The good news: Weeks after a cave-in, 33 miners in Chile have been found alive in a deep shelter. The bad news: They're trapped there, possibly till Christmas.
Another cave-in is possible, though unlikely. Poor sanitation may be a health hazard. And the food reaching them is likely to leave them malnourished, experts say.
The miners' fate, however, likely hinges not on physical conditions but on their mental health and their ability to keep each other hopeful, psychologists say.
"If the miners who are trapped can bond and work together to tick off the days they are separated from their families and friends, it would help them survive the ordeal," said John Cacioppo, a psychologist who specializes in social isolation in humans and animals at the University of Chicago.
(Read "Mining's Hard Rock Legacy.")
Chile Miners Survived on Tuna and Milk
The ordeal began on August 5. The roof of the San Jose gold and copper mine in Chile collapsed, trapping the miners underground in a shelter that, according to some news reports, is only about 540 square feet (50 square meters), or about the size of a small apartment.
For 17 days the men survived in the sweltering compartment by each consuming two mouthfuls of tuna and half a glass of milk from an emergency cache every 48 hours, according to the Reuters news agency.
But on Sunday engineers reported that a 6-inch-wide (15-centimeter-wide) borehole had reached the miners' shelter, nearly a half mile (0.8 kilometer) underground.
On Tuesday a second thin borehole was completed, with one more to come, to ensure the miners won't become cut-off again.
Notes and letters from the miners that have been hauled to the surface report they are all alive and "fine in the shelter."
Engineers predict it will take up to four months to drill a hole large enough to rescue the trapped miners.
(Related: "Mine Tragedy Amid Push to Produce More.")
Miners to Be Malnourished
Water and food in the form of nutritional glucose gel packs have been lowered to the miners through the opening, and this should be enough to allow them to survive for several weeks, said Wayne Askew, a nutritionist at the University of Utah.
"For a three- to four-week time period, if they can get water and a glucose-electrolyte solution down to these people, they're going to come out malnourished, but they're going to survive," Askew said.
If a vitamin-and-mineral mixture and a liquid protein solution can be added to the miners' diets, that should be enough to prolong their survival until their rescue.
By the time the miners are hauled out, this limited diet will likely have left them thinner, with weaker bones and atrophied intestines, Askew said. After rescue, solid food will take some getting used to.
"They're not going to be in very good shape, and they're not going to be very happy, but it should work," Askew said.
In addition to the cramped quarters and liquid diet, the Chile miners are cut off from sunlight and are using the batteries of a truck in the mine to power lights and charge their helmet lamps, according to Reuters.
But the workers' experience in mines should help the men cope with the limited space and lighting, according to John Urosek, the chief of mine emergency operations for the U.S. Mine Safety and Health Administration (MSHA).
Feces Threat for Chile Miners
As the bore-shaft is enlarged, rescue workers should be able to lower more substantial food down to the miners, Urosek said.
With more food, though, sanitation could a problem.
Mine safety shelters in the U.S. typically have rudimentary waste-disposal systems, but these can quickly become overwhelmed, said Urosek, who wasn't sure whether any plumbing is available in the San Jose mine shelter.
With the Chilean miners likely trapped for months, alternative waste-disposal methods will have to be developed to prevent sickness, Urosek said.
The main danger is that fecal-borne pathogens such as E. coli may be reingested and infect the upper gastrointestinal tract, he said. This can lead to diarrhea and even death. (Read "Food—How Safe?")
Feces, Urosek said, may have to be hauled to the surface. Or rescue workers might lower bags or containers to isolate the wastes within the shelter.
Another option could be to keep the miners on a mostly liquid and low-fiber diet, to prevent the buildup of solid wastes, Askew, the nutritionist, said.
"If they're in an area with no provisions [for waste disposal], it would be desirable to not be producing much," he said. "Somebody needs to give some thought to that."
More Cave-ins Unlikely
Another cave-in is among the least likely threats to afflict the miners, though it's always possible, MHSA's Urosek said.
Engineers appear to be taking precautions to minimize any further risks to the miners.
For example, the boring of a person-size hole with diamond-tipped drills is proceeding at a deliberately slow pace, to avoid further destabilizing the rock layers, Urosek said.
"They have a lot of things to do, so I can see why it's taking so long," he said.
Psychological Ordeal for Miners
The long wait for rescue won't be easy for the miners, and it will be vital that they find ways to occupy their time and help each other remain optimistic, the University of Chicago's Cacioppo said.
"If they're a cohesive group and there's good reason to think they can get out alive, they're likely to be fine," Cacioppo said.
"If they were not cohesive to start with, it would be worth trying to do something to build group cohesion so that they remain constructive and work together to solve the challenges that may arise as they await their rescue."
Rescue workers should try to give the miners simple tasks such as writing letters to their families—anything to help pass the time and stay connected to loved ones, he added.
"Give them a clock and calendar so they can standardize their lives. It's like a 120-day sentence, and it's not solitary confinement, so they can do it together." (Read a brief history of solitary confinement.)
Antipathy Is Virulent
If social order breaks down among the miners, or if one of them begins feeling ostracized, trouble could ensue.
"If one of them starts feeling isolated, it can spread like wildfire, and it could be devastating to their morale," Cacioppo said.
Studies have shown that perceived social isolation can lead to depression as well as increased hostility. It can also interfere with sleep and increase stress hormones.
Physical health, he added, can have a concrete effect on mental health.
"If they start to get sick and die, a lot can change, because the 'all for one and one for all' [mentality] works as long as everybody's surviving. When they start to perish, you have new stressors being introduced."
How well the miners get along throughout their ordeal will also affect whether the experience leaves behind psychological scars.
"If they can keep things humane and keep everybody healthy, fed, and working together, and if rescue workers are as responsive to their needs as possible, they'll be fine," Cacioppo said.
"There should be few, if any, long-term consequences."
"They Can Do It"
MSHA's Urosek said the Chilean incident could end up being the longest case of trapped miners that he knows of, but he's hopeful that there will be a happy ending.
"Miners are a tough breed. I really believe that they can do it," he said.
"Now that the rescue workers have found them, they're going to do everything in their power to get them out."