This essay is part of a series designed to celebrate SOT member diversity and showcase the diverse pathways and experiences of its members.
I have a confession regarding my scientific and career journey to toxicology. Despite having taken enough coursework in anatomy, physiology, molecular biology, and similar courses to be able to complete a PhD in biomedical sciences, I never took a full semester course in toxicology along the way. My path to toxicology and consulting has been circuitous. It’s not where I started nor where I necessarily envisioned my career going in my early days. Yet, it has been an exciting path. In some cases, career choices were forced on me by external events. In other cases, choices were based on honing in on my interests and seeing opportunities that allowed me to pursue them.
I received a PhD in molecular biology and microbiology from Tufts University School of Biomedical Sciences in 1976. I did a postdoctoral fellowship at the University of Massachusetts Medical School and Harvard University, where I worked on RNA and protein synthesis in the “social amoeba” Dictyostelium discoidum, quite a distance from toxicology. I thought I would go the standard academic route: assistant professor through tenured full professor. But in June 1978, my postdoctoral advisor informed me that the fellowship I was working on had run out, and he had no additional funding. My husband was going to graduate school that fall (i.e., no income from his side), and I was expecting a baby in September. It was a very stressful time, and my self-confidence took a hit. I wound up taking an unsatisfying one-year postdoc position. The experience helped me recognize that I needed to be proactive, think about the types of science that interested me, and how I could pivot toward that in my career.
Coincidently, I happened to watch a PBS special involving occupational exposure to chemicals, which opened my eyes to toxicology! The program was about workers in Texas who made asbestos insulating sleeves and developed mesothelioma and pesticide formulators in California who developed sterility due to dibromodichlorpropane exposure. I was fascinated about the science identifying links between exposure and disease, as well as the public health element: translating this understanding into preventive activities. I realized this is what toxicology can be about! I recognized it was an area that would offer intellectual challenges and a range of career opportunities.
To further this new path, in 1979, I applied to and was accepted to the recently established Interdisciplinary Program in Health at the Harvard TH Chan School of Public Health. The program was for recent PhDs from multiple disciplines and focused on health, the environment and public policy. It was a great opportunity for me. I worked on a monograph with other fellows regarding variation in susceptibly to inhaled pollutants.
I also worked in the lab of Joseph Brain, ScD, an inhalation toxicology expert. I developed a short-term predictive bioassay of inhaled particulates using hamsters. We tested many different types of particulates: talc, granite, wood stove particulates, and even volcanic ash particulates from the Mount St. Helens volcano in Washington! Joe was a wonderful mentor; I learned much from him about scientific creativity, writing clearly and succinctly, and even how to defuse tense work situations in a productive way. I remain grateful to him ’til this day. During this period, I continued to hone my toxicology credentials, joining SOT and having my first publication in a toxicology journal, Toxicology and Applied Pharmacology, where I am an editor today.
I spent six years at Harvard. I was offered a tenure-track position as an assistant professor at Harvard and ended up turning it down. Only by experiencing the academic path did I fully recognize that I would not enjoy the challenges in getting tenure and spending a large fraction of one’s time writing grants with a low chance of success. Turning down a tenure-track position at Harvard was a surprise to a number of individuals.
Around the same time, US Environmental Protection Agency (US EPA) Region 1 (i.e., the New England states) was providing technical assistance to the New England states that were developing air toxics programs—this was before the 1990 Clean Air Act amendments that established a national air toxics program. I was hired to fill the Regional Expert in Toxicology position. I worked with staff from the states to perform risk assessments on multiple air toxics, such as trichloroethylene and perchloroethylene. I further refined my risk assessment skills and broadened the exposure scenarios beyond air to also include contaminated soil. A fellow toxicologist in Region 1 and I developed one of the first US soil lead cleanup levels by adapting a US EPA model used for risk assessment of lead in air for lead in soil. During this time, I became colleagues with a number of US EPA scientists, such as fellow SOT members Annie Jarabek and Michael Dourson. We are still friends today.
After several years at the US EPA, I knew I needed more autonomy and made another pivot, this time to environmental consulting, where I have been for over 30 years. I learned about Gradient by networking at a local risk assessment club and thought I could expand Gradient’s depth in toxicology. I became the first bona fide toxicologist at the company.
Consulting has provided me with a great variety of work. Project size, scope, subject matter, client, and chemicals of interest can all vary. This variety is one of the things that I really like about consulting. For example, using the physiologically based pharmacokinetic model for lead (the All Ages Lead Model), I have evaluated lead in food with respect to claims under the California EPA Prop 65 statute to demonstrate compliance with a particular food product. As another example, using in vitro and in vivo data, along with physical/chemical characteristics, I have evaluated the likelihood of perfluorooctanoic sulfonate (PFOA), a perfluoroalkyl and polyfluoroalkyl compound, to be absorbed through the skin from water and soil. This analysis was relevant to evaluating the potential significance of the dermal exposure pathway for PFOA.
There are often some common themes to my career as a scientist. Regardless of the context, whether it be in academics, government, or consulting, much of my work has been on metals and inhaled chemicals. My path in toxicology has been circuitous, and I am happy it got me to where I am!
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