Lack of clean drinking water and sanitation negatively impacts access to proper nutrition and food security. Open defecation, improper sanitation facilities, and waste disposal often contaminate food production in the developing world. Unsafe drinking water and poor hygiene often lead to increases in diarrheal diseases rendering nutritional supplements and other nutrition efforts ineffective. Achieving sustainable increases in food production to alleviate poverty and eradicate hunger requires sound land and water management of critical inputs. Recognizing linkages between agriculture, food security, water management, and safe drinking water programs is essential.
Diarrhea, often caused by poor sanitation, hygiene, or dirty drinking water, is the second leading cause of child death in the world today, and the top cause of child mortality in sub-Saharan Africa. Even when food consumption is sufficient, diarrheal disease inhibits nutrient absorption, which can lead to undernutrition as well as underweight and stunted children. Undernutrition and diarrheal disease are closely linked. As diarrhea causes undernutrition, it creates a vicious circle by also reducing a child’s resistance to subsequent infections.1 When it doesn’t kill, repeated bouts of early childhood diarrhea can negatively impact physical and cognitive development.2
Awareness of the health benefits of handwashing to prevent disease transmission such as diarrhea is still low in many poor communities. Reductions in diarrheal disease, which could be achieved by providing improved sanitation and water supply, can prevent long term morbidity and at least 860,000 WASH-related child deaths a year caused by undernutrition.3 Simple handwashing, an element of hygiene programming, can reduce the incidence of childhood diseases, such as diarrheal disease by 42 to 47 percent.4
The World Health Organization (WHO)5 states that one of the three pillars of food security is the “appropriate use [of food] based on knowledge of basic nutrition and care, as well as adequate water and sanitation.” All three pillars, including food availability, access and use, depend on access to sufficient quantities of clean water, sanitation, and hygiene to allow crop growth, nutrient absorption, and health.
 Dewey, K & Brown, H.. Update on technical issues concerning complementary feeding of young children in developing countries and implications for intervention programs. Food Nutrition Bulletin. 2003; 24(1):5-28. http://www.ncbi.nlm.nih.gov/pubmed/12664525.↩
 Guerrant, RL., et al. Early childhood diarrhea predicts impaired school performance. The Pediatric Infectious Disease Journal. 2006; 25(6): 513-20. http://www.ncbi.nlm.nih.gov/pubmed/16732149.↩
 Prüss-Üstün, A., et al., 2008. Safer Water, Better Health: Costs, Benefits and Sustainability to Interventions to Protect and Promote Health. http://apps.who.int/iris/bitstream/10665/43840/1/9789241596435_eng.pdf.↩
 Curtis, V. and Cairncross, S. Effect of washing hands with soap on diarrhoea risk in the community: a systematic review. The Lancet Infectious Diseases 2003; 3(5):275-281. http://www.ncbi.nlm.nih.gov/pubmed/12726975↩
 WHO, 2012. Trade, foreign policy, diplomacy and health: food security. http://www.who.int/trade/glossary/story028/en/.↩