World's Most Useful Tree Purifies Water, Too

(March 20) -- A widely cultivated and useful tropical tree may provide a solution to the diminishing supply of safe drinking water in many parts of the world, a researcher says.

The seeds of the Moringa oleifera tree, which grows in tropical regions, could be used to provide a 90 percent or more reduction in bacterial contamination without any extra equipment, Michael Lea, a researcher at Clearinghouse, wrote in a recent study. Clearinghouse is a Canadian organization that studies low-cost water purification.

The World Health Organization estimated in 2004 that diarrheal disease due to unsafe water resulted in 1.58 million deaths a year, mostly of children in developing countries. Many people in those areas don't have enough fuel to regularly boil their water.

The process of using the Moringa seeds, first discovered by women in water-starved Sudan, is technically complicated but practically simple. A compound in the seeds acts as a chemical coagulant that draws impurities out of the water. Effectively the process is as simple as crushing the seeds and mixing them into the water.

The idea works similarly to the process of sedimentation: letting turbid water sit to allow a large percentage of solids and bacteria to sift to the bottom. But using the Moringa seeds cuts the time required from a day to an hour.

"From a cost-on-the-ground standpoint, this is the cheapest method of household water treatment; this is not a moot point for the poorest of the poor," Lea wrote.

The protocol is not technology so much as process, and Lea believes that the main method for spreading knowledge will be word of mouth. He hopes that local radio broadcasters will follow a script for the dissemination of the technique available on Farm Radio International.

Water purification isn't the only use of what some have dubbed "The World's Most Useful Tree." Other uses include oil for lighting, fertilizer, rope, paper and leather tanning. "Trees for Life," a nonprofit based in Kansas, has been working for 15 years advocating the leaves as a micronutrient-rich diet supplement that can be dried and added to food year-round.

They began by planting trees in India, then realized the real struggle would be educational rather than physical. "Physically, you can only plant so many trees," Executive Director David Kimble said. "We realized that people would only change their dietary habits if they became aware of the benefits themselves, in their local communities."

Kimble added that the biggest challenge was removing the social stigma surrounding eating leaves.

Lea hopes that the new method for water purification will increase the spread of the tree, but he cautions that change in these parts of the world is slow. "To be honest, from field experience, positive change is measured in decades," he said.