Decipher the death of the oldest mummies in the world

Arsenic-contaminated water is the culprit that killed the ancient people in Chile, where the embalming technique was applied as early as human history.

National Geographic said that the ancient people of Chinchorro coastal Chile were the first community to know how to embalm. They invented the embalming technique from about 7,000 years ago. If the ancient Egyptians mainly embalmed the king, queen, nobles and nobles, the Chinchorro embalmed the bodies of civilians, children and even fetuses.

Bernardo Arriaza, a scientist from the University of Tarapacá de Arica, Chile, wants to find out the cause of the deaths of the ancient mummies mentioned above. He and his colleagues analyzed hair samples from 46 ancient mummies that were found at five different locations in the arid Camarones valley in northern Chile and in the Chinchorro coastal region. Many of these mummies are preserved almost intact until today thanks to the dry climate in the valley.

A child mummy is found in Chile.Photo: Bernardo Arriaza.

Results showed that 90% of mummy's hair - dating from 600 to 7,000 years - had arsenic concentrations greater than 1 mg per gram of hair. That concentration is large enough to cause many diseases. In some areas of the valley, the arsenic concentration is much greater.

'I believe that ancient Chileans exposed to continuous arsenic due to drinking contaminated water in the Camarones valley from generation to generation,' Arriaza told National Geographic.

Arriaza said that, based on the date of the mummies, it could be confirmed that the arsenic poisoning process in the Chinchorro coast began at least 7,000 years ago. Because arsenic is an odorless, tasteless substance, people in the Chinchorro region cannot know they are poisoned. Arsenic causes them to have cancers of the skin, lungs, kidneys, bladder and many other dangerous syndromes.

After they died, some people were embalmed. The internal organs of the body were removed and replaced by soil, hay or straw.

The team said that the rocks and volcanic slopes in the Camarones valley contain quite a bit of metal. As the ice on the volcanic slopes melted, they carried poisonous metals into the rivers - which provided drinking water to the people.

After invading the human body, arsenic accumulates in keratin tissues - which form hair, hair and human nails. That explains why a mummy's hair can tell the degree of poisoning of the body.

According to Arriaza, fetuses and babies are very susceptible to arsenic poisoning. Because the mummies are the largest date of the fetus and newborn, he said that high rates of miscarriage and premature birth in ancient times prompted people in Chinchorro region to invent the embalming technique.

Today, Camarones drinking water still contains several hundred times more arsenic than the World Health Organization's safety standards. So people here have to take water from elsewhere to drink.