World's first polluted river was contaminated by Neolithic humans learning to smelt 7,000 years ago

A University of Waterloo professor is among a team of international researchers who discovered a riverbed in southern Jordan that was polluted 7,000 years ago by Neolithic humans teaching themselves how to smelt.

Use of metal instead of stone marks 'beginning of the modern world'

Wadi Faynan, Jordan, where researchers found evidence of ancient pollution caused by the combustion of copper. Their findings have been published in the December 15 issue of Science of The Total Environment. (Sue Haylock/Barqa Landscape Project)

Neolithic humans who were learning how to smelt were responsible for the world's first polluted river approximately 7,000 years ago, a team of international researchers has found.

The riverbed in the Wadi Faynan region of southern Jordan is now dry, but researchers found evidence of pollution caused by heating blue-green copper ore and charcoal over fire during the Copper Age.

The discovery highlights the point in time when humans started to make tools out of metal rather than stone, University of Waterloo anthropology professor Russell Adams said.

"These populations were experimenting with fire, experimenting with pottery and experimenting with copper ores, and all three of these components are part of the early production of copper metals from ores," Adams said in a release about the study, which is published in the Dec. 15 edition of Science of the Total Environment.

"The technological innovation and the spread of the adoption and use of metals in society mark the beginning of the modern world."

Region home to 'world's first industrial revolution'

The items created by the early smelting process were largely for symbolic pieces, such as beads.

But over time, the area grew – mines and factories were built.

"This region is home to the world's first industrial revolution," Adams said. "This really was the centre of innovative technology."

But no one thought to contain the slag – or waste material – from the process. That meant metals like copper, zinc, lead, arsenic and thallium were absorbed by plants, which were then eaten by animals and people.

This likely led to widespread health problems, Adams said, including infertility, malformations and premature death.

Researchers have found high levels of copper and lead in human bones dating back to the Roman period.

The researchers now want to analyze the extent of the pollution during the Bronze Age, which began around 3200 BC, and understand how it affected human societies.