Meet EPA Research Limnologist Dr. Ryan Lepak
EPA Researcher Dr. Ryan Lepak focuses on understanding pathways of PFAS and mercury exposure in fish across the Great Lakes. Using historical fish archives, Ryan and the team construct timelines of PFAS and mercury exposure to analyze lakes’ responsiveness following the reduction of industrial emissions, particularly the voluntary phase-out of PFOS in the early 2000s. With a background in chemistry and environmental toxicology, Dr. Lepak combines his passion for multidisciplinary research with his love for the Great Lakes, striving to connect scientific findings with community engagement to promote environmental health and sustainability.
Tell us about your background.
I hold a bachelor’s degree in chemistry with a minor in mathematics from UW La Crosse. For graduate school, I attended UW-Madison, where I pursued both my master’s and Ph.D. in their interdisciplinary program, “Environmental Chemistry & Technology,” which is part of the civil and environmental engineering department. My Ph.D. research focused on mercury cycling within the Great Lakes, and I also minored in environmental toxicology.
When did you first know you wanted to work in environmental science?
My passion for environmental science began during my first fieldwork experience as an undergraduate. I was immediately captivated by the process of collecting water and fish samples to measure mercury levels. It was far more engaging than the stress of preparing for medical school, which had been my original career path.
What do you like most about your job?
The EPA offers me the opportunity to work in multidisciplinary spaces, enriching the scientific community’s understanding of environmental issues. I appreciate the variety that comes with collaborating across different scientific fields. After conducting research in diverse locations like Alaska, the Florida Everglades, and even tropical Africa, the Great Lakes remain my favorite place to study. Being able to witness the sunrise or sunset of any of the lakes is a truly unmatched experience. Plus, having access to our own research vessels adds a unique dimension to our work.
How does your science matter?
Our work is often focused on the measurable concentration of contaminants, which is crucial for stakeholders interested in reducing environmental and human exposure. However, I believe that true progress comes when we understand the “why” behind these issues. When we identify the causes and potential pathways, we can develop strategies to prevent future contamination and understand how historical efforts to reduce emissions affect fish populations in real-time.
If you weren’t a scientist, what would you be doing?
I’d probably be trying to open a top-notch taco restaurant in Duluth – one that features local culture and fish. Cooking is a passion of mine, especially when it comes to preparing wild game in creative ways – it’s a great stress reliever. That said, my partner often reminds me of the demanding life in the kitchen, and she’s not wrong!
What advice would you give to a student interested in a career in science?
Prioritize people and relationships over projects and productivity. The most influential mentors I had were those who cared about me as a person, not just my work. Although productivity is important, the growth and leadership skills you develop from supportive relationships can be transformative. My goal is to be the kind of mentor that my students can rely on without hesitation, guiding them to reach their goals, even if those goals lie outside the field of environmental science.
If you could have any superpower, what would you choose?
Teleportation, without a doubt. Imagine the freedom of visiting the world’s most beautiful places at the drop of a hat. I’d want a teleportation style that lets me bring loved ones along – just like apparition in Harry Potter.
What do you think the coolest scientific discovery was and why?
It’s hard to choose just one, but I’d highlight the scientific advancements made in creating COVID-19 vaccines. The speed and efficacy with which researchers developed these vaccines to protect people around the globe is truly remarkable.
If you could have dinner with any scientist, past or present, who would you choose and what would you talk about?
There are two scientists who profoundly influenced my development in science, teaching me about respect, kindness, and confidence in research. Although I won’t name them, I wish I had more time to learn from their wisdom. Our conversations would touch on science, life, and the joy of shared experiences – whether it’s fishing on a dock or enjoying a drink while discussing research.
You are stranded on a desert island; how do you use science to survive?
Surrounded by saltwater with no trees or anything? Oh boy, I think I’d start swimming.
What do you think is our biggest scientific challenge in the next 20/50/100 years?
While climate change is undoubtedly a critical issue, I believe that controlling misinformation and maintaining ethical use of generative artificial intelligence are equally important. It’s a complex challenge with no simple solutions, but as we face these hurdles, it’s crucial to stay compassionate and to seek out diverse perspectives.
Editor's Note: The opinions expressed herein are those of the researcher alone. EPA does not endorse the opinions or positions expressed.