The ancient Maya sites across Mesoamerica hold more than relics of a vanished era. They reveal a surprising thread: mercury pollution. Scientists publishing in Frontiers in Environmental Science report that this contamination is not a modern phenomenon but stems from the classical Maya use of mercury-containing goods between 200 and 900 BCE. In some locations, the mercury footprint is so pronounced that it continues to raise health and safety questions for archaeologists exploring these sites today.
Lead author Duncan Cook, an associate professor of geography at Australian Catholic University, notes that environmental mercury pollution is typically linked to contemporary cities and industrial landscapes. Detecting mercury deeply buried in soils and sediments at ancient Maya settlements challenges typical explanations and suggests a long history of elemental exposure tied to daily life in the classical period. The team emphasizes that these findings are based on careful synthesis of soil and sediment analyses from multiple Maya sites, rather than a single outlier.
ancient anthropogenic pollution
Researchers reviewed concentrations of mercury across archaeological sites in the classic Maya world, including settlements that correspond to modern locations such as Chunchumil in Mexico, Marco Gonzales, Chan B’i and Actúncan in Belize, La Corona, Tikal, and Petén Itzá in Guatemala, along with sites in Honduras and Cerén in El Salvador, often called a Mesoamerican Pompeii for its preservation. The mercury signal is detectable broadly, with few exceptions such as Chan B’i, illustrating a widespread pattern of contamination linked to human activity rather than natural background levels.
Concentration measurements range from 0.016 parts per million (ppm) at Actúncan to a striking 17.16 ppm at Tikal, a site known today for its heavy tourist visitation. For context, the established threshold for hazardous residual mercury exposure is defined at 1 ppm. These levels underscore a pollution burden that would have affected ancient residents and, in turn, the surrounding ecosystems for generations.
Major mercury consumers
What drove this contamination? The study identifies sealed vessels containing elemental mercury at several Maya sites, including Quiriguá in Guatemala, El Paraíso in Honduras, and Teotihuacan, a vast multiethnic city in central Mexico. Elsewhere in the Maya region, archaeologists have found objects painted with cinnabar, a mineral that contains mercury. These discoveries point to common practices using mercury-rich substances for decoration and ritual purposes.
The researchers explain that cinnabar pigments and powders would have released mercury into nearby soils and waters as terraces, floors, walls, and ceramics interacted with the environment over time. They note that for the Maya, cinnabar carried symbolic significance related to ch’ulel, the sacred life force associated with blood. Yet this sacred pigment carried an invisible price, leaving a lasting legacy in the soil and sediment around ancient homes and ceremonial spaces. co-author Nicholas Dunning of the University of Cincinnati remarks on the pervasive presence of mercury likely tied to widespread decorative practices.
Because elemental mercury and cinnabar were probably sourced from known mineral deposits in northern and southern parts of the broader Maya region, traders could have imported these materials to multiple cities. The health implications for the ancient Maya would have been significant, with chronic mercury exposure affecting the nervous system, kidneys, liver, tremors, vision and hearing, motor control, and mental health. Such factors could have contributed to broader sociocultural dynamics within Maya communities over time.
Depictions of leaders from Tikal in frescoes, including one ruler around 810 CE who appears obese, offer a visual cue that a metabolic syndrome influenced by long-term mercury exposure could have played a role in health and daily life. This observation fuels ongoing inquiry into how environmental pollutants may intersect with social structures and settlement patterns in ancient civilizations.
Further research is needed to determine whether mercury exposure influenced broader sociocultural changes during the late classical period and into subsequent eras. Co-author Tim Beach from the University of Texas at Austin notes that even civilizations with limited metal production showed high mercury concentrations in their environments. The team suggests a broader view of human impact on ecosystems, framing current times as another phase of the long human footprint—what some scholars call a Mayan Anthropocene or Mayacene.
In summary, the study highlights a long-standing connection between human activities and mercury dispersion in the Maya lowlands. The authors emphasize that this legacy invites renewed exploration of how ancient practices shaped environmental health and cultural trajectories, with implications for understanding the human-environment relationship across history.
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