A hypothesis of sudden body fluid vaporization in the 79 AD victims of Vesuvius

The extent of the threat of an eruption of Vesuvius and its effects on the people of Campania is a widely debated scientific issue, especially considering the vast territory around the volcano, now densely urbanized by the modern metropolis of Naples and its 3 million inhabitants.

Plaster cast of a Pompeiian volcano victim, made from a centuries-old hollow in solidified ash
[Credit: Hand Madej/Laif/Redux]

A new study published in the journal PLOS ONE analyzes the unique aspects of the thermal effects on the victims of the eruption that in 79 AD buried the cities of Herculaneum and Pompeii in only a few short hours, and with them a large part of the plain of Campania.

The archaeological and anthropological surveys conducted in recent decades at the ancient beach of Herculaneum have brought to light more than 300 victims of the eruption, as if they were frozen the time at the last moment of life.

Human victims discovered on the sea-shore area: Skeletons showing "life-like" stance: a child (A) (Ind. 41) and young
adult male (B) (Ind. 22) unearthed from the ash surge deposit (chamber 10) (S1 Table). The child’s corpse displays
flexure only of the upper limbs, indicative of an incipient “pugilistic attitude”. Full exhibit of this
 heat-induced stance is never found in the victims' corpses discovered at Herculaneum
[Credit: Pierpaolo Petrone et al. PLOS ONE, 2018]

The in situ analysis of skeletal remains and volcanic deposits allowed Neapolitan researchers to identify for the first time the degradation byproducts of human hemoglobin through the physico-chemical analysis of numerous iron oxides found on bones and in the ash layers. The presence of these substances is been associated with the rapid vaporization of tissues and body fluids after death, due to the impact with ash and gas clouds at temperatures of at least 500° C.

The extraordinary results of this research highlight the impressive damaging effects of extreme temperatures associated with pyroclastic flows, even at considerable distance from the volcano, and even for people sheltered inside buildings.

This study demonstrates the value of joint bioanthropological and archaeological investigations, both in the field and in the laboratory, able to give information otherwise not obtainable at the level of current volcanic episodes, but also of great importance for the reconstruction of both historical and biological Vesuvian populations in Roman times and the lethal events that characterized the last moments of life.

Source: Università degli Studi di Napoli Federico II [September 27, 2018]