Ancient Mayan cities are dangerously contaminated with mercury . So much so that in some areas contamination can be harmful even to archaeologists who are not careful enough. The meta-study that has been published in Frontiers in Environmental Science concludes that this contamination is not modern , but that it would be a consequence of the frequent use of mercury by the Mayans of the classic period, that is, those who lived between the years 250 and 1100 AD. our era.
“Environmental mercury contamination is often found in contemporary urban areas and industrial landscapes. Discovering mercury buried deep in the soils and sediments of ancient Mayan cities is difficult to explain, until we start looking at the archeology from the region, which tells us that the Mayans used mercury for centuries ,” stated study lead author Dr. Duncan Cook of Australian Catholic University.
In their data review, the researchers have located mercury contamination in many archaeological sites in the Mayan world where measurements have been made, such as Chunchumil in the Yucatan Peninsula (Mexico), in Marco Gonzalez and Actuncan, in Belize, in La Corona, Tikal, Petén Itzá, Piedras Negras and Cancuén in Guatemala, in Palmarejo in Honduras and in Cerén, in El Salvador.
Mercury concentrations range from 0.016 ppm in Actuncan to the extraordinary figure of 17.16 ppm in Tikal. To give us an idea, the Toxic Effect Threshold (TET) for mercury in sediments is 1 ppm.
The Mayans, great consumers of mercury
“The region of Mexico and Central America has a history of mercury use that began at least two millennia before European colonization in the 16th century. Archaeologists have reported the existence of extensive deposits of cinnabar (HgS) and other mercury materials in ancient human settlements in the region,” the researchers write in the publication.
In this sense, during all this time, archaeologists have found sealed containers filled with liquid mercury (Hg0) in various Mayan sites, such as Quiriqua in Guatemala, El Paraíso in Honduras and the ancient multi-ethnic megacity of Teotihuacan, in the center of Honduras. Mexico. In other areas of the Mayan culture, objects painted with paints containing mercury , specifically cinnabar, have been found.
The Mayan civilization would have used paints and powders containing cinnabar to decorate. This mercury would have filtered through the patios, the floors, the walls and the ceramics and would have finally reached the ground and the water.
“For the Mayans, objects could contain ch’ulel, or soul force, which resided in the blood. Thus, the bright red pigment of cinnabar was a priceless and sacred substance, but unbeknownst to it, it was also deadly and its legacy persists in the soils and sediments of ancient Mayan sites,” says co-author Dr. Nicholas Dunning, a professor at the University of Cincinnati.
The Maya must have purchased both elemental mercury and cinnabar, since they rarely occur in the limestone that underlies much of the Maya region. The researchers speculate that the toxics may have been extracted from deposits located on the northern and southern borders of the ancient Mayan world and then sold by traders.
A danger for the Mayans and also for the environment
Mercury is toxic to both humans and ecosystems. The increase in mercury concentrations on the surface of our planet is related to increasing industrialization and urbanization . As pointed out in the publication, mining activities and energy generation through fossil fuels would be responsible for at least half of today’s global mercury emissions. These would then be modern emissions, but there is also mercury from past human activities, such as those of the Mayans.
The frequent and widespread use of mercury by the Mayans would have posed a great danger to their health . Chronic mercury poisoning can cause damage to the central nervous system, kidneys, and liver. It also causes vision, hearing, mental health problems, and paralysis. Metabolic syndrome, manifested by obesity, is also one of the consequences of mercury poisoning.
Precisely the latter seems to be what Dark Sun suffered, one of the last Mayan rulers of Tikal, judging by the representations that were made of him, since they all showed him as an obese person.
“We concluded that even the ancient Maya, who hardly used metals, had very high concentrations of mercury in their environment. This result is further evidence that, like us today, we live in the “anthropocene” “There was also a ‘Mayan Anthropocene’ or ‘Mayacene’ . Metal contamination appears to have been caused by human activity throughout history,” said study co-author Dr. Tim Beach, a professor at the University of Texas in Austin.
Referencia: Cook, D., Beach, T. et. al. Environmental legacy of pre-Columbian Maya mercury. 2022. Frontiers in Environmental Science. DOI: https://doi.org/10.3389/fenvs.2022.986119