POMPEII, Italy — When Mount Vesuvius erupted in 79 A.D., many of its victims in Pompeii were buried under mounds of pumice and ash that hardened over them like a mold, freezing them in time.
During more than two centuries of excavations, plaster casts were made of scores of those long-ago victims, making them a famous and poignant reminder of the unpredictability of death and the boundless power of nature.
But if the way Pompeii’s residents perished is well established, far less is known about how they lived. Now a team of scientists hopes to change that.
In September, an array of specialists — archaeologists, restorers, radiologists, anthropologists and others — set up a sophisticated field hospital of sorts here, complete with a computerized tomography scanner. Better known as a CT scanner, it will be used to peer beneath those opaque, improvised tombs.
In doing so, the team hopes to gather information about the habits and lifestyles of the ancient city’s residents, and along the way possibly to dispel presumptions that have grown up about who the victims were.
“We’re the antidote to an unscientific approach,” said Estelle Lazer, an Australian forensic anthropologist who has researched Pompeian bones for 30 years, publishing a study, “Resurrecting Pompeii,” in 2009.
“Spurious evidence” had given the casts names that stuck, like “the beggar” or “the slave,” diminishing the victims into mere “props to tell a story,” Ms. Lazer said. She criticized the romanticized notion of the Pompeian tragedy promulgated by literature and Hollywood films.
“Now we have a chance to get to know who they really were,” she said.
There was the supposition, for example, that the victims were mostly the very old, the very young, the infirm and women, “on the assumption that they were not fast runners,” Ms. Lazer said.
What has emerged from the data so far is that the victims consisted of a “random sampling of normality” typical of any catastrophe. “Disasters don’t tend to discriminate,” she said.
Almost as soon as the ancient city was discovered in the 18th century, excavators began to make casts of Pompeii’s victims, seeking to preserve their remains by pouring liquid plaster into the cavity that had been left under the hardened ash as the bodies decayed.
The scientific tests, which also include laser imaging and DNA sampling, are part of a larger restoration project on most of the known Pompeian casts, 86 in all, that began in April.
The casts had been “in a precarious condition” and required fresh conservation, said Massimo Osanna, the Culture Ministry official in charge of Pompeii, as he showed reporters the work in progress.
“I want to underscore that this was an interdisciplinary effort because archaeology now takes a global approach,” he added. “It was a scientific enterprise, not to make a show out of death.”
Initially, the radiologists in charge of the CT scan had to grapple with the difficulties presented by the density of the plaster, “which made it difficult to explore,” said Dr. Giovanni Babino, the radiologist who coordinated the CT scan project.
Though CT scans have already been carried out on mummies, the Pompeian plasters had never been examined. “There were no protocols for this in the world,” Dr. Babino said.
So the team had to come up with its own. The CT scanner was set up on the site, in an area off limits to the public, and the casts were transported to be examined, one by one.
The CT scans were carried out on the plasters in the same way they would be on a live person, Dr. Babino said, the only restriction being that the cast had to fit through the 70-centimeter bore in the scanner.
The data was then elaborated to create three-dimensional models, recomposing the skeletons like a puzzle.
One consistency among the victims so far is that most “had all their teeth,” said Roberto Canigliula of Philips Spa Healthcare, which designed and lent the scanner.
The finding suggested a “healthy diet with few sugars,” said Elisa Vanacore, a specialized dentist. The scans also showed that teeth wore away because they were used for cutting, she said. The dental records will help to determine the victims’ ages.
Already the tests are calling into question some assumptions about the victims.
For example, one cast, found in the Forum in 1963, has been known as the “pregnant woman” because of the protuberance of the belly. The CT scan revealed the person was probably not pregnant, and may not have been a woman.
“Any woman with a bit of a stomach is said to be pregnant,” Ms. Lazer said.
Between the restoration, which included the reattachment of limbs, and the scientific testing, “we’ve tried to analyze the victims from A to Z,” said Stefano Vanacore, the chief curator in charge of restorations at the ruins, and the dentist’s cousin.
The DNA testing could “determine the degree of kinship between some of the victims,” he said, like the two girls found hugging each other in the so-called House of the Cryptoporticus.
The new findings could also help validate some theories. Some casts scanned so far showed the existence of fractured bones, suggesting that some died when the roof of their lodgings collapsed because of the weight of the ash and rock that rained down from Vesuvius.
The examination of one cast evinced that the victim was wearing a thickly woven cloth, suggesting that the eruption did not take place in the summer, on Aug. 24, the established eruption date, but rather later in the fall, as Grete Stefani, the site director of Pompeii, has long posited.
In all, 16 victims and two animals have been examined in the CT scanner, but Dr. Babino hopes to carry out more. To develop the three-dimensional images, those casts not able to pass through the CT scanner are being analyzed with X-ray machines and laser scanners.
“From this we will be able to make comparisons on the state of conservation in the future,” Mr. Vanacore said. The scans will also be used to make copies of the casts in plastic, for exhibitions.
The data extracted by the CT scans will now be analyzed by the specialists, who will try to answer many questions, chief among them: Who were these people? The findings will be published this year, officials said.