Drinking water

Key facts

  • Over 2 billion people live in water-stressed countries. The situation is likely to worsen in some regions as result of climate change and population growth.
  • Globally, at least 2 billion people use a drinking water source contaminated with feces. Microbial contamination of drinking-water poses the greatest risk to drinking-water safety.
  • The most important chemical risks in drinking water arise from arsenic, fluoride or nitrate. Emerging contaminants such as pharmaceuticals, pesticides, per- and polyfluoroalkyl substances (PFASs) and microplastics also pose risks.
  • People need safe and sufficient water facilitates to practice sanitary hygiene. Sanitation prevents diarrheal diseases, acute respiratory infections, and many neglected tropical diseases.
  • Microbiologically contaminated drinking water can transmit diseases such as diarrhea, cholera, dysentery, typhoid, and polio. Estimates suggest that contaminated water causes 485 000 diarrheal deaths each year.
  • In 2020, 74% of the global population (5.8 billion people) used a safely managed drinking-water service located on site, available when needed, and free from contamination.


Safe and readily available water is important for public health, including for drinking, domestic use, food production, or recreational purposes. Improved water supply and sanitation, and better management of water resources, can boost countries’ economic growth and contribute to poverty reduction.

Water and health

Contaminated water and poor sanitation are linked to transmission of diseases. Absent, inadequate, or inappropriately managed water and sanitation services expose individuals to preventable health risks.

Inadequate management of urban, industrial, and agricultural wastewater means the drinking-water of hundreds of millions of people is dangerously contaminated or chemically polluted.

Economic and social effects

When water comes from improved and more accessible sources, people spend less time and effort collecting it. Better water access can also result in greater personal safety by reducing the need to make long or risky journeys to collect and carry water. It also means less money spent on health problems.

Children are particularly at risk from water-related diseases. Access to improved sources of water can result in better health and better school attendance.


Climate change, increasing water scarcity, population growth, demographic changes, and urbanization all pose challenges for water supply systems. Over 2 billion people live in water-stressed countries. One important strategy for dealing with this challenge is the re-use of wastewater.

Water sources used for drinking-water and irrigation will continue to evolve. Options include increased use of groundwater and alternative sources, including wastewater. Climate change will lead to greater fluctuations in harvested rainwater. Management of all water resources will need to be improved to ensure supply and quality.

Source: Drinking water
© 2023 WHO

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