A study by researchers at Duke University and the University of Kentucky published in Environmental Science & Technology found the presence of radioactive contaminants in coal ash in the Illinois, Appalachian and Powder River basins, reports Duke. "The study found that levels of radioactivity in the ash were up to five times higher than in normal soil and up to 10 times higher than in the parent coal itself because of the way combustion concentrates radioactivity." The study is the first to compare radioactivity in coal and coal ash, said researchers.
Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment, said, "Until now, metals and contaminants such as selenium and arsenic have been the major known contaminants of concern in coal ash. This study raises the possibility we should also be looking for radioactive elements, such as radium isotopes and lead-210, and including them in our monitoring efforts." He said coal ash disposal sites are not currently monitored for radioactivity.
The Illinois basin exhibited the most levels of radioactivity, followed by the Appalachian and then the Powder River, which is in Wyoming and Montana, reports Duke. "The tests also showed that the ratio of radium to uranium in the parent coal was consistent with the ratio found in its residual coal ash." (Read more)