Uranium Mining-"It's the Latency Effect, says Prof

(From the Roanoke Times 01/11/2008)


Risk assessment a complex task

Experts described the top threat from uranium mining, and regulators cited thorough efforts.

By Duncan Adams 981-3324

One thousand years.
If uranium mining and milling of ore happens someday near Chatham, Va., Virginia Uranium or another company involved could be required by Nuclear Regulatory Commission regulations to design a disposal system that can safely impound mining wastes for a millennium.
The design must provide "reasonable assurance of control of radiological hazards to be effective for 1,000 years, to the extent reasonably achievable, and, in any case, for at least 200 years," according to the NRC.
Related regulations apply to conventional open pit or underground mining. Different disposal regulations would apply if other methods are used.
In short, uranium mining wastes can be dangerous for generations.
Milling leftovers, called tailings, contain radiation and heavy metals. Among other hazards, the tailings release radon gas and can become dust in the wind and groundwater contaminants.
Experts about the dangers of uranium mining say the tailings can present the greatest hazard to human health and the environment.
"My concern would not be so much about radiation from the ore," said Susan Pinney, an associate professor and epidemiologist at the University of Cincinnati. "Usually, exposure comes from the tailings."
Pinney added, "Inhaling uranium dust is really the source of the body burden of uranium."
An early step in preparing uranium for use in a nuclear reactor is the milling process, which crushes and grinds the ore into powder, called yellowcake.
Paul Robinson, research director for the Southwestern Research and Information Center in New Mexico, said "the way tailings are managed determines whether any mining facility is safe."
Generally, though, Robinson believes all uranium mining is dangerous.
Utah State University professor Susan Dawson's primary research interest is occupational and environmental health.
For more than 15 years, she and her husband, professor Gary Madsen, have studied the impacts of uranium mining and milling on the people of the Colorado Plateau.
Dawson said past studies by the National Institute for Occupational Safety and Health have found increased health risks for certain disorders among people who have worked at uranium mills.
According to NIOSH, research has revealed higher than expected rates of blood cancers, chronic kidney disease and nonmalignant lung diseases among mill workers. Lung cancer deaths also were higher than expected.
Modern controls might make milling work significantly safer, Dawson said.
The problem, she said, is that evidence of health problems often takes years to emerge.
"There's a latency effect," she said. "It takes 20 to 30 years for some of these diseases to appear."
Jack Dunavant, chairman of the Southside Citizens Committee, a group opposing Virginia Uranium's plans, shared a similar observation.
"If you get exposed to radiation, you are not going to turn immediately into a block of salt," he said. "Your health risks are a function of time."
But Luke Popovich, a spokesman for the National Mining Association, said regulation of modern uranium mining is intense and thorough.
"Before one spoonful of dirt turns over, Virginia Uranium will have to submit extremely comprehensive environmental assessments and design plans for the mine and waste disposal sites," Popovich said.
Virginia Uranium officials want the state to allow an independent, objective study that will determine whether uranium mining and milling can occur safely at a rural site called Coles Hill.
Walter Coles, chairman of Virginia Uranium, said the study should show which mining approach is best -- whether open pit, underground or "in situ leaching" -- a process that injects sulfuric acid or other chemicals into the ore body to milk out the uranium in a solution sucked to the surface.