New study confirms ancient people of Chile died of slow poisoning from arsenic
Previous studies have established that people of numerous pre-Columbian civilizations in northern Chile suffered from chronic arsenic poisoning between 500 and 1450 AD, through consumption of contaminated water, as evidenced by traces of arsenic in the hair of mummies and in the soil. Now a new study has found evidence of arsenic poisoning across all major cultural periods in the region, spanning several millennia.
Popular Archaeology reports that James Swift of the Australian National University and colleagues from several other institutions in Australia and Chile, performed plasma mass spectrometry trace element analysis of human bone and tooth samples. The samples came from 21 burials covering the period from 3867 to 474 BP (before present) excavated at the site of Caleta Vitor on the Pacific coast of northern Chile.
Caleta Vitor, a small fishing cove of Arica and Parinacota Region in northern Chile. Credit: Llallo
The results showed that populations covering all major cultural periods in the region were exposed to elevated levels of arsenic and one third of the sample population had accumulated levels of arsenic that were indicative of chronic poisoning.
Symptoms from arsenic poisoning begin with headaches, confusion, severe diarrhea, and drowsiness. As the poisoning develops, symptoms include convulsions, vomiting, blood in the urine, cramping muscles, hair loss, and stomach pain. The final result of arsenic poisoning is coma and death.
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In a study conducted last year and published in the journal Analytical Chemistry, scientists used multispectral imaging to analyze the skin, hair, and clothes, as well as the soil encrusting a 1,000- to 1,500-year-old mummy from the Tarapacá Valley in Chile’s Atacama Desert. 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. Analysis of the soil also revealed much lower concentrations of arsenic than that found in the hair.
The results enabled the scientists to conclude that high concentration of arsenic in the mummy's hair came from drinking arsenic-laced water and, possibly, eating plants irrigated with the toxic water.
Mummy found in Caleta Vitor, Chile. Studies on human remains in the area found evidence of arsenic poisoning. Credit: Mauricio Bugueño / Panoramio
Ground water in certain areas of the world, including Chile, have been found to have high concentrations of naturally occurring arsenic. However, lead study author of the 2014 study, Ioanna Kakoulli, an archaeological scientist at the University of California, Los Angeles, explained that in Chile, sediments are also rich in arsenic because of copper-mining activities in the highlands.
However, it is not just ancient populations that were affected by arsenic poisoning. A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning from drinking water.
Featured image: A mummy tested for arsenic poisoning. Credit: Ioanna Kakoulli, UCLA