water scarcity; water supply; sanitation; health impact; human development
Shortages of water could become a major obstacle to public health and development. Currently, the United Nations Children's Fund (UNICEF) and the World Health Organization (WHO) estimate that 1.1 billion people lack access to a water supply and 2.6 billion people lack adequate sanitation. The global health burden associated with these conditions is staggering, with an estimated 1.6 million deaths every year from diseases associated with lack of access to safe drinking water, inadequate sanitation and poor hygiene. In this paper we review the impact of water shortages on health and human development.
The world is facing a critical shortage of fresh water over the next two decades, according to a report from the World Commission on Water.1 The report predicts that the use of water will increase by 40% in the next 20 years due to growing demands from agriculture, industry and urban areas.1 With climate change the situation will get worse; hotter, drier summers will reduce water availability and will lead to an increase in water demand.1
Today, 1.1 billion people have inadequate access to water and 2.6 billion live without access to basic sanitation.2 A lack of water to meet daily needs has serious health consequences. This paper overviews the impact of water shortages on health and human development.
Morbidity and mortality
The health burdens attributable to lack of water and sanitation are significant. Yet more people endure the largely preventable effects of water scarcity and poor sanitation than are affected by war, terrorism and weapons of mass destruction combined.3 These effects are caused by exposure to pathogenic microbes through various routes, which can be summarized in six categories (Table 1). This large number of categories is an indication of the extent to which water-, sanitation- and hygiene-related diseases can affect populations.
Diseases related to unsafe water, poor sanitation and lack of hygiene are some of the most common causes of illness and death among the poor of developing countries. According to the World Health Organization (WHO), 1.6 million deaths each year can be attributed specifically to these health determinants.3
Nearly 60% of mortality is linked to infectious diseases, mainly diarrhea, schistosomiasis, trachoma and intestinal helminths.3,5 Moreover, other diseases with less mortality, like malaria, filariasis, onchocerciasis, dengue and Japanese encephalitis, are becoming more difficult to manage because of the growing resistance of pathogens to drugs and insects to insecticides.3
Table 2 illustrates the global extent of morbidity and mortality figures for diarrhea and other water-, sanitation- and hygiene-related diseases.
Health burden for children
Each year 1.5-2 million children still die from waterand sanitation-related diseases6 and many more are debilitated by illness, pain and discomfort. Although insufficient and unsafe water supplies and sanitation affect people of all ages, children's health and well-being is particularly compromised. Approximately 84% of the global burden of diarrhoeal disease is experienced by children under five and 74% of the health burden from intestinal helminths affects children between five and 14.7
Diarrhoea and intestinal parasites contribute much to malnutrition in children, by causing decreased food intake, impaired nutrient absorption, direct nutrient losses and by challenging their immune systems.8-10
Moreover, poor water supply can affect growth in other ways. When a water supply is situated some distance away, this can contribute to heavy workloads for older children, causing them to burn calories that they depend on for adequate nutrition. Carrying overly heavy containers can even contribute to deformities in bone growth. …