Wild Everest: over the top! - climbing Mount Everest Mt. in the Himalayas: includes a timeline of highlights about people from the West climbing the mountain which was named for a colonial British surveyor, George Everest - includes a Q&A on Mt Everest trivia

Science World, Feb 23, 1998 by Marie L. Chang

It's the ultimate natural wonder of the world. The rugged mountain peak of rock and ice is the planet's highest point of ground where earth and sky collide. Winds whip at 161 kilometers (100 miles) per hour; windchills plunge to 96 degrees Celsius (140 [degrees] F) below zero. But for thrill-driven mountain climbers, reaching the summit of wild Mount Everest is adventure's grand prize, the ultimate dream.

Almost six miles high, Mount Everest soars 8,848 meters (29,028 ft) above sea level--the tallest mountain on Earth in the world's highest and wildest mountain range, the Himalayas, which form the border between China and Nepal.

Climbers who dare to take on Everest face a rash of dangers: frostbite from severe cold, sunburn from glaring sun, snowblindness from the sun's blaze reflected off ice. Breathing the frigid air can cause such violent coughing that ribs crack like dry sticks. Add to that Everest's constant peril--shifting ice, deep chasms, brutal storms--and the prize seems hardly worth the murderous risk.

Yet since the first recorded European expedition in the early 1920s, nearly 600 mountaineers have made it to the top. Still, for every 30 people who seek to scale Everest, one dies. About 150 climbers have lost their lives on the mountain.

A CLIMBER'S GOAL

This spring, mountain climber Tom Whittaker hopes to join the rank of victors. If his dream comes true, he'll be the first disabled climber to reach Everest's summit.

After a car accident in 1979, doctors amputated, or cut off, Whittaker's right foot. But that didn't shatter his goal to become a world-class mountain climber. Born in Wales, Whittaker, 48, now trains future professional mountain guides in Prescott, Arizona.

With the help of a prosthesis, an artificial device replacing his missing foot, Whittaker continued scaling mountains after his accident. But what would inspire him to tackle the world's most daring climb? "Why does anyone run a marathon or play football? It's pitting yourself against something that is big--and you don't know if you can do it," Whittaker told SW.

In 1989, Whittaker reached 7,300 m (24,000 ft) high up Everest but was forced back to Base Camp after a violent storm blew in. In 1995, he tried again--this time mounting Everest's North Face up to 8,382 m (27,500 ft). But his body caved to the rigors of climbing at dizzying altitudes, and he became too ill to continue. This will be Whittaker's third attempt to wrestle Everest.

BREATHING LESSONS

How does Everest take its terrible toll on the human body? "Very few people can stay indefinitely at altitudes above 5,500 m (18,000 ft), and thrive," says Robert Schoene, a high-altitude physiologist at the University of Washington. The main obstacle: the amount of oxygen available for breathing. Oxygen is the gas nearly all organisms depend on to survive. Living things use oxygen to metabolize, or burn food for fuel and energy.

Whether at sea level, where most people live, or at Everest's peak, Earth's air contains 21 percent oxygen. But at such lofty altitudes as Everest's, less oxygen enters the lungs with every breath.

The amount of oxygen usable for breathing is determined by atmospheric pressure--pressure caused by air's weight. The greater the atmospheric pressure, the more closely oxygen molecules are jammed together. At sea level, where air weighs down heavily, living things inhale oxygen-rich air. But at higher altitudes, atmospheric pressure decreases, and air molecules are more spread out. Result: There's less available oxygen for a climber to inhale.

As a result, a mountaineer can easily suffer from hypoxia--lack of oxygen. To compensate, the body initiates a series of "struggle responses." First, a climber will begin to breathe harder, or hyperventilate, as lungs try to draw in more oxygen. Hyperventilating makes the heart beat faster and pump more blood per beat. (Blood carries oxygen to different parts of the body.) The bone marrow--the body's blood factory--also produces more new blood cells to circulate oxygen in the body.

All these responses protect the body from hypoxia, but only to a point. Sometimes the bone marrow produces so many blood cells that a person's blood becomes as thick as motor oil, Schoene explains. Then blood can't flow properly or deliver the body's oxygen efficiently.

MOUNTAIN SICKNESS

In about 25 percent of climbers, the oxygen deficit results in acute mountain sickness (AMS). As the body strives to circulate more blood and oxygen to the brain, the extra blood can cause the brain to swell, leading to headaches, nausea, weakness, and shortness of breath. Drinking plenty of water and getting rest can relieve AMS.

But far more serious forms of mountain sickness attack climbers at altitudes above 3,660 m (12,000 ft). High-Altitude Cerebral Edema (HACE) occurs when the brain swells severely. The sufferer has trouble walking or using his hands, and may start to hallucinate. When fluids accumulate in the lungs, High-Altitude Pulmonary Edema (HAPE) can, in effect, drown a person. Both HACE and HAPE may result in death.