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close this bookTeaching Conservation in Developing Nations (Peace Corps)
close this folderChapter 3: Conservation education in a health center
View the document(introduction...)
View the documentNutrition
View the documentSanitation
View the documentHealth
View the documentSource material - Chapter 3


All living things, together with all non-living things, form our ecosystem. People are a part of the ecosystem; people are a natural resource; since conservation is concerned with the care of natural resources, people must take care of themselves as well as the rest of their environment. Health care is conservation too'

In many parts of the world the major problems of health are malnutrition and diseases carried by insects and parasites. These are environmental problems.

An environment in which there is improper or insufficient food is usually the result of poor agricultural production, poor soil, poor food storage methods, and lack of knowledge about nutrition. An environment which supports a disease-carrying insect cycle, such as the mosquito/malaria cycle, or the tsetse fly/sleeping sickness cycle, is a bad environment for people. An environment which supports the unchecked growth of bacteria is a bad one for people.

People can change the environment to improve the soil, agricultural production and nutrition, to break the cycle of disease carriers, or slow the growth and spread of bacteria, if they understand the problem and learn what steps to take.

A health center provides medical care for its community. It should also provide health education. Just as conservation education shows the relationship between all things in an environment, health education can show the relationship between health problems and the local environment.

To establish a health conservation education program in your community health center, you will need to identify those health problems which are most directly related to your own environment, and which are caused by such things as poor sanitation, erosion or crop destruction, or insect carriers. Choose one of these problems at a time, if your center is small, as a demonstration and education project.


The results of malnutrition on a nation's development cannot be ignored. When a large portion of the population is unable to realize its potential due to improper physical development or disease caused by poor diet, the loss to the nation is great. The periods of infancy and childhood require sizeable resources from both the family and the nation in terms of food and health care. When a child dies in adolescence, his/her use of those resources is totally lost. If he/she does not have a reasonably long or useful working life, again the food and health care used in his development will not be fully repaid, and the nation is losing a valuable natural resource.

The World Health Organization believes that protein calorie deficiency is the greatest public health problem in the world today. A health center conservation project that could be developed in cooperation with an agricultural agency would demonstrate how to develop better soil, how to choose an acceptable protein-rich plant food to grow, and how to prepare it for eating. (Protein-rich soybeans might be a possible crop to introduce). You will need a piece of land for a demonstration garden (see Appendix C for growing information and Chapter 5 for agricultural information).

If other kinds of diet deficiencies are an important problem in your area, a demonstration garden could grow those plant foods which would eliminate the deficiencies. You would have to work with the agricultural agent to identify which plants would grow well, and would also be culturally acceptable to these garden demonstrations. If the climate is suitable, papaya trees could be introduced to provide an easily grown source of vitamins A and C.

Another possibility might be the introduction of fish culture through a program following the Peace Corps/VITA manual, Freshwater Fish Pond Culture and Management Fish are an important protein-rich food and to grow fish in ponds is a more certain way of supplying fish for food than trying to catch fish from lakes, rivers or streams.

Nutrition education can be supported through the schools where children can learn the basic principles of good nutrition. They could grow fresh vegetables or fruits in a school demonstration garden, which they could take home to eat. A government-sponsored food program might be available to provide school children with a nutritionally balanced meal each day.

If floods or erosion are a frequent cause of crop loss in your area, you should encourage efforts in flood and erosion control by farmers, with help from agricultural agents, which would improve the local food supply. (See Chapter 5).

Where food supplies are threatened by loss during preservation and storage, improvement such as that detailed in the Peace Corps/VITA manual, Small Farm Grain Storage (see Chapter Sources), should be actively encouraged and supported by cooperative efforts with agricultural agents. Proper storage can reduce grain loss from 33% to 3% thus making an increased quantity of food available.

In urban areas, nutritional problems are intensified by the fact that consumer goods compete for whatever money is earned, and often the family diet loses out in this competition. An approach to this problem could be to illustrate, by using a flannelgraph story in the health center, that the balanced nutritious diet improves weight, muscular strength, endurance, and capacity to work as well as resistance to disease All of these qualities would tend to increase a person's ability to compete successfully in his/her environment.

Flannelghaph demonstration

Perhaps you could locate some land within the urban area which could be transformed into a community garden for supplementary food needs.

The health center should actively promote food cultivation as a health conservation measure. The health center must be the leader in suggesting and developing ideas to improve the community's nutrition. For an excellent book on the subject, see Learning Better Nutrition by Jean Ritchie/FAO (See Chapter Sources).


Sanitation is the planning and application of measures to maintain a healthy environment. These measures should apply to water supply, sewage and garbage disposal, and control of disease-carrying insects and animals.


A community's water supply may come from a ground water well, a spring, a stream, a river or a lake. Unless there is a community-wide water purification system, whatever water there is should be considered to be a potential source of infection and parasites, because human or animal feces or urine, or other untreated sewage, often infect the supply. Therefore, water should be disinfected by each user. The most effective method of preventing water-carried infection and parasites is to boil the water hard for at least ten minutes. This kills bacteria and parasite eggs in the water.

Water purification can be done on a community-wide basis by adding chlorine or iodine to a water storage area. These methods are discussed in the Village Technology Handbook by VITA (See Chapter Sources).

A health center should be concerned with educating a community to develop a clean water source. This would involve educating people to (1) build and use latrines, not the river or lake; (2) put their garbage in compost piles not in or near the water supply; (3) not bathe in the water supply; (4) keep domestic animals out of the water supply; (5) Use erosion control techniques to keep topsoil from washing into the water supply. Other local sources of water contamination should be studied and remedied.


Sewage is the term used for human wastes. Sewage can be properly disposed of by use of latrines. Latrines can be built for each family, or one or several can be built for the community as a whole. A family is likely to keep its latrine clean, and is likely to use it; too often no one feels personal responsibility for keeping the community latrine clean or in good repair. Where possible, you should encourage people to build family rather than community latrines.

Pit Latrines

A pit latrine is basically a hand-dug hole in the ground, covered with a slab, preferably of concrete, either for squatting or with a seat. A shelter is built around it. Human wastes are isolated and stored in the pit latrine, so that no harmful bacteria or parasites can be passed on from the wastes to new hosts. In the pit, the wastes decompose, first into odorous ammonia products, then into nitrites and nitrates. This decomposition process generally kills the majority of harmful organisms. An exception is the hookworm's eggs which remain alive for up to five months in wet. sandy soil.

Pit Latrines

Hookworm larvae can climb up pit walls and survive on a cracked wooden or earth floor, and once there, they can be picked up by bare feet. It is highly recommended that a concrete slab provide the cover for the pit and that it be effectively and frequently flushed with water. Flies are common carriers of disease organisms found in feces. They crawl and feed on this material, which sticks to the flies' bodies, and which later to the flies' bodies, and which later may be deposited on human food, either directly or through the fly's feces. For this reason, it is important to try to discourage flies in a latrine. The best way to do this is to plan a well-ventilated, dark shelter, since flies do not like darkness, Use fine-mesh screening to cover openings if it is available. A 10% surface layer (2.5 cm) of borax has been found to discourage flies. Use of insecticides has been found to develop a fly population resistant to insecticide control. A cover for the nit opening in strongly suggested.

A health center should provide help and information about latrine building. The most complete source of information and directions is Excreta Disposal for Rural and Small Communities, published by WHO, portions of which appear in Village Technology Handbook by VITA.

You should build a pit latrine at an easy distance from the home so as not to discourage its use. It should be down-hill from any ground water supply, in a dry, well-drained area, above flood level. Around the latrine, clear an area 2 m wide of all vegetation and debris, to discourage shelter for animals and insects. This may be done gradually, to gain acceptance of a latrine in a spot where the surrounding vegetation was formerly used.

Since each geographical area will have certain taboos about the collection and disposal of human waste, you will have to identify these before developing an acceptable solution. Privacy and the separation of the sexes may be important considerations. (Also see Appendix E).


Garbage is basically food waste, but can also include other unwanted materials such as paper, cans, bottles. The more a community consumes, the more garbage to be disposed of.

From a conservation standpoint, food wastes should be returned to the soil as a compost material. This adds both nutrients and organic materials to the soil which will increase its fertility. See Appendix C, for information on making a compost pile. A compost pile can be a family or a community project. If there is space available outside a health center, a demonstration compost pile can be built with organic wastes from the community members. When the compost is ready for garden use, it can form the basis for a demonstration garden, or can be divided among the community members for their own garden use.

Non-organic wastes such as metals or glass should be disposed of in a single community site, a large pit for example, to keep the community clean and free from litter. If possible, the disposal area should be visually separated from the community, either by distance or by a screen of plants.


A health center should also be concerned with the personal hygiene of its community members. It is hard to teach that there is danger from something which cannot be seen with one's own eyes. However, many of the health problems which affect people are invisible, either because the destructive organisms in the environment are too small to see without a microscope, or because the problems develop inside the body.

The health center should develop an education program which teaches the relationship of cleanliness to health. The washing of hands with soap and water before handling food; bathing to keep the body free from harmful bacteria; wearing sandals or shoes to prevent penetration of parasites through the soles of the feet; keeping the home swept and aired to discourage insect or bacteria breeding places; keeping farm animals out of the home, should all be part of a program to up-grade the health of the community.

An effective method of demonstrating insect or parasitic-carried health problems might be to illustrate the cycle on a flannelgraph or flipchart. Two suggestions follow:


The hookworm is one of a number of nematodes, which is found in tropical and subtropical climates, and which lives as a bloodsucking parasite in the intestines of man.

(1) the larvae of the hookworm live in moist soil which is contaminated by human feces. (2) They penetrate exposed skin, usually the soles of bare feet, and are carried by the blood stream (3) to the lungs, where they cause coughing, (4) are raised into the mouth with bloody mucous and are then swallowed (They can also be swallowed in polluted water.) (5) they then travel to the intestine where they attach themselves with "hooks" and feed on the body's blood supply. (6) A female hookworm can discharge 30,000 eggs a day into the human feces, (7) which will then further contaminate the soil and more people.

As a result of the loss of blood to an infestation of hookworm, a person will suffer anemia, abdominal pain, diarrhea and weakness which will make him/her susceptible to other diseases.

In explaining this cycle of the hookworm, you can show that if a latrine is used, the soil will not be contaminated with hookworm eggs; if shoes or sandals are worn, the larvae cannot enter the soles of the foot; if water is boiled, live hookworm larvae will not be swallowed. If a person has bloody mucous, he should go to the health center to be treated with drugs which will kill the hookworms. Each of these actions will break the hookworm's life cycle, and will help to destroy it.

A Situation

Schistosomiasis Cycle



This is a parasitic disease caused by blood flukes, and is found in Asia, Africa, the West Indies, South America, and some Pacific islands.

(1) the eggs of the blood fluke are found in water, deposited there from urine and feces of infested humans. (2) The eggs hatch and penetrate the feet of snails where (3) they develop into a new form and are discharged into the water. (4) The larvae are then free-swimming until they come into contact with persons who work in, who bathe in, swim in, or otherwise come into contact with the infested water. (The larvae can also be swallowed in polluted water). (5) The larvae penetrate the person's skin and are carried through the blood stream to the bowel, bladder, liver, genitals, lungs, spinal chord and other tissues where they attach themselves. (6) The larvae develop into mature flukes which rob these tissues of the blood they need. (7) Eggs of the mature fluke are passed out in the feces and urine.

The disease results in general weakening and eventual death.

In explaining this cycle of the blood fluke, you can show that if a latrine is used, the water will not become contaminated with blood fluke eggs. If people do not bathe in infested waters, or do not do irrigation work without rubber boots, or do not drink untreated water, the fluke larvae will not enter their bodies. Each of these actions will break the blood fluke's life cycle, and will help to destroy it.

If the hookworm or the blood fluke are not health problems in your area, then perhaps you can identify another disease which is carried in a similar fashion, and whose cycle could be broken by improving the environmental conditions of the human population of your area.

Rodents not only destroy food crops and stored grain, they also carry fleas which in turn carry diseases. Certain rat fleas carry typhus and bubonic plague, and fleas also transmit several species of tapeworm. There are chemical methods to control such rodents as rats and mice. You can also alter their environment, which will discourage or reduce their population. Keep your community free from trash, litter and debris where rodents can hide and nest. Make your grain storage rodent-proof as illustrated in the Peace Corps manual, Small Farm Grain Storage. Most especially, encourage the protection of the predators of rats and mice. These may be birds such as hawks and owls, or they may be any of a large number of harmless snakes. You should learn to identify which snakes are beneficial and not harmful to people. The health center might display pictures of those birds and snakes which help eliminate rodents, or you might be able to keep a harmless, helpful snake as an education aid (see Appendix F. Live Animals). Encourage people to see the snake as a friend by explaining what he eats, by showing with pictures how he is different from harmful snakes, and by generally developing an atmosphere of trust toward the animal.

The health center's decision to develop or support a program to educate the community in some aspect of environmental health, should be based on what the specific problems of your area are. Perhaps instead of disease or nutrition, it is the mental health of the community which is suffering from the stress of a crowded and competitive urban environment. Perhaps air pollution is severe enough to cause lung or skin damage, and needs to be explained. The community should be alerted to those aspects of its environment which can cause harm to its members, and should be shown how to improve their health by making beneficial changes in the environment.

Source material - Chapter 3

Almanac of rural living1
Harvey C. Neese
N & N Resources
Box 332
Troy, Idaho 83871, USA

*Conseils de sant la famille africaine2
** Peace Corps information Collection & Exchange
Program & Graining Journal, Reprint series #21
Room M-1214
806 Connecticut Avenue N.W.
Washington, D.C. 20525, USA

Developpons la consomation de proteins3
(also available in English & Spanish)
FAO Nutritional Studies series Food and Agricultural Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy

Donde no hay doctor
David Werner
Editorial Pax-Mexico
Libreria Carlos Cesarman, S.A.
Calle Rep. Argentine #9

Educacion alimentaria en la escuela primaria3
(also available in French & English)
FAO Nutrition Studies series #25
Food and Agriculture Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy

Eliminemos la rata
(also available in English)
Vecinos mundiales
Volumen 6 - numero 35
5116 North Portland Avenue
Oklahoma City, Oklahoma 73112, USA

Engineering measures for control of schistosomiasis
Office of Health
Bureau of Technical Assistance
Agency for international Development
Washington, D.C. 20523, USA

Excreta disposal for rural areas & small communities4
World Health Organization
Geneva, Switzerland

*Freshwater fish pond culture & management5
** Peace Corps/VITA
Program & Training Journal
Manual series number 1B
3706 Rhode island Avenue
Mt. Rainier, Md. 20822, USA

Handbook of tropical & subtropical horticulture1
(also available in French & Spanish)
Agriculture Technical Services Desk
Agency for international Development available from the AID office of U.S. Embassies

*Health education: A study unit on fecal-borne diseases and parasites
** Peace Corps Information Collection & Exchange
Program & Training Journal Reprint series #1
Room M-1214
806 Connecticut Avenue N.W.
Washington, D.C. 20525, USA

*Health training resource material for Peace Corps Volunteers2
** Peace Corps Information Collection & Exchange
Program & Training Journal Reprint series #3
Room M-1214
804 Connecticut Avenue N.W
Washington, D. C. 20525, USA

Human nutrition in tropical Africa3
(also available in French and Spanish)
FAO Nutritional Studies series
Food and Agriculture Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy

Infant nutrition in tropics & sub-tropics4
Derrick Jelliffe
WHO publication
Geneva, Switzerland

Le lait et les produits laitiers dans la nutrition humaine3
(also available in Spanish and English)
FAO Nutrition Studies series #
Food and Agriculture Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy

Learning better nutrition3
(also available in French and Spanish)
FAO Nutritional studies series #20
Jean Ritchie/Food & Agriculture Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section FAO, Via delle Term di Caracalla, 00100 Rome, Italy

La leche y los productos lacteos en la nutricion3
(also available in French and English)
FAO Nutrition Studies series #27
Food and Agriculture Organization of the United Nations available from FAO agents world-wide; or Distribution & Sales Section, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy

Let's get rid of rats
(also available in Spanish)
World Neighbors
Volume 6 - Number 3E
5116 North Portland Avenue
Oklahoma City, Oklahoma 73112, USA

*Manual didactico: Huertos escolares y nutricion2
** Peace Corps Information Collection & Exchange
Program & Training Journal Reprint series #18
Room M-1214
806 Connecticut Avenue N.W.
Washington, D. C. 20525, USA

Mejor salud mediante esfuerzo comunal
(also available in English)
Vecinos mundiales
Volumen 8 - numero 1S
5116 North Portland Avenue
Oklahoma City, Oklahoma 73112, USA

Nutricion infantil en los paises en desarrollo
Derrick Jelliffe
Editorial Limusa
Arcos de Belen 75
Mexico 1, D. F., Mexico

Sewage lagoons for developing countries
Ideas & Methods Exchange #62
Office of International Affairs Department of Housing and Urban Development
Washington, D. C. 2041 0, USA

*Small farm grain storage2
** Peace Corps/VITA
Program & Graining Journal
Manual Series number 2
VITA 3706
Rhode Island Avenue
Mt. Rainier, Md. 20822, USA

Solar cooker construction manual
(also available in French & Spanish)
3706 Rhode Island Avenue
Mt. Rainier, Md. 20822, USA

Village technology handbook1
3706 Rhode island Avenue
Mt. Rainier, Md. 20822,

Water supply for rural areas and small communities
World Health Organization
Geneva, Switzerland

(See also Source Materials for Chapter 4)

1Up to five copies available to Peace Corps libraries from:
Peace Corps Information Collection & Exchange
Room M-1214
806 Connecticut Avenue N.W.
Washington, D. C, 20535, USA

2Multiple copies available from:
National Technical Information Service
5285 Port Royal Road
Springfield, Va. 22161, USA

3English editions of UN and FAO publications available from:
P. O. Box 433
Murray Hills Station
New York, New York, 10016, USA

4WHO publications available from:
Q Corporation
49 Sheridan Avenue
Albany, New York 12210, USA

* Available to Peace Corps Volunteers from:
Peace Corps Information Collection & Exchange
Room M-1214
806 Connecticut Avenue N.W.
Washington, D.C. 20525, USA

** Single copies available to individuals and non-profit organizations working in the Third World, from the above address.