In the current Journal of Archaeological Science, a team led by Bernardo Arriaza of Chile’s Universidad de Tarapaca analyzed hair from 45 Andean mummies taken from ten sites some 7,000 to 600 years old. The mummies dried in Chile’s Atacama desert region, one of the most parched regions on Earth. They were deliberately mummified with sticks, reeds and clay, given wigs and distinctive caps.
“Arsenic is a colorless, odorless and tasteless potent poison commonly found in contaminated rivers and in groundwater in many parts of the world, including the Atacama coastal desert region,” says the study. “We suspect that even the Chinchorro, the earliest inhabitants of this region, were already affected by arseniasis (arsenic poisoning) beginning 7000 years ago.”
In the research, the team cleaned hair samples with de-ionized water, and then blasted them with lasers for chemical analysis. Some modern-day waters in the region have arsenic levels 100 times higher than the 10 microgram-per-liter limits recommended by the World Health Organization.
About 31% of the mummies had arsenic levels above 2.6 micrograms per liter, the study finds, and 89% had arsenic levels at least a tenth of that concentration, enough to trigger health effects. “Our data show that ancient people of northern Chile accumulated significant levels of arsenic in their bodies,” concludes the study.