Chilean Mummies Reveal Signs of Arsenic Poisoning

People of numerous pre-Columbian civilizations in northern Chile, including the Incas and the Chinchorro culture, suffered from chronic arsenic poisoning due to their consumption of contaminated water, new research suggests.

Previous analyses showed high concentrations of arsenic in the hair samples of mummies from both highland and coastal cultures in the region. However, researchers weren't able to determine whether the people had ingested arsenic or if the toxic element in the soil had diffused into the mummies' hair after they were buried.

In the new study, scientists used a range of high-tech methods to analyze hair samples from a 1,000- to 1,500-year-old mummy from the Tarapacá Valley in Chile's Atacama Desert. They determined the high concentration of arsenic in the mummy's hair came from drinking arsenic-laced water and, possibly, eating plants irrigated with the toxic water.

"In Chile, you have these sediments that are rich in arsenic because of copper-mining activities in the highlands," which expose arsenic and other pollutants, said lead study author Ioanna Kakoulli, an archaeological scientist at the University of California, Los Angeles. "When it rains, the arsenic can leach out into the rivers."

Analyzing hair

In fields ranging from forensics to archaeology, hair is widely used to gain insight into the lives of modern and past peoples. Unlike other biological samples, such as bone and skin tissue that change over time, hair remains stable after it forms (keratinizes). This feature, along with hair's steady growth rate, means that it can provide a chronological record of the substances that previously circulated in the blood.

In the past, scientists have analyzed the hair samples of the mummies from the pre-Columbian populations that lived in Chile's Atacama Desert between A.D.
500 and 1450. The remains showed patterns of chronic poisoning, which some researchers have suspected was due to these populations' consumption of water contaminated with arsenic. But the methods didn't allow them to determine how the arsenic got into the mummies' hair.

"They didn't map where the arsenic is precipitated on the hair — they just took it and dissolved it," Kakoulli told Live Science. With this technique, you cannot tell if the arsenic wound up in the hair externally, or if it was ingested and traveled through the bloodstream first, she said.

To learn more about the possible arsenic poisoning of the ancient people from northern Chile, Kakoulli and her colleagues looked at a naturally preserved mummythat was buried in the TR40-A cemetery in the Tarapacá Valley of the Atacama Desert. Using portable techniques that were noninvasive and nondestructive, they imaged and analyzed the mummy's skin, clothes and hair, as well as the soil encrusting the mummy.

As expected, the team detected arsenic in the mummy's hair and in the soil. They also discovered skin conditions indicative of arsenic poisoning. Though these findings were suggestive of arsenic ingestion, they weren't definitive, so the researchers collected hair samples to analyze further in the lab.

Finding the source

Kakoulli and her colleagues imaged the hair samples with a very-high-resolution scanning electron microscope. They also subjected the samples to various tests with the synchrotron light source — a large particle accelerator that analyzes materials with intense, focused X-ray beams — at the Lawrence Berkeley National Laboratory in California, allowing them to map the distribution of the elements and minerals in the hair.

Their tests revealed a uniform, radial distribution of arsenic in the hair. If the hair had been contaminated from arsenic in the soil, the toxic element would have only coated the surface, Kakoulli said. Comparisons of the arsenic in the soil and hair also showed the soil contained much lower concentrations of the element.

Furthermore, the dominant form of arsenic in the hair was a type called arsenic III, while the inorganic arsenic in surface water and groundwateris mostly arsenic V. Studies have suggested that the body "biotransforms" ingested arsenic into arsenic III.

"The results are consistent with modern epidemiological studies of arsenic poisoning by ingestion," Kakoulli said, adding that the technological approach used in the study could prove useful to forensic investigations and toxicity assessments in archaeology.

The team is now using the same approach to see if the ancient people of the Tarapacá Valley used certain hallucinogens, as some individuals were buried with exotic Amazonian seeds and various hallucinogenic paraphernalia. If the people buried with the items didn't use the hallucinogens, it would suggest they were shaman or doctors who used the hallucinogenic plants to aid other people, the researchers said.

"It then becomes a question about the level of interaction they had with the people of the Amazon, because the seeds aren't from Chile," Kakoulli said. "They would've had to have known the properties of the seeds and where to get them."
________________
References:

Castro, Joseph. 2014. “Chilean Mummies Reveal Signs of Arsenic Poisoning”. Live Science. Posted: April 15, 2014. Available online: http://www.livescience.com/44838-chilean-mummies-show-arsenic-poisoning.html

Mercury poisoning ruled out as cause of Tycho Brahe's death

In 2010, Tycho Brahe was exhumed from his grave in Prague, an event which received extensive international media coverage. Since then, a Danish-Czech team of researchers has been working to elucidate the cause of Tycho Brahe's death. The results of this intensive work now make it possible to rule out mercury poisoning as a cause of death.

For over four hundred years, Tycho Brahe's untimely death has been a mystery. He died on 24 October 1601 only eleven days after the onset of a sudden illness. Over the centuries, a variety of myths and theories about his death have arisen.

One of the most persistent theories has been that he died of mercury poisoning, either because he voluntarily ingested large quantities of mercury for medicinal purposes, or because mercury was used to poison him.

Rumours of death by poisoning arose shortly after Tycho Brahe's death. Brahe's famous assistant Johannes Kepler has been identified as a possible murder suspect, and other candidates have been singled out for suspicion throughout the years, according to Dr Jens Vellev, an archaeologist at Aarhus University in Denmark who is heading the research project.

The mercury poisoning theory has received apparent corroboration from repeated tests of the well-preserved remains of Tycho Brahe's beard which were removed from the grave when his body was exhumed for the first time in 1901.

'To definitively prove or disprove these much debated theories, we took samples from Tycho Brahe's beard, bones and teeth when we exhumed his remains in 2010. While our analyses of his teeth are not yet complete, the scientific analyses of Tycho Brahe's bones and beard are,' explains Dr Vellev.

Normal concentrations of mercury

The levels of mercury in Tycho Brahe's beard were investigated by Dr Kaare Lund Rasmussen, associate professor of chemistry at the University of Southern Denmark and Dr Jan Kučera, professor of nuclear chemistry at the Nuclear Physics Institute in Prague.

'We measured the concentration of mercury using three different quantitative chemical methods in our labs in Odense and Řež, and all tests revealed the same result: that mercury concentrations were not sufficiently high to have caused his death,' says Dr Rasmussen.

'In fact, chemical analyses of the bones indicate that Tycho Brahe was not exposed to an abnormally high mercury load in the last five to ten years of his life,' continues Dr Rasmussen, who analysed the bone samples using cold vapour atomic absorption spectroscopy at the University of Southern Denmark.

'Analyses of hairs from the beard were performed using radiochemical neutron activation analysis and proton microprobe scanning in Řež. They reflect the mercury load in the last approximately eight weeks of Tycho Brahe's life, and these analyses show that mercury concentrations fell from the high end of the normal level eight weeks before death to the low end of the normal level in the last two weeks before death,' explains Dr Kučera.

The "silver nose" that wasn't

In addition to his beard, another central element of the Tycho Brahe myth has been subjected to quantitative analysis: his famous artificial nose. Tycho Brahe lost part of his nose in a duel in 1566. According to tradition, the prosthetic nose he wore for the rest of his life was made of silver and gold.

When Tycho Brahe's grave was opened for the first time in 1901, his nose prosthesis was not found, but there were greenish stains around the nasal region - traces left by the prosthesis.

'When we exhumed the body in 2010, we took a small bone sample from the nose so that we could examine its chemical composition. Surprisingly, our analyses revealed that the prosthesis was not made of precious metals, as was previously supposed. The green colouration turned out to contain traces of equal parts copper and zinc, which indicates that the prosthesis was made of brass. So Tycho Brahe's famous "silver nose" wasn't made of silver after all,' explains Dr Vellev.

The reconstruction of Tycho Brahe's face

Researchers also took advantage of the opportunity to perform a CT- scanning Tycho Brahe's skeleton while they had access to his remains in 2010. The researcher team hopes to be able to reconstruct Tycho Brahe's face on the basis of the scanning and their analyses.

Upcoming TV programme on the death of Tycho Brahe

A team of film-makers from the Danish Broadcasting Corporation (DR) has followed the entire project closely, from Jens Vellev's fight to win permission for the exhumation from the authorities in Prague to the analysis of Tycho Brahe's remains and the publication of research results. The documentary Mysteriet om Tycho Brahes død (The Mysterious Death of Tycho Brahe) will be broadcast by DR on Sunday 18 November 7 pm. The film is a DR production in collaboration with Swedish and Czech television with support from Nordvision. American and German TV channels have already expressed interest in the documentary.
__________________________
References:

EurekAlert. 2012. “Mercury poisoning ruled out as cause of Tycho Brahe's death”. EurekAlert. Posted: November 15, 2012. Available online: http://www.eurekalert.org/pub_releases/2012-11/au-mpr111512.php