Smithsonian Magazine examined University of Cincinnati research that found evidence of toxic water pollution in reservoirs in the ancient Maya city of Tikal.
A multidisciplinary team of biologists, chemists, geographers and anthropologists studied former reservoirs found in Tikal in what is now northern Guatemala.
Their geochemical and ancient DNA analyses discovered toxic levels of mercury and blue-green algae or cyanobacteria that likely would have made people who drank the water sick.
The water pollution coincided with a time of severe droughts in the ninth century shortly before the city's population began to decline sharply.
Tikal dates back to the third century B.C. and was a thriving city supported by local agriculture. It's famous for its towering stone temples that rise above the rainforest.
UC's study was published in the Nature journal Scientific Reports.
“The conversion of Tikal’s central reservoirs from life-sustaining to sickness-inducing places would have both practically and symbolically helped to bring about the abandonment of this magnificent city,” the study concluded.
UC biology professor David Lentz, the study's lead author, said their findings help explain the depopulation of Tikal.
“Archaeologists and anthropologists have been trying to figure out what happened to the Maya for 100 years,” Lentz said.