The Connections Between Climate Change, Water, and Nutrition

This blog originally appeared on Climatelinks.  

Climate change is affecting water supplies around the world. Whether too little water in the form of prolonged and severe droughts, or too much all at once through flooding from heavy storms, extreme weather events are reducing the availability of surface water either through drying up or contamination. Given the essential role that clean, safe water plays in all our lives, not having access to it has dramatic knock-on effects on sanitation and hygiene, and therefore on nutrition and health in general.

A USAID technical brief explores the links between water, sanitation, and hygiene (WASH) and nutrition. The brief is one of nine documents in a technical series describing connections with various aspects of WASH programming, including rural and urban contexts, governance, gender equality, and financing. Each contains recommendations for USAID programming.

Undernutrition is an underlying cause of 45 percent of child deaths globally, and 22 percent of children under 2 years old are stunted. While causes of undernutrition are many and complex, poor WASH practices such as open defecation and inadequate handwashing are often contributing factors. According to the technical brief, these practices may affect child undernutrition through four pathways: 1) repeated episodes of diarrhea; 2) frequent and intense digestive infections that reduce absorption of nutrients; 3) poor gut health; and 4) effects from significant time spent accessing water and sanitation.

It is notable that there is no evidence that delivering household level WASH interventions jointly with nutrition interventions yields better results on nutrition outcomes. Nonetheless, given the current evidence, USAID recommends four intervention strategies to maximize improvements to health and nutrition. 

First, community-wide sanitation is more effective at reducing diarrhea than interventions that target individual households alone, a hypothesis called herd protection. Only targeting households with pregnant mothers and children under 2 years, for example, is not recommended. It is also important that approaches to improving area-wide sanitation are well-grounded in the local context, incorporating information about the local sanitation market, social norms, demand, and availability of sanitation products and services. 

Second, in most contexts, effective water quality management over the long term is most successful when managed by professional service providers as opposed to relying on user-intensive household water treatment. Programs should make incremental progress toward piped water services by professionalizing the delivery of water services, strengthening policies and government capacity, and supporting the creation of small piped networks in relatively denser areas to bring water closer to households. 

Third, most past programs encouraging behavior change around sanitation and hygiene have not adequately addressed the structural barriers to actually changing those behaviors. Future programs could use one or more of these three promising approaches: 1) ensure provision of convenient and consistent access to sufficient water supplies—when household water is scarce, hygiene is the first activity to be neglected; 2) promote the use of WASH products that are aspirational, practical, and durable; and 3) understand the social norms, emotional drivers, and economic motivators associated with household adoption of WASH products and services. For example, a study in Benin found that privacy, safety, and prestige were top drivers for latrine adoption, while a study in Ghana found that convenience and cleanliness were top motivators. 

Finally, the household environment remains highly contaminated from multiple sources, including animal feces, in many contexts, and implementing basic household sanitation may not do enough to reduce this contamination. Even so, there is limited evidence on household fecal-oral contamination interventions that successfully affect child health and nutrition outcomes. Therefore, the technical brief does not recommend full-scale interventions related to these fecal-oral pathways. Instead, it encourages USAID implementing partners with research capacity to establish which transmission pathways are most important in any given context and test potentially promising interventions.

The brief points out that USAID recognizes that WASH interventions alone are not sufficient to achieve global nutrition targets. Interventions must address the multiple complex and context-specific determinants of malnutrition including climate change. Investment in all these sectors together is critical to achieving health, economic productivity, and poverty reduction.