EVS presentation

1. Module 7: Human Population
and the Environment

2. Population Growth
• Population may be defined as a group of organism of the
same species occupying a particular space
• Total size of population is generally expressed as number
of individuals in a population. The population size (N) at
any given place is determined by the processes of birth
(B), death (D), new arrivals from outside or immigration
(I) and going out or emigration (E). Therefore, change in
population size between intervals of time (t) is :
Nt (initial stage) + B – D + I – E
• Population density is defined as the number of
individuals per unit area or per unit volume of the
environment

3. Population Characteristics
1. Natality- It is a broader term covering the production
of new individuals by birth, hatching, germination or
fission. The natality rate may be expressed as the
number of organisms born per female per unit time.
Natality is of two types:
i. Maximum Natality- is the theoretical maximum production
of new individuals under ideal conditions which simply
means that there are no ecological limiting factors and that
reproduction is only limited by physiological factors. This is
also called reproductive capacity
ii. Ecological Natality- refers to the population increase under
an actual, existing specific condition. Thus, ecological
natality takes into account all possible existing
environmental conditions. This is also called fertility rate.

4. 2. Mortality- It means the rate of death of individuals in the
population. It is a negative factor for population growth.
Mortality has the following types:
• Minimum mortality- which represents the theoretical minimum
loss under ideal or non limiting conditions. It may be constant for
a population
• Ecological mortality- is the actual loss of individuals under a
given environmental condition like a disease or hazard
3. Doubling Time- The time needed for a population to
double its size at a constant annual rate is known as
doubling time. If a nation has 2% annual growth rate, its
population will double in 35 years.
4. Total Fertility Rate (TFR)- It the average number of
children that would be born to a woman in her lifetime if
the age specific birth rates remain constant. The TFR
values for developed countries is 1.9 to 4.7 in developing
nations

5. 5. Age Structure- The proportion of individuals in each age
group is called age structure of that population. The ratio
of the various age groups in a population determines the
current reproductive status of the population. There are
three major ecological ages in any population: pre-
reproductive (0-14), reproductive (15-44) and post
reproductive(45 and above). The relative duration of these
age groups in proportion to the life span varies greatly with
different organisms. Geometrically the proportions of
different age groups in the population of organism are
given by age pyramid. The following three basic types of
age pyramids are:

6. a. A pyramids with a broad base (or triangular
structure): It indicates a high percentage of young
individuals. In rapidly growing young populations
birth rate is high and population growth may be
exponential as in yeasty house fly, Paramecium,
etc. Under such conditions, each successive
generation will be more numerous than the
preceding one, and thus a pyramid with a broad
base would result (Fig. A). E.g. India, Bangladesh,
Nigeria etc.
b. Bell-Shaped Polygon: It indicates a stationary
population having an equal number of young and
middle aged individuals. As the growth rate
becomes slow and stable, i.e., the pre-reproductive
and reproductive age groups become more or less
equal in size, post-reproductive group remaining as
the smallest (Fig. B). E.g. France, USA, Canada.

7. c. An urn-shaped structure- It indicates a low percentage
of young individuals and shows a declining population.
Such an un-shaped figure is obtained when the birth rate
is drastically reduced the pre-reproductive group
dwindles in proportion to the other two age groups of
the population. (Fig. C). E.g. Germany, Italy Hungary
Japan etc.

8. 6. Aging- The world is aging at unprecedented rates due
to decrease in both birth and death rates. Median age is
the age that divides a population into two numerically
equal groups - that is, half the people are younger than
this age and half are older. It is a single index that
summarizes the age distribution of a population.
Currently, the median age ranges from a low of about
15 in Niger to 40 or more in several European
countries, Canada and Japan.
For India it is 27.9 years.

9. 7. Youth Bulge- The youth bulge is a common
phenomenon in many developing countries, and in
particular, in the least developed countries. It is
often due to a stage of development where a country
achieves success in reducing infant mortality but
mothers still have a high fertility rate. The result is
that a large share of the population is comprised of
children and young adults, and today’s children are
tomorrow’s young adults.

10. Population Explosion
• The term population explosion means the rapid increase in
population which outstrip the growth of national income
and retards the per capita income. It hampers the saving
and invests. The economy remains in the grip of vicious
circle of poverty. The consumption and nutrition standard
of the population are low. They suffer from poor health
and low productivity.
• Between 1959 and 2000, the world’s population increased
from 2.5 billion to 6.1 billion people. According to United
Nations projections, the world population will be between
7.9 billion and 10.9 billion by 2050

11. • Most of the growth is currently taking place in the
developing world, where rates of natural increase are
much higher than in industrialized countries. Concern
that this might lead to over population has led some
countries to adopt population control policies
• Over-population is defined as the condition of having
more people than can live on the earth in comfort,
happiness and health and still leave the world a fit place
for future generations

12. Causes of Population Explosion
1. Improvement in public health: People now are more
aware and educated about proper water and sanitation
2. Control of Diseases: Control of various communicable
diseases due to improved medical services (vaccines and
antibiotics)
3. Advancement in Agriculture: Farmers grow high
yielding crops which has increased food production
4. Better Transport and distribution of food: This protects
from famines.
5. Protection from Natural Calamity: It decreases death
rate.
6. Government Efforts: Government is doing efforts to
provide maximum information’s to the farmers.

13. Effects of Population Explosion
1. Depletion of Natural Resources: Population explosion will
overstress the earth’s resources. All people want to be fed,
clothed, housed, and have access to clean water. To meet
these requirements, water, land, forests and other natural
resources are exploited which leads to deforestation for
urbanization, agriculture and industrialization
2. Over Production of Wastes: The greater amount of waste
from larger populations puts more stress on ecosystem
3. Food Problem: Increased population means more mouths to
feed which, in turn, creates pressure upon available stock of
food. This is the reason, the under-developed countries with
rapid growing population are generally faced with a
problem of food shortage. Despite all their efforts for
raising agricultural production, they are not able to feed
their growing population

14. 4. Overstress of water resources: Competition for water
resources among individuals, regions, and countries
and associated human activities is already occurring
with the current world population
5. Rise in Unemployment: When a country becomes
overpopulated, it gives rise to unemployment as there
fewer jobs to support large number of people. Rise in
unemployment gives rise to crime as people will steal
various items to feed their family and provide them
basic amenities of life

15. Population Explosion: Indian Scenario
The reasons are:
• The birth rate is still higher than the death rate. We have
been successful in declining the death rates but the same
cannot be said for birth rates
• Early Marriage and Universal Marriage System: Even
though legally the marriageable age of a girl is 18 years,
the concept of early marriage still prevails and getting
married at an young age prolongs the child bearing age.
Also, in India, marriage is a sacred obligation and a
universal practice, where almost every woman is married
at the reproductive age
• Poverty and Illiteracy: Impoverished families have this
notion that more the number of members in the family,
more will be the numbers to earn income. Some feel that
more children are needed to look after them in their old
age.

16. Also hunger can be cause of death of their children and
hence the need for more children. India still lags behind
the use of contraceptives and birth control methods. Many
of them are not willing to discuss or are totally unaware
about them. Illiteracy is thus another cause of over
population
• Age old cultural norm: Sons are the bread earners of the
families in India. This age old thought puts considerable
pressure on the parents to produce children till a male child
is born. More the better.
• Illegal migration: Last but not the least, we cannot ignore
the fact that illegal migration is continuously taking place
from Bangladesh, Nepal leading to increased population
density

17. Family Welfare Programmes
• The National Family Welfare Programme (FWP) was
launched in 1952 with the objective of reducing birth rate
to the extent necessary to stabilize the population.
• The FWP seeks to promote responsible and planned
parenthood through voluntary and free choice of family
planning methods
• Some nations like Singapore and Netherlands have already
achieved replacement level fertility while some like
Thailand and Sri Lanka have reached 3-child family
average. Except in Africa where women want 4 children or
more
• The government evolved a more detailed and
comprehensive National Population Policy in 1986 to
promote it on voluntary basis as a ‘movement of the
people, by the people, for the people,

18. • It has given family planning the broadest possible
dimension which include not only health and family
welfare but also child survival, women’s status and
employment, literacy and education, socio-economic
development and anti-poverty programmes
• The salient features of this policy are:
1. Promote delayed marriage for girls, not earlier than age
18 and preferably after 20 years of age
2. Promoting the two child family norm
3. Increasing female literacy rate
4. Enhancing child survival through universal
immunization
5. Prevent and control communicable diseases
6. Achieve 100 per cent registration of births, deaths,
marriages, and pregnancy
7. Achieve 80 per cent institutional deliveries and 100 per
cent deliveries by trained persons

19. Human Rights
• Human rights are moral principles or norms, which describe
certain standards of human behaviour, and are regularly
protected as legal rights in municipal and international law
• They are commonly understood as inalienable fundamental
rights "to which a person is inherently entitled simply
because she or he is a human being," and which are "inherent
in all human beings” regardless of their nation, location,
language, religion, ethnic origin or any other status
• They are applicable everywhere and at every time in the
sense of being universal, and they are egalitarian in the sense
of being the same for everyone
• The ‘Universal Declaration of Human Rights’ was adopted
by the United Nations on December 10, 1948 which states
that “the inherent dignity of all members of the human
family is the foundation of freedom, justice and peace in the
world”

20. Types of Human Rights
1. Social or Civil Human Rights- All human beings are
entitled to:
1. The right to life, liberty and security of persons
2. Right to freedom from slavery and servitude
3. Right to freedom from torture or cruel, inhuman or
degrading treatment or punishment
4. Right to freedom from arbitrary interference with privacy,
family, home or correspondence
5. Right to marry and have family and right to property
2. Political Human Rights- To take part in the political
process, all human beings are provided with some
rights such as:
1. Right to nationality
2. Right to equality before law and equal protection of law
3. Right to judicial remedies, fair trial and freedom from
arbitrary arrest, detention or exile

21. • Right to freedom of thought, expression, belief, faith,
conscience and religion
• Right to freedom of peaceful assembly and association
• Right to take part in government affairs and equal access to
public service
• Right to equal suffrage
• Right to freedom of movement and right of asylum etc.
3. Economic Human Rights: To ensure the economic
interest of the human being, UNO also provides certain
economic rights, such as:
i. Right to social security
ii. Right to work and the right to equal pay for equal work
iii. Right to form trade unions
iv. Right to rest and leisure
v. Right to food, health and adequate standard of living

22. 4. Cultural Human Rights- For the protection of the
various types of cultures, traditions and customs of
the human being, the Declaration of Human Rights
also provides certain rights, such as:
i. Right to participate in the cultural life of the community
ii. Right to enjoy the art and to share in the scientific
advancement and its benefits
iii. Right to the protection of the moral and material interests
resulting from any scientific, literary and artistic
production of which the individual is the author
iv. Right to a social and international order in which the
human rights as provided in the Universal Declaration can
be fully realized.

23. HIV/AIDS
• HIV means human immunodeficiency virus, and its rising
incidence leading to AIDS (Acquired Immuno Deficiency
Syndrome), has been posing grave threat globally to the
lives to people especially women
• Symptoms: Following initial infection, a person may not
notice any symptoms or may experience a brief period of
influenza-like illness. Typically, this is followed by a
prolonged period with no symptoms. As the infection
progresses, it interferes more with the immune system,
increasing the risk of common infections like tuberculosis,
as well as other opportunistic infections, and tumors that
rarely affect people who have working immune systems.
These late symptoms of infection are referred to as AIDS.
This stage is often also associated with weight loss.

24. Transmission
HIV is transmitted by three main routes:
1. Sexual: The most frequent mode of transmission of HIV
is through sexual contact with an infected person.
2. Body fluids- The second most frequent mode of HIV
transmission is via blood and blood products. Blood-
borne transmission can be through needle-sharing during
intravenous drug use, needle stick injury, transfusion of
contaminated blood or blood product, or medical
injections with unsterilized equipment.
3. Mother-to-child: HIV can be transmitted from mother to
child during pregnancy, during delivery, or through
breast milk resulting in infection in the baby

25. Prevention and Control from AIDS
1. Sexual Contact- the only universally medically proven
method for preventing the spread of HIV during sexual
intercourse is the correct use of condoms.
2. Mother-to-child- Programs to prevent the vertical
transmission of HIV (from mothers to children) can
reduce rates of transmission by 92–99%. This primarily
involves the use of a combination of antiviral
medications during pregnancy and after birth in the
infant and potentially includes bottle feeding rather than
breastfeeding
3. Pre-exposure- Antiretroviral treatment among people
with HIV whose CD4 count ≤ 550 cells/µL is a very
effective way to prevent HIV infection of their partner
(a strategy known as treatment as prevention, or TASP).

26. 4. Health Education- Educating people to use protection,
avoid using shared razors and toothbrushes, avoid
sharing needles and syringes and avoiding pregnancy if
the woman is suffering from AIDS. Also media
channels should participate in educating the people
5. Prevention of blood-borne HIV transmission- This
involves screening all donated blood, strict sterilization
in hospitals and clinics and pre-sterilized disposable
syringes and needles
6. Integration of AIDS control programmes- into country’s
primary healthcare system.