Chile’s Chinchorro Mummies in Peril: Increased Humidity Leads to Rapid Deterioration
For more than 7,000 years, the Chinchorro mummies of Chile have been preserved, until now. Increased levels of humidity have caused the mummies to deteriorate rapidly, with skin turning black and becoming gelatinous.
Ralph Mitchell, a professor emeritus of applied biology at Harvard University, was among the researchers who examined the rotting mummies. They found that the humid air was allowing bacteria to grow, feeding on the skin as nutrients. The bacteria are not ancient organisms, but rather those that normally live on people’s skin. As soon as the right temperature and moisture levels were present, they began to use the skin as nutrients.
Around 120 Chinchorro mummies are housed in the University of Tarapacá’s archeological museum in Arica, where humidity levels have increased in recent years. This is unusual for the arid region, which is located near the Atacama Desert, the driest desert in the world outside of Earth’s polar regions.
Chile’s changing climate may be to blame for the increased humidity levels, according to Marcela Sepulveda, a professor of archaeology at the University of Tarapacá. Mitchell’s experiments showed that the skin of the mummies began to fall apart after 21 days at high humidity. In order to save the mummies, the museum must maintain the humidity in the room where they are stored between 40 and 60 percent.
Mitchell’s team adjusted the air’s humidity levels from dry to damp in their experiments, studying how each level affected the skin of the mummies. To limit the amount of mummy skin needed, the researchers conducted initial experiments on pig skin. It was found that higher humidity could cause more degradation, while lower humidity could damage the mummies’ skin.
The Chinchorro mummies offer a unique insight into the rituals and customs of ancient societies. Unless the mummies can be kept under the right temperature and humidity conditions, they will continue to deteriorate, causing a loss of valuable historical and cultural knowledge.