By Sanjay Kumar

NEW DELHI, India (Reuters Health) - More than 1 billion people around the world consume unsafe drinking water and every year 3.4 million people--mostly children--die due to water-related illnesses, according to a report from the World Health Organization (WHO) released on Wednesday to coincide with World Water Day on March 22.

"Much of the suffering is needless," says Dr. Gro Harlem Brundtland, director-general of the WHO, in the preface to a new report. "Most of these illnesses and deaths can be prevented through simple, inexpensive measures," she adds.

People in the developing world are particularly at risk for water-borne diseases. About 2.2 million people die of diarrhea caused by drinking contaminated water and 90% of those deaths are among children.

"Diarrhea can be reduced by 26% when basic water, hygiene and sanitation are supplied," the report states. "Yet...40% of world's 6 billion people have no acceptable means of sanitation, and more than 1 billion people draw their water from unsafe sources," according to the WHO.

Improving drinking water supplies requires a huge investment globally, but the funds have not kept pace with the need, according to Terrance Thompson, regional advisor for water, sanitation and health at the WHO in New Delhi.

"According to estimates globally, (a) $23 billion investment is needed annually to meet the international targets of water and sanitation services by 2015, but our studies show that in the last decade, the actual investment has been only $16 billion per year," Thompson told Reuters Health. "In contrast, it has been calculated that in Europe alone expenditure on ice cream is $11 billion per year, and Europe and US combined spend some $17 billion annually on pet food," Thompson told Reuters Health. "The bill for purchase of alcoholic drinks in Europe is estimated to reach $105 billion per year," Thompson added.

"Waiting for new projects to come is no longer an acceptable option because the health impact of inadequate water and sanitation services, together with poor water-resource management, has already reached unacceptable proportions," Poonam Khetrapal Singh, deputy regional advisor of WHO in the South East Asia Region, told Reuters Health.

"Without new approaches, the situation will worsen," Singh cautioned.

WHO is now advocating low-cost technological solutions, such as chlorination of water, solar water disinfection, and changing behavior to reduce the risk.

Solar water disinfection, promoted by Swiss Institute for Environmental Science and Technology (SIEST), involves keeping transparent water-filled bottles horizontally on a flat surface, preferably black, for about 5 hours in sunlight so that ultraviolet rays kill the harmful microorganisms.

"Solar water disinfection is a nearly cost-free system because sunlight costs nothing, and the only other elements are throw away plastic bottles and a black surface," explained SIEST researcher Martin Wegelin.

Behavior change can be very effective in reducing the incidence of water-related diseases, the WHO points out. Studies by the London School of Hygiene and Tropical Medicine show that the simple act of washing one's hands with soap and water can reduce the incidence of diarrhea by 35%.