World's oldest mummies contain a deadly toxin

If you're a history fan, then you'll know that mummies have been a source of fascination for thousands of years.

But it turns out that you might want to keep a safe distance from the world's oldest mummies, as they actually contain a deadly toxin.

The mummies, which are millennia old (seriously), were found in Chile's Atacama desert and they actually predate the Egyptian mummies - that most of us think of when we hear the word 'mummies' - by thousands of years.

University of Tarapacá

So, how old are they exactly?

Well, the oldest are 7,000 years old and it's for this reason that they were given protection by UNESCO on the World Heritage List in 2021.

As reported by the BBC, these mummies are so old that they are the earliest known example of the artificial preservation of humans.

Their incredible age means that they've been studied at length by scientists, who made a shocking discovery about the bodies themselves.

They contained dangerously high levels of arsenic, which is what ultimately killed them thousands of years ago.

Explaining why the majority of mummies are of children, Bernardo Arriaza, an anthropologist at the University of Tarapaca, told EFE: "The first populations that arrived there to settle were chronically poisoned by arsenic, which leads to high perinatal mortality rates."

The arsenic came from the Camarones River, where arsenic is naturally found at high levels.

When this resulted in mass infant deaths, it is speculated that in a bid to come to terms with the losses, the Chinchorro people began mummifying their dead.

University of Tarapacá

It is also believed that the dead were mummified to make them more palatable to the living and for religious purposes.

Just like in modern embalming processes, this involved alterations to the internal organs, but instead of using embalming fluid, they used clay to slow down the decomposition process.

What makes these mummies so incredible is the fact that the Chinchorro people eventually stopped making them.

This is because they developed natural immunity to arsenic over time, which has been proven by people who live in the area today.

But the arsenic is not the only toxic thing about the mummies, and they were also painted with manganese during the mummification process - a substance that was used for its beauty.

"As a hypothesis, we are proposing that all this continuous, recurrent and intensive use of manganese may have also caused health problems for the Chinchorro people," said a scientist.

You can find out more about the Chinchorro mummies and their deadly toxins in this mini-documentary.