Senior Staff

Karolina Mellor's picture Karolina Mellor, Ph.D.

Program Director

The Global Green Chemistry Innovation and Network Program

- Karolina oversees all education, outreach and international partnerships at the Center. Before coming to Yale in 2014, Karolina received her Ph.D. in molecular biology from the University of Virginia. She also worked at the University Innovation Licensing and Ventures Group where she evaluated patent strategies and explored commercial potential of technologies developed at the university. Now, Dr. Mellor oversees the Yale-UNIDO collaboration that brings green chemistry to practitioners in emerging economies around the globe.  She works with industry, academia and governments to advance dissemination green chemistry and sustainability.

- Outside of the lab, Karolina is an avid runner, salsa dancer and a foodie. She also loves sci-fi and fantasy in any shape or form.


Krystal Pollitt's picture Krystal Pollitt, Ph.D.

Assistant Professor of Epidemiology (Environmental Health Sciences) and Chemical and Environmental Engineering

Dr. Pollitt’s research explores the human exposome through characterisation of environmental and biological samples using analytical and mass spectrometry (MS) techniques. Her group has developed various mass spectrometry (ICP-MS, LC-MS and GC-MS) to measure exposure to complex mixtures of trace elements and organic compounds. She has applied these exposure assessment methods in numerous in epidemiological studies.

Lars Ratjen's picture Lars Ratjen, Ph.D.

Associate Research Scientist

- Lars likes changing places and learning things from nature and people. Before coming to Yale in 2022 he spent almost 9 years in Chile, working for Fraunhofer, at the interface of academia and industry. He is focused on interdisciplinary projects, ranging from chemistry over engineering to environmental health. He is also involved in helping other countries in sustainable development in the Yale-UNIDO initiative, which he is very passionate about.

- Out of the lab Lars enjoys watersports, cooking and trying new food, reading pretty much anything and he is an occasional artisan. There are (almost) no animals he does not like.

Predrag Petrovic's picture Predrag Petrovic, Ph.D.

Associate Research Scientist

- Predrag obtained a Ph.D. degree in organometallic chemistry by applying experimental and theoretical approaches to studying non-covalent interactions in organometallic complexes. In 2017 he joined the Center where his main research focus is setting a foundation for the methodology that will help safer chemical design that complies with the 12 Principles of Green Chemistry by using various computational tools (DFT, ab initio, etc.).

- In his free time, Predrag loves reading sci-fi and fantasy books, riding a bike, taking long walks and (not-so-long) hikes, and very occasionally playing video games .

Yuan Yao's picture Yuan Yao, Ph.D.

Assistant Professor of Industrial Ecology and Sustainable Systems

Dr. Yao's research is motivated by the increasing need for sustainable solutions that can support industrial development without compromising the environment or depleting the resources for future generations. Her research investigates how emerging technologies and industrial development will affect the environment. She uses interdisciplinary approaches in industrial ecology, sustainable engineering, and machine learning to develop systems analysis tools to support engineering and policy decisions towards sustainability. She develops new methods and integrated modeling frameworks to assess, advance, and optimize industrial systems for improved environmental and societal outcomes.

Brooke DeRosa

Program & Financial Administrator

-Brooke provides finance and budgeting support to the UNIDO project. Her prior experience includes public accounting audits of manufacturing and service sector clients, and management of financial reporting and development of budgets in the hospitality industry.

-Her interests include sourdough bread baking, outdoor activities like tennis and gardening, and volunteer work with individuals experiencing food insecurity.


Hanno Erythropel's picture Hanno Erythropel, Ph.D.

Associate Research Scientist

- Hanno supports the oversight of research at the Center. He is passionate about building interdisciplinary bridges between chemistry, chemical engineering, material science, toxicology, and other disciplines to create green chemistry solutions using a systems thinking framework. His work has focused on valorizing different types of biomass, developing highly functional yet biodegradable and non-toxic materials such as plasticizers, and better understanding the composition and content of tobacco products.

- Outside of the lab, Hanno enjoys exploring new places and countries and learning about local language and culture. Hanno is also an avid bike-rider.


Nicole Deziel's picture Nicole Deziel, Ph.D.

Assistant Professor of Epidemiology (Environmental Health Sciences) and Chemical and Environmental Engineering

Dr. Deziel obtained a Master’s of Industrial Hygiene and Doctorate in Environmental Health from the Johns Hopkins Bloomberg School of Public Health. Her research involves applying statistical models, biomonitoring techniques, and environmental measurements to provide comprehensive and quantitative assessments of exposure to combinations of traditional and emerging environmental contaminants. Her exposure assessment strategies aim to reduce exposure misclassification for epidemiologic studies, advancing understanding of relationships between of exposure to environmental chemicals and risk of cancer and other adverse health outcomes.

Darren S. Lee's picture Darren S. Lee, Ph.D.

Associate Research Scientist

- Darren’s research interests lie at the interface of synthesis, flow chemistry and engineering. With a background in organic synthesis, he soon developed an interest in using technology and engineering to explore chemistries that are underutilized at large scales. He has been involved in developing novel reactor designs for photochemistry and electrochemistry. He arrived at Yale in 2022 and is developing green chemical processes using continuous flow technology.

- Outside of the lab Darren enjoys spending time with his family and friends. He is also a keen cook, enjoys reading and going on long walks to explore nature and wildlife.