Perhaps it's somehow easier to talk about infectious disease than toilets. But the unfortunate truth is that more children die every year from illnesses caused by poor water and sanitation than from HIV/AIDS, tuberculosis and malaria combined.

Bindeshwar Pathak has made it his life's mission to do something about it. Over the last four decades, the Indian doctor has replaced open-air defecation and bucket toilets seen—and smelled—throughout his country, reports the AFP. Last week, he was awarded the 2009 Stockholm Water Prize for his life- and water-saving toilet called the Sulabh, which means "easily available" in Hindi.

"Provision of sanitation provides dignity and safety, especially to women, and reduction of child mortality," Pathak said in his acceptance speech. "As a matter of fact, safe water and sanitation go hand in hand for improvement of community health."

Each Sulabh uses about a tenth the water of a common toilet—crucial in regions where water is growing scarce—and houses the flushed human waste in two tanks until the contents can be recycled as a fertilizer. Disease and diarrhea remain confined.

The toilets are sold on a sliding scale—as cheap as $15 for the poorest families and as much as $1,000 for the richest, according to the AFP. And just $1 a month buys a subscription to use any of the 7,500 public toilets. The Sulabh Sanitation Movement, which started in India, has now exported the lavatories to Afghanistan and Bhutan, with plans to furnish the flushables in another 15 countries.

The touchy topic of toilets is gaining widespread attention—from an annual World Toilet Summit to books devoted to what to do with waste. (Check our recent interview with Rose George, the author of The Unmentionable World of Human Waste and Why It Matters.) Some 40 percent of the world (2.6 billion people) still lack access to proper sanitation and toilets, according to the World Toilet Organization, so proper sanitation may be, the organization says, "the best preventive medicine in the world."

Picture of a Sulabh by Alay Tallam via Flickr