The next step will be for geochemists and archaeologists to track down the source of mercury at key sites and, if possible, scrutinise archaeological and human remains for signs of past mercury exposure.

Then there’s the question of whether the Maya were affected by mercury exposure. Where and how did the Maya obtain mercury? Who mined it, traded it, and transported it by foot over hundreds of kilometres across present-day Central America? Our work reveals a rich history of mercury use by the Maya and challenges the idea that pre-industrial societies didn’t have noteworthy impacts on their environments.īut there is much we still don’t know. For example, it’s not clear if the mercury detected at the island Maya settlement of Marco Gonzalez (also in Belize) is from ancient or modern times. While the appealing red cinnabar ore is the likely culprit of mercury pollution, the equally appealing and shimmering liquid mercury is another possible source of persistent pollution in some locations, such as Lamanai in modern-day Belize.Īt more complex sites, elevated mercury levels may be the result of both modern and ancient inputs. Mercury also made its way into some drinking water sources including central reservoirs at Tikal. Locations with elevated mercury are typically areas the Maya occupied, including domestic patios, dating to the Late Classic (600’900 CE). Specifically, seven out of ten sites were found to have mercury levels that equal or exceed modern benchmarks for environmental toxicity.

They test soils and former Maya areas excavated from far below today’s ground surface, which tell us about mercury levels during the Maya’s time.Ĭombined data from these tests show most Maya sites have some amount of mercury enrichment in buried soils. Over the past two decades, scientists working on Maya archaeological projects have tested artefacts, soils, and sediments for their chemical properties, including for mercury, to better understand past human activities. This means the production, trade, and use of mercury would have been highly valuable and logistically challenging - especially for managing toxic liquid mercury! Most Maya settlements were great distances from known mercury sources located in Mexico and Honduras, and perhaps Guatemala and Belize. Liquid mercury from 1,000 or more years ago could have evaporated or oozed away into the environment through time. There are only seven occurrences of liquid mercury at Mesoamerican sites that we are aware of.īut it’s feasible there may have been many more - and that it’s simply invisible in today’s archaeological record. It has been far less common to find liquid (elemental) mercury. The most common form reported is cinnabar (mercury sulfide, or HgS), a bright red mineral used extensively by the ancient Maya for decoration, craft, and ritual purposes such as burials and in tombs. Understanding its origins will also help us understand the trajectory of humanity’s fascination with, use of - and abuse of - this mercurial element.Īrchaeologists have been finding mercury at archaeological sites in Mexico and Central America for more than a century. Our present mercury problem has a deep legacy. In our research, published in Frontiers in Environmental Science, we review the ways the Maya used mercury, the mystery of how they sourced it, and the environmental legacy of past mercury use. Early Mesoamerican societies such as the Olmec had been mining and using mercury in southern Mexico as early as 2000 BCE. One region with an especially long (but poorly documented) history of mercury use is Mexico and Central America. This anthropogenic (human-caused) mercury use has led to mercury entering places globally it wouldn’t otherwise be found, such as in lakes or soils in remote locations. However, in some parts of the world, humans have been modifying the mercury cycle for thousands of years. In the last century, human activities have increased atmospheric mercury concentrations by 300’500 % above natural levels. When leached into the natural environment, it accumulates and builds up through food chains, ultimately threatening human health and ecosystems. Writing in The Conversation, Dr Simon Turner (UCL Geography) and his colleagues explore how the ancient Maya used the toxic element mercury, where they sourced it and its environmental legacy in Mesoamerica.

Ritual abuse mercury poisoning