Who we are

Carsten Prasse, Assistant Professor

Headshot Oct 2022My research is driven by a fascination with environmental chemistry and a deep concern about the public and environmental health impacts of chemicals present in our environment. My research group investigates the fate of contaminants in the built and natural environment using state-of-the-art analytical chemistry techniques (e.g. high-resolution mass spectrometry) with the focus on identifying transformation products and understanding underlying mechanisms of transformation. One of our main areas of interest is the presence of contaminants in the urban water cycle. Even though the efficacy of treatment technologies is still primarily evaluated based on the removal of well-known trace organic contaminants, our research has emphasized the relevance of transformation products as (drinking) water contaminants.

The recognition of the relevance of transformation products as emerging class of water contaminants led to a series of studies in which we investigated the fate of transformation products in treatment trains used in both wastewater treatment and drinking water purification. This was paired with in vitro and in silico toxicological approaches to assess the toxicity of the transformation products. The results have clearly demonstrated that degradation processes can result in transformation products that exhibit an increased toxicity compared to the parent chemicals. This is particularly relevant for the assessment of new treatment technologies as well as alternative drinking water resources, in particular regarding water reuse.

One widely unanswered question is how to prioritize the compounds that are present and how to identify which compounds are most threatening to human and environmental health given that thousands of chemicals are present in our waters. To tackle this problem, our research focuses on using concepts and methods from toxicology and public health. This work is interdisciplinary with the goal of developing new methodologies to inform water treatment technology development, comprehensively assess water quality and characterize the Exposome.

Full list of publications: Google Scholar Citations.

Outside of the lab, I love to hang out with my son and our two cats, go on a run or hike, and listen to music.

Matthew Newmeyer, Research Associate

Newmeyer_ACS2022 Headshot (2)I have always been driven to contribute to the betterment of society through the use and advancement of science. We are at a critical juncture where increased attention and action regarding environmental issues are paramount. My goal is to use my interests in analytical chemistry and toxicology to help better understand these problems and lead to actionable solutions. Through the use of targeted and non-targeted analytical detection methods, we can help characterize the compounds we come in contact with on a daily basis through the water we drink, food we eat and air we breathe. Coupling these finding with toxicological testing can improve risk assessments and improve human health outcomes. Additionally, these data can assist with various environmental issues from improving water treatment practices to assessing air quality, and may ultimately help inform evidence-based public health policies. I am fascinated in this interplay of analytical chemistry, toxicology, public health and policy.

Veronica Wallace, PhD student

OLYMPUS DIGITAL CAMERAEnvironmental Health and Engineering forges interdisciplinary problem-solving approaches across many otherwise disparate disciplines. As a PhD student, I aim to undertake training and research at the confluence of public health, environmentalism, and engineering, targeting issues of immediate concern in our local community and global environment. My research interests are shaped by the environmental and health disparities I have witnessed living in the city of Baltimore, and also by my long-standing interests in medicine and individual health. After completing my BA in Anthropology at Yale University, I received my Master’s of Science in Bioengineering from the University of Pennsylvania. I made my foray into Public Health interning at the World Health Organization in Geneva, Switzerland, with the unique opportunity to bring experience in biomedical engineering to work in the Department of HIV/AIDS Key Populations and Innovation Prevention Team. My post-grad work has since spanned clinical and biomedical research. I moved to Baltimore, MD to work with Dr. Bruce Hope at the NIH National Institute on Drug Abuse, and continued to develop my interests in environmental and public health living and working in Baltimore. Prior to starting my PhD in summer 2018, I worked with a biotech startup in Baltimore. Returning to academia and embarking on my doctoral degree, innovation and interdisciplinary problem-solving are at the forefront of my research endeavors.

Zhuoyue Zhang, PhD student

selfie-e1531422514104.jpgAs the generation born after 1995, I witnessed the rapid deterioration of river systems in my hometown, Xiangyang, which is a miniature scenario of ecosystem status in China under the big background of high-speed economic development. Since my first research project as an undergraduate student on utilization of Advanced Oxidation Processes with assistance of homemade catalysts to degrade dyes in aqueous system, I’ve been intentionally focusing my research interest on water resource and treatment issues. Since majoring in environmental engineering I have never been more compelled about my responsibility since majoring in  environmental engineering majored student after the 12 weeks research internship program in University of Saskatchewan, Canada. It is not because of how interesting my first research experience abroad was, but simply of a camping trip to a small lake there. The purity, the transparency and the beauty of the lake water touched my heart so profoundly that it inspired me to continue my study and research on environmental issue. All of these journeys added up to lead me here to work in the Prasse lab. I really enjoy the interesting research topics and open atmosphere in the lab and strongly believe this research experience will be one of the most unforgettable memories in my whole life.

Daisy Grace, PhD student

Picture1Growing up in a rural town outside of Reading, Pennsylvania, I witnessed how agricultural- and septic-based runoff sparked an increasing frequency of health advisories at a nearby recreational lake due to fecal bacteria and algal bloom contamination. Observing the quality decline of the place where I spent my childhood summers motivated my intellectual curiosity regarding environmental contamination, particularly as a consequence of increased anthropogenic activity.

I decided to pursue my interest in environmental issues at Lafayette College, where I joined Dr. Melissa Galloway’s atmospheric aerosol lab in the Department of Chemistry. In the Galloway Lab, I investigated brown carbon aerosol systems and their radiative properties to help inform global climate modeling. This work familiarized me with mass spectrometry (MS) method development, which served to identify individual products within complex environmental matrices. Seeing how powerful MS was in identifying environmental contaminants, I knew I wanted to continue working with MS in my graduate career. My work with atmospheric aerosols, however, confirmed my inclination toward more solution-oriented approaches in research regarding the fate and transport of aqueous contaminants. This revelation has led to my current position as a PhD candidate in the Prasse Lab, where I can continue to explore my fascination in environmental analytical chemistry while also acquiring a background in engineering and public health. My current project involves designing a novel analytical platform to detect, identify, and prioritize individual toxic contaminants within complex drinking water and wastewater samples. Alongside this project, I am looking forward to participating in the collaborative nature of the Prasse Lab with both the academic and Baltimore communities.

In my free time, I enjoy hiking, swimming, making recycled art, and working through a long list of recommended podcasts.

Casey Smith, PhD student

CaseyMy interests in environmental materials stem from a passion for solving puzzles and a desire to tackle real-world problems with analytical chemistry. While pursuing BS degrees in Chemistry and Biochemistry at Virginia Tech, I had the opportunity to work at a materials analysis lab in Christiansburg, VA. During this time, I learned about the types of polymers that comprise our every-day products, the additives incorporated into plastics to enhance their properties, and the techniques capable of detecting and characterizing these chemicals. While at JHU, I have continued to pursue my interest in analyzing plastic additives, as well as their implications on the environment and public health.

My current research focuses on the release and transformations of polymer additives in aqueous environments. Despite the ever-growing use and disposal of plastics, the factors governing the rate of additive release and the mechanisms and end products of potential transformation remain undetermined. As a co-advised Ph.D. student in both the Prasse and Fairbrother labs (JHU Department of Chemistry), I hope to bridge the gap between materials design and consideration of future health risks.

The diverse background and collaborative nature of the Prasse Lab makes every day insightful and interesting! When not in lab, I enjoy reading, baseball, watching Jeopardy, and spending time with my family.

Kate Burgener, PhD student

IMG_9500I have always been passionate about the natural environment, and increases in pollution and habitat destruction have motivated me to pursue a career in environmental engineering. While an undergraduate at Georgia Tech in chemical & biomolecular engineering my research focused on the use of soft polymers to remove nano pollutants from the surfaces of saturated polymer matrices. Though this work was successful in its goal of removing plastics, it also required the production of more plastic. Recognizing that many remediation technologies utilize technology that creates pollutant byproducts or excessive waste, I aim to engineer remediation technologies that build on natural biological degradation mechanisms to remove anthropogenic pollutants from complex milieus. Prior to joining the EHE department at Johns Hopkins University, I studied chronic wasting disease prions at UW-Madison and their transport through environmental matrices in order to assess environmental sinks and transmission potential. My current work focuses on measuring recalcitrant organic pollutants that sorb to biosolids in waste water treatment processes and their fates and remediation potential following release.

Outside of the lab I enjoy hiking, painting, and photography.

Dominic Sanchez, PhD student


My family frequently talked about sustainability and our responsibility to care for nature, so from a young age I have been intrigued by environmental issues like climate change, pollution, and water quality. To better understand the makeup and behavior of the chemicals that pollute our environment, I pursued a BS in Chemistry at Purdue University where I worked in a lab developing biomimetic adhesives of low human toxicity. During my time there I also took a course in environmental science that focused on policy and ultimately set me on my path towards a career in environmental regulation.

Before transferring to Hopkins, I spent 3 years in the Molecular and Environmental Toxicology program at UW-Madison under Dr. Joel Pedersen studying the metabolism of wastewater-derived disinfection byproducts in crop plants. In the Prasse Lab, I continue my doctoral work on crop plant metabolism, focusing on identifying the metabolites of psychoactive pharmaceuticals found in reclaimed wastewater that is used for agricultural irrigation.

Outside lab, my time is spent videogaming, playing Magic: The Gathering, and making props for cosplay.

Noor Hamdan, PhD student

Prasse Lab HeadshotMy passion for environmental engineering and public health disciplines stems from my upbringing in the global south. Being raised in a third-world country allowed me the personal experience of the lack of safe and accessible drinking water. I devoted my undergraduate career to pursuing a degree in environmental engineering to help understand how I can bring a better quality of water, and in turn life, to my home country.

Before joining JHU, I received a Bachelor’s and Master’s degree in Civil Engineering at Stony Brook University. I investigated the effects of climate change on diverse socioeconomic communities on Long Island in my undergraduate career through an anthology of artwork and essays, along with the bioaccumulation of per and polyfluoroalkyl substances (PFASs) in marine polychaetes. In my graduate career, I focused on high-resolution mass spectrometry method development of PFASs in benthic organisms and treated water. I have also investigated the non-target identification of transformation products of PFASs in water treated with electron-beam technology and thermal plasma technology and the identification of byproducts in a PFOS-spiked media solution treated with bacteria.

When I am not in the lab, I enjoy traveling, reading, and spending time with my cat!

Alyssa Rorie, PhD student (starting Fall 2023)

prasse lab headshot

Growing up on the outskirts of Raleigh, North Carolina, I was constantly surrounded by nature. From volunteering at my local Wetlands center to championing recycling efforts at my school, my passion for the environment began at a very young age. After being introduced to the global water crisis in my 8th grade science class, I became passionate about clean water. I firmly believe that no person should be denied access to potable water, as it is a necessary factor for life. 

While pursuing a bachelor’s degree in chemical engineering at North Carolina A&T State University, I had the opportunity to take part in various research projects including studying the link between breast cancer and phosphorylated branched chain amino acid transferase (BCAT) and working with AI bias with nutrition. However, my passion for wastewater remediation research was ignited after working under Dr. Nirala Singh at the University of Michigan as part of their Summer Research Opportunity Program (SROP) for two consecutive summers. In the Singh lab, I studied how effective direct and indirect oxidation is at eliminating phenol from wastewater. This experience led to my decision to become a doctoral student at JHU in Dr. Prasse’s and Rossi’s lab, where I hope to continue research with understanding and eliminating novel wastewater contaminants. I have a long term career goal of developing processes to provide potable water worldwide and hope to develop my skills further throughout my graduate education. I look forward to joining the Prasse lab, as well as the Department of Environmental Health and Engineering at JHU.

In my free time, I enjoy going to the gym, playing music (I can play 6 instruments!), hiking, dancing, and watching TV/anime.

When I am not in the lab, I enjoy traveling, reading, and spending time with my cat!

Mei-Li Hey, PhD student (starting Fall 2023)


My interest in environmental health was catalyzed by my experience starting a non-profit called Atwero, which focuses on increasing sanitation for persons with disabilities and operates out of Uganda. I observed practices in many agricultural villages that piqued my interest about the link between food production contamination and wastewater contamination. The first step towards improving health outcomes of interventions is accurately determining the etiology of the disease-causing pathogens and their transmission pathways. While exploring this intersection, I intend to keep environmental and health inequities at the center of my studies. Ultimately, I aim to produce research that increases the effectiveness of environmental health interventions by providing the scientific evidence necessary for targeted implementation efforts and policy changes.

I started my career as a Mechanical Systems Design Engineer for NASA’s James Webb Space Telescope (JWST) and simultaneously earned a Master’s in Engineering Management from UCLA. I believe that good engineers are equipped with the tools and knowledge to approach the world’s largest problems, and engineers have a responsibility to prioritize their efforts to maximize equity and positive change. This is my reasoning for switching from aerospace engineering to environmental health. The roots of inequity in the environment and health run deep within our systems, and there are many powerful forces invested in maintaining the status quo. I intend to dedicate my career to conduct research that challenges our health systems and those who run them to increase equity and inclusion, and ultimately to generate better health outcomes around the world.

The Prasse Lab shares my passion for interdisciplinary research and science that results in real, tangible change. Outside of my studies, I enjoy climbing, creating pottery, running, and surfing.

Erica Lopez-Haz, Undergraduate student

thumbnail_Image-2I started my time at Hopkins as a premed student majoring in Molecular and Cellular biology, but changed my major to Computer Science after nearly two years of shadowing and volunteering, and eventually realizing that medical school is just not for me. During that time, I worked as an intern at the National Institutes of Health tagging proteins in Legionella pneumophila and later at the National Cancer Institute determining the efficacy of cancer drugs used in combination. Now, I want to use my research experience in the context of my new major with machine learning. Before joining the Prasse lab, I joined the student-run Delineo Disease Modeling Project as a part of the machine learning team, where we worked with students and professors at the University of Tsukuba in Japan. The aim of the project is to simulate disease spread in a given community using census data and publicly available datasets. This experience really sparked my interest in continuing to learn about the applications of machine learning in public health. Currently, I am working on developing machine learning models to predict the concentrations of potentially harmful chemicals identified in manure samples using non-target analysis. Outside of research and schoolwork, I enjoy drawing, writing stories, studying languages, and singing along to musicals.

Sunny Li, Undergraduate Student

Picture Sunny for homepageI am fascinated by the interconnectedness of the environment and the diversity of life within it. Exploring issues in an environmental context brings additional complexity and significance, requiring us to consider the unintended and unexpected consequences of human activity and expand the limitations of our technology to detect and remediate contamination.  

While I am majoring in Chemical & Biomolecular Engineering with a minor in Environmental Engineering, I aim to learn more about chemicals in the environment and their impacts on ecosystems. Currently, I am working on studying the antimicrobial effects of nonantibiotic drugs and their contributions to antimicrobial cross resistance in bacteria.  

Previous lab member:

  • Christopher Brueck (PhD student): current position: Scientist at Exponent 
  • Sara Nason (Postdoc): current position: research scientist at the Connecticut Agricultural Research Station
  • Angela Stiegler (Postdoc): current position: Postdoc at US EPA
  • Ximin Hu (Master’s student): current position: PhD student University of Washington, Department of Civil & Environmental Engineering
  • Melody Multra (undergraduate student): current position: Engineer at Jacobs Solutions
  • Rafael Ferguson (undergraduate Student): current position: Master’s student Johns Hopkins University, Environmental Health & Engineering
  • Marcos Pascual (undergraduate student): current position: Master’s student Johns Hopkins University, Environmental Health & Engineering
  • Xiaoyue Xin (Master’s student): current position: PhD student Georgia Tech
  • Annabel Mungan (undergraduate student): Master’s student University of Colorado at Boulder
  • Nicholas Pham (High-school student): current position: undergraduate student University of British Columbia.

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