Clean Water

Access to clean water is one of our most basic human needs.

But, one in four people in the world do not have access to safe drinking water. This is a major health risk. Unsafe water is responsible for more than a million deaths each year.

In this article, we look at data on access to safe water and its implications for health worldwide.

Unsafe water is a leading risk factor for death

Unsafe water sources are responsible for over one million deaths each year

Unsafe water is one of the world's largest health and environmental problems – particularly for the poorest in the world.

The Global Burden of Disease is a major global study on the causes and risk factors for death and disease published in the medical journal The Lancet. These estimates of the annual number of deaths attributed to a wide range of risk factors are shown here.

Lack of access to safe water sources is a leading risk factor for infectious diseases, including cholera, diarrhea, dysentery, hepatitis A, typhoid, and polio.¹ It also exacerbates malnutrition and, in particular, childhood stunting. In the chart, we see that it ranks as a very important risk factor for death globally.

The global distribution of deaths from unsafe water

In low-income countries, unsafe water sources account for a significant share of deaths

Globally, unsafe water sources account for a few percent of deaths.

In low-income countries, it accounts for around twice as many deaths.

In the map here, we see the share of annual deaths attributed to unsafe water across the world.

When we compare the share of deaths attributed to unsafe water either over time or between countries, we are not only comparing the extent of water access but its severity in the context of other risk factors for death. Clean water's share depends not only on how many die prematurely from it but also on what else people are dying from and how this is changing.

Death rates are much higher in low-income countries

Death rates from unsafe water sources give us an accurate comparison of differences in mortality impacts between countries and over time. In contrast to the share of deaths that we studied before, death rates are not influenced by how other causes or risk factors for death are changing.

In this map, we see death rates from unsafe water sources across the world. Death rates measure the number of deaths per 100,000 people in a given country or region.

What becomes clear is the large differences in death rates between countries: rates are high in lower-income countries, particularly across Sub-Saharan Africa and Asia. Rates here are often greater than 50 deaths per 100,000 people.

Compare this with death rates across high-income countries: across Europe, rates are below 0.1 deaths per 100,000. That’s a greater than 1000-fold difference.

The issue of unsafe water sources is, therefore, one that is largely limited to low- and lower-middle-income countries.

We see this relationship clearly when we plot death rates versus income, as shown here. There is a strong negative relationship: death rates decline as countries get richer.

Access to safe drinking water

What share of people have access to safe drinking water?

Sustainable Development Goal (SDG) Target 6.1 is to: “achieve universal and equitable access to safe and affordable drinking water for all” by 2030.

Almost three-quarters of the world's population uses to a safely managed water source. One in four people does not use a safe drinking water source.

In the next chart, we see the breakdown of drinking water use globally and across regions and income groups. We see that in countries with the lowest incomes, less than one-third of the population uses safely managed water. Most live in Sub-Saharan Africa.

The world has made progress in recent years. Unfortunately, this has been very slow. In 2015 (at the start of the SDGs), around 70% of the global population had safe drinking water. This has slowly increased over recent years.

If progress continues at these slow rates, we will not reach the target of universal equitable access to safe and affordable drinking water by 2030.

In the map shown, we see the share of people across the world using safe drinking water facilities.

How many people do not have access to safe drinking water?

In the map shown, we see the number of people across the world who do not use safe drinking water facilities.

Improved water sources

What share of people do not use an improved water source?

The definition of an improved drinking water source is: “...those that have the potential to deliver safe water by nature of their design and construction, and include: piped water, boreholes or tubewells, protected dug wells, protected springs, rainwater, and packaged or delivered water.” Note that usage of drinking water from an improved source does not ensure that the water is safe or adequate, as these characteristics are not tested at the time of the survey. However, improved drinking water technologies are more likely than those characterized as unimproved to provide safe drinking water and to prevent contact with human excreta.

In the map shown, we see the share of people across the world who do not use improved water sources.

In the map shown, we see the number of people across the world who do not use an improved water source.

What determines levels of clean water usage?

Usage of improved water sources increases with income

The visualization shows the relationship between usage of improved water sources versus gross domestic product (GDP) per capita. We see that there is a general link between income and improved water source usage.

Typically, most countries with greater than 90% of households with improved water have an average GDP per capita of more than $10,000 to 15,000. Those at lower incomes tend to have a larger share of the population without access.

Although income is an important determinant, the range of levels of usage that occur across countries of similar prosperity further supports the suggestion that there are other important governance and infrastructural factors that contribute.

Rural households often lag behind in improved water usage

In addition to the large inequalities in improved water usage between countries, there can also be large differences within countries. In the charts, we plotted the share of the urban versus rural population with usage of improved water sources and safely managed drinking water, respectively. Here, we have also shown a line of parity; if a country lies along this line, then access in rural and urban areas is equal.

Since nearly all points lie above this line, with very few exceptions, usage of improved water sources is greater in urban areas relative to rural populations. This may be partly attributed to an income effect; urbanization is a trend strongly related to economic growth.²

The infrastructural challenges of developing municipal water networks in rural areas are also likely to play an important role in lower usage levels relative to urbanized populations.

Definitions

Improved water source: "Improved drinking water sources are those that have the potential to deliver safe water by nature of their design and construction, and include: piped water, boreholes or tubewells, protected dug wells, protected springs, rainwater, and packaged or delivered water"

Usage of drinking water from an improved source does not ensure that the water is safe or adequate, as these characteristics are not tested at the time of the survey. However, improved drinking water technologies are more likely than those characterized as unimproved to provide safe drinking water and prevent contact with human excrement.

Safely managed drinking water: "Safely managed drinking water" is defined as an "Improved source located on premises, available when needed, and free from microbiological and priority chemical contamination."

'Basic' drinking water source: an "Improved source within 30 minutes round trip collection time."

'Limited' drinking water source: "Improved source over 30 minutes round trip collection time."

'Unimproved' drinking water source: "Unimproved source that does not protect against contamination."

'No service': access to surface water only.

Hannah Ritchie, Fiona Spooner and Max Roser (2019) - “Clean Water” Published online at OurWorldInData.org. Retrieved from: 'https://ourworldindata.org/clean-water' [Online Resource]

@article{owid-clean-water,
    author = {Hannah Ritchie and Fiona Spooner and Max Roser},
    title = {Clean Water},
    journal = {Our World in Data},
    year = {2019},
    note = {https://ourworldindata.org/clean-water}
}

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