An important aspect of primary health care is the provision of clean water in adequate quantities.  For many people in developing countries this is one of the most difficult problems to cope with.  Yet approximately three out of five people in developing countries do not have easy access to safe drinking water. 

Water has a vital impact on people's health.  A large percentage of the infectious and parasitic diseases that plague the developing world are associated with inadequate water and sanitation. 

  • Diarrhoea directly kills four to five million children in developing countries every year, and contributes to malnutrition 

  • Trachoma affects some 500 million people at any given time, often causing blindness 

  • Parasitic worms infect nearly one half of the entire population of the developing countries, often with very serious consequences.  For example, 200 million people in   70 countries suffer the debilitating effects of schistosomiasis 

  • Malaria each year kills about three-quarters of a million children under one year old in Africa south of the Sahara alone 

The provision of water for household use in most societies is the task of women.  They spend sometimes as much as six hours a day walking long distances and carrying heavy loads of water.  In years of insufficient rain Dogon women in Mali, for example, have to undergo extreme hardship while collecting water from remote places in the mountains.  This arduous task uses much of women's energies and time, which in turn has serious consequences for their and their families health.  The heavy jars or cans that they carry on their heads can lead to back-trouble, while tasks such as child-care or income-raising activities may suffer due to lack of time.  In addition, in many places women spend more time actually working in the water washing clothes for instance - and so may be more often exposed to the water-borne diseases. 

Because of its association with women, the provision of water is one of those tasks always undervalued and largely ignored.  As a result, appropriate technology to alleviate this burdensome task is lacking, and insufficient efforts are made to provide communities with safe and convenient sources of water.  Inadequate provision of water and safe sanitary facilities is in turn very costly to the community or to the government.  The economic loss due to diseases and disability resulting from lack of water and sanitation is enormous, and the overall development of society is delayed. 

Diseases which are prevalent when water quality, water quantity, water accessibility and/or sanitation are deficient can be grouped into five categories: 

Water-borne diseases: 
Transmitted when water, contaminated either directly or indirectly with infective organisms of disease, is consumed. 

Water-washed diseases: 
Spread when personal and domestic hygiene is inadequate, infective organisms are spread with dirty fingers, utensils, food, towels etc.  Aggravated when excreta disposal is deficient and domestic water supplies are inadequate. 

Water-based diseases: 
Diseases for which the causative organism must spend a portion of its life in an aquatic animal before developing into infective larvae.  Transmitted when larvae are consumed with drinking water (guinea worm) or when they penetrate human skin (schistosmiasis). 

Water-related diseases: 
Spread by the 'bite' of insects, especially mosquitoes, part of whose life cycle is spent in water and which, in some cases, live near water. 

Diseases related to inadequate sanitation: 
Spread when the disposal of excreta is defective.  Hookworm is mainly transmitted when larvae in contaminated soil penetrate human skin.  Virtually all of the water-borne and water-washed diseases are aggravated by defective sanitation.  

These diseases exact a high toll in human life and suffering.  Although women are the providers and main users of water, they are seldom consulted when it comes to the initiation of water projects.  Preparatory meetings are often held at times when women cannot attend, and little effort is made to ensure their participation.  Male engineers and administrators usually believe that women are incapable of managerial roles in relation to water and sanitation.  This belief is based on an insufficient understanding of women's managerial roles in the home, where they are obliged to make careful decisions about the allocation of family resources and the budgeting of time and energy.  However, women are more effective in protecting pumps, latrines and water sources and are also capable of learning the skills necessary for their maintenance.  Therefore, it is in the interest of the entire community to provide the necessary know-how to those who will actually use the water-sources most. 

The relationship of poor hygiene to poverty is particularly important but often overlooked.  Without concurrent hygiene education, especially for women, the benefits of safe water supply and sanitation, so essential for basic health, are limited.