Remembering Karen Wetterhahn

On June 8, 1997, the Dartmouth community suffered a tragic loss: the death of Karen Wetterhahn, a beloved professor. A specialist in metal toxicology, Wetterhahn had spent over 20 years in the Chemistry Department elucidating the mechanisms of chromium and nickel metabolism in cells. In August of 1996, while following standard safety protocol, Wetterhahn spilled a few drops of dimethyl mercury onto her latex glove. Five months later, she began to notice curious health problems – impaired coordination, nausea, weight loss, and slurred speech. As was revealed in subsequent laboratory tests, acute mercury poisoning was to blame for these symptoms. The latex gloves Wetterhahn had worn were thought to be protective, but were in fact highly permeable to the toxic compound. The level of mercury in her blood was 80 times the threshold of toxicity (1). Despite intense chelation therapy, her condition worsened rapidly. In February, she fell into a coma. Four months later, Wetterhahn died at the age of 48, leaving behind loved ones, colleagues, and students, who were all devastated by her death.

Wetterhahn was known as an inspired researcher and an accomplished scientist. She received her undergraduate degrees in chemistry and mathematics from St. Lawrence University, and completed a doctorate in inorganic chemistry and physical biochemistry at Columbia University. Soon after, she began her career at Dartmouth, becoming the first female professor in the Chemistry Department (1). Wetterhahn specialized in studying how carcinogenesis is induced by chromium and nickel, and was a tremendous force in her field. A prolific author, she contributed to over 85 research papers. Her work illuminated the mechanisms by which chromium damages DNA and promotes cancer development. According to Brooke Martin, who worked in the Wetterhahn lab as a doctoral student, Wetterhahn “established one of the major paradigms in chromium toxicology” (1).

In 1995, Wetterhahn began the Toxic Metals Research Program at Dartmouth, after receiving a $7 million grant from the National Institute of Environmental Health Sciences to study how toxic heavy metals affect the human body (1,2). The grant reflected both the strength of her past work and her potential to further expand our understanding of metal toxicology and carcinogenesis. The development of the Toxic Metals Research Program also highlighted Wetterhahn’s promotion of the interdisciplinary study of science. John Winn, a Professor of Chemistry who was the chair of the department at the time of Wetterhahn’s accident, recalls that she demonstrated to her colleagues the importance of chemistry of the life sciences. Winn credits Wetterhahn with the development of strong research connections linking chemistry to other departments (3). In her roles as Associate Dean of the Sciences and later, Acting Dean of the Faculty, she worked to encourage such collaboration, arguing that partnership enriches scientific research (1).

In addition to her research, Wetterhahn was passionate about teaching and getting students excited about science. She was an advisor and mentor to scores of postdoctoral researchers, graduate students, and undergraduates in her lab (2). Winn asserts that “one of her goals from day one was to be able to encourage all students who were interested in science in general and in her work in particular to have opportunities here at Dartmouth to do that kind of work” (3). Concerned about the higher rate of dropout from the sciences among undergraduate women compared to men, Wetterhahn worked with Carol Muller ’77, who was then the Assistant Dean of Engineering, to develop the Women in Science Project (WISP) in 1990-1991 (1). Since its inception, the program has grown significantly. The stated goal of WISP is to “encourage more Dartmouth women to persist in science, math, and engineering by creating and fostering a supportive academic and social climate that will aid women in pursuing science as a major and a career” (4). WISP works toward this objective by providing first-year women with research experiences that will engage their interest in science, and encourage them to develop strong research skills. Since the initiation of the program, 1255 first-year women have participated in research internships with over 300 faculty sponsors (5). WISP also seeks to connect upper-class women in science with their first-year counterparts, in the belief that peer mentoring gives students the opportunity to share advice and information that will help them succeed in their scientific pursuits. Reflecting on the success of the program with respect to Wetterhahn’s goals, Winn commented, “It has been more than what she hoped for in the sense that so many faculty have embraced it as a way of getting really good students into their labs” (3). The success of WISP and the continuing support that it provides to undergraduate women in science indicate Wetterhahn’s profound impact on Dartmouth.

Wetterhahn’s death provoked an intense investigation by her colleagues to discover how standard safety precautions had failed. Material Safety Data Sheets (MSDS) for dimethyl mercury at the time recommended the use of rubber or neoprene gloves, or “chemically impervious gloves” (1), upon which the MSDS did not further elaborate. The latex gloves in Wetterhahn’s lab were tested for their permeability to dimethyl mercury, and the results suggested that the nonpolar compound could pass through a typical latex glove in under 15 seconds (1). According to Winn, knowing the structure of dimethyl mercury and latex, it is unsurprising that the latex gloves failed to serve as a barrier. However, he argues, “She wasn’t at fault. It wasn’t something she should have done differently, given the information everyone had at the time” (3). After Wetterhahn’s death was reported to the Occupational Safety and Health Administration (OSHA), safety guidelines were changed to reflect the incredible risk associated with the use of dimethyl mercury. The original memorandum produced in response to Wetterhahn’s death may be found on OSHA’s official website (6). Within the notice are the revised recommendations for the safe use and handling of dimethyl mercury. First among these recommendations is a discouragement of the future use of dimethyl mercury, unless strictly necessary. This information came at an enormous cost, and, thankfully, it will help to protect the health and safety of researchers to come.

A decade later, new students and faculty pass through the halls of Burke and Steele. Although many are aware of the accident that resulted in Wetterhahn’s death, there are fewer who are as familiar with the events of her life. Winn remembers her even temper and vibrant personality: “I always heard her laughing – I never heard her yelling. For the most part, I’ll remember her giggle” (3). She was passionate about her work and equally devoted to her family, including her husband and her two children, who were teenagers at the time of her death (1). When asked about what the past ten years would have entailed for Wetterhahn, Winn imagined more of the same: competent stewardship of the Toxic Metals Research Program (now directed by Professor Joshua Hamilton, who worked as a postdoctoral student in Wetterhahn’s lab), further illuminating research in metal toxicology, and the raising of her children. This past June, Winn was struck by the fact that ten years had passed since her death: “I think that Karen’s memory is still quite strong among those of us who knew her, and we pass that on to those who weren’t here when she was. I think of her often” (3).

As students who are deeply interested in scientific research, we at DUJS recognize how exceptional Karen Wetterhahn was, as a scientist, a teacher, and an individual. We honor her enthusiasm for her work and her dedication to helping students explore science. She is remembered by those who knew her as a brilliant researcher and an insightful mentor, and Dartmouth was changed for the better as a result of her work. This year marks the tenth anniversary of the dedication of the annual undergraduate scientific research symposium to Karen Wetterhahn. It serves as a fitting tribute to her legacy at Dartmouth.

Acknowledgements
The author would like to thank Professor John Winn for his thoughtful reflections, which were invaluable in the writing of this article.

References
1. K. Endicott, Dartmouth Alumni Magazine, April 1998. Available at: http://www.udel.edu/OHS/dartmouth/drtmtharticle.html (16 January 2008).
2. N. Serrell, A Tribute to Karen Wetterhahn, Available at: https://sites.dartmouth.edu/toxmetal/about-us/a-tribute-to-karen-wetterhahn/ (16 January 2008).
3. J. Winn, personal communication.
4. Women in Science Project at Dartmouth College: Mission Statement (2008). Available at: http://www.dartmouth.edu/~wisp/menu_test_frames.html (28 March 2008).
5. M. Pavone, personal communication.
6. U.S. Department of Labor, Occupational Safety and Health Administration, Dimethyl Mercury: Hazard Information Bulletin (15 February 1991). Available at: http://www.osha.gov/dts/hib/hib_data/hib19980309.html (28 March 2008).