Growth of Human PopulationFlame Institute

History of man is only about 50,000 years old. In the course of human history there have been three major explosions, each corresponding to a major changes in the environment. The first population explosion occurring about 20,000 years ago. It was brought about by the use of tools that allowed improvement in hunting and food gathering methods. The second revolution occurred about 6,000 years ago, and was brought by improvements in farming. The third revolution was brought about 300 years ago and was caused by improvement in food production, industry and medicine. If the present birth rate is maintained, it is stated that only one square feet of the earth surface will be available per one person within the next 700 years.

Definition : The term population refers to the total number of individuals of the same species occupying a particular geographic area at a given time. This definition of population was given by Clark in 1954.

Demography : The scientific study of human population is called demography. It deals with

(1) Change in population i.e. growth or decline in population.

(2) Composition of population i.e. age groups, sex ratio etc.

(3) Distribution of population in space.

Census : Census is an official count of the people of a country, state, or district, with statistics as to age, sex, employment, education, etc. In India census started in 1891, and, since then, it has been conducted uninterruptelly every ten years. Census is conducted as per the provision made under the census Act, 1948, as amended.

Population Dynamics

(1) Population density : Population density is the number of individuals present per unit area or volume at a given time. For instance, number of animal per square kilometer, number of trees per area in a forest, or number of plank tonic organism per cubic meter of water. If the total number of individuals is represents by letter N and the number of units of space by Letter S, the population density D can be obtained as D=N/S. Space is indicated in two dimensions (m²) for land organisms, and in three dimensions (m³) for aquatic organisms and for the organisms suspended in space.

(2) Birth rate or Natality : The birth rate of a population refers to the average number of young ones produced by birth, hatching or germination per unit time (usually per year). In the case of humans, it is commonly expressed as the number of births per 1000 individuals in the population per year.

The maximum birth rate of a species can achieve under ideal environmental conditions is called potential natality. However, the actual birth rate under the existing conditions is much less. It is termed realised natality.

(3) Death rate or mortality : The death rate of a population is the average number of individuals that die per unit time (usually per year). In humans it is commonly expressed as the number of death per 1000 persons in a population per year. Lowest death rate for a given species in most favourable conditions is called potential mortality, while the actual death rate being observed in existing conditions is called realized mortality.

(4) Survivorship curve : The death rate of population can be easily represented by survivorship curve. In this curve time is plotted against number of survivors. There are three kind of survivorship curves.

(i) Diagonal curve : If death rate of different age group organism are equal then the curve is represented or plotted as a straight line.

Example : Hydra, mice and many adult birds.

(ii) Convex curve : When organism completed their potential life spawn and died in old age then the curve is convex, the curves goes horizontal till potential life spawn and then decline rapidly.

Example : Men, rabbit and many mammals.

(iii) Concave curve : This kind of curve most found in such organism who die before their potential life spawn.

Example : Fish, Oysters and Invertibrates.

(5) Vital index : The percentage ratio of natality over mortality is known as vital index i.e. natality / mortality ×100. It determines the growth of a population.

(6) Immigration : It is permanent entry of additional person into the existing population of a country or region from out side. Example; Many Nepalese and Chinese come to settle in India.

(7) Emigration : It is the permanent departure of some persons from the existing population of a region to a different state or a foreign country. Example; Many Indians go to Western countries to settle there.

Immigration and emigration bring about redistribution of population, and are common in animals. These occur for various reasons, such as search for food, escape from competition due to overcrowding, need of shelter etc.

(8) Sex ratio : The number of females in a population per 1000 males is called sex ratio.

Sex ratio =

(9) Age structure : The age structure of a population is the percentage of individual of different ages such as young, adult and old. Age-sex structure of a population can be shown by a pyramid-like diagram by plotting the percentage of population of each sex in each age-group. Figure shows the age-sex structural pyramids for India over the 20-year period from 1971 to 1991. These pyramids show that Indian population may still take many years to be stabilized.

(10) Age distribution : The relative abundance of the organisms of various age groups in the population is called age distribution of population. With regard to age distribution, there are three kinds of population.

(i) Rapidly growing or Expanding population : It has high birth rate and low death rate, so there are more number of young individuals in the population.

(ii) Stationary or stable population : It has equal birth and death rates, so population shows zero population growth. The pyramid of this type of population is ‘bell’ shaped.

(iii) Declining population : It has higher death rate than birth rate, so the population of young members is lower than that of old members e.g. Japan (Ageing population). The pyramid of this type of population is ‘urn’ shaped.

Human population has three age groups : Pre reproductive, Reproductive, and post reproductive.

Factors affecting the age composition

(i) Number of infants below one year of age and the older people as these have higher mortality rate than individuals of other age groups.

(ii) Proportion of reproductive active males and females in a population.

(iii) Number of females in active reproductive age (i.e. between 15 to 44 years)

(11) Change in Population Size and Growth Rate : Whether a population grows, declines or maintains it size depends upon the balance between the above factors:

The above expression in words may be represented in a simple way by a mathematical model. suppose N = population size and t = time. The Greek letter delta, , indicates change. We can now represent change in population as N, and time interval as . The verbal equation can be written as DN/Dt=(B+I) – (D+E) in which B is absolute number of births in the population during the time interval, and D =the absolute number of deaths during that interval; I means immigrant and E, emigrants. I and E , being insignificant, may be ignored. Then the equation simplifies to DN/Dt =B-D.

Migration is a two-way movement of a population for adjusting to seasonal changes. It occurs in some fishes (Anguilla, an eel), birds (Siberian crane), and mammals (fur seal). Migration is not considered a determinant of population size.

Annual average growth rate is the percentage of increase in population size per year. It can be calculated with the help of following equation :

Where P₁= Population size of previous census. P₂= Population size of present census.

N= Number of years between the two census.

Growth of Human Population

Population growth refers to the increase in its size. It is determined by the number of individuals added to the population and the number of individuals lost from the population. Addition occurs by births and immigration. Loss results from deaths and emigration. If more individuals are added than are lost i.e., the vital index is more than 100, the population will increase or show positive growth. If more individuals are lost than are added i.e., the vital index is less than 100, the population will decrease or show negative growth. If addition and loss are balanced, i.e., the vital index is 100, the population will become stationary or show zero growth.

Malthus Theory of Human Population Growth : Thomas Malthus, a British political economist, put forward a theory of human population growth in 1778. Malthus in his “Essay on the principle of population” pointed out that population tends to increase in geometric progression while food supply increase only in arithmetic progression. Faster growth of population than of its requirements causes an imbalance between the two. When this imbalance reaches a certain limit, environmental factors like famine, epidemic of a disease, earth quake, flood, war etc reduce the population to a size, the available resources can support. The factors that control the population size were called positive checks by Malthus.

Natural Control of Population Growth : Growth of a population is controlled by an interaction between three factors : biotic potential, environmental resistance and carrying capacity of environment.

(1) Biotic or reproductive potential : Biotic potential is the natural capacity of a population to increase at its maximum rate under ideal environmental conditions and stable age and sex ratios. The biotic potential for all animals is very high. If unchecked, the numbers of any species will quickly over run the world. Biotic potential in the human female is estimated to be about 12 per female during its reproductive period between the puberty and the menopause period.

(2) Environmental Resistance : In nature full biotic potential of an organism or population is never realized, since conditions are rarely ideal. Various harmful environmental (abiotic) factors like non-availability of food and shelter, natural calamities like drought, cloud bursts, floods, fires, temperature fluctuations, accidents, etc. and certain biotic factors like pathogens, parasites, predators etc. check the biotic potential from being realized. The sum of all these inhibitory factors is called environmental resistance.

(3) Carrying capacity : It is defined as “Feeding capacity of an environment of an ecosystem for a population of a species under provided set of conditions”. When a population reaches the carrying capacity of its environment, the population has zero growth rate. So the population generally stabilizes around the carrying capacity. The carrying capacity of the earth for human population is considered to be about 8 to15 billions. Carrying capacity of the environment for a population depends upon three major components :

(i) Productive systems which produce food and fibre e.g. croplands, orchards, etc.

(ii) Protective systems which buffer air and water cycles and keep moderate environmental temperatures e.g. ocean etc.

(iii) Assimilative systems which utilize the wastes produced by human activities e.g. waterways, wetlands, etc.

Productive system and protective systems collectively form the life-supporting capacity, while assimilative systems collectively form the waste assimilative capacity.

(iv) Population fluctuations and population cycles : The populations are not stable and do change due to a number of extrinsic as well as intrinsic factors. These variation in the population size are of two types :

(a) Population fluctuations or irruptive variations : In these changes, population density tends to fluctuate irregularly above and below some steady-state level. These are characterized by sudden increase in population in short time which is followed by equally quick decrease in population size. These are caused by random seasonal or annual changes in availability of resources (food or energy) or extrinsic factor (e.g., temperature, rainfall etc.) e.g., more birds during early summer due to their hatching period, more insects during summer months and more weeds in rainy season.

(b) Population cycles : These are regular changes in the population size. In these, population size is nearly constant over long period of time. These are caused by seasonal changes in environment e.g. population cycles (of 3 to 4 years) of lemmings of Tundras (Elton, 1942) Lemmings (Lemmus lemmus) (small mouse-like rodents found in arctic regions of Canada and Norway) increase in their number for a period of about 3 years when it reaches a peak beyond the carrying capacity of that area. They eat up all the available food. In the winter months, the lemmings migrate in large numbers in the sea and swim till they are drowned due to exhaustion. The surviving lemmings multiply and repeat the process.

Patterns of Population Growth : Growth of a population can be expressed by a mathematical expression, called growth curve in which logarithm of total number of individuals in a population is plotted against the time factor. Growth curves represent interaction between biotic potential and the environmental resistance.

Two basic types of growth curves

(i) Sigmoid or S-shaped growth curve : It is shown by yeast cells and most of organisms. It is formed of five phases :

(a) Lag phase. In which the individuals adapt themselves to the new environment, so there is no or very little increase in population.

(b) Positive Acceleration phase. It is the period of slow increase in population in the beginning.

(c) Logarithmic or Exponential phase : It is the period of rapid rise in population due to availability of food and requirements of life in plenty and there being no competition.

(d) Negative Acceleration phase : In which again there is slow rise in population as the environmental resistance increases.

(e) Stationary (Plateau) phase : Finally, growth rate becomes stable because mortality and natality rates become equal to each other. So there is zero growth rate. A stable population is said to be in equilibrium, or at saturation level. This limit in population is a constant K and is imposed by the carrying capacity of the environment. S-shaped curve is also called logistic curve. Sigmoid growth curve was described by Verhulst, (1839)

(ii) J-shaped Growth curve : It is shown by small population of Reindeer experimentally reared in a natural environment with plenty of food but no predators. It has only two phases:

(a) Lag phase : It is period of adaptation of animals to new environment so is characterized by slow or no growth in population.

(b) Logarithmic or Exponential phase : It is characterized by rapid growth in population which continues till enough food is available. But with the increase in reindeer population, there is corresponding decrease in the availability of food and space, which finally become exhausted, which leads to mass starvation and mortality. This sudden increase in mortality is called population crash. Lemming of Tundra, some insect, algal blooms and annual plants also show J-shaped curves. The population growth curve is S- shaped in most of the organisms, Human population also shows S-shaped curve.

Table : 10.13-1 Difference between S-shaped and

J-shaped Growth curves

S.No.	S-shaped Growth Curve	J-shaped Growth Curve
(1)	It is formed of 5 phases : lag phase, positive acceleration phase, exponential phase, negative acceleration phase and stationary phase.	It is formed of 2 phases : lag phase and exponential phase.
(2)	Finally the population shows zero growth rate as birth rate equals death rate.	Finally, the population shows a population crash due to rapid increase in mortality rate.
(3)	Examples. Yeast cells in a culture medium.	Examples. Reindeers, algae blooms, lemmings of Tundras

(iii) Human Population Growth Curve : The modern man (Homo sapiens sapiens) appeared about 25,000 years ago. For a very long time, the human population remained in the lag phase, having little or very slow growth. By the year 1 A.D., there were about 0.25 billion people in the world, and by 1600 about 0.5 billion. Thus, it took 1600 years for the population to become double. The exponential phase of growth of the human population started about 1750. Since then, the time taken by the population to become double has considerably shortened. It doubled in 200 years (1600-1800 A.D.), becoming 1 billion; then doubled in 130 years (1800-1930 A.D.), growing to 2 billion; then doubled in only 45 years (1930-1975 A.D.), reaching about 4 billion. At present, the world human population grows at a rate of 2 percent a year, and it has now reached 6 billion. If the present growth rate persists, there would be 8 billion people on earth by the year 2017.

World population gain is 2 persons every second; 200,000 people every day; 8 million every month; and 70 million every year. The high rate of growth is often referred to as “population explosion” The word “explosion” may be defined as a rapid and expansive change of state.

The future of human population is difficult to predict. It may stabilize and have S-shaped growth curve or decline rapidly and have J-shaped growth curve. The population will stabilize if the birth and death rates are balanced in the near future. It will rapidly decline if it overgrows the carrying capacity of the environment.

Population Trends in the World and India

Population Trends in the World

The distribution of human population is not uniform throughout the world. Only about one third of the total land area is inhabited. Of the inhabited areas, some are thickly populated, others sparsely. This depends upon the availability of the requirements of life. About 56% of the total world population resides in Asia alone. Bangladesh is the most thickly populated country, and Australia, the most thinly populated.

Table : 10.13-2 Annual Birth, Death and Growth Rates for Human Population in 1973

S. No	Region	Population (Millions)	Average Annual Birth Rate per 1,000 Individuals	Average Annual Death Rate per 1,000 Individuals	Annual Growth Rate Percent
(1)	World	3860	33	13	2.0
(2)	Developed Countries	1120	17	9	0.8
(3)	Developing Countries	2740	39	14	2.5

Population Trends in India

(1) Population : India with a population of 1027 million as 2001 census stands second in the world. The world leader in the matter of population is China with a population of 1160 million. India has only 2.42% of the world’s land area but supports over 15.5% of the world’s population. Thus, one in every 6 persons in the world is an Indian. India’s population has been steadily rising since 1921. However, from the year 1921, often called the “big divide”, its population started to swell up sharply. India’s population has increased 3 times since independence (1947) when its population was 340 million. About 1800 individuals are born every hour, 17 million every year. India’s population crossed one billion (100 crores) mark on May 11, 2000.

Table : 10.13-3 India’s Population 1901 to 2001

Years	Population	Year	Population
1901	238,396,327	1961	439,234,771
1911	252,093,390	1971	548,159,652
1921	251,321,213	1981	683,329,097
1931	278,977,238	1991	846,302,688
1941	318,660,580	2001	1,027,015,247
1951	361,088,090

(2) Sex Ratio : Sex ratio is defined as the number of females per thousand males in a country or state. Sex composition is affected by three factors : (i) differentials in male-female ratio at birth, (ii) differentials in mortality conditions of males and females, and (iii) sex-selective migration. India is one of the few countries where the males are more than the females.

Table : 10.13-4 India’s Sex Ratio 1901 to 2001

Year’s	Population density
1901	972
1911	964
1921	955
1931	950
1941	945
1951	946
1961	941
1971	930
1981	934
1991	927
2001	933

(3) Literacy Rate : The literacy rate was 65.28% according to the 2001 census. It was 76.40 % for males and 54.16% for females. The literacy rate has been steadily increasing since 1951. Among the Union Territories, Lakshadweep has the highest literacy rate of 87.52%. Literacy rate is highest in Kerala (90.92%) and lowest in Bihar (47.53%). Any person who can read and write with understanding in any language is recorded as literate in census. All children below 7 years are shown as illiterate in the census.

Table : 10.13-5 India’s Literacy Rate 1961 to 2001

Years	1961	1971	1981	1991	2001
Literacy Rate	24.02	29.45	43.56	52.21	65.38

Factors Favouring Population Growth

(1) Decrease in death rate.

(2) Increase in average life span.

(3) Better medical facilities.

(4) Control of insect vector’s of fatal diseases and epidemics.

(5) Better sanitation.

(6) Proper care of new-born children and their mothers.

(7) Better nutrition and life amenities.

(8) Protection against wild life and adverse whether through living in houses.

Table : 10.13-6 Details of India’s Population of 1981, 1991 and 2001

Date		1981 Census	1991 Census	2001 Census	Rise/ Fall
Population :	Total Males Females	683,329,097 364,214,409 319,114,688	843,930,861 437,597,929 406,332,932	1,027,015,247 531,277,078 495,738,169	+ + +
Decennial Population Growth :	Absolute Percentage	135,169,445 24.66%	160,601,764 23.50%	183,084,386 21.34%	+ –
Annual Population Growth Rate		2.46%	2.35%	2.13%	–
Population Density per square Kilo metre		216	267	324	+
Sex Ratio		934 Females Per 1000 Males	929 Females Per 1000 Males	933 Females Per 1000 Males	+
Literacy Rate :	Total Males Females	43.56% 56.37% 29.75%	52.11% 63.86% 39.42%	65.38% 75.85% 54.16%	+ + +

Table : 10.13-7 India’s Population Density 1991 to 2001

Year’s	Population density
1901	73
1911	77
1921	76
1931	85
1941	97
1951	110
1961	134
1971	167
1981	208
1991	267
2001	324

Table : 10.13-8 Percentage Age Groups in India

Years	0-14 Years	15-59 Years	60 plus Years
1970	42	54.5	3.5
1980	40	54.8	6.2
1990	36	57.5	6.5
2000	31.7	60.8	7.6

Parameters of 2001 census

Population ………………… 1027.015

(+183 million)

Males =531.277 million

Females = 495.738 million

Population density…………….. 324 persons/sq. Km. (+60 persons/sq. Km.).
Sex ratio……………. 933 F : 1,000 M.
Absolute decennial population growth ……………….. +183 million.
Percent decennial population growth………………. 21.34%(-2.52).
Literacy rate……………….. 65.38%(+13.27%).
Male literacy………………. 75.85%.
Female literacy..…………. 54.16%(+14.74%).
Birth rate…………… 26 per 1,000.
Death rate………… 8 per 1,000.

Other Information about Census 2001 :

Most populous state of India = Uttar Pradesh (166 millions) (18.17%).
Second Most populous state of India = Maharashtra (95 millions).
Least populous state of India = Sikkim (5.40 lakh).
Most densely populated state of India = West Bengal (904 persons per sq. Km.).
Second most densely populated state of India = Bihar (880 persons per sq. Km.).
Least densely populated state = Arunachal Pradesh (13 persons per sq. Km.).
Union territory with maximum population density = Delhi (9,294 persons per sq. Km.).
Union territory with minimum population density = Andaman and Nicobar (43 persons per sq. Km.).
State with highest Decennial population growth = Nagaland (64.41%).
State with lowest Decennial population growth = Kerala (9.42%).
Average life expectancy in India = 64 years.
Sex ratio in Kerala state = 1,058 F :1,000 M.
State with highest literacy rate = Kerala 90.92% (94.2% in males and 88% in females).

Population trends in Madhya Pradesh and Chhattisgarh

Population : India’s population according to the provisional totals of Census of India 2001 at the 00.00 hours of I^st March 2001 is 1,027,015,247, out of which the population of Madhya Pradesh is 60,385,118, state thus contributing 5.87% share to India’s total population.

Madhya Pradesh is the 7^th largest state population-wise whereas it is 2^nd in terms of its geographical spread and contributes 9.38% to the country’s total area of 3,287,263 sq.km.

Table : 10.13-9 Population 1901 to 2001 in Madhya Pradesh

Year	Population	Year	Population
1901	12,679,214	1961	23,217,910
1911	14,249,382	1971	30,016,625
1921	13,906,774	1981	38,168,507
1931	15,326,879	1991	48,566,242
1941	17,175,722	2001	60,385,118
1951	18,614,931

Growth Rate : The population growth rate in 2001 has come down to 24.34% from 26.75% in the 1991 and is even less than 24.73% growth rate of 1961 census. The growth rate of 24.34% of the state is higher than the growth rate of 18.06% of newly created state of Chhattisgarh. The average growth rate for the country as a whole is 21.34% and there are 12 districts viz. Bhind, Damoh, Shahdol, Neemuch, East Nimar, Betul, Katani, Dindori, Mandla, Chhindwara, Seoni and Balaghat where the population growth is less then the country’s average with Balaghat having the lowest growth rate of 5.85%. In fact, Balaghat is one such district which over the decades have been registering the lowest population growth rate in the state, except in 1981 when it was replaced by Mandla with population growth rate of 16.28%.

Density : Before the creation of new state of Chhattisgarh, Madhya Pradesh in the country was largest state with an area of 443,436 sq. km. But today it occupies the second position in the country with an area of 308,245 sq. km., Rajasthan becomes the largest state in the country with an area of 342,239 sq.km. and Maharashtra the third largest with an area of 307,713 sq.km.

Density is the number of persons per sq.km. The density of Madhya Pradesh today is 196 persons per sq.km. which is less than country’s density of 324. Density-wise Madhya Pradesh is the 13^th in ascending order, whereas population-wise it holds the 7^th position. Higher density may indicate more urbanization but at the same time low density also means better space. Though, state’s density is low compared to country’s density but in 100 years period of 1901 to 2001, the state’s density has increased by 378.05% whereas country’s density has increased by 343.84%.

Table : 10.13-10 Population Density 1991 to 2001 in Madhya Pradesh

Year’s	Population density
1901	41
1911	46
1921	45
1931	50
1941	56
1951	60
1961	75
1971	97
1981	124
1991	158
2001	196

Sex-Ratio : The sex ratio in Madhya Pradesh has always been adverse to females as has been the case in most of the states in the country as a whole i.e., the number of women per thousand men is always less than one thousand. The sex-ratio in entire country this time has registered a upward trend compared to 1991 census and so also in Madhya Pradesh. Whereas country’s sex ratio has gone up from 927 to 933, Madhya Pradesh ratio has increased form 912 in 1991 to 920 in 2001.

Table : 10.13-11 Sex Ratio 1901-2001 Madhya Pradesh and Adjoining States

Year’s	Madhya Pradesh	Chhattisgarh
1901	972	1046
1911	967	1039
1921	949	1041
1931	947	1043
1941	946	1032
1951	945	1024
1961	932	1008
1971	920	998
1981	921	996
1991	912	985
2001	921	990

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Literacy : A person is considered literate if he is able to read and write with understanding in any language. One who can merely read but cannot write is not considered literate. To qualify as a literate it is not necessary that a person should have received any formal education.

In three censuses of 1961, 1971 and 1981, children in the age group of 0-4 were considered as illiterate. But from 1991 Census onward, 0-6 age group is being considered as illiterate. In 1951 the literacy rate was calculated on the basis of a sample and not on the basis of 100% enumeration of illiterate population. In the year 1991, Indore was the most literate district in the state with literacy rate of 66.32%, but in the following decade Narsimhapur has replaced Indore with literacy rate risen to 78.34% from 55.65% in 1991. 24 districts have literacy rate lower than country’s average. Jhabua is the lowest literacy district with rate of 37.08% followed by Badwani with literacy rate 41.35% and Sheopur being the third in that order with litercy rate 46.61%.

Table : 10.13-12 Literacy Rate 1961-2001 in Madhya Pradesh

Years	1961	1971	1981	1991	2001
Literacy Rate	21.41	27.27	38.63	44.67	64.11

Table : 10.13-13 A-Demograpic profile of Madhya Pradesh (Highlights)

S.N.	Particulars	Figures	Rank in the country
1.	Total population	60348023	07
2.	Growth Rate	24.26	12
3.	Density	196	17
4.	Sex-Ratio	919	21
5.	Sex Ratio (0-6)	932
6.	Literacy Rates
	(i) Total	64.11	18
	(ii) Males	76.06	15
	(iii) Females	52.16	22

Table : 10.13-14 Highest and lowest districts of Madhya Pradesh

S.N.	Particulars	District
		Highest		Lowest
		Name	Figures	Name	Figures
1.	Population
	(i) Total	Indore	2465827	Harda	474416
	(ii) Rural	Rewa	1652743	Bhopal	360792
	(iii) Urban	Indore	1730363	Dindori	26870
	% of Population
2.	Growth Rate	Bhopal	36.41	Balaghat	9.67
3.	Density	Bhopal	665	Dindori	78
4.	Sex-Ratio	Balaghat	1022	Morena	822
5.	Literacy Rate
	(i) Total	Narsimhapur	77.73	Jhabua	36.89
	(ii) Males	Narsimhapur	86.13	Jhabua	47.97
	(iii) Females	Narsimhapur	68.47	Jhabua	25.7

Table : 10.13-15 A-Demograpic profile of Chhattisgarh (Highlights)

S.N.	Particulars	Figures	Rank in the country
1.	Total population	20833803	17
2.	Growth Rate	18.27	19
3.	Density	154	20
4.	Sex-Ratio	989	02
5.	Sex Ratio (0-6)	975
6.	Literacy Rates
	(i) Total	64.66	17
	(ii) Males	77.38	12
	(iii) Females	51.85	19

Table : 10.13-16 Highest and lowest districts of Chhattisgarh

S.N.	Particulars	District
		Highest		Lowest
		Name	Figures	Name	Figures
1.	Population
	(i) Total	Raipur	3016930	Kawardha	584552
	(ii) Rural	Raipur	2099312	Koriya	411536
	(iii) Urban	Durg	1072309	Kanker	31385
	% of Population
2.	Growth Rate	Surguja	24.67	Mahasamund	8.73
3.	Density	Durg	329	Dantewada	41
4.	Sex-Ratio	Rajnandgaon	1023	Koriya	946
5.	Literacy Rate
	(i) Total	Rajnandgaon	77.21	Dantewada	30.17
	(ii) Males	Rajnandgaon	87.17	Dantewada	39.75
	(iii) Females	Rajnandgaon	67.55	Dantewada	20.75

Methods of Birth Control

Meaning : The regulation of conception by preventive methods or devices to limit the number of offspring is called birth control.

Methods : A variety of methods are known for birth control. The birth control methods which deliberately prevent fertilization are referred to as contraception. These methods are of 2 main types : temporary and permanent.

(1) Temporary Methods : These are further of many types :

(i) Safe Period (Rhythm Methods) : A week before and a week after menses is considered the safe period for sexual intercourse. The idea is based on the following facts-

(a) Ovulation occurs on about the 14^th day (may be 13^th to 16^th day) of menstruation.

(b) Ovum survives for about 1-2 days.

This method may reduce the chances of pregnancy by about 80 percent. However, a great care is needed in its use. Rhythm method is also called natural family planning. i.e., a few days before and a few days after ovulation. Changes in cervical mucus and body temperature during the menstrual cycle mark the ovulation time. Thus, the natural family planning requires adequate knowledge of these physiological signs. Some couples use the natural family planning method of increase the chances of conception so that unplanned pregnancies are avoided.

(ii) Coitus Interruptus : This is the oldest method of birth control. It was in use over 2,000 years ago. It involves withdrawal of the penis from the vagina by the male before ejaculation so that semen is not deposited in the vagina and there is no fertilization.

(iii) Spermicides : Foam, tablets, jellies, pastes and creams, if introduced into the vagina before sexual intercourse, adhere to the mucous membrane and immobilise and kill the sperms. These contain seprmicides such as lactic acid, citric acid, boric acid, potassium permanganate and Zinc sulphate.

(iv) Mechanical Means : These are of 3 types :

(a) Condom (Nirodh) is a thin sheath, usually made of rubber, to cover the erect penis. It is the most widely used contraceptive by males in India as it is cheap and easily available. It is given free also by government. It checks pregnancy by preventing deposition of semen in the vagina. Condom is also a safeguard against infection of AIDS and sexual diseases.

(b) Diaphragm and cervical cap are dome-shaped rubber plastic covers that are fitted on the cervix in the female’s vagina, and check the entry of sperms into the uterus. These must be kept fitted for at least six hours after sexual intercourse. They are smeared with a spermicidal jelly or cream each time they are used. The diapharm and cervical cap are the counterparts of condoms in the female

(c) Intrauterine devices (IUDs) are plastic or metal object placed in the uterus by a doctor. These include loop, copper-T, spiral, ring, bow, shield, etc. They prevent the fertilization of the egg or implantation of the embryo. Their presence perhaps acts as a minor irritant and this makes the egg to move down the Fallopian tubes and uterus rather quickly before fertilization or implantation. Drawbacks of IUDs include their spontaneous expulsion, even without the woman’s knowledge; occasional haemorrhage; perforation of uterus; tubal pregnancy (implantation of the embryo) in the oviduct; and chance of infection. Use of mechanical contraceptives have pregnancy rates of less than 10%.

(v) Physiological (Oral) Devices : Birth control pills (oral contraceptives) check ovulation by inhibiting the secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) that are necessary for ovulation. Hence, no eggs are released in a woman on the pill and conception cannot occur. The birth control pills have side effects such as nausea, breast tenderness, weight gain and break-through bleeding (slight blood loss between menstrual periods) and high blood pressure. Pill Mala D is taken daily, and the pill Saheli is taken weekly. Oral contraceptives have pregnancy rates less than 1%. Birth control pills are likely to cause cardiovascular problems.

(vi) Other Contraceptives : Certain contraceptives, such as progestin minipill, are implanted under the skin of the upper arm. They prevent pregnancy for 3 to 4 years. They steadily release a tiny amount of progestin into the blood. Injectable one- month contraceptives are made in Germany, Maxico and China. These are marketed to many countries.

(vii) Abortion : Abortion is the medical termination of pregnancy (MTP) before the foetus becomes viable. It is one of the most widely used methods of fertility control in world. Certain pills act as abortants. They function by inducing menstruation which checks the implantation of the zygote or detaches the implanted egg. There are movements against abortion practically all over the world. A drug named RU-486, an analogue of progesterone, developed in France terminates pregnancy within the first few weeks, It blocks the progesterone receptors in the uterus, thereby preventing progesterone from maintaining pregnancy.

(viii) Abstinence : The best and 100% reliable way to avoid conception is to abstain from sexual intercourse. It is an unnatural mode of birth control, and seems impracticable. Some couples practice abstinence at certain times with success.

(2) Permanent Method : Sterilization provides a permanent and sure birth control. It is called vasectomy in man and tubectomy in woman. It involves the removal of a short segment of each vas deferens or oviduct and tying up of the remaining ends tightly with surgical thread. The operations are minor, usually performed under local anesthesia, give very little discomfort, and do not affect the sexual life.

(i) Laparoscopy : Now a telescopic instrument called laparoscope is used in tubal ligation. This blocks the fallopian tubes. Eggs continues to be produced because the ovaries are intact, but they fail to pass into the uterus and sperms fail to reach the eggs for fertilization.

(ii) Most Effective Birth Control : Sterilization is at present the most effective means of birth control. It is difficult to reverse.

(iii) Extent of Contraceptive Use : According to a UN report in the Tribune dated 24.8.87, half of the world couples use contraception and one in three chooses, sterilization.

(iv) Medical Advice : The birth control measures should be used with the guidance of qualified doctors. The government provides these facilities free at the family planning centres. Contraceptives are given free or at nominal prices at these centres to the couples of reproductive age desirous of preventing conception.

(v) Advice for Fertility : The couples who are not getting children can also seek advice and remedy at the family planning centres.

(vi) Abortion or Medical Termination Pregnancy (MTP) has now been legalised in India.

Table : 10.13-17 Method of Birth Control

S. No	Method	Action
(1)	Rhythm method	No intercourse during woman’s fertile period (day 12-20).
(2)	With drawl	Penis is withdrawn before ejaculation.
(3)	Tubectomy / Tubal ligation	Woman’s fallopian tubes are cut and tied, permanently blocking sperm release.
(4)	Vasectomy	Man’s vasa deferentia are cut and tied permanently blocking sperm passage.
(5)	Intrauterine device (IUD)	Small plastic or metal device placed in the uterus, prevents implantation. Some contain copper, other release hormones
(6)	Oral contraceptive	Synthetic estrogens and progesterones prevent normal menstrural cycle; primarily prevent ovulation.
(7)	Male condom	Thin rubber sheath on erect penis collects ejaculated semen.
(8)	Female condom	Plastic pouch inserted into vagina catches semen.
(9)	Diaphargm	Soft rubber cup covers entrance to uterus, prevents sperm from reaching egg and holds spermicide.
(10)	Cervical cap	Miniature diaphragm covers cervix closely, prevents sperm from reaching egg and holds spermicide.
(11)	Foams, creams, jellies, etc.	Chemical spermicides inserted in vagina before intercourse, prevent sperm from entering uterus.
(12)	Implant ( Norplant)	Capsules surgically implanted under skin, slowly release hormone that blocks ovulation.
(13)	Injectable contraceptive (Depo-Provera)	Injection every 3 months of a hormone that is slowly released and prevents ovulation.

Amniocentesis

Aim : It is a technique to determine :

(1) Sex of the developing baby.

(2) Genetically controlled congenital diseases.

(3) Metabolic disorders in foetus.

So amniocentesis is a pre-natal diagnostic technique.

Procedure : It involves following steps :

(1) Location of the foetus is determined by a technique called sonography (using high frequency ultrasound waves) to prevent accidental damage to the foetus.

(2) A fine hollow needle is passed through the abdominal and uterine wall of a pregnant female (about 14^th to 15^th week after conception) into the amniotic cavity.

(3) A small amount of amniotic fluid is withdrawn. It contains foetal skin cells and a number of proteins, especially enzymes. The cells can be cultured in vitro for further examination.

Significance

(1) Sex determination : The somatic cells of foetal skin drawn with the amniotic fluid are stained to determine the presence of sex chromatin (barr body). Presence of barr body indicates that the developing foetus in female as female is with 2 X-chromosomes out of which one X-chromosome is active, while other X-chromosome is heterochromatised into a darkly stained barr body.

(2) Congential disease : By Karyotypic studies of somatic cells, abnormalities due to changes in chromosome number like Down’s syndrome, Turner’s syndrome, Klinefelter’s syndrome etc. can be determined.

(3) Metabolic disorder : By the enzyme analysis of amniotic fluid, different types of inborn metabolic disorders like phenylketonuria, alcaptonuria etc. can be detected. These inborn errors are caused by the absence or inactivity of specific enzymes due to gene mutations. So with the help of amniocentesis, if it is confirmed that the child is likely to suffer from some incurable, congenital defect, the mother can go for abortion.

(4) Drawback : However, these days, the amniocentesis is being misused also. Mothers even get their normal foetus aborted if it is a female. This is just equivalent to killing of a normal child. So Govt. of India enforced the Pre-natal Diagnostic Techniques (Regulation and Prevention of Misuse) Act, 1994, since January 1, 1994 under which all genetic counselling centres and laboratories are required to apply for registration. The violation of this Act can bring a fine of Rs. 50,000 and imprisonment for two years. The doctor’s registration is also cancelled till the complaint is disposed of.

(5) Chorionic Villus Sampling (CVS) : Amniocentesis is possible without a chance of injuring the foetus with the needle only after the sixteenth week of pregnancy. At this time, abortion is not safe. A new technique, named Chorionic Villus Sampling (CVS), can be done during the eighth to tenth week of pregnancy when abortion is safe for the woman. For CVS, cells are sucked into a catheter passed through the cervix. CVS technique provides a mass of rapidly dividing foetal cells, thus facilitating the examination of chromosomal disorders.

Test Tube Babies

The technique of in-vitro fertilization and in-vitro development followed by the embryo-transfer in the uterus of the normal female to start the development and finally leading to normal birth, is called test tube baby.

History : First attempt to produce a test tube baby was made by a Italian scientist, Dr. Petrucci (1959 A.D.). Although, this human embryo survived for only 29 days, but his experiment opened a new filed of biological science. The first test tube baby was born to Lesley and Gilbert Brown on July 25, 1978, in Oldham, England. Mrs. Brown had obstructed Fallopian tubes. Dr.Patiricke Steptoe and Dr. Robert Edward both from England experimented on Mrs. Brown successfully. the world’s first test tube baby (a baby girl) was named as Louise Joy Brown. Later, test tube babies were also born in Australia, United States and some other countries. India’s first test tube baby was born on 3^rd October, 1978 in Kolkata. Her name was Kanupriya Aggarwal and was created by Dr. Subash Mukherjee.

Procedure : It involves the following steps :

(1) Removal of unfertilized ovum from reproductive tract of a female.

(2) Ovum is kept under aseptic conditions.

(3) Fusion of sperm and ovum in a culture medium, outside the female body, to form the zygote.

(4) Zygote is stimulated to develop in vitro upto 32-celled stage.

(5) Developing embryo is implanted on the endometrium of the uterus at 32-celled stage. So the pregnancy in the woman starts and further development of the child continues in the womb till it is born. Such a baby called a test tube baby.

Significance

(1) It is boon to infertile mothers.

(2) It can be used for men with Oligospermia (low sperm count).

(3) Old superior cows can donate oocytes.

Embryos can be frozen and preserved in an embryo tank for 10 years for future use.

In very rare cases, a surrogate mother may have to be used to bring up in vitro fertilized ovum to maturity. Though biological realization of a test baby is a remarkable achievement, it has raised several ethical and legal problems like the right over the child.

National Population Policy-2000 : Main objective

? Aims for population stabilization by 2045 A.D.

? Compulsory school education upto 14 years of age.

? Reduction of infant mortality rate from the current 72 per 1,000 live births to 30 by 2010.

? Reduction of maternal mortality rate from 407 per 100,000 live births to 100

? Reduction of TFR from 3.3 to 2.1 by 2010

? To promote delayed marriage for girls, not earlier than age 18 preferably after age 20.

? 100 per cent registration of births, death, marriage and even pregnancy.

? Promoting the two-child norm.

? Freeze on current Lok Sabha strength to be extended from 2001 to 2026.

? Facilities for safe abortion to be increased.

? Strict enforcement of Child Marriage Restraint Act and Pre-Natal Diagnostic Technique Act.

? A National Commission of Population chaired by the Prime Minister has been announced to guide and implementation of the policy.

First Human Development Report (April, 2002) :

? Best stated to live in : Kerala (1); Punjab(2); Tamil Nadu(3); Maharashtra(4) and Haryana(5).

? Human development index improved by 3% a year from 1993-94 to 2001. Urban-rural disparities declined.

? Percent of people below the poverty line declined from 44.5% in 1983 to 36% in 1993-94.

? Gender equality index moved from 62% in the 1980s to 67.6% in the 1990s.

? Kerala has been declared as the “First baby-friendly state of world”.

? In India, Tamil Nadu and Karnataka state have attained replacement levels of fertility.

? In India, marriageable age is 18 years for female and 21 years for males.

? China (1234 million) and India (953 million) are two most populous countries; USA (265.8 million) and Indonesia (200.6) come next.

? India’s population growth rate is about 2% a year and China’s 1.4%.

? Maximum population growth rate in the world is in Kenya (5.5%).

? Austria has shown a negative growth rate.

? The most thickly populated country of the world is Bangladesh.

? Greenland is the most thinly populated country (45/Km²) followed by Australia.

? The International Conference of Population and Development (ICPD) was held at Cairo in September 1994.

? Mumbai will become the second largest megapolis in the world by the turn of the century with a population of 18.9 million.

? Tokyo is the largest city with 26.5 million people.

? In last census Nagaland registered the highest growth rate of 56.86% while Kerala the lowest, 13.98%.

? The most thickly populated state of India is West Bengal (766/Km²); the most sparsely populated area of the country is Arunachal Pradesh (10 Km²).

? The first district to become 100% literate is Ernakulam in Kerala.

? Chandigarh has the lowest number of females per 1000 males with 790.

? Bihar stood at the bottom with a literacy rate of 38.48% with Rajasthan being close to it having 38.55 literacy percentage.

? National average of infant mortality rate is 72, where as U.P., It was 86, in Bihar 73, In Rajasthan 85 and In M.P. 89 while that of Kerala is only 15.

? Indian population is a young population, while the population of USA, England, Germany, etc. is ageing population.

? Population explosion : Also called Population holocaust. It is high growth rate of human population.

? Nearly half of the world population is distributed in four countries : China (1120 million), India (844 million-1991 census),USSR(291 million) and USA (251 million).

? World Population Day : 11 July. (since 1987 when on 11 July on that year, the world population crossed five billion).

? In July, 1997, Indian population was growing at the rate of 16 million per year which means 45,000 per day and 31 per minute.

? Indian Population Project-VI (IPP-6) ended in March, 1997.

? According to revised estimates, if the present trend continues, India will surpass China in 2050 A.D. With population of 2160 million.

? After 40 years of age, contraceptive pills increase the chances of cardiovascular diseases.

? Matez Gasper : World’s fifth billion child, a male infant born in Zagreb (Yugoslavia) on July 11,1987.

? Fatima : World’s 6^th billion child, a female infant born in Sarajevo (Kosovo) on October 14, 1999.

? In China, person is considered as of “one year age” at the time of birth.

? Couple protection rate : Bringing eligible couples under the umbrella of various modes of contraception.

? Family Planning Programme was adopted as a National Programme in 1995 A.D. Now it has been renamed as Family Welfare Programme.

? Central Drug Research Institute (Lucknow) has developed a plant-based spermicidal cream “Consap” from Reetha (Sapindus mukrosii).

? UN Population Award, 1992 was awarded to an Indian Industrialist, J.R.D. Tata, for his efforts to stabilize Indian population.

? UN Population Award, 1998 : It was jointly awarded to a group of Ugandan Elders (credited to reduce the practice of female genital mutilation) and head of Jamacia’s Family Planning Board

? India’s first test baby was “kanpuriya Aggarwal”. India’s second test tube baby was “Kumari Harsha” She was born on August 6, 1986.

? Ogino (1930) : Described “Safe period” or “Calander period” to control pregnancy .

? Success rate of test tube baby is less than 20%.

? G.I.F.T. – Gametic Intra- Fallopian Transfer is the latest technique to produce the child.

? Gamete-Intra Fallopian tube transfer : Sperm (obtained by masturbation / electro ejaculation) and ovum obtained by laproscopy are injected into the mid part of the oviduct by a separate catheter in a cycling female (in proliferative stage).