It has been known for a number of years that coal contains high levels of radiation, but in a new study it has been found that coal ash can be up to 10 times more radioactive than unburned coal. This is something you should know about as coal ash is the second most common type of waste in the US.
The study was led by Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment. The findings have raised concerns because currently the storing of coal ash is unregulated and it is unknown what the possible risks coal ash could have on the environment and human health.
“So we don’t know how much of these contaminants are released to the environment, and how they might affect human health in areas where coal ash ponds and landfills are leaking. Our study opens the door for future evaluation of this potential risk,” Vengosh said in a statement.
The study revealed that the levels were up to 10 times higher than the parent coal and this is due to the way the combustion concentrates the radioactivity. It was also found that the coal ash was up to five times higher than normal soil.
“Until now, metals and contaminants such as selenium and arsenic have been the major known contaminants of concern in coal ash,” Vengosh said, “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,” she added.
Because of its uranium and thorium content, coal naturally has radium isotopes and lead-210 as a chemical by-product. In Vengosh’s research it has shown how the fly ash gets its additional enrichment of radioactivity. When coal is burned the radium isotopes concentrate in the coal ash residue. The lead-210 then becomes chemically volatile and then it reattaches to the particles of fly ash, which gives it the additional radioactivity.
“Radioactive radium and lead-210 ends up concentrated in these tiny particles of fly ash, which though individually small, collectively comprise the largest volume of coal ash waste going into holding ponds and landfills,” lead author, Nancy Lauer said.
The largest utility corporation, Duke Energy, was responsible for the massive 2014 spill that had 39,000 tons of coal ash and approximately 27 million gallons of coal ash sludge leak into North Carolina’s Dan River.
A spokesman for Duke Energy said, “This issue has been researched over many years,” and that “The U.S. Geologic Survey notes the majority of coal fly ash is not significantly enriched in radioactive elements, and this does not represent a health concern for plant neighbors,” reported 10WAVY.com.
The spokesman also said that Duke Energy has tested for isotope levels and had found no hazard and that they may conduct more tests in the future if they think it’s necessary.
“The level of radioactive elements in groundwater near ash basins is either not detectable or extremely low and similar to what’s naturally in the soil,” the spokesman added.
“I think we have to treat this seriously,” Vengosh told WAVY-TV. “This should be defined as a hazardous waste and therefore should be treated as such.”