An Aug. 15 Duke University study details just how toxic coal ash is: Samples taken from the Dec. 28, 2008, coal-ash spill near Kingston, Tenn., contain high levels of toxic metals and radioactive elements, including arsenic, mercury and radium. As the sludge dries, risk of exposure via inhalation increases dramatically, the Duke team found.
“Our study highlights the high probability that as the ash dries, fine particulates enriched with these elements will be re-suspended in the air as dust and could have a severe health impact on local residents or workers who inhale them,” says Avner Vengosh, associate professor of earth and ocean sciences at Duke’s Nicholas School of the Environment. And the smaller the particulates, the greater the concentration of toxins, he adds. Vengosh also notes the potential risk to aquatic life in affected rivers, the Cinch and Emory, as well as tributaries: High concentrations of mercury have been found in samples downstream of the spill.
The Tennessee Valley Authority clean-up efforts have focused on preventing the ash from becoming airborne, and state/federal monitoring has revealed no violations of the National Ambient Air Quality Standards for particulates in the air.
Funded by a one-year, $105,000 grant from the National Science Foundation, the Duke team is conducting a systematic monitoring program to evaluate the origin of high mercury levels found in the river sediments and to monitor its effects on the aquatic life. The research team included graduate students and researchers from the Nicholas School, the Duke Comprehensive Cancer Center and the Georgia Institute of Technology.
— Margaret Williams
(photo by Avner Vengosh)