Ancient Maya red pigment contaminated lakes with toxic mercury
A study in Science Advances found that cinnabar used in temples and burials damaged aquatic ecosystems across the Yucatán Peninsula.
A new study published in Science Advances has found that a mercury-rich mineral used by the ancient Maya to produce red pigment contaminated lakes across Mexico's Yucatán Peninsula. The mineral, cinnabar, was used to decorate temples, pottery, and burial chambers.
According to the Times of India, researchers collected sediment cores from beneath lakes near the ancient Maya cities of Coba and Xcach to examine mercury concentrations. At Xcach, contamination was recorded between approximately 125 and 200 AD, with another spike between 535 and 820 AD. At Coba, mercury levels rose around 250 AD and remained elevated for roughly 150 years.
The study found that mercury levels exceeded modern sediment toxicity thresholds. Biological markers in the sediment showed that several groups of aquatic organisms, including bacteria, algae, cyanobacteria, snails, ostracods, and non-biting insect midges, declined or disappeared during periods of high mercury concentration.
The contamination affected multiple levels of the aquatic food chain. Researchers suggested that ancient Maya residents may have been exposed to the toxic heavy metal through contaminated fish or drinking water, though the study does not establish the exact amount of exposure.
While mercury may have been a contributing stressor alongside droughts and deforestation, researchers cautioned there is no direct evidence linking the contamination to the eventual decline of Maya cities.