In memoriam of Joel Pedersen

This issue of Environmental Science: Nano is a fitting way to honor and memorialize our friend and colleague, Professor Joel Pedersen. We have been missing him since his all-too-early death in June 2022. Joel was deeply embedded in the ES: Nano community as an editor, author, and reviewer, leading the way with his deep knowledge of both chemistry and environmental science as well as his passion for collaborative, careful, and impactful work. We write this tribute as his colleagues in the NSF Center for Sustainable Nanotechnology: an ambitious collaboration where Joel played a central role with his broad and deep knowledge of science and with his strong personal commitment to enhancing sustainability of the Earth's resources. With the difficult task of encapsulating all that Joel meant to us and this field, we turned to other members of the NSF Center for Sustainable Nanotechnology. Their words clearly demonstrate some of the qualities we most admire and most miss with Joel's passing.

As shared by Prof. Cathy Murphy, “I really valued the knowledge and wisdom of Joel. He crafted beautiful experiments to answer fundamental questions, and was not afraid to forge ahead into unknown territory. His work led to provocative questions about how nanomaterials interact with cell membranes, and how the environment may serve as a reservoir of misfolded proteins that cause disease.” Cathy clearly reveals the two areas where Joel chose to make important intellectual advances. First, he published many beautiful studies exploring the relationship between model membranes with varied chemistries and a range of engineered nanomaterials, often exploiting the exquisite quantitative ability of quartz crystal microbalance measurements and often pairing these measurements with collaborative computational studies. Second, he made insightful contributions at the molecular level to better understand prions and their fate in the environment. This sentiment is seconded by Prof. Juan Pablo Giraldo who shared, “Joel was a great colleague who inspired me to work on nanomaterial–membrane interactions and biomolecule coronas. We deeply miss him and his unique intellectual contributions that were instrumental for Center for Sustainable Nanotechnology research on biointerfaces.” We are confident that Joel would be heartened to know that this work continues, including with some of his mentees, in labs like those of Profs. Cathy Murphy and Juan Pablo Giraldo.

Prof. Howard Fairbrother wrote, “When I think of Joel, I always think of his commitment to the science, his attention to detail and to ‘getting it right’, and his overarching desire to contribute to a better understanding of the environment.” This concept of Joel is one that resonates with everyone who had the opportunity to work with him. Joel was a careful and thoughtful scientist. He cared much more about getting things right and about advancing the field than getting things done quickly. This careful approach to planning experiments and writing papers may have yielded fewer publications, but always yielded work of impeccable quality.

Prof. Rigoberto Hernandez presents a complementary and expansive appreciation for Joel: “Joel was a careful and deep thinker, but never averse to thinking outside the box. He was all in on collaborating in spiral feedback between his experiments and our computations, and we pushed each other to be better. I will miss him as a collaborator, a colleague and a friend.” The balance identified in this memory, both careful and expansive, is admirable and something that we would all do well to aspire to. These paired qualities of Joel's are what made him the right person to help found the NSF Center for Sustainable Nanotechnology, one of NSF's Centers for Chemical Innovation. His aim for careful molecular-level work at the edge of innovation is at the heart of the success of this center. We are all thankful that the Center for Chemical Innovation program allowed us to work together and learn from Joel for as long as it did.

Prof. Vivian Feng shared, “I miss Joel as a collaborator whom I could count on to challenge me to think critically and rigorously about my science. I also miss him as a friend who shared many intellectual interests with me about history, languages, music, and the world.” This sentiment will resonate profoundly with many people. Joel was challenging and rigorous while also being kind and thoughtful. He clearly loved his scientific work and the people who he did that work with. He was also intellectual and engaged in many areas beyond academic science, as Vivian reflects. Joel spoke many languages and appreciated a broad range of cultures and engaged intellectually in a wide range of topics.

Joel mentored a large number of students during his career, and two of them shared some thoughts about working with him. First, a former student who is now a professor herself, Prof. Arielle Mensch shared, “Joel was the ideal interdisciplinary scientist for me to look up to and aspire to. As a first-year graduate student quite uncertain about what research I wanted to pursue, it was through conversations with Joel that I started to hone in on my interests. He taught me how to bridge my love of chemistry with my interests in environmental science and biology. His course, “Toxicants in the Environment”, had a lasting impact on how I view environmental pollutants and has guided many of the questions my research group currently investigates. Joel taught me how to be a good scientist and how to write scientific papers, but most importantly, Joel taught me what it means to be a good mentor, which is something I will forever value and strive to be for my students.” Second, a student who was working with Joel during his illness and death, Caroline Anastasia, shared, “While deciding on a PhD advisor as a wide-eyed first-year graduate student in the very large chemistry department at UW-Madison, I was struck by Joel's calm yet passionate demeanor, which was a marked but welcome contrast to the frenzied feeling of much of the rest of the department. I eagerly joined his group as a result and was glad to see that same demeanor extended to his mentoring style. It was an easy decision to move to Johns Hopkins when he accepted the new job, and although I only got to work for him for 2.5 years, he had a great impact on who I am as a scientist. I am grateful for the short time I got to spend as his student.” We are confident that Joel would have been most proud that he had the admiration of his graduate students, both while they worked with him and long afterward.

In addition to being an excellent scientist, collaborator, mentor and friend, Joel was also a member of many non-academic communities, an athlete, a husband, and a father. His loss is profound, and we hope he would be pleased with the tribute in this issue. Perhaps the best way for all of us to honor Joel's memory is to take inspiration from his work and his personal philosophy; we are all lucky to benefit from his contributions to this field.

---