Hygiene, Sanitation and Water Access: Public Health Impact, Evidence and Proposed Research Projects

Hygiene, sanitation and access to safe water (WASH) remain central determinants of public health globally, with an estimated one-third of the world's population lacking basic sanitation and roughly 2.5 billion people living without adequate sanitation facilities. This paper reviews the public health significance of hygiene and sanitation, including their links to child mortality, diarrhoeal disease, under-nutrition and the Sustainable Development Goals, and examines Oral Rehydration Therapy (ORT) as a low-cost, effective intervention for diarrhoeal dehydration. Building on this review, five research project proposals are outlined, covering greywater reuse and reed-bed filtration, aquatic biota as an indicator of water quality, personal hygiene among students, assessment and treatment of drinking water in schools and communities, and the cognitive and behavioural impact of extended electronic media exposure on children. The paper further considers evidence on the relative impact of water quality versus sanitation interventions, and presents two illustrative cases: the design of a low-cost monitoring solution for elderly people living alone, and a study of sustainable hygiene behaviour change in Kerala, India. The paper concludes that hygiene, sanitation and water access must be treated as a shared public health priority, requiring coordinated action across the health, education, water and policy sectors. Keywords: Hygiene; Sanitation; WASH (Water, Sanitation and Hygiene); Oral Rehydration Therapy; Public health; Sustainable Development Goals; Water quality; Hand washing