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SAC History
SAC Meetings
All SAC Members, past and present


Roger O. McClellan – Chair

SAC McClellan

MCCLELLAN, Roger O., D.V.M.  

Scientific Member

10/1/2010 – 3/31/2020

Roger O. McClellan is currently an advisor to public and private organizations on inhalation toxicology and human health risk analysis issues. He received a Doctor of Veterinary Medicine degree with Highest Honors from Washington State University (1960). He is a diplomate of the American Board of Toxicology and the American Board of Veterinary Toxicology and a Fellow of the Academy of Toxicological Sciences, American Association for Advancement of Science, Society for Risk Analysis and American Association for Aerosol Research.

He is an internationally recognized authority in the fields of inhalation toxicology, aerosol science and human health risk analysis. He is also well known for the leadership he provided to the Lovelace Inhalation Toxicology Research Institute (1966-1988) in Albuquerque, NM and the Chemical Industry Institute of Toxicology (1988-1999) in Research Triangle Park, NC. Both organizations are internationally recognized for their research on the mechanisms of action of pollutants and assessing human health risks. He has authored over 300 scientific papers and reports and edited 10 books. He frequently speaks on risk assessment and air pollution issues in the United States and abroad. He is a Past President of the Society of Toxicology and the American Association for Aerosol Research. He serves in an editorial role for a number of journals, including continuing service as Editor of Critical Reviews in Toxicology. He serves or has served on the Adjunct Faculty of 8 universities.

McClellan has served in an advisory role to numerous public and private organizations including service on senior advisory committees for 8 federal agencies and on many committees of the National Academy of Sciences/National Research Council. He is past Chairman of EPA’s Clean Air Scientific Advisory Committee and served on Panels that have reviewed the National Ambient Air Quality Standards for all of the Criteria Pollutants.

McClellan’s contributions have been recognized by receipt of a number of honors.  He was elected in 1990 to membership in the Institute of Medicine of the National Academy of Sciences. He received the Society of Toxicology Merit Award and Founders Award and the New Mexico Distinguished Public Service Award. In 2005, The Ohio State University awarded him an Honorary Doctor of Science degree for his contributions to the science under-girding improved air quality. In 2008, Washington State University presented him the Regents Distinguished Alumnus Award, the highest recognition the University can bestow on an alumnus. He is a strong advocate of risk-based decision-making integrating information from epidemiological studies, clinical investigation, laboratory animal bioassays and mechanistic studies using molecules, cells, tissues and intact mammals.

Luiz Bertelli – Scientific Member


Scientific Member
(Health Physics)

4/1/2018 – 3/31/2021

Heather J. Hoffman – Scientific Member

HOFFMAN, Heather J., Ph.D.

Scientific Member
(Epidemiology, Biostatistics)

10/1/2016 – 3/31/2020

After earning my PhD in Biostatistics from Virginia Commonwealth University in 2005, I began my career as an Assistant Professor of Epidemiology and Biostatistics at The George Washington University. Since then, I have expanded my research interests across a vast array of application fields, including HIV/AIDS prevention, care, and treatment; breast and lung cancer; diabetes; cardiovascular disease; and environmental and occupational health. I have developed a solid foundation of statistical theory applicable to a wide range of disciplines and strong skills for successfully communicating statistical concepts to researchers and students. Currently, I serve as a biostatistician for the Elizabeth Glaser Pediatric AIDS Foundation contributing to and developing study designs and data analysis plans, analyzing data, and interpreting study results. I am also an active member in the GWU Biostatistics and Epidemiology Consulting Service, which has enhanced my knowledge of the multifaceted issues related to HIV/AIDS behavioral and prevention studies. Incorporating my research experiences into my classroom has enhanced my graduate-level courses, including Biostatistical Applications for Public Health, Use of SAS for Data Management and Data Analysis, Advanced Data Analysis, Advanced SAS, Applied Survival Data Analysis for Public Health, and Quantitative Methods.

Timothy J. Ledbetter – Ethics Representative

SAC Ledbetter

LEDBETTER, Timothy J., D.Min., B.C.C.

Ethics Representative

10/1/2013 – 3/31/2020

I am honored to be invited to offer support from the perspective of ethical considerations to the good work of the USTUR Advisory Committee. This appointment follows the conclusion of a most enjoyable term serving on the Central Department of Energy Institutional Review Board (CDOEIRB) as a non-scientific community member. In addition, I have been privileged to assist the Battelle-PNNL IRB in a similar capacity over the past 16 years. I have found congruency of concerns and discernment processes between research ethics and clinical ethics. In my capacity as member and co-chair of biomedical and hospice ethics committees, I have come to appreciate the vital and critical importance of clear and consistent ethical deliberation practices. Toward this end, I have extensively utilized what I believe is the seminal work on clinical ethics, Clinical Ethics 7th ed., by AR Jonsen, M Siegler & WJ Winslade (2010, McGraw-Hill). (Albert R. Jonsen is a godfather of the modern ethics movement and co-author of the Belmont Report which established primary ethical principles.) Several years ago, the PNNL IRB manager at that time and I developed and utilized a human subjects protection discernment protocol based on this text. Finally, in my vocation as hospital and hospice chaplain, I have learned the importance of finding ways to help survivors and future generations benefit from knowledge gained from the past and present. My desire is to appreciate and further the mission and values of the USTUR and assist wherever I can to its unique contributions to the health of our communities and world.

Thomas L. Rucker – Scientific Member

SAC Rucker

RUCKER, Thomas L., Ph.D.  

Scientific Member

10/1/2015 – 3/31/2022

Dr. Rucker has more than 40 years of experience in analytical chemistry; radiochemistry; radiological detection and measurement; dose assessment; environmental and waste management; and nuclear material disposition, control, accountability, and non-proliferation. His experience in radiochemistry and radiation detection and measurement includes laboratory management; laboratory automation; research and development; quality assurance/quality control (QA/QC) program management; information management, and statistical analysis. He has extensive experience in alpha and gamma spectroscopy, liquid scintillation counting, and nuclear nondestructive and field analysis techniques. Dr. Rucker also has extensive experience in radioanalytical data evaluation and validation. Dr. Rucker’s dose assessment experience includes the interpretation and implementation of radiation protection regulations in technical basis documents for internal dosimetry, establishment of internal dosimetry bioassay programs; and evaluation of nuclear accident dosimetry programs.

Arthur W. “Bill” Stange – Scientific Member

STANGE, Arthur W. “Bill”, Ph.D.

Scientific Member
(Occupational Health)

10/1/2016 – 3/31/2020

Dr. Arthur W. “Bill” Stange has over 30 years’ experience in epidemiology, environmental health, and occupational health exposure assessments. Throughout his career, he has been involved in numerous industrial hygiene monitoring and medical surveillance programs, and has created computer procedures for monitoring and characterizing employee illnesses, injuries, and absenteeism. Dr. Stange has advised Fortune 100 corporate medical and management directors concerning the implications of hazardous occupational exposures, designed procedures for tracking and characterizing employee illness and developed management training programs concerning employee productivity. Dr. Stange is presently the Manager of Health Studies for Oak Ridge Associated Universities, and is responsible for health studies data collection, epidemiologic analyses, and the publication of findings for the National Supplemental Screening Program (NSSP), a U.S. Department of Energy (DOE) Former Worker Medical Screening Program. He has provided epidemiological oversight and analysis of medical surveillance findings for the DOE Rocky Flats Plant Beryllium Medical Surveillance Program and the Oak Ridge Associated Universities Nationwide Beryllium Medical Surveillance Program. Dr. Stange is an active member of the Beryllium Health and Safety Committee (BHSC) that promotes activities and efforts to help individuals better understand and prevent beryllium-induced conditions and illnesses, including beryllium sensitization and chronic beryllium disease. On the BHSC he serves as the co-chair of the Medical and Epidemiology Subcommittee, which focuses on understanding the health effects associated with beryllium. He attained his PhD in Epidemiology from Colorado State University, completed a Master of Science in Cellular Biology from the University of Nebraska-Lincoln, and received his Bachelor of Science in Biology from Nebraska Wesleyan University.