Tufts Medicine

Radioactivity isn’t the only thing to fear about uranium. Ingested, traces of the toxic metal can damage kidneys and boost the risk of cancer when consumed over a year or more. Now a recent investigation by the Associated Press has shown that many thousands of people living in California’s agricultural areas are taking in uranium at levels considered unsafe by state and federal standards.

“Uranium, the stuff of nuclear fuel for power plants and atom bombs, increasingly is showing up in drinking water systems in major farming regions of the U.S. West—a naturally occurring but unexpected byproduct of irrigation, of drought and of the over-pumping of natural underground water reserves,” according to the story, published late last year. The AP focused on California’s central farm valleys, an area roughly 250 miles long and encompassing major cities, citing a claim from the U.S. Geological Survey that as many as one in 10 public water systems in the region had elevated levels of uranium.

“We should not have any doubts as to whether drinking water with uranium in it is a problem or not. It is.”

Schools in the area have stopped using public drinking fountains and are trucking in bottled water instead. “We don’t have a choice,” said one elementary school principal quoted in the story. “You do what you have to do.”

Geologists and other experts are still trying to figure out exactly how the uranium has spread through public water systems and private wells the way it has, but they suspect the rise of farming over the past 150 years has been a contributing factor. Mountain snowmelt in California washes uranium-laced sediment down to the flatlands. Irrigated plants leech uranium from the soil, and the metal eventually sinks down into aquifers tapped by wells.

Doug Brugge, a professor of public health and community medicine at Tufts, has been concerned for years about the deleterious effects of uranium on people exposed to it. “We should not have any doubts as to whether drinking water with uranium in it is a problem or not. It is,” he told the AP. “The larger the population that’s drinking this water, the more people that are going to be affected.”

Research teams at Tufts and the University of New Mexico have joined forces to explore uranium’s health impacts in more detail. “There has not been an appreciation of the number of people exposed”—the issue has not drawn the attention it deserves, said University of New Mexico researcher Johnnye Lewis. Early findings suggest that long-term exposure to uranium also can lead to reproductive and genetic damage, among other problems.