Skip to main content

A cross-divisional department spanning

Dr. Kirsten Koehler Faculty Research

Kirsten Koehler's Research Team

Research Group

woman smiling

Sandra Albornoz, PhD, Research Associate

Sandra Albornoz joined the Koehler lab as a Research Associate. Sandra holds a bachelor’s degree in chemistry from the District University in Colombia, and a master’s degree in chemical and biochemical processes from the Technological University of Parana. She also completed her PhD in Chemistry from the Federal University of Parana in Brazil, where she focused on analytical chemistry and investigated the chemical synthesis of nanomaterials. During her PhD she gained expertise in various characterization methods, including vibrational spectroscopy (Raman spectroscopy) and Diffuse Reflectance Spectroscopy (DRS). She also completed an exchange program as a visiting doctoral student at Johns Hopkins University's chemistry department, where she gained experience in X-ray Photoelectron Spectroscopy (XPS). Sandra is proficient in various electron microscopy techniques, including Scanning Electron Microscopy (SEM-EDS) and Transmission Electron Microscopy (TEM-SAED). She also has practical experience in liquid and gas chromatographic techniques, such as HPLC-UV-FL, and GC-MS. Her current research interests focus on the laboratory evaluation of low-cost monitors to measure the precision and accuracy of VOC sensors, whole air sampling collection, and the analysis of Volatile Organic Compounds (VOCs) by Gas Chromatography/Mass Spectrometry (GC/MS).

man smiling standing outdoors on s sunny day

Kyle Aune, PhD, postdoctoral fellow

Kyle Aune is an environmental epidemiologist and postdoctoral fellow who uses high dimensional climate and other environmental datasets along with data science and spatial statistical methods to answer questions about the health effects of climate change. He earned his PhD in the Department of Environmental Health and Engineering at the Bloomberg School of Public Health in 2022 and holds an MPH in epidemiology from the University of Alabama at Birmingham’s School of Public Health and a BS in biomedical sciences from Auburn University. His research aims to improve climate threat exposure assessments with big climate data; explore climate and environmental determinants of infectious diseases using existing public datasets, vital records, and large climate datasets as well as through primary data collection; and identify and remedy climate and environmental justice issues. Dr. Aune’s work in the Koehler lab is focused on a JHU-SCIBAR funded project exploring the effects of cool roof installation on indoor air quality and sleep among residents of Baltimore rowhomes.

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.

young woman smiling at camera

Sophia Le, PhD student

Sophia Le is a PhD student in the Exposure Sciences and Environmental Epidemiology Track in the Department of Environmental Health and Engineering. She holds an MSPH in Environmental Health - Epidemiology from Emory University and a BS in Biochemistry from Arizona State. Her research interests focus on the application of satellite remote sensing in air pollution exposure models, spatial statistics, and the evaluation of low-cost sensors for personal exposure assessment. Sophia’s dissertation research in the Koehler lab focuses on modeling personal PM2.5 exposure at a high spatial and temporal resolution between urban and rural settlements in South Central Uganda. Her work aims to integrate aspects of satellite observations, GPS tracking, and low-cost air quality sensors to improve air pollution exposure assessment in limited resource settings.

Nan Ji, Phd, postdoctoral fellow

Nan Ji, Phd, is a postdoctoral fellow in the Department of Environmental Health and Engineering at Johns Hopkins Bloomberg School of Public Health. She has expertise in environmental epidemiology, with a specific focus on the application of mixture approaches in assessing the human health impacts of environmental mixtures. She was also trained in causal inference methods, which are essential tools for understanding the causal pathways between environmental pollution and health. Her overall research goals are: 1) To examine the impacts of exposure to individual and mixtures of environmental pollutants, on the development of metabolic diseases and cancer; 2) To explore the effects of potentially modifiable factors that are on the causal pathway between environmental pollution and health.”

man wearing suit and tie

Salvatore (Sal) Milletich, PhD Student

Salvatore (Sal) Milletich is a first-year PhD student in the Environmental Health and Engineering department at Johns Hopkins Bloomberg School of Public Health in the Exposure Science and Environmental Epidemiology track. He holds a BA in Anthropology from Arizona State University and an MPH with a concentration in Environmental Health from the University of Florida. His research has utilized GIS, statistical and mathematical modeling, qualitative methods, and interdisciplinary skills to further wastewater-based epidemiology and environmental justice efforts. His current research interests focus on occupational health and applying those methods to further health equity.

Shilpi Misra, MPH, PhD student

Shilpi is a PhD student in the Department of Environmental Health and Engineering. Before coming to Johns Hopkins University, Shilpi was an ASPPH/CDC fellow at the National Institute for Occupational Safety and Health (NIOSH) in Spokane, Washington, within the Spokane Mining Research Division. While at NIOSH, Shilpi worked on a project focused on building an evidence-based framework that provides new knowledge of the patterns of hazard exposures for current miners and the burden of disease and adverse health conditions among current and retired metal and nonmetal miners. Shilpi analyzed large Mine Safety Health Administration (MSHA) exposure datasets in metal/nonmetal mines and disseminated findings in conference proceedings and peer-reviewed publications. Born and raised in Nashville, TN, Shilpi received her MPH from the Milken Institute School of Public Health, focusing on epidemiology in 2020. She earned her BS in psychology from the University of North Carolina at Chapel Hill (UNC-Chapel Hill) in 2015. She has previously worked at the Milken Institute School of Public Health and RTI International. She is passionate about public health and has a background in analyzing environmental and occupational health research. Shilpi previously worked on a project evaluating the effects of the Department of Housing and Urban Development’s smoke-free public housing rule on air quality and health in Washington, D.C. At George Washington University, Shilpi worked on a project examining the impact of hazardous exposures on children engaged in artisanal gold mining. This included identifying methodological limitations of measuring pediatric mercury and lead exposure, policy gaps for prevention, exploring health education programs for mine families, and developing surveys to seek information about children’s health and involvement. Shilpi completed her master’s thesis with the National Cancer Institute’s Division of Cancer Epidemiology & Genetics. She focused her research on estimating the effects of pesticide exposure and body size on endometrial cancer incidence among spouses of pesticide applicators in the Agricultural Health Study.

man wearing tie and jacket smiling

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

young man wearing glasses smiling for the camera

Zachary Smith, PhD student

Zachary Smith (he/him) is a first year PhD student in the Department of Environmental Health and Engineering at the Johns Hopkins Bloomberg School of Public Health. He is co-advised by Dr. Kirsten Koehler and Dr. Louis Fazen. He is interested in the health effects of climate change and using epidemiologic methods and exposure science to inform public health decision-making at the local, state, and federal levels. Prior to starting doctoral studies, he was the Tuberculosis Controller and Epidemiologist for the State of Delaware Division of Public Health. He also worked at the National Association of County and City Health Officials and the American Institutes for Research. He received a Master of Public Health from the University of California, Berkeley and a Bachelor of Science in Public Health from American University.

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

Selfie of a young man wearing glasses with earphone around his neck

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

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.

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

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.

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.

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.