TELLURIDE – As the Telluride community anxiously awaits a decision from the Colorado Department of Public Health and Environment in the coming weeks on whether the agency will permit the nation’s first uranium processing mill in nearly three decades, the Piñon Ridge Mill, to be built about 60 miles upwind in Paradox Valley, it learned about new evidence suggesting that exposure to uranium could have broader health impacts than previously understood.
“My goal is to give you information that will inform you and help you think about this problem,” said Doug Brugge, PhD, an assistant professor of public health and community medicine at the Tufts University School of Medicine in Boston, who spoke Monday evening at the Michael D. Palm Theatre. Dr. Brugge’s presentation was titled “Dirty Secrets: the Health Effects of Uranium Mining, New Research Findings.”
Brugge, who has studied the impact of uranium mining and processing on Native Americans and testified before Congress in 2007 on those effects, went through a list of published research before an audience of about 100 people. Many of the findings were “concerning,” including one study where mice were exposed to uranium: fetal death, reduced pregnancy rate, cleft palate and skeletal defects.
Unlike studies of the past that tended to focus directly on the impacts to uranium miners and others in the industry, the newer studies are beginning to look at what might happen to wider sections of the population as a result of genetic and reproductive defects developed after living in proximity to the industry.
“It’s at least enough to be concerned that something similar might happen in humans,” he said.
Another mouse study showed, Brugge said, that relatively high doses of uranium “can have some very visible biological effects” on oocytes – the immature egg cells in female mice.
A 2007 study at Northern Arizona University, one that actually gave small doses of uranium to mice in order to mimic the comparable levels found in drinking water on the Navajo Nation, discovered that uranium is a potentially estrogenic compound.
At the lowest levels, exposure appeared to cause similar defects to diethylstilbestrol – or DES – a synthetic estrogen originally prescribed between 1938 and 1971 for women who experienced miscarriages or premature deliveries. While it was initially believed to be safe for both mother and child, it was later discovered to increase the mothers’ risk for breast cancer and the risk for a rare vaginal cancer in her female offspring, and non-cancerous testicular cysts in male offspring.
“To find that uranium did something [in mice] very similar [to DES], I think is particularly concerning,” said Brugge.
Given those and other findings suggesting a possible link between uranium and reproductive problems, Brugge admitted that he wished he had given more weight to the reproductive concerns voiced to him by Navajos he interviewed for his research.
“At the time I was a little dismissive,” he said.
Studies in Nambia and India in the mid-1990s found increases of chromosomal aberrations in workers in uranium mines, as did a 1995 study in Texas that also looked at nearby communities.
“[That study] suggests the potential for genetic damage is not just to the miners but [also] for people living . . . in the immediate proximity,” said Brugge.
While there’s a growing body of evidence pointing in the same worrisome direction, unfortunately, very little of it has been discovered in human trials.
“We know there are concerns beyond mortality,” Brugge said. “We are very concerned if a child is born with chromosomal abnormalities.”
One unpublished study done on the Navajo Nation may suggest a correlation between proximity to uranium mines, or tailings, and hypertension, diabetes and kidney disease.
“I think there’s growing evidence for kidney effects,” said Brugge. “There’s growing evidence around reproductive harm, especially if this estrogenic thing plays out. It’s a significant concern.
“I also think the genetic work is very preliminary,” he cautioned, “but is something that needs to be looked at more.”
While these findings are new and the jury is still out, the question, Brugge said, is “What decisions do you make when you have imperfect knowledge? As evidence is accumulating, where do you decide to take some action?”