An analysis of sediments from five North Carolina lakes near coal-burning power plants has found that coal ash pollution of surface waters has been more persistent and widespread than was previously known.
The findings, from scientists at Duke University and Appalachian State University, show that large quantities of coal ash have been transferred and deposited in lake sediments since the beginning of coal operations in North Carolina.
“The bottom sediments of a lake represent a complete history of what has fallen into the lake water and settled to the bottom,” said Avner Vengosh, a Duke University Distinguished Professor of Environmental Quality at the Nicholas School of the Environment. “Using our age-dating methods, we were able to go back in time, in some cases even before the coal plant was built, and reconstruct the history of the lakes.”
Coal ash is the residual material from burning coal to generate electricity, and is known to contain hazardous metals including lead, chromium, cadmium, mercury, arsenic, selenium and molybdenum, many of which have been tied to human cancers and other health effects.
Read more at Duke University
Image: Bottom sediments from five North Carolina lakes near coal-fired power plants shows coal ash contamination that likely entered the lakes by three different routes. (Credit: Avner Vengosh)