Very cool

According to this, 'World's Most Useful Tree' Provides Low-Cost Water Purification Method For Developing World, there is a simple help to the problem of dirty surface water right under people's noses in many areas of the world where too many people still die because of lack of clean water:

A low-cost water purification technique published in Current Protocols in Microbiology could help drastically reduce the incidence of waterborne disease in the developing world. The procedure, which uses seeds from the Moringa oleifera tree, can produce a 90.00% to 99.99% bacterial reduction in previously untreated water, and has been made free to download as part of access programs under John Wiley & Sons' Corporate Citizenship Initiative.

"Moringa oleifera is a vegetable tree which is grown in Africa, Central and South America, the Indian subcontinent, and South East Asia. It could be considered to be one of the world's most useful trees," said Lea. "Not only is it drought resistant, it also yields cooking and lighting oil, soil fertilizer, as well as highly nutritious food in the form of its pods, leaves, seeds and flowers. Perhaps most importantly, its seeds can be used to purify drinking water at virtually no cost."

This is yet another reason why we need to be careful to prevent species extinction. Who knows what uses may yet be found for the many, many kinds of plants out there?