Fallon cancer cluster research may connect tungsten to reproductive issues

While researching the cancer cluster in Fallon, where 17 children were diagnosed with leukemia between 1997 and 2004, Dr. Mark Witten, a toxicologist at the University of Arizona, observed something that surprised him: Exposing mice—young or old—to tungsten resulted in damaged testicular tissue.

Witten had been giving mice tungsten in their water of an amount similar to that found in Fallon water. He wanted to investigate what effect exposing older male mice to tungsten would have on their offspring. This approach was used because the Fallon fathers of the leukemia patients tended to be older than average fathers. The problem is, the mice weren’t reproducing. Witten looked at their testicular tissue: “The cells were damaged, which is why they couldn’t get the females pregnant,” he said at a cancer cluster symposium at the University of Nevada, Reno in early October (See “Family ties,” Green, this issue). He repeated the experiment with younger mice and found that 20 percent of the testicular tissue in tungsten-exposed young male mice was damaged.

Witten said prenatal exposure to tungsten may increase susceptibility to viruses, and that tungsten exposure may be associated with reproductive disease, but he emphasized these results are not conclusive and can’t be used to link tungsten to leukemia.