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Biosphere Crew to End Stay in a World of Their Own : Science: They have spent two years sealed in a self-sustaining ecosystem, but still face scientific doubts.

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TIMES SCIENCE WRITER

If God had been a Texas billionaire, the Garden of Eden might have looked like Biosphere II--a wilderness under glass with a tiny ocean, where the chosen few can stroll to a desert, a tropical forest or a video conference center without leaving the house. In lieu of original sin, there are tourists.

Nestled among the prickly pear and flowering barrel cactus in the high desert outside Tucson, Biosphere II encompasses 3.15 acres of interconnected geodesic domes, crystalline enclosures, and a towering glass pyramid that, back-lit at sunset, seems pregnant with the shadow of the artificial rain forest it contains.

For two years, eight men and women have been locked inside the glistening $150-million greenhouse on the rim of the Canyon del Oro in the Santa Catalina Mountains, in an unprecedented experiment in human ecology: the development of a completely sealed, self-sustaining test-tube Earth.

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While the biblical Adam and Eve were expelled from their earthly paradise, the “Biospherians,” as the dome’s inhabitants call themselves, will emerge voluntarily Sunday in matching flight suits to the strains of Vivaldi’s “Four Seasons” and a media fanfare. The eight will have set a record for living in a closed system--breaking one set by a team of Russian researchers.

The crew’s two-year stint as fauna in the world’s largest terrarium completes the shakedown cruise of what project officials say is an open-ended ecology experiment that will last a century, to investigate the processes that sustain life on Earth and the pollution that threatens it. Their findings also may aid the design of future space colonies. A new crew plans to be sealed in the Biosphere next year.

Managing about 3,800 species of plants and animals, the crew members came close to their goal of complete self-sufficiency. They raised 88% of their food, recycled all their waste and almost all their air and nurtured a self-sustaining ocean ecosystem, project officials said.

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Funded largely by Houston oil billionaire Edward P. Bass, the controversial project is a jarring mixture of serious science and New Age eco-kitsch.

Peer-reviewed research projects coexist with $13 guided tours of the grounds and souvenir stands hawking $17 Bio-2 T-shirts, $42 Biosphere watches, cans of Rain Forest Crunch, bottled “Bio-water,” and fabric globes called “Hugg-A-Planet” in a theme park that is surpassed only by the Grand Canyon as Arizona’s most popular tourist attraction.

During the months the crew was inside, the project weathered charges that it is a hoax or the product of a religious cult obsessed with Mars, as well as considerable criticism over the absence of verifiable scientific controls.

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In January, six months after formally raising concerns over the project’s scientific credibility and the project leaders’ penchant for secrecy, the Biosphere board of outside science advisers resigned en masse.

Last week, several former board members still would not elaborate on their reasons. A spokesman for former board Chairman Thomas A. Lovejoy, assistant secretary for external affairs of the Smithsonian Institution, said it would not be appropriate.

When the crew emerges Sunday, they will be greeted by a crowd of enthusiasts and a wad of talk show invitations, including requests from “Nightline,” “Good Morning America,” “Donahue,” “Maury Povich” and “The Tonight Show.” Two speakers’ bureaus have been hired and a book is already in galleys.

The four men and four women will step into the limelight thinner, healthier, hungrier, and, after two years in the half-light of their self-contained ecosystem, paler than when they entered on Sept. 26, 1991. While visitors can dine on lobster and leek bisque at the Biosphere Cafe, crew members have been living on a subsistence diet of about 2,200 calories a day.

Abigail Alling, 34, who tends the miniature Biosphere ocean, cheerfully confessed that she has been sustained by fantasies about her first post-Biosphere feast “starting with a chilled glass of white wine, then bread, salad, the main course, cappuccino . . . “

The crew also may be dizzy when they step outside--not from the public attention, but from the richer oxygen content and lower carbon dioxide levels in the air outside the habitat. The concentrations of carbon dioxide inside Biosphere hovered at more than four times that found in Earth’s atmosphere, according to figures published by the American Institute of Biological Sciences.

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Managing the internal atmosphere was perhaps their most complex challenge. It is a testament to the rigors of the experiment that they almost did not survive.

No sooner was the crew sealed inside their new world than the biosphere started evolving an atmosphere that readily supported life--but not human beings, project scientists said.

Oxygen levels slowly dropped to about two-thirds the normal level found in air. Crew members suffered unusual fatigue, migraines, sleeplessness and other symptoms of altitude sickness. By last January, the oxygen level had fallen below 14.5%--about equal to the level found at an altitude of 13,400 feet.

“Plants do very well at lower oxygen levels. We animals don’t do so well,” said Mark Nelson, the 46-year-old co-founder of the venture, who joined the crew at the last minute when one of the original candidates developed a medical problem.

That’s when project officials outside the Biosphere intervened. They pumped in enough new oxygen to raise the level to 19%, still below the normal level of 21.94%, but survivable.

“I didn’t realize what a strain and stress it was until we started restoring the oxygen levels. I turned from 175 years old back to my own age in a phenomenal rejuvenation,” Nelson said.

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Project researchers still are not positive where the oxygen went, but they are confident that the Biosphere is so tightly sealed that it did not simply leak. The fact that only oxygen and no other constituent of the air was depleted also indicates that something other than a leak is responsible.

The most recent theory suggests that the oxygen has bonded chemically with the concrete sheathing of the structural spars and artificial cliffs.

As the oxygen levels slowly dropped, the carbon dioxide levels also started to get out of hand. The crew had to stave off a runaway greenhouse effect, orchestrating plant growth to soak up the extra carbon dioxide. They boosted rainfall in some areas and irrigated others. They also lowered nighttime temperatures to slow the exchange of gases between the soil, which absorbs carbon dioxide, and the Biosphere air.

“We didn’t take our air at all for granted in here,” Nelson said last week. He spoke by telephone from inside a glass booth at the edge of the Biosphere’s human habitat, where crew members can meet face to face with friends or family. Crew members press their hands against the glass in greeting--as close as they can get to touching someone outside.

“If we acted as irresponsibly inside the Biosphere as people do outside, it would not just be biocide, it would be suicide. The humans don’t sit here hoping everything works. They can manipulate the Biosphere,” he said.

If the crew members will be able to breathe more easily outside, they also will be able to eat more heartily as well. For two years, they have all followed a rigid low-calorie, low-fat subsistence diet, long on vegetables and short on meat.

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“We will probably emerge with smooth arteries,” said Dr. Roy Walford, the 69-year-old crew physician who designed the diet that sustained them.

On their 2,200 calories a day, the eight lost an average of 16% of their weight. They also showed sharp drops in cholesterol levels, white blood cell count and blood pressure, according to a report published in the Proceedings of the National Academy of Science.

“The calories are below recommended levels, but the health is good,” said Walford, who has studied, and is an advocate of, caloric restriction as a means of better health and perhaps extending life span.

Like several other crew members interviewed last week, Walford seemed healthy but gaunt.

Even more than its human inhabitants, the coral reef in Alling’s 900,000-gallon ocean is a sensitive barometer of the Biosphere’s environmental health and an example of what the crew says is their success. The “ocean” is 25 feet deep, washed by mechanical waves, and contains 1,000 species of plants and animals.

“It has evolved in its own right and is self-supporting,” she said. “I don’t give it an ounce of fish food. The intriguing fact is that it’s real. We’ve been able to prove we can create a reef. We’ve proved we can sustain it.”

Perhaps the most significant achievement of Biosphere II is the engineering that isolates it. Two mammoth, bellows-like lungs allow air inside to expand and contract without shattering the glass enclosure, as the internal temperatures shift from 65 to 95 degrees every day.

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The building has an annual leak rate of less than 10% a year, far less than any other manned closed system, said Bill Dempster, who is in charge of the project’s engineering systems. “I give it an A-,” he said.

By comparison, NASA’s space shuttle, designed to sustain life in the near vacuum of space, leaks like a sieve--50 times the rate of the Biosphere.

Some National Aeronautics and Space Adminstration scientists are skeptical. They are eager to see the hard data.

“The Biosphere is not what you can call controlled experimental research,” said William Knott, chief of the biological sciences office at NASA’s Kennedy Space Center, which researches self-replenishing habitats for astronauts. Knott said he questioned the way Biosphere officials had calculated the leak rates and wondered whether such claims could be substantiated. “To build systems and simply watch them for hundreds of years is not how you are going to understand something.”

The ability to seal the world in a bottle is what makes the Biosphere II an important scientific tool, said the project’s research director, John B. Corliss. For the first time, he said, scientists will be able to set up controlled experiments to explore the planet’s complex ecology and atmosphere--experiments that would be overwhelmed by the natural variation of conditions outside the Biosphere.

Corliss is a former NASA scientist who joined the project last spring after the science board resigned. He presides over the Biosphere’s network of science consultants and will be responsible for ensuring the integrity of the project’s future work.

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“You can’t be a scientist at the cutting edge unless you are rigorously honest with yourself,” Corliss said. “People ask, ‘Where are all the scientific papers?’ We are just finishing the first experiment.”

Life in the Biosphere

Eight people will emerge Sunday after two years inside Biosphere II, where five wilderness ecosystems, or biomes, contain nearly 3,800 species of plants and animals. The biomes help recycle the air, wastes and water and balance the internal atmosphere’s complex chemistry.

THE RAIN FOREST

* Designer: Botanist Ghillean Prance, director of the Kew Royal Botanic Gardens in London.

* Environment: Patterned on an Amazonian jungle; 20-foot-tall trees shelter 300 species, which include bush babies and lemurs.

THE SAVANNA

* Designer: Peter Warshall of the University of Arizona.

* Environment: The savanna has grassland plants and animals from Africa, South America and Australia. Fish, toads and aquatic insects live in the tropical stream that flows through the savanna and into the marsh below.

THE MARSH

* Designer: Marine biologist Walter Adey of the Smithsonian Institution.

* Environment: Scooped up virtually intact from the Florida Everglades and transported to Arizona, the marsh contains mangroves and other plants, insects, frogs, turtles and crabs.

THE OCEAN

* Designer: Also developed by Adey.

* Environment: The 900,000-gallon, 25-foot-deep ocean contains a living coral reef imported from the Caribbean and more than 1,000 species, including parrotfish, starfish and anemones.

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THE DESERT

* Designer: Ecologist Tony Burgess of the U.S. Geological Survey and Warshall.

* Environment: Modeled on the coastal fog desert of Baja California. Its plants grow most vigorously in the winter when many of the other plants in the structure are dormant. Lizards and tortoises are the primary inhabitants.

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