Environmental Sanitation Introduction
Globally the importance of environmental sanitation can't be over emphasized hence environmental sanitation deals with those factors in man's physical environment which if neglected could affect health adversely.
These factors are:
- Unclean environment arising from accumulation of waste
- stagnant pools in gardens of houses, on the streets and in surrounding areas of towns or villages due to improperly planned living quarters.
- Poorly constructed dwellings, schools, offices etc
- Existence of slums and lack of recreational facilities
- Pollution of the environment by smoke and toxic fumes, chemicals and industrial waste
- Lack of or inadequate water supply
- inadequate food hygiene
All the above mentioned factors constitute a definite health hazard to the individual and the community. We shall now discuss these hazards individually as it relates the importance of environmental sanitation globally
Environmental Sanitation Problems
Waste and Refuse
Man's way of life greatly promotes the accumulation of waste and filth in his environment which, if not properly disposed of, leads to breeding of vermin, flies and other vectors of diseases. Rodents are involved in transmission of plague relapsing fever and rat bite fever. The fleas that directly transmit plague to man live in close association with rats. when an infected rat dies, the fleas seek another rat to live on. If this rat should come in close contact with man, the fleas may jump onto the man, bite him and thereby transmit the plague organisms into his blood. Bubonic plague is still a common disease in many developing countries today. Flies especially house fly, love to breed in filthy environments where they pick up germs into the home onto food about to be consumed and deposit the germs. On ingestion of the contaminated food, the individual becomes infected. Also the existence of filth and refuse scattered all over the premises and street is aesthetically not a pleasant sight. Lastly, in adequate disposal of excreta promotes the breeding of flies, offensive odour and the transmission of many worm infestation and bacterial infections, e.g. hookworm infection, typhoid and dysentery.
In many developing countries, towns and villages are not properly planned. Inadequate drainage promotes the accumulation of water from domestic activities. This collects in the open spaces in and round the dwellings and the streets. Drains , often improperly constructed, are left open. Mosquitoes which are vectors of malaria parasite, breed abundantly in the open collection of water. Communicable disease abound in many developing countries because of poor sanitation. This outlines the importance of environmental sanitation globally.
Poorly Constructed Dwellings
Overcrowding is a common feature in many developing countries because the house are inadequate, the rooms are small and the families are often too large. Building materials commonly used are of poor quality and many dwellings are improperly sited, so that when there is a storm or a heavy wind, many of these houses are readily destroyed and the occupants suffer from exposure.
overcrowding is known to promote the spread of diseases such as cerebrospinal fever, tuberculosis, scabies and pediculosis. Moreover in certain parts of the world some vectors live in cracks in the walls, e.g. triatomid bugs, vectors of American trypanosomiasis. Rats and mice have no difficulty in invading these homes and thereby come into contact with food and the inhabitants of these houses.
Accumulation of many improperly constructed dwellings in a poorly designed and overcrowded area of a town leads to existence of slums and attendant socio-medical problems.
Atmospheric, soil and water pollution is fast becoming a worldwide problem and developing countries are no exception. Chemical and other wastes from factories, fumes from the exhausts of automobiles, the use of chemical poisons to control crop pests in agriculture etc lead to the exposure of man to these toxic substances which can cause certain diseases in him.
Very many communicable diseases that affect people in the developing countries are directly connected with the unclean and inadequate water supply available for domestic and other uses. Guinea worm, typhoid, biharziasis, poliomyelitis and dysentery are all largely attributable to poor water supplies. Personal cleanliness is also related to the amount of water available for use in the community; everybody needs pure clean water (about 120 liters daily)
It is probably not an exaggeration to say that gastrointestinal infection is a leading cause of mortality in childhood and a very important cause of morbidity in all age groups in the developing countries today. Improper hygienic practices contribute largely to this situation; a visit to the open markets in tropics will convince the reader. Food items are left uncovered on the stalls so that they are readily invaded by flies and are open to contamination by termites and alos by airborne germs being excreted by infected persons. Many developing countries lack properly constructed and maintained abattoirs. Slaughtered meat offered for sale should be properly inspected by Health Inspectors, so as to eliminate diseases like bovine tuberculosis, trichinosis and those caused by tapeworm. A large proportion of food handlers suffer from one or more types of worm infestation and from bacillary or amoebic dysentery, typhoid or tuberculosis. The risk of spread of disease by food is, therefore very great. Improper food hygiene in home also plays a part in the spread of gastrointestinal infections.
Control of Environmental Sanitation
All diseases which afflict man as a result of the pollution, contamination and neglect of his surroundings can be controlled and even eradicated if adequate attention is paid to environmental sanitation.
Environmental sanitation consists of activities which result in a clean environment, adequate construction of dwellings, proper drainage, control of flies through adequate disposal of refuse and faeces and elimination of the breeding places of mosquitoes and vectors of communicable disease.
In addition it is essential that food and water supplies are clean and free from bacterial contamination.
Maintaining a clean environment is as much the responsibility of the local government agencies as it is of individuals in the community. In many developing countries it is often essential to educate members of the public and the agencies in order that they may actively participate in the task of preventing communicable diseases through proper environmental sanitation.
Clean water supply can be obtained from adequately constructed wells, or from reservoirs where water has been properly treated and pumped into a pipe-borne system. For a well to be adequate it must be sited far away from the latrines and refuse dumps. It must be deep enough to avoid contamination by surface water . Shallow wells are often easily contaminated. The edge of the well must be high above the ground and a lid must be provided. Water from wells is usually good for washing and bathing, but it should be boiled and cooled before drinking. Water from springs and streams should also receive the same treatment to render it safe. Other sources of water include: rain, lakes, ponds, rivers, and the sea. Where the water is cloudily and full of sediments and suspended matter, it is an indication of heavy contamination. Such water is best avoided. But in some rural areas such water may be the only water available for use. The individual must first store such water and allow sedimentation to take place. The water is then boiled before it is used.
Other methods of water purification include the use of a domestic filter, addition of chemicals such as chlorine or Milton (4ml per liter). Storage is a natural means of water purification. A pipe- borne water supply is the best form to obtain potable water, especially when it is piped into the homes.
There are many methods available for the disposal of refuse that can be practiced at a village or at community level without involving much expense. An incinerator can be constructed very cheaply with a fence round it for people to throw in their refuse for burning. Refuse dumps can also be located away from homes, where after tipping and the addition of soil, the material could be used for manure. Marshy land can be reclaimed by the tipping of refuse into the land over a long period. After an interval, sand is added to cover the refuse so as to prevent the breeding of flies and children playing on the refuse. This is often practiced by the health department of the local authorities who are able to run a fleet of trucks. Refuse from health centre's like dirty dressings should be burnt. Other organic material should be kept in covered refuse bins which must be emptied daily and disposed of safely.
Disposal of Excreta
Pit latrines are easy to dig and every house built in a rural community should have one. Communal latrines such as borehole latrines should be constructed in market places and community halls. Every school should have a latrine and a good water supply. In the absence of an effective waterborne sewage disposal system, individual houses in areas where it can be method of treating water-borne sewage from a single house or a small group of houses. Bucket and water latrines have many disadvantages and should be condemned. Disposal of excreta in trenches is only useful if it is properly managed and the faeces re covered.
Village and Town Planning
If more effort could be exerted by people living in developing countries, their villages and towns could be well planned in a way that would not promote the existence of stagnant pools, marshy areas and slums. Houses should be well located away from marshy areas so as to avoid contact with the vectors of disease that breed in such places. The individual dwellings should be constructed according to the rules and by-laws which exist in every district. It is essential for the houses to be inspected during construction, so as to ensure adherence to the rules and good quality of walls, floors, waterproof roofs and damp-proof course. Adequate space must be provided in the living rooms and the ventilation must be good. Latrines, washing facilities, kitchens and storage spaces are all essential components of a house.
Many developing countries have begun to industrialize . This involves the construction of factories, the importation and application of chemicals, heavy machines and sometimes radioactive materials. The sitting of a factory should always receive adequate consideration so that waste, smoke and other unwanted products from it do not contaminate the environment in which it is situated. In some advanced countries, smokeless zones in the cities have been created by law. Adequate security precautions ought to be taken when poisonous chemicals are introduced into illiterate communities. The application of pesticides in agriculture, food storage and food processing should be vigilantly supervised so as to avoid excessive contamination of food.