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A cross-divisional department spanning

Dr. Kirsten Koehler Faculty Research

Kirsten Koehler's Research Team

Ashley Newton, Postdoctoral Research Associate


Ashley received her PhD degree from the Department of Environmental Health and Engineering at the Johns Hopkins Bloomberg School of Public Health and her BA in chemistry from Columbia University. Her thesis research focused on improving analytical methodologies for measuring personal exposure to airborne particulate metals and validating a novel lung deposition sampler as a means for determining the body burden of welding fume. Her current postdoctoral research in the Koehler lab includes validating a novel UV-filter device intended to remove bioaerosols from ventilation systems, exploring the relationship between ultrafine and fine particulate exposure and inflammatory biomarkers in inner-city asthmatic children, and analyzing the repeatability and precision of urine metals biomarkers. In her free time, Ashley enjoys baking, crocheting, and watching re-runs of West Wing on Netflix.




Magdalena Fandiño, PhD Student


Magdalena is an environmental engineer who graduated with honors from a Master of Science degree in Engineering with emphasis on air quality and emissions. As a research assistant at the University of los Andes in Bogota, she developed the point source emissions inventory for the city and participated in the development of the Air Quality Management Plan for Bogota. Magdalena has experience in emissions estimations, sustainable transport and climate change.

Magdalena is currently working in Dr. Koehler’s lab in a field intervention in Puno, Peru trial of liquefied-propane gas (LPG) stove use compared to standard cooking practices with open-fire biomass burning stoves. The objective of the project is to determine if provision of cleaner fuels will result in important reductions of household air pollution and consequently an improvement in cardiopulmonary outcomes over a one-year period.



Carolyn Gigot, PhD Student


Carolyn received a bachelor's degree in Organismic and Evolutionary Biology with a secondary field in Earth and Planetary Sciences from Harvard University in 2016. Before beginning her PhD, she worked for the US Environmental Protection Agency as an ORAU contractor, contributing to IRIS chemical health hazard assessments and supporting the integration of additional systematic review tools and methods. She is interested in spatial analysis for exposure and risk assessment. She also enjoys running, biking, and listening to podcasts.





Andrew Patton, PhD Student


Andrew comes from a background in human health risk assessment consulting. He holds a BS in Molecular Toxicology from UC Berkeley and an MS in Environmental Management with a Certificate in Geospatial Technology from the University of San Francisco. His interests are the use of spatial techniques to assist with exposure assessments and risk assessments.








Nima Afshar-Mohajer, PhD, Postdoctoral Research Associate


Dr. Afshar-Mohajer received his PhD degree from Department of Environmental Engineering Sciences of the University of Florida; and his M.Sc. and B.Sc. from Sharif University of Technology in Tehran, Iran. His previous studies involved characterization and control of airborne particulate matter, PAHs and VOCs in different environments from occupational setting of a 3D printing lab to the lunar atmosphere. His current research includes characterization of particulate matters and gaseous emissions when chemicals are added to an oil spill contaminated seawater and evaluation of low-cost sensors for mapping air pollutants within an industrial facility.

His personal interests include watching movies, running and playing badminton.





Misti Levy Zamora, PhD, Postdoctoral Fellow


Dr. Zamora received her PhD degree from Texas A&M University in Atmospheric Chemistry, where her thesis research focused on the production, transformation, and fate of atmospheric pollutants. Specifically, she collected laboratory and field air pollution data, with a particular emphasis on nitrous acid (HONO), black carbon, and particulate matter. She also collaborated on several projects concentrating on determining the mechanism by which prenatal exposure to particulate matter alters fetal health and childhood development.

Dr. Zamora is now assessing person-specific exposures to urban air pollutants, particularly the contribution by energy-related factors (i.e., transportation, power generation, and characteristics of the built environment). The goal of this work is to evaluate the human health and environmental impacts of current and future energy options with innovative approaches to enhance assessment of human exposures.

Outside of lab, Misti enjoys the photography, painting, and playing board games with her husband, Ryan.


Dorothy Clemons-Erby, BS, Senior Research Program Coordinator


Dorothy graduated with a Bachelor of Science in Biology and minor in Psychology from the University of South Carolina Aiken.

Outside of the lab, Dorothy's hobbies consist of reading, trying new food, listening to various podcast and hanging with friends.










Tim Green, Laboratory Coordinator


Looking for a bridge between high school and college, Tim began working at JHU as a laboratory technician less than one month after graduating high school. Although originally hired to work solely in the lab, he showed an interest in learning all aspects of the research field. A quick learner, he soon found himself handling many different responsibilities both in and outside of the lab. After five years at the Asthma and Allergy Center, it was his background with field sampling along with his laboratory experience that allowed him to transition into his role at the School of Public Health. Additionally, Tim studied film extensively at Anne Arundel Community College and Stevenson University.

Outside of the lab, Tim enjoys reading, fiction writing, and watching sports.





Lei Hao (Haolei), Research Specialist II 


Haolei assists with a study evaluating air quality in Baltimore City using low-cost sensor technology. His primary responsibilities include managing large datasets, developing computer code  to manipulate, clean, and organize data, and assisting with equipment maintenance & installation. Outside of the lab, Haolei enjoys the photography, fishing, and watching dance performances with his wife, and cooking traditional Asian foods.







Megan Wood, Data Manager


Megan earned her master’s degree in 2008 at Sonoma State University studying the ecology and habitat quality of Marine Protected Areas in Northern California. She went on to support numerous projects researching the health of coastal habitats in and around San Francisco Bay before moving to Dr. Koehler's lab and transitioning into air quality research in April 2018 as a data manager and analyst.  In her free time, Megan runs marathons, travels and is an avid knitter.







Former Group Members

Jesse Berman, PhD, Postdoctoral Associate


Jesse graduated with a PhD in Environmental Health Sciences from JHSPH in 2013. He is an environmental epidemiologist whose research focuses on complex environmental exposures and how these impact health. He has a strong interest in spatial statistics and utilizes this tool heavily in his research.

Jesse recently completed a postdoc with Dr. Michelle Bell at Yale School of Forestry and Environmental Studies, where he investigated the association between drought and adverse health in the western United States. He current work with Dr. Koehler uses spatial tools to optimize air monitoring networks within large occupational settings. He is also studying how environmental factors influence academic performance among Baltimore City school children.





Josiah Kephart, MPH; PhD Student


Josiah's current research focuses on reducing air pollutants and health effects related to cookstoves in low and middle-income countries (LMICs). He is interested in the application of spatial analysis and data science tools to environmental epidemiology in LMICs.

Josiah's previous research includes exploring the relationship between microclimate and malaria incidence in Peru, the long term effects of HIV and HCV infection, and characteristics of the built environment associated with type 2 diabetes progression.








Ehsan Majd Faghihi, PhD, Postdoctoral Fellow


Dr. Majd received his PhD degree from Queensland University of Technology (QUT) in Brisbane, Australia in 2015, where his thesis research was focused on "Quantitative Assessment and Characterization of Airborne Engineered Nanoparticles." Since he joined Dr. Koehler’s research team in February 2016, Dr. Majd has been involved in different research studies related to particulate exposure and asthma. He is currently working on a study aiming to determine the association between respiratory effects in inner-city children with asthma and factors including ultrafine particulates, microenvironment, and peak exposure taking into account obesity as a susceptibility factor.

In his free time, Ehsan loves to travel. He also enjoys playing tennis, watching movies, and reading books.




Christopher Zuidema, PhD Student


Chris is a PhD student in the Exposure Sciences and Environmental Epidemiology Track in the Department of Environmental Health and Engineering. Chris holds a BS in Earth and Atmospheric Sciences from Cornell University and an MSc in Industrial Hygiene from the Harvard School of Public Health. Prior to starting his PhD, he worked for the Vermont Department of Health coordinating the school environmental health and radon programs. Chris’ work focuses on exposure assessment in outdoor and occupational environments for epidemiologic studies, risk assessment and exposure reduction.

Chris is an outdoor enthusiast, reluctant runner, committed bicyclist and amateur hop farmer.