Avalanches, blizzards, altitude sickness -- working on Qomolangma is perhaps one of the most dangerous jobs on earth.
The mountain environment squad is made up of 30 members, mostly guides or liaison officers from the climbers' association. Dondrup is one of only three locals on the team.
The three of them pick up garbage from between 5,200 meters at base camp and 6,500 meters. In the off-season, Dondrup is a doctor in Tosanglin village at the foot of the mountain, but has been working as a trash collector during the climbing season for three years.
"We do a lot of walking. One worker collects only 10 kilograms of garbage each day," the 30-year-old said. Dondrup is paid 4,500 yuan (about 714 U.S. dollars) every month, not much compared to villagers working in other sectors.
"I don't do it for money. My family have lived here for generations. It is my job to protect the mountain," he said. "A lot of tourists and climbers come and leave a lot behind. We must work hard to keep up."
From 6,500 meters, only professional mountaineers like Cering can do the job. At above 7,000 meters -- the death zone -- even professional climbers face physical limits. Any unnecessary movement is risky and can cause the loss of life.
Reaching 8,000 meters, and even the guides suggest climbers abandon their equipment, such as oxygen tanks which weighing about 2 kg each.
Penma Trinley, deputy director of the Tibetan Mountaineering Association, said the garbage dumped on the mountain one year is usually taken down the mountain the next so that safety is maintained as the key priority.
PROTECTING THE HOLY MOUNTAIN
Since last year, Qomolangma cleaning work has been better organized.
Domestic garbage is classified as recyclable and non-recyclable, and handed over to Qomolangma nature reserve administration.
Abandoned equipment is carried back to Lhasa, where it is auctioned or turned into art.
Tibet regional sports bureau gives two garbage sacks to each climbing team. Everyone descending the mountain needs to carry at least eight kilograms of garbage. If their garbage weighs less than that amount, they are fined.
Volunteers and amateur climbers, though often suffering altitude sickness, have also done their part, picking up bottles and plastic bags whenever possible.
Protecting the holy mountain goes far beyond just picking up trash. New legislation has been enacted at the Mount Qomolangma reserve to conserve the environment surrounding the mountain.
New discipline has been set for mountain-climbing, tourism, scientific exploration and engineering projects.
The legislation prohibits tree-felling, herding, hunting, as well as collecting and sabotaging turfs in the reserve. Those that disobey the rules are subject to criminal punishment.
Cleanup teams are also to be set up on Mount Qowowuyag and Mount Shishabangma, which are both over 8,000 meters high.
"In Tibet, we have the bluest skies and highest mountains," Cering said. "If I could choose again, I would still become a guardian of the holy mountain."