Oldest traces of heavy metal pollution caused by humans uncovered

September 21, 2015
This photo released by the CNRS on September 2, 2014 shows a view of the Gorham's Cave in Gibralta
This photo released by the CNRS on September 2, 2014 shows a view of the Gorham's Cave in Gibralta

The oldest signs of heavy metal pollution caused by human activity, dating from the early Stone Age, have been found in caves in Spain and Gibraltar, officials said Monday.

The findings, published in the journal Scientific Reports, indicate prehistoric humans inhabited caves with high levels caused from fires, fumes and ashes which could have played a role in their tolerance of environmental pollution.

The highest levels of heavy metals—copper, lead, nickel and zinc—were found in Gorham's Cave in Gibraltar, a tiny British territory on Spain's southern tip, where well preserved Neanderthal hearths have been found.

"It is the earliest known evidence of heavy resulting from ," the government of Gibraltar said in a statement.

Traces of heavy metal pollution were also found in Vanguard Cave in Gibraltar from fires as well as in El Pirulejo in southern Spain linked to the use of galena, a lead sulphide used as a source of pigment or as raw material to manufacture beads, according to the study.

The scientists also found heavy metal pollution at Gran Dolina, a cave site in the Sierra de Atapuerca region of central Spain near Burgos. But they concluded that this came from bat and bird droppings and not from human activity.

They said the sites mentioned comprised "earliest evidence of pollution by heavy metals in archaeological sites" anywhere in the world.

"Despite these high pollution levels, the contaminated soils might not have posed a major threat to Homo sapiens populations," the study said.

"Altogether, the data presented here indicate a long-term exposure of Homo sapiens to these elements, via fires, fumes and their ashes, which could have played certain role in tolerance, a hitherto neglected influence."

Explore further: Study shows no lead pollution in the oil sands region of Alberta

Related Stories

Monitoring heavy metals using mussels

September 22, 2014

A research team in Malaysia has concluded that caged mussels are useful for monitoring heavy metal contamination in coastal waters in the Strait of Johore. Initial results indicate more pollution in the eastern part of the ...

Study shows no lead pollution in oilsands region

October 24, 2014

New research from a world-renowned soil and water expert at the University of Alberta reveals that there's no atmospheric lead pollution in Alberta's oilsands region—a finding that contradicts current scientific knowledge.

Heavy metal pollution causes severe declines in wild bees

February 29, 2012

Wild bees are important pollinators and numerous studies dealing with pollination of wild plants and crops underline their vital role in ecosystems functioning. While honey bees can be easily transported to various location ...

Recommended for you

Life cycle of sulphur predicts location of valuable minerals

October 23, 2018

A team of researchers from The University of Western Australia and two Canadian universities has applied a first-of-its-kind technique that measures the long-term life cycle of sulphur, helping to explain the preferential ...

Fish give up the fight after coral bleaching

October 22, 2018

Researchers found that when water temperatures heat up for corals, fish 'tempers' cool down, providing the first clear evidence of coral bleaching serving as a trigger for rapid change in reef fish behaviour.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.