Ancient Mayan cities were polluted due to use of mercury - study

Evidence of pollution was found in today's Mexico, Belize, Honduras and Guatemala, and was detrimental to the Maya's health.

 A Mayan pyramid in Tonina (photo credit: Wikimedia Commons)
A Mayan pyramid in Tonina
(photo credit: Wikimedia Commons)

Mayan cities between 250 and 1100 CE were reportedly polluted due to their frequent use of mercury and products that contained it, according to a study conducted by researchers from the US, UK and Australia.

The peer-reviewed study, published in the journal Frontiers in Environmental Science on Friday, argued that pollution back then could still be threatening to archaeologists today should they look in heavy places to study ancient Mayan civilization.

"Mercury pollution in the environment is usually found in contemporary urban areas and industrial landscapes," said the study's lead author Dr. Duncan Cook, who is also an associate professor of Geography at the Australian Catholic University. "Discovering mercury buried deep in soils and sediments in ancient Maya cities is difficult to explain until we begin to consider the archeology of the region which tells us that the Maya were using mercury for centuries.”

Where is the proof of the pollution?

The researchers involved in the study reviewed data on which Mayan archaeological sites had concentrations of mercury. 

"Mercury pollution in the environment is usually found in contemporary urban areas and industrial landscapes."

Dr. Duncan Cook

Pollution data was found at Chunchumil in today’s Mexico, Belize, the ancient Maya court residence La Corona in Guatemala and the Palmarejo locality in Honduras.

 The INAH recovers a complete Mayan vessel from a cave in Playa del Carmen, Quintana Roo. (credit: INAH/Handout via REUTERS) The INAH recovers a complete Mayan vessel from a cave in Playa del Carmen, Quintana Roo. (credit: INAH/Handout via REUTERS)

How did the pollution happen back then?

The researchers indicate in their study that sealed vessels filled with elemental mercury have been found at several Maya sites and found objects painted with mercury-containing paints.

The researchers conclude that the Maya used mercury-containing paints such as cinnabar for decoration, which likely contributed to the pollution with stains on floors and walls.

The mercury would also have been detrimental to the ancient Maya's health, as poisoning from the mercury can damage one's vision, hearing, central nervous system, kidneys, liver and even cause mental health problems, according to the study.