CHAPTER :-7 Environmental Science : Human Population and Environment

 CHAPTER :-7

Environmental Science :

Human Population and Environment

Introduction

Human society is governed by interaction and cooperation with other  human  beings. Latest trends in technology and medical knowledge are available to control human population growth and to improve the health. Still population continues to increase and poverty become greater than ever before. Humans are social animals  who  have  freedom  of  choice.  They largely take decision by heart rather than mind. It is evident from historical records, social situations, ethical and religious considerations and personal desires. Today the greatest hindrance to controlling human population is no more biological but falls into the province of philosophers, theologians, politicians, sociologists, and others. The cause of the population problem is to be understood if we are to deal successfully with the population problem.

Carrying Capacity

The carrying capacity of an area is the number  of  individuals  of  a  species  that  can survive in that area over time. In most populations, four broad categories of factors determine the carrying capacity for a population. These factors are: (1) the availability of raw materials,

(1) the availability of energy, (3) the accumulation of waste products and their means  of disposal and (4) interactions among organisms. The total of all of these forces acting together to limit populations size is known as environmental resistance, and certain limiting factors have a primary role in limiting the size of a population. In some cases, these limiting factors are easy to identify and may involve lack of food, lack of oxygen,  competition  with  other species, or disease.

Population Characteristics

A population can be defined as a group of individuals of the same species inhabiting an area. Some of the characteristics or a population are nasality (birth rate), mortality (death rate), sex ratio, age distribution, growth rates, and special distribution.

Natality refers to the number of individuals added to the population through reproduction. In human populations, natality is usually described in terms of the birth rate, the number of individuals born per one thousand individuals in the population per

year. It is important to recognize that the growth of a population is not determined by the birth rate (natality) alone.

This is expressed as

B (Natality rate) =  Nn/t which means = No. of new individuals added to population time.

Mortality is the number of deaths per year. In human population studies, mortality is usually discussed in terms of the death rate, the number of individuals who die per one thousand individuals in the population per year.

Population Density is population size in relation to some unit of space and time. It varies with food availability and climatic conditions. It can be measured as:

D = N/ a

t

where D is population density,  n = number of individuals,  a = area and  t = time.

Population Age Distribution refers to the individuals of different age groups in a population. The natality and mortality is also different  for  respective  ages.  Bodenhelmer (1938) recognized three ecological ages as: (i) Pre reproductive, (ii) Reproductive and

(iii) Post reproductive Fig.  1.  Duration  of  these  ages  varies  in  different  organisms  e.g. Insects have a very long pre-reproductive period, a  very  short  reproductive  period  but  no post reproductive period at all. In man all the three stages are equal in length.

Type of  Population

Biotic Potential is the maximum reproductive power. The constant percent growth rate of a population under optimum environmental conditions thus represents its biotic potential or reproductive potential. Letter designates it g.

g =AN / AT

N

where, N = number,  t = time,  D = constant.

The sex ratio refers to the number of males relative to the Number of females in the population.

The Human Population Issue

Current population growth has led to famine in areas where food production cannot keep pace with population growth; political unrest areas with great disparities in availability of resources (jobs: goods, food); environmental degradation by poor agricultural practices (erosion, desertification); water pollution by human and industrial waste; air pollution caused by the human need to use energy for personal use and for industrial applications; extinctions caused by people converting natural ecosystems to managed agricultural ecosystems; and. destructive effects of exploitation of natural resources (strip, mining, oil spills, groundwater mining). In addition to population size, the kind of demands a population places on its resources is also important. Highly industrialized populations require much more energy and material resources to sustain their way of life than do the populations of the less-developed world.

A Population Growth Curve

Sex ratios and age distributions within a population directly influence the rate of reproduction within a population. Each species has an inherent reproductive capacity, or biotic potential, which is its ability to produce offspring. However, this high reproductive potential results in a natural tendency for populations to increase. For example, two mice produce four offspring, which, if they live, will also produce offspring while their parent’s are also reproducing. Therefore, the population will tend to grow in an exponential fashion.

Population growth tends to follow a particular pattern, consisting of a lag phase, an exponential growth phase, and a stable equilibrium phase. Fig. 15 shows a typical population growth curve. During the first portion of curve, known as the lag phase, the population grows very slowly because the process of reproduction and growth of offspring takes time. Most organisms do not reproduce instantaneously but must first mature into adults. Mating and the development of the young ones into independent organisms follow this period. By the time the first batch of young has reached sexual maturity, the parents may be in the process of producing a second set of offspring. Since more total organisms now are reproducing, the population begins to increase at an exponential rate. This stage in the population growth curve is known as the exponential growth phase. This growth will continue for as long as the, birth rate exceeds the death rate. Eventually, however, the death rate and the birth rate will come to equal one another, and the population will stop growing and reach a relatively stable population. size and is said to be the stable equilibrium phase. Hence, populations cannot grow continuously because of the concept of carrying capacity.

a) S-Shaped growth curve

When a species is introduced into a new habitat, the population grows exponentially until the individuals become numerous. The further increase in their number is checked by the environmental resistance factors that the population growth declines until zero population growth is reached. (i.e. constant) and it becomes stable (K). Such curves are called sigmoid curves.

The study of growth curves in S-shaped growth pattern is a self-limiting one where the rate of growth is more and more as density increases. If the limitation is linearly proportional to density we get a symmetrical S-curve so as to approach upper level or limit-K, the carrying capacity. This pattern enhances stability as population regulates itself. Actually the density often overshoots or is more than K and because of time lags in feedback control resulting in oscillations as shown in graphs.

(b) J-Shaped growth curve

The population increases whenever there is an  increase  in  birth  rate  over  death  rate. The factors of environmental resistance do not check population  growth  or  stabilize  the growth (zero growth not established) then a J-shaped curve is obtained Fig. 3. It is hard to speculate in the future of human population growth curve whether it will be S-shaped or J-shaped. Growth curve are thus the graphical representation of a population in given time period. It may be of S-shaped or J-shaped as mentioned.

When population increase in exponential (E) or geometric fashion (e.g. 2, 4, 8, 16, 32

.........) until the population runs out of some resources or encounters, some other limitation (N). Growth then comes to a more or less abrupt halt in  such  cases  and  density  usually declines rapidly until conditions for another rapid growth is  restored.  Population  with  this kind of growth form instability unless regulated by factors outside the population.

(i) Growth rate decreases as density increases. (Self-limiting or inverse density- dependent type.)

(ii) Growth rate is high until density become high and factors from outside of the population become limiting. (Density independent type.)

(iii) Growth rate is highest at intermediate density.

Causes of Population Growth

There is an ultimate carrying capacity for  the  human  population  and  limiting  factors will come into play to cause populations to stabilize. However, unlike populations of other

kinds of organisms, human populations are also influenced by a variety of social, political, economic, and ethical factors. Humans have accumulated knowledge that allows for predictions about the future and can make conscious decisions based on the likely course of events and adjust their lives accordingly. Part of that knowledge is the certainty that as populations continue to increase, death rates and birth rates will become equal. This can be accomplished by allowing the death rate to rise or by choosing to limit the birth rate. It would seem that controlling human population should be a simple process. Once everyone understands that lowering the birth rate is more human than allowing the death rate to rise, most people should make the “correct” decision; however, it is not quite that simple.

Biological Reasons for Population Growth

The study of human populations, their characteristics, and what happens to them is known as demography. Demographers can predict the future growth of a population by looking at several different biological indicators. When we look at birth rates and death rates in various countries of the world, in almost all cases the birth rate exceeds the death rate. Therefore, the size of the population must increase. Some countries that have high birth rates and high death rates, with birth rates greatly exceeding the death rates, will grow rapidly (Afghanistan and Ethiopia). Such countries Usually have an extremely high mortality rate among children because of disease and malnutrition. Some countries have high birth rates and low death rates and will grow extremely rapidly ~Guatemala and Syria). Infant mortality rates are moderately high in these countries. Other countries have low birth rates and death rates that closely match the birth rates and will grow slowly (Sweden and the United Kingdom). These and other more, developed countries typically have very low infant mortality rates.

Obviously, the most important determinant of the rate at which human populations grow is related to the number of women in the population who are having children and the number each will have. The total fertility rate of a population is the number of children born per woman per lifetime. A total fertility rate of 2.1 is known as replacement fertility, since in the long run, if the total fertility rate is 2.1, population growth will stabilize. When population is not growing and the number of births equals the number of deaths, it is said to exhibit zero population growth. The age structure of a population also has a great deal to do with the rate of population growth. If a population has a large number of young people who are in the process of raising families or who will be raising families in the near future, the population will continue to increase even if the families limit themselves to two children.

Factors Controlling Population Growth

Man is the only one who has regulated his population by developing new astonishing technologies for better and secured future on one  hand.  And  on  other  hand,  created  a problem of population explosion. Some factors are:

(i) Famines in a country or state lead to destruction.

(ii) Natural calamities like floods, droughts, earthquakes and volcanic eruptions, hurricanes etc. lead to death of thousands of people.

(iii) Epidemic diseases,  endemic  diseases  wipe  a  big  number  of  populations.

(iv) Wars cause heavy casualties.

(v) Unnatural accidents caused during transportation, fires etc. Some factors that have helped the population growth are:

(a) High production of food and better technologies for storage, processing and distribution.

(b) Better medical facilities provided during childbirth and under five years age by immunization.

The factors  are  many  but  they  can  be  grouped  into  three  as:

(i) Geographic factor: Like climate, soil, water, mineral  resources,  transportation etc.

(ii) Demographic factor: Like birth rates (natality), death rates (mortality), sex ratio etc.

(iii) Socio-economic factors: Like marriages,  job  availability,  resources  etc. In the developed countries, population has started declining because of-

(i) Better medical and family planning facilities.

(ii) The low death and high birth rates. .

(iii) The educated people who know about ‘the abuses of over  population  have small family.

Population and Standard of Living

Standard of living is a difficult concept to quantify since different cultures have different attitudes and feelings about what is good and desirable. Here, we compare averages of several aspects of the cultures in three countries: (1) the United States, which is an example of a highly developed if industrialized country; (2) Argentina, which is a moderately developed country; and (3) Zimbabwe, which is less developed. Obviously, tremendous differences exist in the standard of living among these three countries. What the average U.S. citizen would consider a poverty level of existence would be considered a luxurious life for the average person in a poorly developed country. Standard of living seems to be closely tied to energy consumption.

Population Explosion-Family Welfare Programme

Growth of Human Population

Emigration: The number of individuals going out from a population to join another population in a new locality resulting in decrease of the original population.

Immigration: It is the addition of new individuals to the population from other localities.

Density dependent factors: An increase in population leads to competition, since all its individuals have identical requirements for food and space. Population increase causes scarcity of food, consequently leading to death due to starvation.

Density  independent  factors:  Interaction  between  populations  in  a  given  area can lead to mutual benefits, to competition for resources or dependence of one on the other.

Population explosion: The very great and continuing increase in human population in modern times. This is a great hazard to the development  and  prosperity  of  a nation.

Consequences of population explosion:

(i) It can lead to depletion of resources.

(ii) Severe competition for food and space.

(iii) Increase in psychological stress and strain.

(iv) Rapid pollution  of  environment.

(v) Large scale unemployment.

To meet the demands- of growing population, forests are cut, oceans are exploited and the entire natural equilibrium gets disturbed. A growth human population first faces  the problem of food, then shelter and thirdly other socio-economic problems. Even if enough food is produced and the population growth does not show a steady slow growth but explosions then many secondary problems will certainly arise which are more persisting and problematic. Like in increase in competition for shelter, education, medical, rise in price index, ecological crisis etc.

Human Population: Malthus’s Human Population Theory

In 1798 T.R. Malthus published an essay on population, the great economist outlined the problem of population graphically and stated that human population tends to increase in geometrical pattern (1-2-4-8.......) whereas the food production increases by arithmetic progression (1-2-3-4. ). This is called as theory of human population growth proposed by Malthus. For nearly 150 years Malthus view was nearly forgotten as the advancement of technologies to place. The world population during Stone Age was only 10 million as indicated in records. Earlier the annual growth rate, in last three centuries was  roughly  0.4  =  0.5% where as it reached. to 2% in last two decades. The doubling time (the time required by a population to double itself) reduced from 200 years in 1650 A.D. to merely 35 years in 1980. During 1800 A.D. the birth rate and death rate was almost balanced.

Current Population Trends

Currently, the world population is over 5.5 billion. By the year 2010, this is expected to increase to just over 7 billion people. In Africa, Asia, and Latin America, which already have nearly 80 percent of the world population. The total population of Africa, Asia, and Latin America will increase from the current 4.4 billion to over 7 billion by 20 I 0, when they will contain 83 percent of the world’s people. These regions not only have the highest population growth rates, but also have the lowest per capita gross national product (GNP). The GNP is an index that measures the total goods and services generated within a country. This large difference in economic well being is reflected in a dissimilarity in the standard of living, an abstract measure of the degree to which necessities and comforts of daily life are met.

Consequences of Continued Population Growth

As the human population continues to increase, the pressure for the necessities of life will become greater. Differences in standard of living between developed and less-developed countries will remain great because most population increases will occur in less-developed countries. The supply of fuel and other resources is dwindling. The pressure for these resources will intensify as the industrialized countries seek to maintain their current standard

of living. People in less developed countries will  continue  to  seek  more  land  to  raise  the crops needed to feed themselves unless major increases in food production per hectare occur. Developed countries may have to choose between helping the less developed countries while maintaining their friendship, or isolating themselves from the problems of the less developed nations.

Even if the industrialized countries continue to get  a  disproportionate  share  of  the world’s resources, the amount of resource per person  will  decline  as  population  rises.  It seems that, as world population increases, the less developed areas will maintain their low standard of living.

Environmental Implications of Food Production

The human population can increase only at the expense of the  populations  of  other animals and plants. Each ecosystem has a finite carrying capacity and, therefore,  has  a maximum biomass that can exist within that ecosystem. There can be shifts within ecosystems to allow an increase in the population  of  one  species,  but  this  always  adversely  affects certain other populations because they are competing’  for  the  same  basic  resources.  When the population of farmers increased in the prairie regions of North America, the population of buffalo declined.

When humans need food, they turn to agricultural practices and convert  natural ecosystems to artificially maintained agricultural ecosystems. Mismanaged agricultural resources are often irreversibly destroyed. In most cases, if the plants were fed to animals, many people would starve to death. In contrast, in most of the developed world, meat and other animal protein sources are important parts of the diet. Many suffer from over nutrition (they eat too much); they are “malnourished” in a different sense. The ecological impact of one person eating at the carnivore level is about ten times that of a person feeding at the

herbivore level. If people in the developed world were to reduce their animal protein intake, they would significantly reduce their demands on world resources.

The current situation with respect to world food production and hunger is very complicated. It involves the resources needed to produce food, such as arable land, labour and machines, appropriate crop selection, and economic incentives. It also involves the mal- distribution of food within countries. This is often an economic problem, since the poorest in most countries have difficulty finding the basic necessities of life, while the richer have an excess of food and other resources. Improved plant varieties, irrigation and improved agricultural methods have dramatically increased food production in some parts of the world. In recent years, India, China and much of southern Asia have moved from being food importers to being self-sufficient, and in some cases food exporters.

Population trends in India

India accounts for nearly. 1.5 per cent of the world population. Population has undergone an approximately three-fold increase during the last 80 years.  According  to  the  census  of 1901, there were 235,396,327 people in this country.  The  number  slightly  came  down  in 1921 as a result of some epidemics. In ‘1951, the population was 361,008,0,90, which went up to 439,234,771 and 548,159,652 in 1961 and 1971, respectively. The main reason for the rapid growth is fall in death rate as a result of better medical care. The sex ratio in India’ in 1981 was 1071 males per 1000 females. In Punjab in 1981, there were 1138 males per 1000 females whereas the number of males to  females  in  Kerala  was  969:  1000.  The  age ratio of Indian population shows that there is high proportion of young people belonging to the pre-reproductive age group i.e. 42.2 per cent in the age group of 0-14 years.

Measures to Control over Population

Various methods  for  discouraging  population  growth  in  shortest  period  are:

(i) To educate the people about the abuses of overpopulation (Population education), food production, self-employment.

(ii) To provide  free  family  planning  aids  (Family  planning  methods).

(iii) Motivating people to undergo sterilization process (Birth control) .

(iv) More incentives  to  families  observing  family  planning  norms  (Limited  family)

(v) By imposing  legal  restrictions  (by  laws).

(vi) Over-population is one of the numerous problems facing India. The solution of the population problem is very urgent. The population problem can be solved by major steps, which are given below:

(a) Education: The enormous rate at which Indian parents have been producing children is because of illiteracy and  ignorance.  People  should  be  educated about the consequences of over-population and uses of planned  and  small family.

(b) Family planning: The expression family planning  means  a  deliberate  effort, and the  adoption  of  suitable  methods,  to  restrict  the  growth  of  family.  That is to say family planning involves a deliberate limitation on the size of family. Following are some of the important family planning measures:

• Use of contraceptives (Mechanical, Chemical and Natural methods): Contraception means the prevention of conception. There are many contraceptive techniques available for use e.g. Today etc.

• Sterilization

• Abortion

• Use of  other  natural  methods

Mechanical method

• Condom (For male’s use): The condom is a sheath of rubber, which fits over the erect penis. It is placed on the penis of male before it is introduced into the vagina for copulation.

• Diaphragm (For female’s use): The diaphragm is a rubber cup stretched over collapsible metal spring coil.  It  is  designed  to  fit  over  the  cervix  (the  mouth of uterus).

• Intrauterine Contraceptive Device (IUD): It is a small metal or plastic device, which is designed to fit inside the uterus mouth. A doctor must fit and remove IUD.

• Norplant: A new implant has been cleared by Health Ministry of India. The implant placed below the skin, ensures the contraceptive power up to 5 years. It is new contraceptive to India and there is some resistance to woman’s body. Initially it will be used in urban areas.

Chemical Method

• Jellies, creams and foam: A number of different  spermicidal  jellies,  creams, and foams are available for use of contraceptive agents. These jellies, creams or foams are inserted into vagina five to fifteen minutes before copulation to take place. Oral contraceptive: These are popularly known as pill are combinations of synthetic sex. Hormones (estrogens and progesterone) e.g. overall, mala. They suppress the production  of  ovum  by  hormones  and  alter the adulatory cycle.

• Sterilization: It is surgical  technique  by  which  the  passage  of  sperms  or ovum is disconnected. Both men and women can be sterilized without loosing their ability to function sexually.

• Vasectomy: In man the sterilization procedure is called a vasectomy. In this procedure the vesa differentia, the tubes that lead from the testes to the ejaculatory ducts, are cut so that the sperm produced in the testis cannot reach the ejaculatory ducts to enter the ejaculate.

• Tubectomy: In females tubectomy is done. In this procedure, the fallopian tubes, which transport the egg from the ovaries to the uterus are cut and tied off.

Environment and Human Health

Webster Collegiate Dictionary defines health as “the state  of  being  hale  and  sound  in body mind or soul especially from physical disease or pain. The concept of health incorporates physical state free from diseases, social and mental caliber of  a  human  being.  Community refers to a group of persons living at one place that shares and have social contact. A healthy man is an asset to the country, but a  sick  man  is  a  burden.  Community  health  services provide medical treatment of various diseases, controls the spread of communicable diseases, control of pests and insects, social welfare health service, maternity and child welfare services, school medical services, hospital, research institutions etc. Lack of nutrition, clothing and improper housing, etc. spread many communicable diseases.  Maternal  and  infant  mortality rate raises poverty also leads to child  abuse,  liquor  and  drug  addiction,  exploitation  and crime against women, etc.

Environment and health are inter-dependent. Physical  environment  include  climate, sound and radioactive pollution sunrays and heat, air pressure, water and air directly or indirectly affect our health. A person is surrounded by biological environment where insects and many other biological microbes, which in turn spread diseases. Social and economic environment also determine the  standard  of  health.  Man’s  social  environment  is  developed in a family and family is the basic unit  of  a  society.  Small-sized  families  where  family members are happy and prosperous their health will be in good condition. In large families rearing of children become a difficult  task.  Meeting  the  demands  of  nutritious  food  and health are not given priority with the result children’s personality and overall development suffers.

(i) Socio-economic factor

Leads to inadequate family resources, which cannot fulfill the wants and thus reduces the health standards and food problem is more prevalent in poor families. Lack of sanitary

habits and inappropriate nutritional food will develop communicable and harmful diseases. Illiteracy is one of the major defects to raise the standard of living, sanitation and health.

(ii) Communicable disease problem

In India communicable diseases generally spread on a large scale. The contaminated food and water intake, dirt, sewage waste, improper light and pure air, Improper ventilation arrangements in the house, stagnant water and dirt, over crowding, lavatory and cleanliness are some of the causes for the spread of diseases. Communicable diseases may spread through air, contact, contaminated food and water directly. Cholera diarrhea, typhoid etc., are some of the diseases. Insects and microbial parasites spread malaria and plague like diseases.

IMPORTANCE OF ENVIRONMENT

Vegetative plants and trees are called autotrophy because they can produce their own food through the process of Photosynthesis, this category is primary productive unit and their entire living organism depends on the vegetation for acquiring food. Photographs like insects, animals, birds and all human beings cannot produce their own food. Some microorganisms like bacteria, fungus, microbes, etc., derive food from dead plants and animals. Thus, all the living organisms are interdependent for their survival.

Human being is always adjusting to the ever-changing environment and in the past he has never attempted to alter it. But after twentieth century there has been a tremendous increase in physical wants and desires. Fast development in every sphere of life has undergone with the ever-increasing wants and demands for food products. Ever increasing pressure on land has caused forestland to be utilized for cultivation.

There is all-round development and progress in the field of science and industries, new technology is being introduced and I variety of products are now being produced. As a result environmental pollution has increased. New technology has provided us goods to make our lives happier, more comfortable and luxurious, pollution hazards and its ill effect are being observed in every sphere of life. There is  general  reduction  in  physical  power  and  energy, also deterioration of health standards. Development and destruction are co-related and give rise to many problems due to environmental pollution, water pollution, air  pollution, destruction of forests, disappearing wild life, radiation effect, on living organisms.

Man is acquiring essential resources from the nature itself. Hence, it is essential to protect and preserve the natural resources. Natural disaster and destruction have increased the temperature on the earth is steadily rising. Certain drastic steps are needed in order to save our planet.

DISEASES

(a) Through respiration: By nose, mouth, lungs, cough, sneeze, spit, spreads cold, measles, tuberculosis, pneumonia, etc.

(b) Through intestine: Human excreta spread typhoid, diarrhoea, intestinal worms, cholera, poliomyelitis, etc.

(c) Skin: Scale of the skin, skin pus like smallpox, measles, etc.

(d) Through blood: AIDS, malaria, yellow fever, dengue, filarial, etc., are some of the diseases which spread through blood.

1. DIPHTHERIA

It is an acute infectious and communicable disease caused by involvement of respiratory system. The microorganisms of this disease attack the tonsils,  trachea,  nasal  passage  and sound box and secrete a false membrane of oxotoxin, which cause inflammation. In severe conditions it causes difficulty in breathing. This disease is quite common among the children of the age of 6 months to five years. It can also occur up to the age of 15 years. The mortality rates are 50% in respect of diphtheria occurring below the age of 5 years.

Pathogenic organism: The microbes spreading diphtheria  belong  to  bacillus  group  and are of three types:

1. C. Diphtheria gravies

2. C. Diph. Intermedius

3. C. Diph. Miti

Mode of  spread:  The  spread  of  this  disease  may  be  by:

(a) Direct contact chiefly through the carriers, whether sick or healthy. Nasal carriers are more dangerous than throat carriers.

(b) Indirect transmission through infected articles such as, clothes, toys, utensils, etc.

Incubation period: It is of 2 to 5 days duration when the microbes enter the body.

Infective period: After the patient shows the  symptoms  of  diphtheria  and  the  period when microorganism leave the body is of 2-5 weeks on an average.

Symptoms: Initially the patient feels weak, nausea, and loses appetite and alertness.

Immunization: D.P.T. (Diphtheria, Whooping cough, Tetanus) vaccine is introduced to the child at the age of 6 weeks to 9 months in three doses. This vaccine is given at the interval of one month. A booster dose is given at the age of 2 years.

Prevention and Control

• The patient should be isolated.

• Disinfections of the home, bedding clothes, toys, utensils, etc., is done thoroughly.

2. WHOOPING COUGH OR PERTUSIS

Whooping cough or pertusis is an acute respiratory infections disease caused by Bacillus pertusis involving trachea, bronchi and bronchioles creating intense cough. Whooping cough occurs in all ages. Effect of cold weather and in colder regions enhances  the  incidence  of disease.

Spread of disease: Since it is  an  infectious  disease  main  source  is  the  nasal  discharge and cough. It spreads directly from person to person.

Incubation period: It is of seven to fourteen days.

Infective period: Three weeks after the symptoms are observed. Symptoms: The patient coughs frequently and its severity increases at night loss of appetite insomnia, weakness persists. Immunization: Vaccine is prepared from dead bacillus and is administered along with D.P.T. (Diphtheria, pertusis, tetanus).

3. TUBERCULOSIS

It is a chronic bacterial disease and highly infectious. Tuberculosis spreads through air and affect the lungs  of  the  person.  It  is  caused  by  tubercle  bacillus.  This  is  prevalent  both in tropical  and temperate climate.

Spread of disease: Tuberculosis spreads in the following manner:

(a) The infection spreads by inhalation of droplets expelled by the patient through, sneezing, coughing, yawning etc.

(b) Through direct  contact

(c) Infected articles, clothes, utensils, etc. may spread the disease.

Incubation period: Incubation period is about four to six weeks.

Symptoms: Initially, the patient feels easily exhausted, fatigue doing ordinary work and feels excessive fatigue. Loss of appetite, hoarseness of throat, pain in the chest due to infected lungs. Patient sweats profusely at knight and feels weak.

Immunization: Child should be given B.C.G. (Bacillus Chalmette Guerine) vaccine by intra-dermal injection within the first three months of age.

Control and prevention: Following steps need to be undertaken to control the spread of tuberculosis:

• Health and general sanitary conditions of the community should be taken good care of. Every human being should live in fresh air and sunshine.

• Workers of cotton and ginning mills, coalmines, tobacco bidi making etc. should wear protective shield to prevent inhalation of dust or silica dust.

• Patient should be isolated. The disinfections of clothes, utensils, articles rooms etc. should be properly ensured.

4. CHOLERA

Cholera is an acute infectious disease caused by the infection of intestinal canal, characterized by sudden vomiting, watery diarrhea, cramps in legs and leads to  fast dehydration.

Pathogenic organisms: Cholera producing microorganisms  are  Vibrio  species  and  they can belong to two sub-groups:

1. Vibrio cholerae

2. Vibrio El tor

Vibrio cholerae: Vibrio cholerae is found in stools and vomits of the patient. It is active, mobile and grows in alkaline medium. It dies at 55°C in minutes. In contaminated water the organism can survive for two weeks. Insects, particularly housefly disseminates this disease.

Vibrio El tor: The other germ Vibrio el  tor  spreads  in  the  Bay  of  Bengal  and  coastal areas in large scale through direct contact,  unhygienic  conditions,  over-crowding,  fair  and feast on festivals incubation period: The duration of incubation period is very short, ranging from a few hours to five days.

Period of communicability: Lasts until the patient is free from cholera germs.

Symptoms: Patient starts vomiting and suffers loose motions. This may lead  to  loss  of water and minerals in the body.

Immunization: Vaccine is prepared from dead Vibrio cholera and is given when there is a danger of spread of cholera.

Prevention and Control

• All deject should be collected in the can in which quick lime is placed at the bottom.

• Anti-fly measures  should  be  adopted.

• Avoid eating of rotten fruit, boiling of water and  milk,  protection  from  flies  and dust.

• Phenyl, bleaching powder and other disinfectant should be sprayed in the area.

• Segregation and  disinfections  of  soiled  clothes,  articles  used  by  the  patient.

5. MALARIA

Malaria spreads in the rainy season. The malarial parasite is a protozoon named ‘Plasmodium’. It survives in the red blood corpuscles of the human blood. Man acquires infection by the bite of an infected female anopheles mosquito, which inject the malarial parasites in the form of spores.

The malarial parasite is of four types:

(i) Plasmodium: It  has  a  life  cycle  of  48  hours  causing  fever  after  every  two  days. .

(ii) Plasmodium malaria: It has a life cycle of 72 hours causing fever after every three days.

(iii) Plasmodium falciparum: Irregular fever may occur after every ’48 hours. The symptoms are very severe and of malignant type: high fever, delirium and death

(iv) Plasmodium ovale: This virus produces mild kind of malaria. They are found mostly in Africa.

Incubation Period: The time when the insect bites and till the  symptoms  appear  is called incubation period, which is as follows:

1. Plasmodium vivex—14  days

2. Plasmodium malaria—30 days

3. Plasmodium falciparum—12  days

Spread of disease: Female anopheles mosquito spreads malaria disease. For the spread of the disease, the optimum conditions are a mean temperature of 20° to 30°C with 63% humidity. Economic conditions, insufficient food, over-crowding, increase the incidence of malaria. Irrigation, leakage in canals, water logging, and rice cultivation may serve as the breeding place for mosquitoes.

Symptoms

The cold stage: The patient feels cold and suffers from fever, headache, nausea and vomiting.

Anemia and enlargement of spleen and liver are the after- effects of the disease. Prevention of Malaria:

Malaria can  be  prevented  in  the  following  manner:

• Proper drainage, removal of stagnant water.

• To destroy mosquitoes at some stage of his life cycle i.e., during larva stage, or adults. Use of oil, diesel, kerosene. Gammexane, etc. can destroy the breeding.

• Cutting of vegetation, which has grown thickly, and servers as a breeding place in the daytime. Putting net, wire grill on doors and windows.

6. TETANUS

A toxin of tetanus bacillus induces tetanus or lockjaw, followed by wound. Tetanus bacillus lives in the contaminated soil of road, gardens and agriculture land. These microbes survive in the intestinal track of horses and cattle. They attack the nervous system and causes instant death.

Spread of disease: The bacillus  enters  the  body  through  various  wounds  and  spread their toxin in the blood stream like during operations, unhygienic deliveries of babies, etc.

Incubation Period: Generally it is of 8 to 10 days.

Immunization: Tetanus toxoid vaccine is given along with D.P.T. (Diphtheria, Pertusis, Tetanus). Intra-muscular injection is given in three doses at the interval of one month. One booster dose is given at the age of 5-6 years and another booster dose is repeated when the child is 10 years and 16 years of age. Tetanus vaccine is given as a preventive measure.

Prevention

All wounds should be treated carefully especially if there is a fear of contamination with refuses or soil wound should be thoroughly cleaned with disinfectant or 3% iodine solution. In addition, ATS (Anti Tetanus-serum) injection should be given.

Human Rights

A right may be defined as something to which an individual has a just claim. Human rights are those that individuals have by virtue of their existence as human beings. The right to life itself and the basic necessities of food and clothing may be considered fundamental human rights. Human rights traditionally have been put in two categories as:

(i) Natural rights and

(ii) Civil rights.

Natural rights are those that belong  to  individuals  by  virtue  of  their  humanity:  the right to remain alive, to sustain life with food and shelter and to follow the dictates of their conscience.

Civil rights are based on positive law: they are derived from laws and judicial decisions.

Civil or legal rights are those granted by a government.

The entitlements are defined in the Universal Declaration of Human Rights adopted by the United Nation’s General Assembly on Dec. 10, 1948, as  “a  common  standard  of achievement for all people and nations”. It urged the right to political, economic, social and cultural self-determination the right to peace, the right to live in a healthful and balanced environment and the right to share in the Earth’s resources.

Here, we are dealing with that part of Human natural rights which encompasses protection of environmental issues as these ultimately govern human health and survival:

(i) The right to life.

(ii) The right to an adequate standard of living and social security.

(iii) The right to education.

(iv) For children,  the  right  to  freedom  from  exploitation.

(v) The right of access to health-care services, with States aiming to reduce infant and child mortality and abolish traditional practices prejudicial to health.

(vi) The right of access to clean air to breathe.

(vii) The right  of  access  to  drink-clear  and  clean  water.

(viii) The right  to  live  in  noise  pollution  free  environment.

(ix) The right of access to gifts of nature/ resources.

(x) The right to live in a disease free environment.

VALUE EDUCATION

Aims of Health Education

The aims  for  community  health  education  are  as  follows:

(i) Healthy practices in day-to-day living should be inculcated among the children from a very early age. This is how they will be able to understand the importance of health, hygiene and sanitation. .

(ii) The knowledge about our body and various organs of our body and their functions helps a person to understand the disease, its causes and common ailments.

Such factors which affect the health standards like smoking, eating tobacco, drug addiction intake of liquor etc., can be checked by resorting to some law and amendments to Improve the health standards. .

(iii) In order to create a clean environment in a city or town, people should be encouraged and awareness be created. Clean and safe drinking water system, good sanitary lavatories be provided at  crowded places.

(iv) Proper arrangements for providing better health services to the people should be ensured and they should be introduced to various governmental health programmes like mother and child welfare, child welfare services, family planning, etc.

(v) Training programmes for officers, health workers, private doctors, nurses, midwives, etc. should be undertaken from time to time.

(vi) Health education can be imparted in an effective manner by personal contact programmes.

(vii) Personal hygiene, regular exercise and rest, importance of nutritive foods, ventilation and its effect on health, clean sanitary environment, causes of pollution and its prevention are  some  of the general topics  for  health education.

(viii) Practical knowledge should be provided about communicable diseases, serious health problems and  first aid  and emergency  services.

Principles of Health Education

Every individual learns and understand some thing from his  culture  and  social background. Based on school health programme adult-education programme is planned accordingly. Before understanding various teaching methods one should know the principles behind learning. These  principles are as  follows:.

(i) Every individual has learning capacity throughout his life.

(ii) Learning capacity is not affected by advancing age of an individual, but by lack of interest and desire for learning.

(iii) For learning the same material, all individuals will not learn the same way. This variation is due to the background experiences and individual’s circumstances and exposure.

(iv) Individuals own effort will play a significant role in making a change in habits and concepts. Learning is not the outcome of one individual saying something to other individual, but it is learnt through his own efforts and willingness.

(v) An individual learns for love, satisfaction. and basic human needs of survival, food and social approval. .

(vi) People learn faster when they are acquainted with the objectives and goals. Means of achieving those goals and use the resources properly should be clear.

(vii) An individual take an appropriate time to learn something new, so one should be given enough time to absorb what he has learnt.

Purification of water at domestic level

Purification of water at domestic level can be achieved by the following methods:

1. Distillation

2. Boiling

3. Filtration

4. Chemical method  of  sterilization

5. Ultra-violet sterilization.

(i) Distillation: In the process of distillation water is  heated  and  evaporation  takes place, whereby water changes back to water when cooled. This process is called condensation. The condensed water is the purest form of water, free from microbes and impurities.

(ii) Boiling: It is boiled for ten minutes to kill the microbes present  in  it  and  also removes the temporary hardness of water.

(iii) Filtration: Different varieties of filters are used to purify the water at domestic level.

Chemical methods for water sterilization

(i) Aluminium sulphate: It is largely used to purify muddy water.

(ii) Chlorine: Chlorine gas  or  tablet  is  added  to  destroy  disease-producing  germs.  It is a very cheap and convenient method.

(iii) Potassium  permanganate:  It  oxidises  the  organic  matter  and  destroys  98%  of the microorganisms in four to six hours.

(iv) Purification by the  use  of  ultra-violet  rays:  Ultra-Violet  rays  have  the  power of destroying microorganisms from the water without any chemical  change.  They exert their action only when the water is fairly clear and bright.

VENTILATION

Ideal ventilation is possible only when there is sufficient pure air. Ventilation is defined as the  “Science  of  maintaining  atmospheric  conditions  which  are  comfortable  and  suitable to the human body.” Ventilation incorporates comfortable and appropriate balance of gases, also optimum temperature adequate humidity, movement or flow of air and free from disease producing microorganisms.

(a) Internal Ventilation

Proper ventilation of the rooms is known as ‘internal ventilation. Lack of efficient and adequate ventilation leads to many discomforts and diseases. When the carbon-dioxide concentration exceeds 0.04% and reaches 0.06% then the air in the room  gets  suffocating. Every person needs 3000 cu feet of air every hour and if the impurities  in  the  air  exceed 0.02%, the air is regarded as impure and unhealthy.

(b) External Ventilation

Fresh air flows into the house from the surroundings and open space. This type of ventilation is known as external ventilation. This is ensured by making the streets wide and straight, providing open space, parks and gardens.

Artificial Ventilation

Artificial ventilation is easily controlled and, installed. The means of artificial ventilation are coolers, air conditioner, which are more frequently, used equipments. Humidifiers and dehumidifiers are used where there is problem of humidity. Exhaust fans also play an important role in bringing in fresh air and flushing out polluted and impure air.

Inadequate Ventilation and Health

Inadequate ventilation  has  following  effect  on  the  occupants  of  the  room:

(i) Lack of oxygen leads to early fatigue and reduces alertness.

(ii) Results in sweating, heat exhaustion and faintness.

(iii) Foul odours from skin, mouth, stomach and clothes produces uneasiness, sickness etc.

(iv) Unventilated environment leads to digestive disorder loss of appetite, anemia, metabolic disturbances, etc.

(v) Cold, cough, infectious diseases, influenza, pneumonia etc. are some of the problems of inadequate ventilation.

(vi) Gases from exhaust vehicles and industries damage the eyes and trachea.

The Aids Pandemic

The AIDS (Acquired Immune Deficiency Syndrome) virus has caused a worldwide epidemic, which can be called a pandemic because it continues to spread throughout the world. Millions of people have been infected. The virus was first identified as the cause of AIDS in the late 1970s. Since then, individuals with the infection have been reported in nearly every country in the world. Estimated mortality rates are about 60 percent, according to the U.S. Centres for Disease Control and Prevention. The disease is spread through direct physical contact, between individuals in which body fluids containing the, virus enter the bloodstream. Sharing of contaminated needles among intravenous drug users and sexual contact are the most-likely methods of passage. In the United States, the disease was once considered a problem only for the homosexual community and those who use intravenous drugs. This perception is rapidly changing. Many of the new cases of AIDS are being found in women infected by male sex partners and in the children of infected women. In parts of Africa, the disease has always been primarily a heterosexual disease.

In the poor countries of central Africa, many believe that permissive sexual behaviour and prostitution have created conditions for a rapid spread of the disease. In addition, there is little opportunity for medical care.  Many  people  have  already  died  from  the  disease. Others who are currently infected will die in the near future. Some villages are  already beginning to notice a change in the structure of their populations. With the death, of young infected’ adults, villages  are  composed  primarily  of  older  people  and  children.  The  disease is spreading at an alarming rate, and, it  has  no  cure  as  yet  and  no  vaccine  so  far.  The disease is almost fatal. People in the age group 20-39 are more susceptible to getting AIDS.

Causative germ  of  AIDS  is  a  virus  named  HIV  (Human  Immunodeficiency  Virus).  It has been detected in body fluids like blood, semen, saliva, tears and urine.  It  attacks  the immune system (i.e. the’ cells that fight against infections) and the patient suffers seriously from even minor infections of other diseases. Even cancers appear when the immune system fails.

Incubation period i.e. the time between receiving the infection and the’ appearance of symptoms may even be more than 10-12 years. During this period the persons show positive results for HIV infection and they are popularly called HIV-positive. Most individuals, when AIDS is fully developed, die within 3 years from other infections or cancers. Symptoms during this period may include swollen lymph nodes, fever, night sweats and weight loss.

Transmission of Aids

The AIDS virus is highly infective. It is transmitted by any one of the following methods:-

(i) Sexual intercourse between a man and woman, when anyone of two is infected. (The virus occurs in the fluids of the reproductive passages). Prostitution is the biggest source to spread the infection. Safest is the single partnership wife and husband relationship.

(ii) Homosexual intercourse (anal sex) with an infected person. The disease is more common in homosexual males.

(iii) Contaminated blood transfusions. In many  situations  the  patients  have  to  be given blood transfusions as in excessive bleeding resulting from injury, or during surgery, etc. Some children are born with the disease thalassemia with defective hemoglobin of the blood. Such children have to be given regular blood transfusions usually every 3-4 weeks and very often the blood transfused is from professional donors.

(iv) Mother to child transmission. The germ from the infected mother may cross through the placenta and reach the embryo in the womb.

(v) Injection needles if shared by more than one person may introduce the virus from one individual to another. The disease is quite. common in drug abusers. For the same reason, doctors in hospitals now use only disposable syringes, which are used just once. AIDS is not transmitted by contact with patient’s clothes and other articles, shaking hands, eating together and sharing bathrooms and toilets.

Women and Child Welfare

Women and Environment

As child bearers, family caretakers and consumers; as food-products, fuel and water gatherers and users; as field, forest, factory and office workers, women are primary managers, and often preservers of natural resources. Women’s work  is  generally  undervalued.  As  a result, women constitute a disproportionate number of the poorest groups of people and are victims of hunger, illiteracy, poor health, scarce social and technical services, inadequate population policies and other consequences  of  poverty.  In  addition,  women’s  participation and influence is inadequately represented in decision-making spheres concerning environment and development  issues  affecting the quality of their  lives.

Child Power

Children begin to acquire an extremely important economic role. They do many crucial tasks like caring for younger children, fetching fuel, fodder and water and grazing animals, so that the adults can undertake waged labour. “Children have become the unwitting victims of the continuing energy hunger in a family below the poverty line, is compelled to meet its energy needs only by producing several children.” But this will not only have important implications for the education, health and nutrition of children but also for the country’s massive family planning programmes and the health of women. If underfed and overworked, women are also expected to bear many children, the impact on their health will obviously be drastic.

Some organizations  working  for  women  and  child  welfare  are:

• National Institute  of  Public’  Co-operation  and  Child  Development  (NIPCCD)

• World Health Organization

• Central Social Welfare Board

• Voluntary Health Association of India

• Indian Council of Child Welfare

• United Nations Children’s Fund and others.

(A) Central Social Welfare Board

Central social welfare board was established in 1953 under the social Welfare Ministry. It generally assists  in  the  improvement  and  development  of  social  welfare  activities.  Grant in aid programme, welfare programme development, control  and  evaluation  work,  training and motivation are the main objectives of the social welfare board. Its functions are:

(a) The spirit of continued partnership between statutory and voluntary welfare services to act as complementary and supplementary to each other.

(b) Provides technical and financial aid to the Panchayati Raj Institutions in accordance with the schemes and principles approved by the government of India.

(c) Promotes social welfare activities intended for family, women, children and the handicapped. Assistance in case of unemployment, under employment, old age, sickness, disablement and other cases of under served organization.

(d) It is change over from un-organized charity  to  the  systematic  line  of  support  by state government wherever considered necessary or desirable.

(e) Need for rationalizing the system of rendering financial assistance to voluntary organization for the uncovered areas.

(f) Conducting of regular surveys regarding the needs and requirements of the social welfare organization.

(g) Co-ordination and cooperation among the voluntary organizations functioning at all levels, amongst themselves and with the governmental agencies, between the concerned government departments at central and state level, district and local levels.

Other functions of Central Social Welfare Board

(i) Mahila Mandal Programme: Various voluntary Mahila Mandals are getting assistance from the central social welfare board.

(ii) Holiday Homes for Children are organized for 15 days for socially and economically backward families. The camp aims at giving training to children in discipline, sense of group living and team spirit, help in national integration, apart from exposure to new surroundings.

(iii) Creches Programme: This programme provides day care services for children of working and ailing mothers.

(B) VHAI-Voluntary Health Association of lndia

Indian Women’s Sabha: The Indian Women’s  Sabha  organizes  Maternity  and  child health centres. The branches of this Sabha ate found all over the country, clinics, hospitals, adult education centres, milk distribution centres and family planning programmes  are managed by the women’s sabha.

(C) Indian Council of Child Welfare (ICCW)

Indian council of child welfare was established in 1952 for the welfare of children and providing health services to them. The council has its branches in every state with its head quarters at New Delhi. The main functions of the institution are:

(i) Initiate, undertake or aid directly or through its branches or affiliated bodies schemes for the furtherance of child welfare in India.

(ii) It provides dissemination of knowledge and information and to educate public opinion for child welfare programmes on a scientific basis.

(iii) Establish a central bureau for the study and collection of data and statistics in respect of  child welfare  work.

(iv) It cooperates with national and international organizations having similar objectives.

(D) United Nations Children’s Fund (UNICEF)

It is an international agency, a subsidiary body of the General Assembly. It came into being on 11th December 1946 after the Second World War. Now the words ‘international’ and ‘emergency’ have been dropped from the name of the organization. It is now called United Nations Children’s Fund but abbreviation in vogue is still UNICEF. UNICEF has completed 48 years of service in India. UNICEF is not financed through the regular U.N. budget, but by voluntary contributions from the member countries, besides individual organizations. 10% of its resources come from the sale of UNICEF greeting cards. Aid is given only for those projects, which aim to prevent disease and promote health of the mothers and children.

India and UNICEF

UNICEF has completed 48 years in the year 1997 and has provided assistance, training programmes and many regional projects started from  time  to  time.  UNICEF  has  changed many facets and programmes for the  ever-changing  health  standards.  In  1959  WHO  and  F AO along with  UNICEF  started  a  nutritional  programme  for  the  children  of  less  than  5 years of age. Then it was changed to Extended Nutritional Programme, which was organized through Mahila Mandals. In 1963 this programme was made more useful by giving nutrition to children and also to pregnant and lactating mothers and named as Applied Nutrition Programme. In the decade 1980-90, UNICEF expanded its services to remote rural areas.

Functions of UNICEF

(i) Child Development and Survival

UNICEF provides priority to infant  and  children’s  health  and  nutrition  programmes. Child and infant mortality rate during the decade 1985-95 declined from 110/1000 children to 8711000.

(ii) Universal Immunization

Expanded Programme  on  immunization  (EPI).  This  programme  was  started  by  the

W.H.O. in 1974 for providing immunization  against  six  fatal  diseases  i.e.  measles, poliomyelitis, diphtheria, whooping cough or pertusis,  tetanus  and  tuberculosis.  This  fulfils the concept of providing primary health protection for all children.

(iii) Nutrition

UNICEF assist in conducting the Applied Nutrition Programme by establishing nutrition centres, school and community gardens. Provides funds for training and nutrition programme at rural level.

(iv) Primary Health Care

The UNICEF sponsors Child health care programmes. It provides funds for the training of doctors, nurses, and public health officers, health workers. UNICEF is providing equipment and material for primary health centres and sub-centres as well as hospitals and laboratories, which support them.

(v) Formal and Informal Education

UNICEF provides stipends for refresher training to teachers including primary-school teachers.

(vi) Water and Sanitation

Water and sanitation are part of health programming and UNICEF co-operates in programmes to  supply  safe water  and  improved sanitation.

(vii) Urban Services

UNICEF provides stipends to more women and girls for training  in  child  care,  home- crafts, food preservation and income-earning skills and provide stipends to train local leaders to help organize activities in their own villages and communities.

Information and Electronic Revolution

With the beginning of the electronic age in recent years, Our world has become a place where information and communication are regarded as the  most  valuable  resources.  Our world has now shrunk to a ‘global village’ and we now have access to places our grandparents didn’t know existed. Information from cosmopolitans to unexplored frontiers are all now available at a drop of a hat, it’s just a matter of mouse-click. Data flows at the speed of light in today’s wired world, or shall, we say the wireless, paperless and non-messy world.  The advent of the Internet has, in a way, brought continents together once again.

Modern technology has also minimized our utilization of resources; e.g. today’s, sophisticated engineering has replaced the blind usage of metals in every production. Thanks to the marvel of lightweight alloys  and  composite  building  materials,  automobiles  now require half as much metal as they typically used to do a generation ago. Today 1,000 soft drinks cans are manufactured with around 6 kg of aluminium, which once used to require 50 kg of steel. In the 1970’s, when the fear of an impending shortage of metals gripped the world, countries like the United States began stockpiling essential minerals to keep their resource inventory up-to-date. Copper for electric wiring,  telephone  cables,  and  electric motors were in short supply. But then glass-fibre optic cables, ceramic magnets, microwave relay systems and satellite communication networks were invented. We now have a copper surplus.

Similarly, technology has also cut down our fuel consumption. Diesel engines replaced coal-based steam engines in locomotives, which were, further replaced by more efficient and pollution-free electric engines. The popularity of high-mileage yielding, fuel-efficient vehicles have made the gasoline guzzling vehicles obsolete in the market. Such advancements in the field of information technology have made distance between two places immaterial. Today, people can communicate via teleconference and transmit data through fax machines and computer networks, and save precious time & fuel wasted earlier in traveling for meetings and business appointments. It is no longer necessary for all workers to commute to an office

building in the congested city to do their  work.  Increasingly,  workers  have  home  offices linked electronically to co-workers, clients, libraries, databases, and business opportunities elsewhere in the world. Commercial establishments are moving away from the brick-and- mortar set-ups to more affordable, cost-efficient, far-reaching virtual offices on the Internet.