SINCE climbers started to make their way to the highest point in the world, the once untouched mountain has become littered with evidence of human conquest — tons of garbage and some of the bodies of the 172 people who failed to reach the peak.

In the 50 years since Tenzing Norgay and Sir Edmund Hillary first scaled Mt Everest in May 1953, so much refuse has piled up on the world’s highest mountain that some took to calling it the world’s highest garbage dump. By the early 1990s, an estimated 50 tons of metal, glass and plastic, including many hundreds of abandoned oxygen canisters, had been left behind by climbers struggling to reach the summit.

The Nepalese government in 1993 began imposing fines on any climbers failing to bring back with them oxygen bottles and gas cartridges.

The kingdom also set up a major park in the valley leading to Everest and forbade the cutting down of trees — a practice once common by climbers seeking to warm themselves.

The government and the private sector have also financed a number of clean-up expeditions, often funded by the royalties paid by the climbers. The last such mission collected 2.4 tons of garbage and practically clearing the mountain of oxygen bottles, as well as burying four bodies.

Now amid increasing awareness of the pollution and a series of clean-up efforts, the 8,848-meter (29,028-foot) mountain is finally being restored to its former state.

The main source of pollution now is human excrement left behind by climbers, particularly at high levels where it is impractical to send down waste in buckets, said Ken Noguchi of Japan, who has led four cleanup missions on the mountain since 2000.

Even as climbers become more conscientious about treading lightly, the high-altitude landscape continues to be threatened by an ever-growing number of expeditions that try to make it to the top each year.

Bed Upreti, a pilot of tourist flights around Everest and author of the book Everest from the Air, said the world’s highest mountain has become much more tidy. But, he added, there was still a lot of work to be done.

This year, during the Everest golden jubilee, there were some two dozen expeditions, and for climbers sometimes fighting for their very lives, the future preservation of Everest can be a secondary concern. — Samina Iqbal