Heavy mercury contamination at Maya sites reveals a deep historic legacy

In the last century, human activities have increased atmospheric mercury concentrations by 300-500 per cent.

Mercury is a toxic heavy metal. When leached into the natural environment, it accumulates and builds up through food chains, ultimately threatening human health and ecosystems.

In the last century, human activities have increased atmospheric mercury concentrations by 300-500 per cent above natural levels.

However, in some parts of the world, humans have been modifying the mercury cycle for thousands of years. 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.

One region with an especially long (but poorly documented) history of mercury use is Mexico and Central America. Early Mesoamerican societies such as the Olmec had been mining and using mercury in southern Mexico as early as 2000 BCE.

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.

Our present mercury problem has a deep legacy. Understanding its origins will also help us understand the trajectory of humanity’s fascination with, use of – and abuse of – this mercurial element.

Archaeologists have been finding mercury at archaeological sites in Mexico and Central America for more than a century.