Ancient Maya reservoirs contained toxic pollution

Reservoirs in the heart of an ancient Maya city were so polluted with mercury and algae that the water likely was undrinkable. Researchers found toxic levels of pollution in two central reservoirs in Tikal, an ancient Maya city that dates back to the third century B.C. in what is now northern Guatemala. New findings suggest droughts in the ninth century likely contributed to the depopulation and eventual abandonment of the city.