Unsafe Water Source

Unsafe Water Source is one of the modifiable risk factors tracked by the IHME Global Burden of Disease Study. The attributable deaths shown here represent the estimated number of deaths that could be prevented if exposure to this risk factor were eliminated or reduced to optimal levels. Understanding risk factor contributions helps prioritize public health interventions and policy decisions.

Risk factor attribution uses comparative risk assessment methodology. A single death may be partially attributed to multiple risk factors, so attributable death counts should not be summed across risk factors. Data covers 204 countries from 1990 to the latest available year.

Unsafe drinking water is a major environmental risk factor for mortality, contributing to approximately 1.2 million deaths annually from diarrheal diseases, typhoid, cholera, and other waterborne infections. An estimated 2 billion people worldwide use a drinking water source contaminated with faeces, and an estimated 703 million lack even a basic drinking water service. Sub-Saharan Africa has the lowest access to safely managed drinking water, followed by Central and South Asia. Chemical contamination — including arsenic (affecting 140 million people in Bangladesh and other countries) and fluoride — adds to the health burden. Climate change is exacerbating water insecurity through droughts, floods that contaminate water sources, and saltwater intrusion in coastal aquifers. Children under five in low-income countries bear the highest mortality burden from unsafe water, with repeated waterborne infections contributing to malnutrition and stunting.

Unsafe Water Source contributes to mortality from diarrheal diseases, typhoid, cholera, hepatitis A, and 1 other conditions. The magnitude of impact varies by country depending on exposure levels, population demographics, and the availability of preventive and treatment services.

Investment in water treatment and distribution infrastructure — from community-level systems to piped municipal supply — is the fundamental solution. Household water treatment (chlorination, filtration, solar disinfection) provides interim protection where infrastructure is lacking. Source water protection through watershed management and regulation of industrial and agricultural pollution prevents contamination. Water quality monitoring and surveillance systems enable rapid response to contamination events. SDG 6 targets safely managed drinking water for all by 2030.