Evidence of pollution in the Palaeolithic

We generally recognise that this process began with the Industrial Revolution which started in the United Kingdom in the mid-18th century and then spread to the rest of Europe and other regions of the world.

Humans, as a species, are inherently associated with technology and we have always transformed the natural environment around us, generating waste – of course an assemblage of fractured stones does not compare to the levels of carbon dioxide we see today. So when did we start producing dangerous levels of pollution? It turns out that it was long ago and the evidence has come from the Neanderthals who inhabited the caves of Gibraltar.

A study was carried out not long ago, in which sediments from important prehistoric Iberian sites such as Gran Dolina in Atapuerca, Burgos (Homo antecessor, pre-Neanderthals), Vanguard and Gorham’s Caves in Gibraltar (Neanderthals) and El Pirulejo in Cordoba (Anatomically Modern Humans) were analysed.

The results from Gran Dolina yielded some levels of pollution, but this was not generated by humans, but rather by the accumulation of bat guano, so it didn’t fit with what we were looking for.

At Vanguard and Gorham’s Caves, polluted levels containing the presence of the heavy metals as a result of the fires which the Neanderthals had lit inside the caves were found. These is the oldest-known example anywhere. Finally, at El Pirulejo, heavy metal pollution was related to the manipulation of galena, the natural mineral form of lead, used for burial rituals as a source of pigments for pearls and pendants.

The results obtained from Gorham’s and Vanguard Caves are very revealing and answer our question, since the level of heavy metal accumulation achieved would today meet the contaminated soil criteria.