Human waste

Mt. Everest, the world's highest mountain, is seen from the viewing point at Lukla in northern Nepal.

Mount Everest has a problem — with poop

Environment

The Nepal Mountaineering Association says human waste is a bigger problem than trash on Mt. Everest. But the climbers aren’t going away, so we asked an Everest expedition leader how he plans to safely heed the call of nature atop the world’s tallest mountain.

As the Ebola epidemic peaks, new challenges are emerging in Liberia

Now that Ebola is subsiding, the question is what to do with contaminated sewage

Health

Turning Waste to Fertilizer — Humanure