Four billion people in the world without access to drinking water

In Poland, more than 99 percent. households can drink water straight from the tap, and this seems normal and obvious. However, this is not the case everywhere. According to a recent study by Swiss scientists, more than half of the global population does not have access to drinking water, which is a clear violation of basic human rights. Through an in-depth analysis, we are able to see where the situation is worst and what causes it.

New approach to measuring water supply

Access to drinking water for all is one of the Sustainable Development Goals (SDG 6.1). Unfortunately, so far its implementation on a global scale is far from successful. To find out how far, researchers from the Swiss Federal Institute of Technology and Water Sciences Eawag, led by PhD student Esther Greenwood and in cooperation with the Federal Institute of Technology (ETH) in Zurich, decided to find out. Their efforts were supported by, among others. World Health Organization (WHO) and UNICEF.

Published on August 15 of this year. in the journal Science, the results of the study are based on an innovative approach that combines information gleaned from national household censuses with geo-spatial data obtained as a result of Earth observation. As a result, the Greenwood team succeeded in creating models that cover previous information gaps with the help of calculations, and additionally allow important conclusions to be drawn about the interdependence of factors limiting access to drinking water.

The study used data from 27 countries around the world from 2016-2020. Based on these, it was possible to use machine learning technology to create predictive maps depicting communities’ access to a safe drinking water supply in regions where data is incomplete.

GDP level vs. access to drinking water – the cruel truth

The Eawag Institute’s analysis focused on 135 low- and middle-income countries. After applying the models developed, it found that in 2020. only 33 percent. of the citizens living there had access to drinking water that met safety requirements. Of these, 61 percent. lived in Asia, 25 percent. in Africa, 11 percent. in the Americas and 3 percent. in Europe. At the same time, the Greenwood team suggested that as many as 4.4 billion people in these zones are not adequately supplied with drinking water. That’s as much as twice as much as previous estimates by the WHO-UNICEF Joint Monitoring Program indicated.

In this way, the researchers were able to fill in the gaps in missing data from countries in sub-Saharan Africa,, Latin America and the Caribbean, and to a lesser extent Asia, Europe and Oceania. The lowest rates of access to drinking water were found in 12 countries in sub-Saharan Africa, where less than 10 percent. of the population was adequately supplied with water fit for consumption.

A very high percentage of the population without access to potable water (above 75 percent) is also predicted for Micronesia, Melanesia and Polynesia, while the largest absolute number of citizens without water supply lives in South Asia (about 1.2 billion).

What is the problem?

For the analysis, Swiss researchers adopted four criteria to qualify access to potable water in a region as safe:

• water source protection defined as the natural or structural potential to provide safe water;

• household availability;

• Availability at the time of need;

• No fecal contamination defined as no E. coli in 100 ml of water .

They found that up to 88 percent of of people living in low- and middle-income countries have access to a secured water source, such as piped flowing water. Unfortunately, this is not a sufficient factor, as this level of security does not fully protect against fecal contamination, which appears in almost half of water sources (48 percent).

As much as 36 percent. of the population from poor countries also cannot count on access to potable water where they live – as many as 650 million people in sub-Saharan Africa. The study’s authors emphasize how crucial it is to invest heavily in infrastructure to reduce the gender inequality associated with women’s obligation to carry water long distances.

What factors limit access to drinking water?

Through a comprehensive approach, Eawag researchers have also been able to identify factors that are clearly associated with water supply shortages. Most of these are directly related to human activity and include low levels of urban development and low population density in an area. Access to potable water is clearly lower in rural areas.

Another important factor is, of course, annual precipitation. When it’s too low, underdeveloped regions are at risk of drought; when it’s elevated, the risk of water poisoning from E. coli bacteria increases, further encouraged by high temperatures . Researchers point out that in tropical climate countries, the results of household drinking water access surveys depend largely on whether they are conducted during the dry or rainy seasons.

Biogeographic factors, such as vegetation index and tree density, were found to be the most important for predicting water availability at the time of need. The last key group of factors are hydrogeological factors, of which the depth at which the bedrock is located was considered the most important.

What does the analysis show?

The study in question is groundbreaking in two respects. First, it shows the interrelationship between different groups of factors and access to drinking water, making it easier to forecast the situation in areas lacking reliable data. Second, the innovative approach of the Swiss researchers suggests that we are much further away from achieving Sustainable Development Goal 6.1 than previously thought.

The analysis shows that of the 4.4 billion people who lack access to safe drinking water, a sizable proportion suffer from fecal contamination of the resource. Unfortunately, constant monitoring of E. coli levels in drinking water requires considerable expense, and as a result, in poor countries up to half of the population is not subject to regular microbiological cleanliness testing. Consumption of fecal bacteria-contaminated water causes diarrhea, which in turn is one of the most common causes of death in children under the age of 5.

The mere presence or absence of E. coli in water sources is not a sufficient measure of public health safety, according to the study’s authors. It is necessary to develop faster, more sensitive and specific tests to control contamination by bacteria, parasites and viruses. Another problem, not included in this analysis but requiring monitoring, is the content of arsenic and fluoride in drinking water. Values above 10 μg/lfor arsenic and above 1.5 mg/lfor fluorine are considered to make water unsafe for consumption. Both elements are associated with an increased risk of cancer and other health problems.

The maps, prepared by Swiss scientists, are intended to help mobilize and efficiently allocate funds and human resources to combat impediments to access to drinking water around the world.

Photo. main: Achor Uteno/pixabay