Gains in world health brought by improved access to safe drinking water have been undermined by the lack of similar improvements in basic sanitation, the United Nations says.
One in every three people on the planet, some 2.4 billion people, are still without sanitation facilities, including almost a billion who simply have no choice but to defecate in the open, a report released jointly by the World Health Organization and the UN Children's Fund (UNICEF) says.
"Until everyone has access to adequate sanitation facilities, the quality of water supplies will be undermined and too many people will continue to die from waterborne and water-related diseases," says Dr. Maria Neira, director of the WHO Department of Public Health, Environmental and Social Determinants of Health.
While improvements in sanitation have been slow in coming, there has been considerable success in bringing safe drinking water to the peoples of the world, the WHO and UNICEF report says.
Since 1990 an additional 2.6 billion of the world's 7 billion people have gained access to reliable sources of safe water, bringing the percentage of the global population that has such access to 91 percent.
Resultant improvements in child survival have been significant, the report authors say; the 1990 figure of 2,000 children dying each day from diarrhea caused by inadequate or unsafe water has been cut in half.
Still, they say, the lack of improvements in sanitation is an ongoing worry.
They point to inadequate investments in behavior change campaigns and lack of affordable sanitation products for the world's poor, hampered by some social norms that continue to accept or even promote open defecation.
The link between sanitation practices and health proved harder to get across in many global communities than was a similar association between improved health and safe water, says UNICEF's Chief of Water, Sanitation and Hygiene Sanjay Wijesekera.
"It had to overcome the enormous hurdle of very strong cultural norms," he explains, with many people not seeing the need to change sanitation habits in place for generations.
Right now just 68 percent of the world's population uses some form of improved sanitation facility, which is defined as one that can separate human waste from human contact, the report says.
"The global model so far has been that the wealthiest move ahead first, and only when they have access do the poorest start catching up," says Wijesekera. "If we are to reach universal access to sanitation by 2030, we need to ensure the poorest start making progress right away."