Ancient Toxicity

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The ancient Mayans left grandiose sites filled with intricate art and majestic pyramids in what is now Central America.

But archaeologists recently discovered that the Mesoamerican civilization had major mercury pollution in its cities, Cosmos Magazine reported.

Researchers reviewed available data on mercury pollution at 10 different Mayan archaeological sites and found that seven had contamination in at least one location.

Most of these sites date from the Late Classic era, which happened toward the end of the first millennium CE. By the 10th century, every site had been abandoned.

The mercury levels in these spots ranged between 0.016 parts per million (ppm) to 17.16 ppm.

Researchers explained that in some areas the heavy metal levels in the soil exceeded modern guidelines for safe exposure. They added that the World Health Organization recommends the safe limit for mercury on agricultural land should be 0.05 ppm.

“Our review shows that numerous Maya sites have total mercury levels that, if found in a playground or a building site (today), would be cause for concern,” said lead author Duncan Cook.

It’s still unclear how hazardous these sites are. Meanwhile, Cook’s team hasn’t determined how the toxic heavy metal got there.

Archaeologists have previously discovered vessels of pure mercury at a number of sites. Others pointed at the bright red cinnabar mineral, made from mercury and sulfur, which was an important and sacred pigment for the Mayans.

Still, the authors hope that future research will show how mercury affected the health and behavior of the ancient Mayans.