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Who We Are

Melissa A. McDiarmid, MD, MPH, DABT

Dr. McDiarmid is Professor of Medicine, Epidemiology and Public Health and Director of the University of Maryland School of Medicine’s Division of Occupational and Environmental Medicine where she teaches, sees patients, and directs a surveillance program for Gulf War Veterans.

Dr. McDiarmid received her B.A. degree from the University of Maryland Baltimore County, in Biological Sciences; her M.D. from the University of Maryland at Baltimore and her M.P.H. from The Johns Hopkins School of Public Health where she also completed fellowship training in Occupational Medicine. She is board-certified in Internal Medicine, Occupational Medicine and Toxicology.

Dr. McDiarmid was Director of the Office of Occupational Medicine for the U.S. Occupational Safety & Health Administration (OSHA) in Washington, D.C., a position she held from 1991 until 1996. From 1987 until moving to OSHA, she was Assistant Professor of Environmental Health Sciences at The Johns Hopkins School of Hygiene and Public Health where she directed the Occupational Medicine residency. She retains her Hopkins affiliation as an adjunct professor of Environmental Health Science.

Dr. McDiarmid has authored numerous journal articles and book chapters on occupational and environmental medicine topics related to healthcare workers, medical surveillance and management, reproductive hazards, occupational cancers, and Gulf War environmental exposures.

Dr. McDiarmid's Faculty Profile

Sammy Almashat, MD, MPH

Dr. Almashat is board-certified in both Occupational Medicine and General Preventive Medicine & Public Health. After completing his General Preventive Medicine residency, he conducted extensive research into various areas of pharmaceutical and medical device safety and policy, in addition to occupational health and safety topics, such as chronic beryllium exposure, heat stress, long medical resident work shifts, and state occupational health and safety regulations. He then completed an Occupational Medicine residency and subsequently worked for several years in an occupational medicine clinic, treating a wide spectrum of acute and chronic workplace injuries and illnesses.

Since joining the faculty, he has been involved in the long-term surveillance of cohorts of veterans exposed to depleted uranium and with potential systemic metal exposures from embedded munition fragments, in addition to former construction workers as part of a U.S. Department of Energy-funded program. Dr. Almashat also provides ongoing employee health-related administrative and clinical services for the University of Maryland’s Faculty Physicians, Inc. (FPI) and both the Baltimore and College Park campuses of the University of Maryland.

Dr. Almashat's Faculty Profile

Marianne Cloeren, MD, MPH

Dr. Cloeren is board-certified in both Occupational Medicine and Internal Medicine. After graduating from the University of Pennsylvania with a B.A., she attended Temple University School of Medicine, graduating with her M.D. in 1987, and then entered post-graduate training in Internal Medicine, followed by Occupational Medicine, in the Johns Hopkins system, where she earned a Master of Public Health in 1991. She has broad clinical experience, including primary care of Veterans, hospital medical service management, consulting, military occupational medicine and case management. 

Dr. Cloeren has a long-standing interest in medical education, in particular online training of clinicians, and in 2017 completed coursework at the University of Wisconsin - Stout, earning a Graduate Professional Development Certificate in Instructional Design. She has applied this training to develop an 8-hour continuing medical education course for the American College of Occupational and Environmental Medicine, called "Getting Your Patients Back to Work". Dr. Cloeren has particular interest and expertise in teaching medical providers how to make decisions that do not inadvertently lead to prolonged work disability in their patients. She is also an experienced educator on the topic of opioid decision-making, including clinical appropriateness, alternatives, informed decision making and monitoring. 

Dr. Cloeren is a leader in the American College of Occupational and Environmental Medicine, having served two terms on the Board of Directors, serving as past Chair and current member of the Council on Occupational and Environmental Medicine Practice, serving as current Chair of the special interest section on Work Fitness and Disability, and serving as a member of the Council on Education and Academic Affairs.

Dr. Cloeren joined the faculty in April 2017, and is the newest member of the Depleted Uranium Program, providing clinical surveillance related to potential adverse impacts of depleted uranium exposures in Veterans. 

Dr. Cloeren's Faculty Profile

Marian Condon, MS, RN

Marian Condon has a BSN from Johns Hopkins School of Nursing and an MS in Community/Public Health Nursing from the University of Maryland, School of Nursing. She has worked in the areas of environmental and occupational health and has given presentations and written articles on a variety of environmental and occupational health topics. She works as a VA employee on the Toxic Embedded Fragment Surveillance Center as well as the Depleted Uranium program with the Division of Occupational and Environmental Health at the University of Maryland, School of Medicine.

Walter Frauman, PhD

Dr. Frauman is an Exposure Assessment Specialist working on the VA’s Military Exposures Research Project (MERP), handling projects advancing research into the effects of exposures to toxicants incurred during military service. He received his B.A. from St. Mary’s College of Maryland in Chemistry in 2013 and his PhD in Chemistry and Biochemistry from the University of California San Diego in 2022.

Joanna Gaitens, MSN, MPH, PhD

Dr. Gaitens is an Assistant Professor at the University of Maryland School of Medicine and serves as the Coordinator for the VA’s Toxic Embedded Fragment Surveillance Center and Registry which allows the VA to follow and manage the medical surveillance for veterans who have retained fragments from wounds received while serving in Iraq and Afghanistan.

Dr. Gaitens received her A.D.N. Degree from Norwich University in 1994; her BSN Degree from the University of New Hampshire in 1997; her MSN/MPH Degree from the Johns Hopkins School of Nursing and Bloomberg School of Public Health in 2000; and her PhD from the Johns Hopkins Bloomberg School of Public Health in 2006.

Prior to joining the University of Maryland faculty, Dr. Gaitens worked for several years as a nurse in skilled care before transitioning into public health. Her dissertation focused on the neurobehavioral effects associated with polychlorinated biphenyl exposure in older adults. She also has worked in the field of lead poisoning prevention.

Dr. Gaitens' Faculty Profile

Patricia Welsh Gucer, PhD

Dr. Gucer is an Assistant Professor at the University of Maryland School of Medicine. She is co-Principal Investigator on two studies examining safe resident lifting practices and their impact on caregiver injuries in long-term care facilities. She also works on a surveillance study of Gulf War Veterans exposed to depleted uranium.

Dr. Gucer received her A.B. Degree from Dumbarton College of Holy Cross in 1963, and her PhD from the Johns Hopkins University Department of Sociology in 2001.

Dr. Gucer has taught secondary school science, managed data for a longitudinal study of school children, and has been Baltimore Study Manager for a large multi-center clinical trial testing the effects of beta carotene on the incidence of lung cancer.

Dr. Gucer's Faculty Profile

Marc Oliver, RN, MPH, MBA

Mr. Oliver is a research nurse and data analyst for the VA’s Depleted Uranium program and various research projects, including collaborative work with NIOSH. Mr. Oliver does data management for the Employee Health program for the faculty practice of the University of Maryland School of Medicine.

Mr. Oliver received his A.D.N. Degree from Alfred State College in 1996; his MPH Degree from the Johns Hopkins Bloomberg School of Public Health in 1998 and his MBA from University of Maryland University College in 2005.

Gary Orr, MS, PE, CPE

Mr. Orr is a certified ergonomist and industrial engineer who collaborates with the division staff on assessments of workplace musculoskeletal hazards and ergonomic and human factors interventions. He worked for OSHA on the development of the ergonomics standard, enforcement cases, outreach, and education. He has worked with the Joint Commission on the integration of ergonomics into the environment of care standards. He has assisted OSHA in the development of their ergonomics guidelines. He received a Bachelor's degree in Industrial Engineering from Auburn University and a Master's degree in Industrial Engineering/Human Factors from the University of Oklahoma.

Dr. Gary Orr's Faculty Profile

Tracy S. Roth, RN, BSN

Tracy is a research nurse on the Occupational Health team, where she organizes outreach programs, health education and the development of educational materials. She is the study coordinator for several University of Maryland medical surveillance programs.

Tracy received her Bachelor of Nursing Science degree in 1980 from the University of Bridgeport, Connecticut. She has worked in multiple clinical and public health settings. 

Sheila Williams, BS, MS

Ms. Williams is our executive administrative assistant and focal point of the division. Before joining our program in 2000, she worked in health care for 10 years. Her wide variety of skills comes from working in such various environments as mental health, family preservation, and shelters for women, and administration. She provides executive assistance to the division faculty and staff while also serving our programs’ patients, clients and students.

Ms. Williams received her Executive Administrative Assistant A.A. Degree from Baltimore City Community College. She is currently pursuing her BS Degree in Human Resources Management from the University of Maryland University College.