Plastic water bottles — and their potential health risks — may seem like a relatively recent invention. But thousands of years ago, Native Americans in present-day California were already making their own water bottles by coating woven baskets with a sticky form of petroleum.
Researchers now think those ancient water bottles also may have been a hazard to human health.
For a new study, a team of scientists recreated these ancient water bottles, relying on the same methods that California Indians would have used. Their goal was to discover whether these containers could have been linked with declining health among the Chumash people, who lived along the California coast and on the Channel Islands.
Water stored in these replica bottles turned out not to contain high concentrations of harmful chemicals. But during the production of the bottles, the researchers detected significant airborne emissions of polycyclic aromatic hydrocarbons — chemicals associated with cancer, hormone imbalances and other health problems.
"Producing the bottles and heating the petroleum in order to apply it to the baskets — that process created fumes that were a little bit unhealthy," said Stockholm University's Sebastian Warmlander, one of the study's authors. As a rough comparison, Warmlander said breathing in the emissions was likely a bit worse than smoking cigarettes.
The researchers said this is the first study to connect long-term declines in health among ancient California Indians with this form of tool production.
"Recent technological advances have given us a lot of new tools to study the ancient past and ask new questions that relate to the world today," wrote Smithsonian Institution anthropologist and study co-author Sabrina Sholts in an email to KPBS. "By doing this, we can better understand human health in the 21st century within a much longer story of human ecology and evolution."
