The world’s oldest man made mummies which is preserved remarkably well for over 7,000 years, the Chinchorro mummies of modern-day Chile, is now under a threat of rapid deprivation from increased levels of moisture.
Scientists began noticing the degradation of the mummies at the University of Tarapacá’s archeological museum in Arica, Chile, where nearly 120 Chinchorro mummies are housed. According to the Harvard School of Engineering and Applied Sciences (SEAS), they found that in some cases, specimens could be seen turning into black ooze.
“In the last ten years, the process has accelerated,” said Marcela Sepulveda, professor of archaeology in the anthropology department and Archeometric Analysis and Research Laboratories at the University of Tarapacá. “It is very important to get more information about what’s causing this and to get the university and national government to do what’s necessary to preserve the Chinchorro mummies for the future.”
Sepulveda asked for the help of scientists in Europe and North America, including Ralph Mitchell, professor of applied biology at Harvard SEAS.
“We knew the mummies were degrading but nobody understood why,” Mitchell said. “This kind of degradation has never been studied before. We wanted to answer two questions: what was causing it and what could we do to prevent further degradation?”
According to Live Science, an analysis taken from the microflora on the bodies of the mummies showed that the bacteria were not from ancient organisms, but simply bacteria that normally live on people’s skin. The bacteria are known as “opportunist” because “as soon as the right temperature and right moisture appeared, they started to use the skin as nutrients,” said Mitchell.
“The key word that we use a lot in microbiology is opportunism,” said Mitchell. “With many diseases we encounter, the microbe is in our body to begin with, but when the environment changes it becomes an opportunist.”
Climate – and, specifically, the humidity level – seemed to play an important role in the degradation process of the opportunist bacteria. Researchers believe that the museum will need to keep the humidity in the room where the mummies are stored between 40 and 60 percent. Higher humidity may cause more degradation while lower humidity could damage the mummies’ skin.