Water and sanitation
Household water security
The public health importance of diarrhoea among children lies partly in the high mortality rates as well as in the interactions between malnutrition, recurrent diarrhoea and impaired child development. Contrary to breastfed infants, bottle-fed infants are highly exposed to the effects of unsafe drinking-water. It cannot be overemphasized that the transmission routes for infectious agents are complex and thus contribute to the complexity of prevention. Interventions in water supply, sanitation and hygiene are estimated to reduce diarrhoeal incidence, on average, by a quarter (25%) and child mortality by 65%. However, selected interventions have been shown to be much more efficient in certain settings.
Some dangerous chemicals also occur naturally in groundwater, notably fluoride and arsenic. The consumption of fluoride-rich drinking-water results in serious health effects, ranging from dental fluorosis to crippling skeletal fluorosis, both effects being irreversible. Children whose teeth and bones are still developing are most susceptible to high fluoride concentrations. This is further aggravated by poor nutritional status. Symptoms start to develop during childhood, and preventing exposure represents the only effective intervention. At least 25 countries across the globe are affected.
Selenium in water is another element that may cause health effects in children when consumed in either insufficient or excessive amounts. Like fluoride, selenium is an essential element at low doses for optimum growth and survival; however, when consumed beyond a certain threshold, these elements become toxic and may lead to severe health problems. Children are particularly vulnerable to essential trace element deficiencies and poisoning.
In Bangladesh and India (West Bengal), high concentrations of arsenic have been found in tubewells and arsenicosis has become widespread. Arsenic can cause severe and irreversible health effects, even at chronic and low levels of exposure, with onset in early childhood and symptoms emerging gradually. There are at least twelve other countries suffering from naturally high arsenic levels in water.
The availability of at least minimal amounts of water for drinking and other personal purposes is considered as important as its quality. Already, one third of the world’s population lives in countries facing moderate to high water stress, if not water scarcity, and water tables are falling in every continent. If present trends continue unchecked, it is estimated that two out of three people on earth will live in water-stressed conditions by the year 2025. Globally, 1.1 billion people are today without access to a clean and adequate water supply. And too little water for basic needs makes it virtually impossible to maintain the necessary minimum of personal hygiene and sanitary conditions in the home.
Traditionally, improvements in water supply and sanitation have been promoted as essential public health measures to improve the population’s health status. If universal piped and regulated water supplies were to be achieved, about 7.6 billion episodes of diarrhoea could be prevented annually, a 70% reduction. These are critical interventions for the health of populations and of children in particular.
Further strengthening of the evidence base, with better geographical coverage and specificity for children in different age groups is required in the area of water accessibility and safety, and this should underpin policymaking and advocacy for cost-effective interventions. Improved water supply and sanitation has long been targeted as a priority for health and development. It was central to the International Drinking Water Supply and Sanitation Decade, and more recently is reflected in the Millennium Development Goals set by world leaders at the UN Millennium Summit in September 2000. The target is to “halve, by 2015, the proportion of people without sustainable access to safe drinking water” through the promotion of affordable and environmentally sound technologies.
Action has also to be accelerated to fulfil the commitment made at the UN Millennium Summit to halt the unsustainable exploitation of water resources by developing water management strategies at the regional, national and local levels, which will secure both equitable access and adequate water supplies.
Capacity-building efforts should be geared towards strengthening the enforcement of existing environmental regulations on water quality and resource protection. This requires also close monitoring of drinking-water quality at the local service level through practical and cost-effective methods.