A human right that may not be enjoyed by half of the world's population is clean water access.

More than 4.4 billion of the approximately 8 billion people on Earth do not have access to safely regulated drinking water, according to a study published in Science on August 15. The estimate is more than twice as high as the amount determined by the World Health Organization and is based on computer simulations using data from low- and middle-income countries.

According to environmental microbiologist Esther Greenwood of Eawag, a marine research institute in Dübendorf, Switzerland, it is possible that a large portion of the population is not receiving the essential human right to clean drinking water.

This is partially due to the fact that gathering information about the number of people utilizing appropriately managed water supplies can be challenging, particularly in areas with low access to technology. International efforts to increase access to clean water are hampered by the incomplete information. According to Greenwood, the new work attempts to close this disparity.

Greenwood and colleagues created maps for 135 nations that depict regions that most likely had safely managed drinking water services in 2020 using a computer simulation that combines environmental data with survey data from almost 65,000 people worldwide. The number of individuals without access to clean drinking water was calculated by the researchers by comparing those maps with UNICEF population data.

The team discovered that sub-Saharan Africa, South Asia, and East Asia have the lowest rates of clean water use. The most frequent barriers to accessing safe drinking water are inadequate infrastructure, chemical and microbiological pollution, and contamination. For example, the researchers discovered that almost 650 million individuals in sub-Saharan Africa lack access to clean drinking water at or close to their homes. 

Although high-income nations were left out of the analysis, the team admits that some of these nations' people may not have had enough access to clean drinking water.