Summary:

- The article discusses the discovery of high levels of mercury in the drinking water of ancient Maya cities, which may have contributed to the decline of their civilization.

- Researchers analyzed sediment cores from a lake near the ancient Maya city of Tikal and found that mercury levels in the water spiked around the time the city began to decline.

- The mercury pollution likely came from the Maya's use of mercury in their rituals and ceremonies, and the contaminated water may have caused health problems that weakened the population and contributed to the collapse of the Maya civilization.