Together they were a lethal combination. But that was only the start of the story. What now seemed to be happening was that a new range of viral infections and diseases was taking over from the age-old diseases such as polio, smallpox, malaria, typhoid, and yellow fever, which medical science had conquered. Medical theory said that environmental changes over the past quarter century had triggered off a new and mysterious strain of illnesses. There was Reye syndrome, which attacked children between the ages of five and eleven, and killed nearly a third of all those who contracted the disease. Cause unknown. There was Lyme disease, in which patients suffered skin lesions and painfully swollen joints caused by bites from the tiny parasite
Somehow, in a way not yet properly understood, chemical changes in the environment had created the conditions that were ripe and ready for new plagues to replace the old.
Ruth's experience with the Diagnostic Research Unit in Denver had hardly been adequate to cope with this. And so far she'd received scant support in setting up a clinical investigative facility here in New "lork.
Although quite a lot was known about emphysema--the fusing together of the air sacs in the lungs, which reduces the total area of efficient oxygen-carbon dioxide interchange--anoxia had never until now been thought of as a chronic condition. The only people known to suffer from it in the past were airmen, mountaineers and deep-sea divers. Ruth had read up on the subject, combed through textbooks and medical journals, and talked with air force doctors and physiologists in an effort to understand the nature of the condition.
The simplest definition of anoxia was "an insufficient supply of oxygen to the tissues." In tests on pilots the air force had found that if the oxygen supply was cut off and then turned back on, pilots would black out within seconds and just as quickly regain consciousness without being aware of what had happened. They would have absolutely no knowledge of the incident, not even a blank space in their memories.
More crucial, however, as Ruth realized, was at what point did anoxia begin to have a permanent debilitating effect on the brain and the body?
The average adult takes ten to fourteen breaths a minute, each breath lasting four to six seconds. In one minute this is an intake of about ten pints of air, which can increase to as much as twenty gallons of air a minute with sustained strenuous exercise. In a normal day an adult will breathe in roughly 3,300 gallons of air, or 530 cubic feet, and in a lifetime approximately 13 million cubic feet. This is equivalent to two and a half times the capacity of the airship R.101.
For this vast interchange of gases an efficient machine is required, and the lungs, developed from the buoyancy air bladder of man's fishy ancestors, serve that purpose admirably.
Each pair of lungs weighs about two and one-half pounds and covers an area of roughly one thousand square feet, largely made up of the honeycombed globule clusters of alveoli, which consist of 300 million tiny chambers where the transfer of oxygen to blood in exchange for carbon dioxide takes place.
The red blood cells pass through tiny capillaries one at a time, pick up their oxygen atoms in three quarters of a second, and are pushed on into the arterial system. When the heart is pumping vigorously, during exercise or states of emotion, the blood cells can pick up their load in one third of a second through the wall of each alveolus, which is twenty-five thousandths of an inch thick.
This is how a healthy system works when breathing in unpolluted air with an oxygen content of 20.94 percent. Emphysema, the fusing of the millions of air sacs to form larger, less efficient clusters, inhibits the exchange of oxygen between the air and the bloodstream. It is a gradual process and the sufferer hardly notices as his lungs become less and less able to meet his body's oxygen demand until it's too late. Death follows by slow suffocation.
From her study Ruth had learned that 15,000 feet, or nearly three miles up, was the maximum altitude at which human beings could survive for long periods of time. At that height the pressure was 40 percent lower than at sea level. Mountain climbers had scaled higher peaks without oxygen, but by God-like coincidence it seemed that Everest, at 29,141 feet, was the highest man could reach unaided, even had there been a higher peak to climb.
