Water and health: how access to water reduces childhood diseases

It is one of the most direct links in all of global public health: the water a child drinks largely determines their chances of survival. Not in an abstract way, but through precise, well-documented biological mechanisms. Understanding how water kills makes it possible to understand why a well saves.

Which diseases does unsafe water transmit?

Contaminated water is not simply “dirty”: it is a transmission vector for a whole family of diseases. According to the WHO, microbiological contamination of drinking water can transmit diarrhoea, cholera, dysentery, typhoid fever and polio.

The mechanism is almost always the same, and it is important to understand it: faecal matter, human or animal, contaminates the water source. The pathogens it contains are ingested when people drink or cook. They then attack the digestive system.

That is why surface water, in a pond or an open river, is so dangerous: nothing protects it from run-off, livestock or open defecation. A drilled well, by contrast, reaches an underground water table that is naturally protected.

Why are children the first victims?

Around 1,000 children under five die every day worldwide from causes linked to unsafe water, lack of sanitation and insufficient hygiene. This figure, put forward by the WHO and UNICEF, deserves a closer look at its causes.

Three factors explain why young children are so over-exposed.

1. An immature immune system. An adult can absorb a bacterial load that will floor a two-year-old. Their defences are not yet built.

2. Rapid dehydration. This is the decisive point. It is not diarrhoea itself that kills, but the loss of water it causes. A small body becomes dehydrated within hours, whereas an adult will hold out for several days.

3. Maximum exposure. Children play on the ground, put their hands in their mouths, and drink whatever water is available without a second thought.

The result: according to the World Bank, around 446,000 children under five die of diarrhoea every year, which represents 9% of all child deaths worldwide.

The vicious circle between water, diarrhoea and malnutrition

Here is the mechanism least known to the general public, and yet one of the most destructive. People believe diarrhoea is a passing episode. In reality, in a young child, each episode leaves a lasting mark.

According to the WHO, in low-income countries children under three experience an average of three diarrhoeal episodes per year. And each of these episodes deprives them of the nutrients they need to grow.

The circle then sets in: contaminated water causes diarrhoea, diarrhoea prevents the absorption of nutrients, undernutrition weakens immune defences, and the weakened child falls ill more easily at the next contact with contaminated water. Each turn of the wheel makes them more vulnerable.

This explains a phenomenon that often puzzles people: in some regions, food can be distributed without malnutrition receding, quite simply because the problem is not only food intake, but the body’s inability to absorb it. Without clean water, nutrition does not follow.

The 3 levers that push back childhood diseases

The good news is that these diseases are preventable. According to UNICEF and the WHO, 88% of diarrhoea deaths worldwide are attributable to unsafe water, inadequate sanitation and poor hygiene. In other words, by acting on these three levers, the vast majority of the problem is eliminated.

1. Water protected at the source. This is the role of the drilled well: reaching an underground water table sheltered from surface contamination, rather than drawing from a pond exposed to run-off and livestock.

2. Suitable sanitation. Without latrines, faecal matter goes back to contaminating water sources and the cycle starts again. That is why water and sanitation are inseparable. Our article Sanitation and hygiene: the water-health-education trio explores this point further.

3. Hygiene, and above all handwashing. It is the most cost-effective act in all of public health: according to UNICEF and the WHO, handwashing with soap reduces diarrhoeal diseases by more than 40%. But water still has to be available to wash your hands, which brings us back to point 1.

These three levers only work together. Clean water without latrines, or latrines without water to wash hands, are not enough to break the cycle.

What a well concretely changes in a village

When a village gains access to protected water, the health effects are not long in coming. Diarrhoeal episodes become rarer, children finally absorb their nutrients, medical consultations and costs fall, and the growth of the youngest picks up again.

The effect goes beyond health alone. A child who is no longer permanently ill can go to school. A mother who no longer spends her days caring for the sick or fetching water can work. A village that spends less on healthcare can invest elsewhere.

This is the logic that structures Life ONG’s water programme. A village well, drilled to around 20 metres and fitted with a pump, serves about 500 people, and its specifications include a laboratory analysis of the water’s drinkability before any consumption. Funding amounts to €2,650 in Africa, or around €901 after the 66% tax reduction. To understand the full course of the works, our article Building a well in Africa: steps, costs and real impact details each phase.