Who We Are

Kelly Reynolds


Kelly A. Reynolds, MSPH, PhD

Since 1990, Dr. Reynolds has worked as a researcher and public health educator in environmental science, specializing in water quality, food safety, and disease transmission. Her extensive experience in those research areas includes her role as Principal Investigator of numerous projects and the publication of hundreds of journal articles, book chapters, and professional reports. Dr. Reynolds is working on several projects, including one in which she joins UA engineers to apply lasers to detect human viruses in drinking water. This type of technology would not only expedite the process of discovering waterborne viruses, but it could detect viruses that were previously undetectable. She is also the Principal Investigator of two other projects, which look for contaminants in the water supply and in the home. In the water study, Dr. Reynolds aims to assess the risk of tap water by analyzing the types of disease-causing organisms captured in the filters of water vending machines. In the home hygiene study, Dr. Reynolds is monitoring Methicillin-resistant Staphylococcus aureus (MRSA) in the home by identifying the bacteria's survival in soft surfaces, including carpets and towels. MRSA bacteria can cause severe skin infections and result in hospitalizations and, more rarely, death.

Marc Verhougstraete


Marc Verhougstraete, PhD

Dr. Verhougstraete is an accomplished integrated water quality researcher, specializing in understanding the sources, occurrences, and transport of waterborne microorganisms. He has extensive experience integrating microbial occurrences with hydrological catchment dynamics, landscape patterns, and Quantitative Microbial Risk Assessment to improve environmental management practices that protect human and ecosystem health. Since joining ESRAC in 2013, Dr. Verhougstraete has been investigating the effects of intervention practices in the healthcare systems to reduce agents of healthcare-associated infections and define best monitoring practices for irrigation waters in the Southwest United States.

Leslie Dennis


Leslie Dennis, PhD

Dr. Dennis’ research focus is on melanoma and prostate cancer etiology and prevention as related to environmental risk factors. She has used tools such as mailed questionnaires, telephone interviews along with molecular analyses of trace elements and sexually transmitted infections to conduct this research. She also has expertise in conducting meta-analyses as related to risk factors for cancer. Dr. Dennis is a reviewer for several cancer and epidemiological journals. She has reviewed R03 and K07 applications for the NCI and spent 5 years as a grant reviewer for the American Cancer Society, including chairing the Clinical Research, Cancer Control, and Epidemiology peer grant review committee.

Mary Kay O'Rourke


Mary Kay O'Rourke, PhD

Dr. O'Rourke has conducted interdisciplinary environmental research relating environmental exposure to human health for more than 25 years. Her current research focuses on exposures in three areas: children's exposure to pesticide, the spatial relationship between arsenic exposure and cancer prevalence, and the relationships among soil type, Coccidioides immitis presence, and cocci prevalence. She was a Co-Principal Investigator on several exposure assessment surveys investigating metal, pesticide, volatile organic compounds (VOC) and polynuclear aromatic hydrocarbons (PAH) exposures. These studies include the National Human Exposure Assessment Survey, the Arizona Border Survey, two surveys examining pesticide exposure among children in Yuma Co. Arizona, and a pesticide exposure in the Gila River Indian Community. She has extensive experience in designing and implementing exposure assessment field surveys, quality assurance programs, and the data processing protocols for large studies.

Jonathan Sexton

Research Specialist, Senior

K-12 Outreach Coordinator

Jonathan Sexton, PhD

Dr. Sexton is a researcher in environmental science, specializing in the occurrence and control of environmental pathogens. He has worked in a variety of settings, including homes, offices, hotels, healthcare facilities, transportation, restaurants, agriculture, and fire stations. Currently, Dr. Sexton is evaluating the applied use of disinfectants and sanitizers on porous and non-porous surfaces in the healthcare arena. In addition to research, Dr. Sexton has a large involvement in community outreach. Since 2005, he has regularly spoken at local K-12 schools, after-school programs, and other community events to help kids and adults develop an interest in science. Presentations showcase the importance of hygiene and simple interventions to minimize risk of infection.

Program Coordinator

Ashton Norman

Miss Norman has worked at the University of Arizona since 2007 and joined ESRAC in 2016. Her work often involves translating research into accessible and engaging formats for the public, including development and design of training content for the WQRF Education and PreventLD projects.  Miss Norman's research interests include waterborne illnesses, potential long-term effects of infectious disease, and a systems approach to assessing human health and risk.