Some Western tailings piles, like those outside of Monticello, Utah, or Grand Junction, Colo., have been cleaned up. But those on tribal lands have fallen through yawning bureaucratic and regulatory gaps. It's estimated that up to 25 percent of unregulated water sources on the Navajo Reservation exceed federal drinking water standards for uranium. And many families still haul water from these wells, despite warnings by health providers and advocacy groups.

In her lab experiments, Raymond-Whish applies concentrations of uranium that match those of water supplies in parts of the Four Corners, at or slightly above the current EPA standard. She will treat the mammary cells - which come bathed in a red wash of nutrients that resembles weak Kool-Aid - twice in nine days with differing doses. She will then collect the breast cells, extract their protein signatures, and use a tedious process to examine differences in the number of their estrogen receptors. She will also feed rats different mixtures of uranium-tainted water and examine their mammary glands for altered development. She will compare those results to rats fed a well-known synthetic estrogen, diethylstilbestrol, or DES, and to rats that have drunk plain tap water. She'll look for changes to the mammary glands' terminal end buds, lobules and milk ducts, changes that may make them more prone to breast cancer. The work is controversial, and its implications, both for the science of breast cancer and for the treatment of past and future mining pollution, could be profound.

Like Marie Curie over a century before, Raymond-Whish is both repelled and fascinated by the heavy element's mysterious abilities to alter living cells. In some respects, Raymond-Whish and Curie are not dissimilar. Curie, a Polish Jew working in anti-Semitic France, was the first woman to teach at the Sorbonne. As the first Navajo to be awarded a Ph.D. in the Biology Department of NAU, Raymond-Whish displays a confident ease in navigating a different dominant culture. Like Curie, she is driven by an unrelenting curiosity.

If it was a difficult journey from being Rookie of the Year in barrel racing to creating stunning presentations on heavy metals, Raymond-Whish doesn't show it. She moves through the fluorescent-lit lab in a quiet, deliberate fashion, her long, shiny hair neatly in place.

 "I like it that you're working on something no one knows the answers to and you're finding the answers," says Raymond-Whish. She grew up in Colorado and New Mexico with her siblings, stepfather and mother, who was a high school guidance counselor before becoming a breast-cancer activist. Forty-four percent of Navajos do not graduate from high school, but Raymond-Whish's mother made sure that she did. "Everybody's saying it's a big deal for me to get a Ph.D. For me, nothing less was expected than, 'You're going to college.' "

The lab work is routine - even tedious - but it's also demanding and consuming. She is tired. With her oral defense looming before a committee of distinguished faculty, she doesn't slow down. In the mornings, she drops her two kids at school. Her husband, Bryan, a Wichita Indian, works nearby in the university's admissions office. She shuttles from the tissue culture room down a long linoleum-floored corridor to the animal histology lab with its wide-screened computer that magnifies mouse ovary sections 40 times over. Scrolling across the screen to count the follicles is her least favorite job. "I get motion sick," she says. The ovaries dominate the screen like giant pink potato chips, lightly salted.


The science of endocrine disruptors, which studies chemicals that mimic hormones, is a little over 10 years old and still rife with skeptics. It has only been in recent years that very low doses of chemicals - in the parts-per-billion range - have been measurable. (A part per billion is the equivalent of one kernel of corn in a corn-filled silo 45 feet tall.) But natural hormones do their work at these very low levels in the human body. One theory holds that certain environmental chemicals, both natural and man-made, can bind to and deceive the hormone receptors.

These receptors are the signal towers that trigger - or prevent - cellular responses that govern everything from metabolism to sex. Artificial chemicals scramble the signals. They appear to be interfering with normal cellular communication and altering how and when the cells, glands and organs develop. Endocrine disruptors have been implicated in obesity, infertility and the timing of puberty as well as in cancer. When many older women stopped taking synthetic estrogen a few years ago, breast cancer rates in this country dropped for the first time in 40 years. DES, the control substance used by Raymond-Whish, was given to pregnant women to prevent miscarriages up until 1971. Their daughters, who were exposed to it in the womb, have been stricken with unusual reproductive cancers, and recent studies have shown an increased risk of breast cancer as well.

Typical carcinogens cause a cell's DNA to mutate, eventually leading to cancer. Radiation causes the fragile chains of DNA to break, also leading to errors and mutations. Scientists know a lot about these two types of cancer-causing agents. But endocrine disruption is far more mysterious.

Which is why scientists like Raymond-Whish find themselves at a unique moment in science, just as the traditional models of understanding disease are shifting. The field of breast cancer research in particular is driving the debate. Chemicals such as atrazine and DDT (an herbicide and a pesticide, respectively), plastics - such as the bisphenol A compound found in Nalgene that was banned from baby bottles this spring in Canada - and now uranium, are challenging and confounding scientists seeking to understand the actions of chemicals in the human body.

In the dynamic field of environmental health, toxicologists - who study traditional dose-response curves of carcinogens - and endocrinologists - who study extremely low levels of chemicals that do not always follow expected linear curves - frequently disagree. Because it is not yet known exactly how chemicals like uranium act upon cells, some scientists flatly dispute Raymond-Whish's findings. "Uranium is not plausibly linked as an endocrine disruptor," says toxicologist Margaret Ruttenber, director of the environmental health studies program of the Colorado Department of Public Health and the Environment. "There is an absence of a known mechanism."