*FREE* Four billion people in low- and middle-income countries lack safe drinking water

More than 4.4 billion people in low- and middle-income countries lack access to safely managed drinking water, with fecal contamination affecting almost half the population of these regions, according to a new geospatial analysis. The findings reveal that previous global estimates of safe drinking water availability are greatly underestimated – particularly for some of the most vulnerable populations – and highlight an urgent need for targeted investments to improve water quality monitoring and infrastructure in these regions. Access to safe drinking water is a human right and is central to the United Nations (UN) 2030 Agenda for Sustainable Development. However, data on safely managed drinking water services (SMDWS) are lacking for much of the global population, especially at the subnational scale in low- and middle-income countries (LMICs). What’s more, the primary limiting factors affecting access to safe drinking water are largely unknown.

By combining household survey data with global Earth observation data and geospatial modeling techniques, Esther Greenwood and colleagues created detailed maps of SMDWS use across 135 LMICs. Greenwood et al. found that only one in three people in these countries had access to safely managed drinking water in 2020. This leaves an estimated 4.4 billion people in LMICs lacking SMDWS – roughly twice the estimate of 2 billion people in 2020 given by the World Health Organization and United Nations Children’s Fund Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP), the official UN program tasked with monitoring progress towards the Sustainable Development Goal on clean water access. The findings also show that SWDWS use in LMICs is primarily limited by fecal contamination, indicated by E. coli contamination in the primary drinking water source, and affects almost half of the population of these regions. Detection of fecal contamination in drinking water is concerning as ingestion of fecal pathogens is a major public health risk and driver of young child mortality globally. In a Perspective, Rob Hope discusses the study and its findings in greater detail.