The World Health Organization issues latest U.N.-Water Global Annual Assessment of Sanitation and Drinking Water report, which finds a small investment in water and sanitation returns big dividends.
People in developed countries take a glass of safe water from the tap and a flush toilet for granted. But the situation is quite different for many people in developing countries.
The World Health Organization reports 884 million people in poor countries have no access to safe drinking water and 2.6 billion people have no access to basic sanitation.
The World Health Organization says unsafe water and inadequate sanitation kill an estimated 2.2 million children under the age of five every year, and 1.5 million of these deaths are due to diarrhea.
WHO Director of Public Health and Environment Maria Neira says it would take very little to prevent these unnecessary deaths.
"Unfortunately, and in spite of the fact that we know very well that for every single dollar that you invest on water and sanitation, you will have a return, which will be between .. four and $34," she said. "In spite of that, we know and we have all the evidence, it still is not the case."
One of the Millennium Development Goals is to cut deaths from water and sanitation in half by 2015. The WHO report says there is compelling evidence that achieving this target would lower health-care costs, increase school attendance and boost productivity.
Despite the clear benefits of investing in this sector, the report says donors provide far less money for water and sanitation than they do for other social areas such as education and health.
Coordinator Robert Bos, of the WHO Water, Sanitation, Hygiene and Health Unit, says when donors contribute to water and sanitation projects, they get their priorities wrong.
"In the context of water and sanitation, more money seems to be going to large-scale sophisticated piped water projects than into the community-based small-scale-bringing the essential safe water to these people who are in greatest needs," he said. "In other words, those that already have some level of access, just jump higher on the ladder. But, the ones that are at the bottom, stay where they are - at the bottom."
The report says conditions are worst in Africa. But it says some countries in Asia are making improvements in accessing safe drinking water and sanitation.
The findings of this report will be presented at a U.N.-sponsored meeting of finance ministers from 20 developing countries and 12 major donors Friday in Washington.
The organizers say their aim is to inform the participants of the links between water, sanitation and economic growth.