•
Warning
of threats and
identifying opportunities
•
Sustaining
and if possible improving
existing resources
•
Where possible improving ‘quality of life’
•
Identifying
new technology or policies that are useful
• conserve natural resources;
•
promote
energy efficiency;
• eliminate waste;
•
reduce
emissions associated with climate change; and
develop
and implement specific requirements for new facility construction, existing
facility modification, and equipment selection that will reduce our impact on
the environment.
1. Any 8 Major environmetal problem
1.
Over- population: The population of the
planet is reaching unsustainable
levels as it faces a
shortage of resources like water, fuel
and food.
Population explosion in less developed and developing countries is straining
the already rare resources.
Intensive
agriculture practiced to produce food damages the environment through the use of chemical fertilizer, pesticides and insecticides.
Overpopulation is also one of
the crucial current environmental problems. it cause human
sufferings directly and amplifies all other environmental problems.
2.
Pollution: There
are 7 key types of pollution – air, water, soil, noise, radioactive, light and thermal and
these are primary causes that affect our environment in many ways. All these
types of pollution are interlinked
and influence each other. Therefore we need to tackle all of them
together.
Pollution
of air, water and soil requires millions of years to recoup. Industry and motor vehicle exhaust are the number
one pollutants. Heavy
metals, nitrates and plastic are toxins responsible
for pollution.
It makes vital resources less
useful and reduces the quality of life.
• 3. Soil Degradation
Globally, food security depends on
the factor whether or not soils are in good condition to produce crops.
According to UN
estimates, about 12
million hectares
of farmland a year
get seriously degraded.
• Soils
get damaged due to
many reasons. Such reasons include erosion, overgrazing, overexposure
to pollutants, monoculture
planting, land-use conversion and
many more.
4.Global Warming:Climate changes like global warming
are the result of human practices like the emission of greenhouse gases. Global warming leads to rising temperatures of
the oceans and the earth’ surface causing natural disasters that
include flooding, melting of polar ice caps, rise in sea levels and
also unnatural patterns
of precipitation such as
flash floods,
5. Waste Disposal
•
The overconsumption of resources and the creation of plastics are creating a
global crisis of waste disposal. Developed countries are notorious for
producing an excessive amount of waste or garbage and dumping their waste in
the oceans then
less developed countries.
•
Nuclear waste
disposal has tremendous health hazards associated with it.
Plastic, fast food, packaging and cheap electronic wastes
threaten the well being of humans. Waste disposal is, therefore, one of
the urgent current environmental problems.
6. Deforestation: simply means clearing of
green cover and make that land available for residential, industrial or commercial purposes.
•
Our forests are natural
sink of carbon
dioxide and produce fresh oxygen, as well as helps
in regulating temperature and rainfall. significant losses of world forests will continue over
the next 20 years as demand for forest products and fuel wood increases. The
worlds forest currently disappearing
at the rate over 20
million hectares
per year, with most of the loss in the
humid tropical forests of Africa, Asia and South America.
• 7. War: this may be caused by or may
cause all other environmental problems modern ( chemical/biological) warfare
threatens the survival of the human species.
8. Overfishing: It affects natural ecosystem severely and leads to an imbalance of ocean life. Around 63% of global fish
stocks are estimated to be overfished. Overfishing caused fishing fleets to
migrate to new waters that would further deplete the fish stocks.
• Moreover, it has negative effects on coastal
communities that rely on fishing to support their living.
•
3.
Define
ecosystem.
DEFINITION
OF AN ECOSYSTEM :
The
term `eco' refers to a part of the world and `system' refers to the
co-ordinating units. The living
organisms of a habitat and their surrounding environment function together as a
single unit. This ecological unit is called as an `ecosystem’.
4.Component of
ecosystem.
•
An
ecosystem has abiotic and biotic
component:
•
ABIOTIC
COMPONENT-The abiotic components are the
non-living components of the ecosystem. They are of three categories
•
1. 1.Meterological components:( Climatic and physical factors )
•
air, water, soil and sunlight; rainfall,
temperature, humidity, soil texture and geomorphic conditions.
•
Sunlight is necessary for
photosynthesis; it influences organisms and their environment; it has a
profound effect
•
on the growth and development of life.
•
* Water is the elixir of life; all
living things require water for their survival, but some can live with
lesser amounts
•
* Temperature -- all living things have
a range of temperatures in which they can survive; beyond those limits it will be difficult for them to live.
•
* Oxygen -- many living things require
oxygen; it is necessary for cellular respiration, a process used to obtain
•
energy from food; others are actually
killed by the presence of oxygen (certain bacteria)
•
2. Edaphic factors: which relate
to the composition and structure of soil- its physical and chemical properties.
•
* Soil type , soil profile , pH, amount
of water it holds, available nutrients, etc determine what type of organism
•
can successfully live in or on the soil;
for example, cacti live in sand, cattails in soil saturated with water
•
3.a)
Inorganic substances
•
There are various nutrient elements and
compounds, such as carbon, nitrogen, sulfur, phosphorous, carbon-di-oxide,
water, etc. These are involved in the
cycling of materials in the ecosystems.
•
b)
Organic compound:
various dead and decomposed bodies of the organism and excretory materials of
different organism mix up with soil and form organic components. Such as
protein, carbohydrates, lipids and other complex molecules.
•
Biotic components -
include all living organisms and their products. This group includes all animals, plants,
bacteria, fungi and their waste products like fallen leaves or branches or
excreta.
•
Based on their activity, biotic components are
classified into four categories as
•
a) producers
b) consumers c) transformers
and d) decomposers.
•
Biotic
components - include all living
organisms and their products. This
group includes all animals, plants, bacteria, fungi and their waste products
like fallen leaves or branches or excreta.
•
Based on their activity, biotic components are
classified into four categories as
•
a) producers
b) consumers c) transformers
and d) decomposers.
•
PRODUCERS: Producers are
called energy transducers. They
convert solar energy into chemical energy, with the help of organic and
inorganic substances. The producers
are called as autotrophic ( auto = self; troph = nourishing) organisms. They are capable of synthesizing food from
non-living inorganic compounds. They
are largely represented by green plants on land (trees, grasses, crops) and
phytoplanktons on water.
•
CONSUMERS :
Consumers are the organisms, whose food requirement are met by feeding
on other organisms. They consume the food materials prepared by the producers
(autotrophs). Hence, consumers are
called as heterotrophic organisms.
Animals belong to this category.
Depending upon their food habits, consumers are classified into primary,
secondary and tertiary consumers.
•
The PRIMARY CONSUMERS are solely feed on plants. Herbivores are plant eaters - grasshopper, rabbit, goat, sheep are primary consumers.
•
The SECONDARY CONSUMERS feed on some primary
consumers. Carnivores-are flesh eaters.
Eg. - Hawks ,Tiger and Lion. Omnivores
(Biophages ) - eat both vegetables and flesh( cockroaches, fox, humans). Secondary consumers are those which predate
on primary consumers. Eg. several species of insects and fishes.
•
TERTIARY CONSUMERS are the predators of
predators. They are mostly larger animals.
•
TRANSFORMERS : Transformers are certain types of bacteria .
They attack on materials excreted by other living organisms (even dead plants
and animals ). They transform the above into either organic or inorganic
substances. These substances are suitable for the nutrition of green plants. Transformers help in recycling the nutrients
which came as waste already.
•
DECOMPOSERS : They are also called as microconsumers. They
depend on dead organic matter for their food . They are chiefly micro organisms
like bacteria and fungi. They break the complex organic matter
found in plant and animal bodies, and release simple substances . These
substances will be used by autotrophs once again. Some invertebrate animals like protozoa and
earthworms use these dead organic matter for their food. They are called as
secondary decomposers
5. function of
ecosystem
•
Ecosystem functions
1. To maintain supportive environment &
services to the biological community including humans.
2.To create & maintain favourable food chain and resource supply.
3.To ensure ecosystem stability.
4.To maintain resilience.
6. Resilience and its importance.
•
In
ecology, resilience is the capacity of an ecosystem to respond to a disturbance by resisting
damage and recovering quickly.
•
The
concept of resilience in ecological
systems was first introduced by the Canadian ecologist C.S Holling.
A resilient ecosystem has the capacity to withstand
shocks and surprise and if damaged, to rebuild itself.
•
In a resilient ecosystem , the process of
rebuilding after disturbance promotes renewal and innovation. Without resilience, ecosystems become vulnerable to
the effects of disturbance that previously could be absorbed.
7. Ecological stability.Its Growth and
Reduction factor.
The forces that affect an
ecosystem stability are the factors that control the size of its populations.
There forces can be broken down into two group.
•
Growth
factor + reduction factor= Ecosystem balance.
•
BIOTIC
FACTORS-
•
Reproductive
rate.
•
Ability to adapt to environmental change.
•
Ability
to migrate to new habitat.
•
Ability to compete, hide, defend to find food.
•
Adequate food supply.
•
ABIOTIC FACTORS-
•
Favourable light, temperature and chemical
environment.
•
BIOTIC
FACTORS-
•
predators, disease, parasites, competition,
lack of food, lack of suitable habitat.
•
ABIOTIC
FACTORS-
•
Unfavourable weather.
•
lack of water, alternation in chemical
environment
•
If
the growth and reduction factors are in balance the population will be in
balance.
•
if all the population are in balance , we can
expect the entire ecosystem to be in balance too.
8.Define drug.
A drug is an externally administered substance that modifies or affects Chemical reactions in the body.
9.Different types of
drug. Effect of heroin, alcohol and smoking.
(
Describe the possible effects of the abuse of a named drug.) 6
10.Suggest why many people regard
smoking tobacco as no longer socially acceptable( Passive smoking)
1.
Sedative/
Depressant drug:
·
Are drugs that affect the central nervous system.
·
Slow down the rate at which impulse conducted to and from the brain and make us feel sleepy.( transmission
of nerve impulses )
·
Remove all feelings of anxiety , creating a feeling of extreme
well being.
·
Example- alcohol, heroin, tranquilizers and sleeping pills, wine, liquor
2.
Stimulant drug:
·
Speed up the action of the brain and make us feel alert. .(
speed up
transmission of nerve impulses).
·
Increase heart rate,
breathing and blood pressure.
·
Sometimes given to people
who are suffering from severe depression.
·
Example- coffee, tea,
nicotine cocaine. Amphetamines.
3. Hallucinogenic drugs:
·
Mind –alerting drug
·
cause a person to experience illusion, hallucinations and
distorted images so abusers lose sense of time and space.
·
Example- cannabis ( called marijuana) LSD ( lysergic acid diethylamide)
4.
Opiates:
·
Narcotic drug who relieve
pain and induced sleep and stupor.
·
Include Opium, morphine and heroin. ‘
Ø Heroin:
·
Heroin is
a drug which is a powerful depressant.
·
Affect
the central nervous systems slowing
the rate at which impulses are conducted .
·
It is a narcotic which removes all feelings of anxiety ,creating a
feeling of extreme wellbeing and
reduces severe pain.
·
The body
develops a tolerance, as a result of which progressively increased dosages are required in order to give the same Effect.
·
The physical addiction to this drug develops very quickly which may end up in a
state of dependency in which they
can not face life without the drug.
·
Addiction
can lead the user into a life of crime
in order to obtain money
or regular supplies of the
drug.
·
Heroin
is a drug normally taken by injection into a vein. If several addicts use the same unsterilized needles they
are at a high risk of contracting blood-borne
disease such as hepatitis and AIDS.
·
withdrawal symptoms :
·
The user
begins to crave the drug, and if unable
to obtain further supplies, suffers severe withdrawal symptoms which include
·
diarrheaea, nausea, vomiting,muscular pain, shaking, sweating,
·
hot/cold flushes, hallucination, anxiety, depression. These are signs that abuse of
the drug has led to addiction.
Cure:
·
The only
cure is their determination to stop the abuse.
·
There
are rehabilitation centers and help groups available for addicts.
·
Alcohol:
Alcohol is a more widely available
and more widely used drug. It is generally
regarded as a more ' socially acceptable’ drug by many Societies but its effects are as follows:
·
It is a powerful depressant
creating a feeling of well-being.
·
It slows the impulse rate which takes longer reaction time (increasing the risk of accident), poor
coordination, balance, reflexes are
sluggish, blurs the vision leads to poor judgment in the driver resulting in fatal road
accident
·
long –
term excessive drinking lead to alcoholism.
·
When consumed in excessive quantities, it leads to loss of self-control leads to
slurring of speech.
·
Many people
under the influence of alcohol behave in a way in which they
would be
ashamed of when sober.
·
It also leads
to liver damage ('cirrhosis') as the liver can no longer
detoxify the blood which can eventually
prove fatal.
·
During pregnancy can damage the fetus, and increase the risk of miscarriage, and birth defects.
·
Like heroin,
alcohol is a drug of addiction, and
thus, to prevent withdrawal
Symptoms ( which
are not as severe as those for heroin), a considerable amount of money are
spent to satisfy the cravings. often a person's family suffers, not only
from a lack of financial support but
also from physical violence.
social problems associates with alcohol:
1.aggressive
behaviour/fighting;
2 family break
up/loss of friends;
3 inabilities
to concentrate/pootimekeepingng – loss of job;
4 financial
problems/money spent on alcohol;
5 lacks of
personal care or hygiene;
6 problems with
law/ so lead a life of crime like theft;
7 drunk driving,
higher risk of accidents/lose licence;
8 homelessness
1.
Effect of Tobacco smoke:
Ø
Nicotine is the drug of addiction present
in cigarette smoke A. person suffers (relatively ) mild withdrawal symptoms if
the craving is not satisfied. Nicotine has
the following effects:
·
It is a poison that increases heart rate and blood pressure by releasing adrenalin.
·
It may cause arterial constriction and diposition of fat in
the atrial wall therefore blood clotting increases the risk of thrombosis which if in the coronary artery of the heart will result in a heart' attack'
.clotting of the capillaries of the brain cause stroke.
·
Stimulates
the brain making the smoker alert and relaxing the muscle then dulls the brain and senses.
Other harmful components of
cigarette smoke:
Ø
Tar:
·
It forms a Layer over the walls of the alveoli, restricting gaseous exchange. It is also responsible for
the inflammation of bronchi and the destruction of cilia.
·
It is also
a carcinogen (i.e. a cancer
producer) and prolonged exposure to it may lead to lung cancer.
Ø
Carbon monoxide
·
Is taken
up, permanently, by hemoglobin in Preference
to oxygen ( forming carboxyhemoglobin
).
·
It thus greatly reduces the ability of the blood
to carry oxygen to the extremities (fingers
and toes), which can be especially affected, as can those parts that require a
lot of oxygen to keep working - such as the heart.
·
Damage the
lining of the blood vessels- increasing the tendency of the blood to clot and
so block vessels.
Ø
Irritant chemicals and particles in smoke cause
cells lining the bronchi and bronchioles to increase their
production of mucus. These chemicals
also destroy the cilia lining the
trachea.
·
Cilia sweep
away the dirt in a ‘moving carpet' of mucus and carry it to the throat for swallowing.
The build-up of mucus is relieved only by continual coughing
(smoker's cough).
·
Persistent
coughing eventually damages the walls
of the alveoli (emphysema).
Ø
Effects of smoking during
pregnancy:
Ø
A
pregnant woman who smokes also risks the
health of her baby.
·
Less oxygen reaches the baby as a result of
the effects of carbon monoxide, and nicotine can pass from the mother's to the
baby's blood which causes blood vessels narrow.
·
As substances pass from the mother’s blood to the
fetus’s blood across the placenta so fetus may have
impaired development. Babies born to mothers who
smoke during pregnancy are underweight. Baby
born prematurely.
·
perhaps less intelligent, and there is a greater
risk of miscarriage, stillborn
Ø
Passive smoking. Evidence now exists that
breathing the smoke from other people can be harmful, For example, It affects asthmatics patients and pregnant women. and cigarette smoke is certainly –an irritant to the
eyes and leaves a lingering smell in clothes. Smoking is therefore increasingly becoming a socially unacceptable habit.
Disease-associated with smoking:
Other than the risk of heart
disease smoking greatly increases
the chances of suffering from
the following diseases:
1.
Chronic bronchitis: Bronchitis is an inflammation
of the airways ('chronic' means extending over a long period). It leads to an overproduction of mucus which tends to block the bronchi and bronchioles, making breathing difficult, and decreasing the efficiency of the gaseous exchange process. Less oxygen reaches the blood, with consequent effects on organs such as the heart muscle, the brain, and
the extremities. It also
causes a distressing cough.
2.
Emphysema: Emphysema is a condition
often associated with chronic bronchitis. The walls
of the alveoli become stretched and lose their elasticity. They do not empty properly
creating a build-up of carbon dioxide in the lungs.
The patient suffers from breathlessness, and decreased efficiency of the heart, brain, etc., through too much carbon dioxide (and
insufficient oxygen) in the blood.
3.
Lung cancer: Cells in the lungs begin to
divide uncontrollably, forming thickened tissues through
which gases cannot pass, and which may block airways. Unless treated
early, it is likely to be a fatal condition.
11.why antibiotic is not effective against
virus. 3
Antibiotics
are ineffective against virus:
Antibiotics are produced by microorganisms to kill or control the
growth of other microorganisms by blocking specific
metabolic pathway within the cell mainly works upon
synthesis of bacterial cell walls. Moreover bacteria are so
indifferent to human cells, antibiotics can be taken by humans to kill bacteria
without harming the human cells.
viruses do not
carry out any metabolic processes themselves like protein
synthesis, respiration and do not have
any cell wall or cell membrane which are
the targets for antibiotics. .viruses are not considered as living
organism therefore viruses cannot be
treated with antibiotics
12.STI ( way of
transmission and prevention) 5
AIDS: Acquired immune deficiency syndrome (AIDS) is the
most widely known STD (sexually transmitted disease) caused by a virus called human immunodeficiency virus
(HIV). The term (AIDS) refers to the most advanced stages of HIV
infection. HIV destroys the body immune
system- the system that protects a person against infection.
● AIDS is called a ‘syndrome’ because it is a
disease with many signs or symptoms
occurring at the same time.
● victims
of AIDS usually die within two years. so far, no cure has been found.
Signs
and symptoms:
It may take months to years before HIV
infection develops into AIDS. Signs and
symptoms of AIDS include:
● chronic or persistent fever.
● severe diarrhea lasting for months.
● pneumonia
● cancer of the blood vessels
● brain infection
● widespread tuberculosis affecting many organs at the same time.
Transmission
The AIDS virus (HIV) lives in body fluids such
as blood and semen.
● It is thus transmitted from host to host when drug abusers share unsterilized needles to inject
themselves since there is usually a little blood from the previous user which
is injected along with the drug into the second (and subsequent) user. needles
used for tattooing, acupuncture or ear-piercing may also transmit the
disease if they are not sterilized properly.
●
It is transmitted in semen from one partner to the blood of
another. If there is any tearing of tissues during intercourse.
●
It is transmitted from an infected mother's blood to her baby’s blood through placenta
and umbilical cord during the birth
process.
●
It may be accidentally transmitted
in untreated blood during blood transfusion.
Controlling measure:****
1. Educating the public about
how it is spread and what precautions
can be taken.
2. Never sharing needles or using unsterilised needle.
3. Avoiding sex with prostitutes since they are often
carriers of the
disease .Stay
with one STD-free partner.
4. If in doubt, always use a. condom or other barrier method of
contraception
which prevents direct contact between the body fluids of the two partners.
5. Treat all blood
and blood products used in transfusions to destroy HIV by screening blood.
6. abstinence of sexual intercourse.
13. Malaria (
spread and control) 5
The transmission of malaria:
Malaria is a disease caused by a single-celled microorganism called Plasmodium that lives in red blood cells. It is carried from person to person (host to host)
by the female Anopheles mosquito.
The mosquito is thus described as the
vector (i.e. carrier) of the microorganism. Usually at night, while the
host is asleep, she injects her saliva into a (healthy) person before she
starts to suck the blood which she needs
for her developing eggs. The saliva contains a chemical to stop the blood
from clotting. If the mosquito has recently taken blood from a person infected
with malaria it may also contain the parasite Plasmodium. The parasite has now
been transferred from the blood of one host, where it lives and develops, to
the blood of a second host.
Control of malaria:
Malaria can be controlled in three ways:
1. by controlling
the mosquito vector
2. by avoiding
mosquito bites
3. by treating
the parasite in the blood.
1.Controlling the mosquito: All mosquitoes, anopheles
mosquitoes go through four stages in their life cycle: egg, larva, pupa, and adult. The first three stages are aquatic and last 7-14 days,
depending on the species and the ambient temperature. The biting female
Anopheles mosquito may carry malaria.so it may said as amphibian organism.
•
cover water tanks with netting to stop mosquitoes laying their eggs in the water.
•
Drain swamps and areas of stagnant water where mosquitoes lay their eggs.
•
Introduce fish such as Tilapia into the swamps to feed on mosquito larvae.
•
cover the surface of the water with light oil. Larvae cannot then use the water film from
which they hang as they breathe air from the
atmosphere. The larvae and pupa therefore
suffocate.
•
Use insecticides or mosquito coils
to kill adult mosquitoes inside
buildings.
2.Avoiding mosquito bites:
•
Place
nets over doors and windows.
•
wear
clothes which cover wrists and ankles , specially in the evenings, when mosquitoes are most
active.
•
Use insect repellent sprays.
•
Sleep
under mosquito nets.
3.
Protection against the parasite plasmodium
Take
drugs regularly to kill the parasite if it enters the bloodstream (e.g.
Paludrine but the correct drug must be taken for the particular type of Plasmodium found in any
particular region).
Treat patients suffering from malaria with a higher dosage of antimalarial drug, and
isolate them to prevent the
spreading of the disease.
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