Primary analysis sheds light on the last moments of the Pompeii victims | research

Initial analysis performed on plaster casts of seven victims of the volcanic eruption that buried the ancient Roman city of Pompeii confirmed that suffocation was the likely cause of their deaths. The project used portable X-ray fluorescence (XRF) techniques to gain insight into the final moments of the people who lived in the city when Mount Vesuvius erupted in AD 79.

Casts from Pompeii were first created in the 1870s by injecting plaster into spaces left by corpses decomposing under volcanic ash. Because of the way they are made, molds contain structural residue and retain the original body shape.

While these casts provided insight into the eruption and its consequences, analysis of biological material proved difficult due to grout contamination. “The main (components) of plaster and bone are[calcium-based]but the proportion of phosphorus changes,” explains Gianni Galileo, an archaeologist at the University of Valencia in Spain, who led the project.

Using portable XRF technology to scan six casts from the Porta Nola area and one from the Terme Suburban in Pompeii, the researchers compared the initial compositions of those bones that had been cremated nearby before the eruption or buried in Valencia, Spain. By focusing on the ratios of phosphorous to calcium in the samples, the team developed a statistical model to distinguish between gypsum and bone within the casts. “The soiled bone is more like plaster, while the less soiled bone is more like burnt bone,” Galileo says. This resemblance to burnt bone is thought to be due to chemical processes that leached out carbonates and phosphates.

Preliminary data provides evidence that suffocation from ash inhalation killed the Porta Nola victims, before the bodies were buried with more volcanic material. The researchers noted that the chemical similarity of the cast bones to the burned bones, as well as the victims’ prone and relaxed posture, indicated asphyxiation as the cause of death.

Piero Delino, a professor of volcanology at the University of Bari in Italy, agrees with these conclusions. “People weren’t killed by the mechanics or other things. People were killed because they were breathing in the ash.” “It wasn’t hot, just the eruption lasted a few minutes longer than one could breathe.”

For Galileo, the most important thing to learn from this work is the importance of collaboration in science. “A really multidisciplinary approach is essential in this type of study,” he says. “[Our work provides]an additional tool that uses chemical data to study these amazing remains.”

Delino echoed that sentiment. “The fragmentation of science and looking only at the biological, natural, ecological or geological side does not tell the real story because this world is complex,” he says.

According to Delino, studying the history of the regions surrounding Vesuvius not only allows people to learn about the past, but also allows them to prepare for the future. “Vesuvius is the most dangerous volcano in the world,” he says. “The red zone (around) Vesuvius has 700,000 people at risk.” “If you study a thunderstorm, or if you study a great flood, you understand very little during the event. But after the event is like a crime scene – you can understand many things after the event, and then (develop plans) for (future) mitigation.