A deadly peril lurks on Mount Everest, the highest summit in the world.

It is far more dangerous than the freezing cold, gale winds and recently posted security forces who are empowered to shoot at the sight of political activities.

The new hazard comes from hundreds of tonnes of human waste scattered along the mountain slopes.

"Toilet paper and human excreta litter the Everest base camp (at an altitude of 6,400 metres), the slopes, and even the summit (8,848 metres) itself," says Ang Tshering Sherpa, chief of the Nepal Mountaineering Association, which is entrusted with promoting mountaineering in Nepal.

"In summer, when the snow melts, the frozen human waste comes into sight and starts raising a stink. The grave health and environmental hazard the untreated excreta pose is a matter of great concern."

While conscientious mountaineers have been trying to clear the garbage left on the mountains, nothing has been done to treat the human waste. In the past, expeditions have collected and brought down used oxygen cans, tents, food tins and other litter.

"As it remains frozen during the expeditions, it is very difficult to remove it," Sherpa said.

In a bid to prevent the world’s tallest mountain from turning into the highest cesspool, an expedition is introducing, for the first time in the history of the Everest, bio-degradable toilets.

Sherpa’s son Dawa Steven Sherpa is leading the 24-member Eco Everest 2008 expedition to the summit in memory of the peak’s greatest benefactor, Sir Edmund Hillary, to try and clean the garbage.

The team is taking three Clean Mountain Cans, a portable toilet manufactured by a North American company. The bins are lined with bio-degradable bags that decompose the human waste deposited in them. The expedition has 200 bags.