Archaeologists at the Universitat Rovira i Virgili and the Catalan Institute of Human Paleoecology and Social Evolution have revealed that hunter-gathering people have been recycling since the Upper Paleolithic Age. They came to this conclusion after researchers found burnt artifacts in the Molí del Salt site in Tarragona, Spain.

Traditionally, the question of whether prehistoric people recycled has not really been addressed, because it is difficult to find evidence of recycling. But the study, published in Journal of Archeological Science, found that evidence is not impossible to obtain.

"In order to identify the recycling, it is necessary to differentiate the two stages of the manipulation sequence of an object: the moment before it is altered and the moment after. The two are separated by an interval in which the [artifact] has undergone some form of alteration. This is the first time a systematic study of this type has been performed," Manuelo Vaquero said in a statement.

At the site in Tarragona, researchers found burnt remains. They chose to study them in detail to verify if the artifacts were, in fact, modified after being exposed to fire. They found that recycling was common in the Upper Paleolithic Age, and that tools were normally converted into household equipment. Though their results indicate that tools were rarely recycled, multiple-purpose devices were often modified. Interestingly, researchers said that many objects were not originally conceived to have multiple purposes; instead, a new purpose was often tacked on afterwards through recycling.

Recycling has been commonly used throughout human history. Archeologists have discovered that, in times of scarcity, societies often would have fewer amounts of household waste, like pottery and ash. That indicates that more items were being recycled in lieu of producing new items. However, the study is still intriguing, because it shows that people have been recycling for longer in history than was previously thought.