KATHMANDU, Nepal — Japanese mountaineer Ken Noguchi and his team have brought 500 kilograms of garbage down from Mount Everest in his latest campaign to clean the world's highest mountain.

It was the fifth trip by Noguchi, who began his campaign to clean up the mountain in 2000.

Noguchi, who was aided by two other Japanese mountaineers and 12 sherpa guides, thinks Everest is much cleaner than before because more people are aware of the impact of leaving garbage on the mountain.

"During this year's cleanup expedition, I found that the amount of waste left on the mountain has been drastically decreased,'' Noguchi told reporters Monday.

Noguchi says he's collected about 9,000 kilograms of garbage over the course of his five trips.

Everest has been nicknamed the world's highest garbage dump. In recent years, the Nepalese government has tightened its laws, and climbers and their guides are now required to carry out all gear and trash or forfeit a US$4,000 deposit.

There have been several expeditions to clean up Everest in the past, but many have been accused of concentrating more on scaling the peak than on bringing down garbage.

The high altitude, deep snow, icy slopes and low level of oxygen make it difficult for climbers to carry much on the mountain.