Making a name in medical geology: Brenda Buck


Hiking, horseback riding, and working on her family’s remote Montana ranch as a child, Brenda Buck was filled with questions: Why does a river flow here and mountains loom over there? Why does this field look different from that one? Geology, her parents told her, is where the answers lay. “Okay,” she replied, “that’s what I want to do.” And she has now, for more than 20 years.

It turns out, though, that the actual trajectory of her career would be much harder to foresee. Buck, a professor of geology at the University of Nevada, Las Vegas, has studied everything now from agronomy to ancient soils to archeology—and, lately, the most unexpected subject of all: medical geology. How did she arrive here? By doing the same thing she did as a child, she says: “You keep chasing the questions that come up.”

Here’s what else she had to say to Soil Horizons about her path.

Soil Horizons: Let’s start with medical geology? What is it?

Buck: Medical geology is an interdisciplinary field studying how the earth affects human and animal health. Because soils are commonly the interface between the earth and people or animals, soil science is an extremely important component of medical geology.

Soil Horizons: What’s a typical day like for you as a medical geologist? Do your activities differ much from those of soil scientists and geologists in other fields?

Brenda Buck

Buck: What’s different in my work is that I have to speak many different scientific “languages.” To be successful in medical geology, you need to be able to communicate with medical doctors, toxicologists, epidemiologists, public health specialists, geologists, mineralogists, soil scientists, and chemists. And everybody speaks a different scientific language and has different ways of visualizing and tackling problems. I spend a significant amount of time gathering these specialists together and facilitating everyone working together as a team. This often requires me to translate what one person said in a language that another scientist can understand. I never thought this was a special talent until I realized how often and easy it is for people to not understand one another. This leads to friction and misunderstanding that can slow or prevent collaboration.

Otherwise, like most academics, I am busy teaching all levels of students from high school students working in my lab, to undergraduates, graduates, and postdocs, as well as supervising faculty who work with me. I also run a self-supported research laboratory, publish papers, do fieldwork, serve on committees, and somewhere in there try to find a “life”!

Soil Horizons: How did you get interested in geology and soil science?

Buck: I knew I wanted to be a geologist when I was five years old as I worked on my family’s cattle ranch in western Montana. Later, as a graduate student working for the U.S. Geological Survey (USGS) as a summer intern, I was introduced to paleosols (ancient soils that are buried and preserved and are now part of the rock record) and found the idea of ancient landscapes fascinating. Then, while doing my M.S. thesis on paleosols, I wanted to better understand modern soils because geologists often say, “The key to the past is the present.” This drove me to pursue my Ph.D. in agronomy. Since then I’ve worked on arid soils and paleosols all over the world—in 18 countries on six continents so far—and answered questions pertaining to archaeology, paleoclimate, landscape evolution, heavy metal and radionuclide contamination, geologic hazards, tectonics, soil genesis, and other applications.

Recently, I started doing work on dust in the Las Vegas Valley and this led to my work in medical geology. Currently, we have an ongoing human health risk assessment, for the Bureau of Land Management, on mineral dust from the Nellis Dunes Recreational Area. Our research group includes toxicologists, medical doctors, and biochemists, as well as geologists, soil scientists, and geochemists. We’re particularly interested in this area because approximately 300,000 people a year use Nellis Dunes for off-road-vehicle (ORV) recreation, and the dust contains the highest concentration of arsenic yet measured from a natural surface. Importantly, dust is generated by both natural (wind) and anthropogenic (ORV driving) processes.

Soil Horizons: Tell me about dust: Why is it important to study in the context of human health? Is human exposure to dust increasing? Or are we just now realizing the potential health effects?

Buck: Dust is important to study in the context of human health because the air we breathe is an enormous source of exposure. And human exposure to dust is increasing, especially with expanding and accelerating land use: recreation, urbanization, farming, and so on. All these activities change the surface of the land, and this increases dust—more so in drier climates.

The potential health effects have long been recognized, so this isn’t new. What’s needed though is better interaction between specialists. For example, there is a long history of medical professionals performing experiments with mineral dusts to determine carcinogenicity. But, they often didn’t work with geologists or soil scientists to adequately characterize the materials they were testing because they weren’t aware of the complexity of natural dusts or even individual minerals. Therefore, there is much more research that’s needed to know which specific minerals, in what crystal form, with what chemical compositions, and in what combinations and quantities, cause disease. There’s also much work to be done to better understand the transport of these materials into human populations.

As far as personally realizing the health effects, I think that depends on your experience. I certainly had no idea what the potential consequences to dust exposure were until a few years ago. I’ve spent most of my life digging soil pits and breathing in enormous amounts of dust without giving it a second thought. I think it would be very beneficial for soil scientists in particular to become more aware of the potential negative health effects of mineral dusts and do more to protect themselves and, especially, their students.

Soil Horizons: What’s the research question most on your mind right now?

Electron micrograph of erionite, a mineral

Buck: Right now I’m really excited to work with the USGS’s John Wesley Powell Center for Analysis and Synthesis, looking at the distribution of fibrous erionite in the United States and the implications for human health. Fibrous minerals are a concern for health because some silicate minerals can form long, very thin crystals that can cause lung disease.

Erionite, for example, is a fibrous zeolite mineral that in laboratory studies has been found to be between 200 to 800 times more carcinogenic than some asbestos minerals. But unlike asbestos minerals, erionite is not regulated. Erionite is the cause of an epidemic of malignant mesothelioma in Cappadocia, Turkey, and my colleagues recently found that erionite-containing rocks were being used to gravel roads in North Dakota. (It’s important to note, though, that fibrous minerals are not hazardous unless they become airborne, making them available for human exposure.) 

For our study, we’re gathering existing GIS datasets relating to fibrous mineral occurrences, local and regional geology, soils, climate, dust generation potential, population density, and the prevalence of relevant diseases. We’ll use this information to help reduce the risks of future exposure and disease, and to better understand the mechanisms that cause some silicate minerals to cause disease, while others do not. This project is just starting, and the Natural Resources Conservation Service has been a huge help in contributing soils databases to this project.

Besides erionite, I’m also working with scientists at the University of Hawaii School of Medicine to test if other fibrous minerals could cause disease. In particular, we’re interested in two fibrous minerals that commonly occur in arid soils, palygorskite and sepiolite.

Soil Horizons: What’s the most rewarding thing you’ve learned through your research?

Buck: The most rewarding part of my research is knowing that our findings will save lives. Through our work, we can help people avoid exposure to hazardous materials and lead healthier and longer lives.

Soil Horizons: Is medical geology a growing field? Any advice for students who might want to pursue it in the future?

Buck: Medical geology is a growing area of research, and there’s definitely a demand for people who can successfully communicate in more than one scientific field—whatever field you choose. My advice for students interested in this topic—or any multidisciplinary topic—would be the following:

  1. Become an expert in something that isn’t just medical geology. You need a backup plan in case you can’t find a good fit for your skill set—especially initially.
  2. Become exceedingly well trained in all that you do. You’ll be competing with people who only focus on one field, whereas you need to be an expert in at least two, if not more.
  3. Expect to be lonely. My experience is that people in each field often will perceive you as an outsider and be reluctant to embrace you into their group. Hang in there…this, too, will pass.
  4. Be creative about finding funding. Traditional sources may not want to fund research that doesn’t fit nicely into their boxes.

However, remember that the major breakthroughs in science generally occur at the intersections between disciplines. No matter what field(s) you go into, I think the extra work it takes to be able to communicate with other disciplines is well worth it! I don’t regret my choices at all!

This article originally appeared in the Sept.-Oct. 2012 issue of Soil Horizons.



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