TERA Staff

TERA's professional staff bring diverse backgrounds to the development of risk assessment values and methods. To find contact information for an individual TERA staff member, click on the name below. General questions or comments can be sent to tera@tera.org.

Click a name for biography and contact information.

Patricia M. McGinnis, PHD., DABT., Science Director

LinkPHONE: (513) 542.7475 ext. 102

EMAIL: Ms. McGinnis

Bio Coming Soon )

Judy Pollock, Financial Administrator

PHONE: (513) 542-7475, extension 12
FAX: (513) 542-7487
EMAIL: Ms. Pollock

 Ms. Pollock joined TERA in April 2002   In her role as TERA’s financial administrator, Judy is responsible for all aspects of TERA’s financial management.  Before joining TERA, Judy worked for several small businesses simultaneously as bookkeeper or business manager.  Her role in these companies included all facets of bookkeeping, general office administration and design and layout of business forms and publications.  She specialized in setting up small office accounting systems that were then maintained on a weekly basis.  Judy is very active in the community and is a member of the Northside Community Council, where she served as Council treasurer from 2000-2001.  Judy is currently pursuing a degree in accounting.


TERA Visiting Scientists and Fellows Programs

TERA has developed both the Visiting Scientist and TERA Fellow Programs to encourage collaboration with others and to improve risk assessment practices.  Our program includes:


bullet Visiting Scientists are those engaged with TERA for a fixed period of time or on a defined project.  Project work may or may not be onsite at TERA’s Cincinnati office.  While visiting scientists are often senior, positions can also be considered for scientists who are beyond internship level, but for whom a period at TERA would be of mutual benefit. 

bullet TERA Fellows are senior scientists associated with TERA on a longer-term basis with ongoing scientific interactions. 

TERA Fellows and Visiting Scientists are not employees of TERA, but rather scientists who share TERA's mission and values and seek to improve the practice of risk assessment. TERA collaborates with Visiting Scientists and/or TERA Fellows on projects of mutual interest.    

In the past, scientists have worked with TERA and coauthored manuscripts or reports on a variety of topics, including methods for evaluating persistent and bioaccumulative chemicals, exposure assessment methods, dose-response modeling, mixtures assessment, and investigating the magnitude of adult-to-child toxicokinetic differences in inhalation dosimetry of gases. 

Individuals interested in either program should contact Dr. Andrew Maier.

TERA Fellows & Visiting Scientists

Andrew Maier, Ph.D., CIH, DABT, Chair

PHONE: (513) 558-2407
EMAIL: Dr. Maier

Dr. Maier has 18 years of professional work experience in the areas of environmental health, occupational hygiene, and toxicology. He currently serves as the Chair of TERA Fellows Program and I serve as an Associate Professor in the Division of Environmental and Occupational Hygiene, Department of Environmental Health, College of Medicine at the University of Cincinnati. Active research includes methods in occupational risk assessment, including derivation of occupational and environmental exposure limits, cumulative risk assessment, and field validation studies of exposure models.


Dr. Maier completed his Ph.D. in toxicology with research interests in the molecular mechanisms of toxicity. Dr. Maier is also currently serving as a Toxicology Fellow with the National Institute for Occupational Safety and Health.  He is a Diplomate of the American Board of Toxicology (DABT).  

- B.S., Natural Resources, Ball State University (1988)
- M.S., Industrial Health, University of Michigan (1989)

- Ph.D., Toxicology, University of Cincinnati (2000)
-Certified, Comprehensive Practice, American Board of Industrial Hygiene (1994)

-Certified, American Board of Toxicology (2004)


plusJohn P. Christopher, Ph.D., DABT, TERA Fellow


John P. Christopher, Ph.D., DABT., was named a TERA Fellow in 2009.  Dr. Christopher received his education at Georgetown University (B.S., 1967), Stanford University (M.A., 1972), and Oregon State University (Ph.D., 1979).  After working in contract laboratories for five years as a director of safety studies in animals, he came to California government in 1985.  He served as a risk assessor for pesticide registration, evaluation of toxicity of chemicals, and regulatory risk assessment for hazardous waste sites for four years, then worked in the private sector as an environmental consultant from 1989-1992.  He returned to the California Department of Toxic Substances Control (DTSC) in 1992, from which he is retiring in March, 2010.  Dr. Christopher’s principal duties at DTSC included regulatory review of risk assessments for hazardous waste sites, especially military bases.  He has been the internal expert at DTSC on biostatistics and analysis of ambient levels of metals.  Dr. Christopher has served on some 30 panels since 1997 as a peer reviewer for TERA , U.S. EPA , U. S. Department of Defense, and Health Canada .  Subjects for review included toxicity criteria for industrial and environmental chemicals, bioavailability of metals, children’s risk assessment, and evaluation of non-lethal weapons.  In 2008, he led a successful team competing for a $900,000 grant from U.S. EPA on bioavailability of arsenic in soil from former mining lands.  Dr. Christopher is a member of the Society of Toxicology.  He is also a founding member and past President of both the Risk Assessment Specialty Section and Northern California Chapter of the Society of Toxicology.  He has received numerous service awards from DTSC, the Risk Assessment Specialty Section and the Northern California Chapter of SOT.  In 2007, he received a Lifetime Achievement Award for waste cleanup from the International Symposium on Contaminated Soil, Groundwater and Air.

Richard Hertzberg, Ph.D., TERA Fellow

Biomathematics Consulting
1932 Grist Stone Ct NE
Atlanta, GA



Richard Hertzberg, Ph.D. is a biomathematician who is internationally recognized for innovations and expertise in quantitative methods for environmental health risk assessment of chemical mixtures. Dr. Hertzberg has a B.S. in mathematics from Harvey Mudd College and a Ph.D. in biomathematics from the University of Washington. He retired from the U.S. Environmental Protection Agency in 2006 after working for 25 years as a Mathematical Statistician with EPA’s Office of Research and Development, National Center for Environmental Assessment. He is presently a visiting Associate Professor at Emory University, and on the graduate committee for one student at Emory and one student at Carnegie-Mellon University.

Dr. Hertzberg is the primary author of both the EPA’s 1986 Mixtures Guidelines, the first such guidelines by any federal agency, and the EPA's 2000 Supplementary Guidance for the Health Risk Assessment of Chemical Mixtures, and chaired both workgroups that developed those reports. He led the creation of MixTox, the EPA's database on binary toxicologic interactions, and co-developed with Patrick Durkin the EPA's interaction-based Hazard Index, which allows quantitative incorporation of toxic interaction information into a mixture risk assessment. He has co-developed and presented a mechanistically based model for a combination of two herbicides, showing significant interaction only at near lethal exposure levels, and has evaluated the numerical properties of the interaction-based Hazard Index using data on trihalomethanes. For the past ten years, he has co-taught a workshop on risk assessment of chemical mixtures at both the Society for Risk Analysis and the Cincinnati Toxicology and Risk Assessment annual meetings. Dr. Hertzberg initiated the use of ordinal regression to describe toxic severity, an approach that spawned the EPA's CatReg software and its use for acute exposures to air toxics. He has worked on EPA’s Office of Pesticide Programs' Cumulative Risk Work Group, EPA's Risk Assessment Forum cumulative risk technical panel, and external advisory groups on mixture risk for ATSDR, NIOSH and the Dutch Health Council. While at EPA he received two silver and two bronze medals and several awards for his advances and leadership in chemical mixtures risk assessment. He is a member of the Society for Risk Analysis, and the American Statistical Association, and is a recipient of the distinguished achievement medal from the ASA section on Statistics and the Environment.

read moreSteven Lewis, Ph.D., D.A.B.T., TERA Fellow

14 Merlin Drive
Washington, NJ 07882
908-689-8644 (voice & voice-mail)
stevencraiglewis@comcast.net (primary email)

President & Principal Scientist, Integrative Policy & Science, Inc.
Adjunct Professor, Robert Wood Johnson Medical School
Fellow, Toxicology Excellence for Risk Assessment (TERA)
Distinguished Scientific Associate, ExxonMobil Biomedical Sciences, Inc. (retired)
Senior Fellow, University of Texas at Dallas

Dr. Lewis holds a B.A. in Chemistry from Indiana University at Indianapolis (1970) and a Ph.D. in Toxicology (minor in Biomedical Sciences) from Indiana University School of Medicine (1975).

During the period of his graduate-school training and research, Dr. Lewis served as Analyst and Manager of the Indiana State Tumor Registry (the state-wide statistical cancer research unit).  After joining Exxon (now, ExxonMobil), he held various technical, consulting and management positions, including Head of the Petroleum & Synthetic Fuels Group.  For more than 28 years, Dr. Lewis served as a corporate advisor on scientific and science-policy issues in occupational and environmental health.  Dr. Lewis’ research and safety assessment activities have focused on assessing potential health risks from exposure to petroleum and chemical carcinogens, toxicants to the nervous system, and chemical hazards to reproductive health. On special assignment, Dr. Lewis served as the senior on-site health scientist (in Alaska) following the oil spill event of 1989.  His assignments included managing the human scientific program to assess potential human health impacts of the oil spill and clean-up.  Dr. Lewis is a four-time winner of ExxonMobil’s most prestigious awards for excellence in the health and environmental sciences: Exceptional Achievement Award in 1993 and consecutive ExxonMobil Ambassador Awards in 2001, 2002 and 2003.

Following retirement from ExxonMobil Biomedical Sciences, Inc. (December, 2003), Dr. Lewis founded an independent consulting service, Integrative Policy & Science, Inc. (IPSi).  The mission of IPSi is to provide public and private sector clients with advice in the specific areas of Dr. Lewis’ expertise, including general toxicology, qualitative and quantitative assessment of risk from occupational and/or environmental hazards, science policy (i.e., the interplay of the biomedical and environmental sciences with environmental health policy-making), and legislative/regulatory affairs.  Dr. Lewis has extensive experience in facilitating public engagement in environmental issues and decision-making, as well as in the area of risk communication.

In the role of Adjunct Professor, Department of Environmental and Occupational Medicine, Robert Wood Johnson Medical School (University of Medicine and Dentistry of New Jersey), Dr Lewis collaborates in undergraduate and post-graduate teaching.  Dr. Lewis is also a regular lecturer in the Science and Engineering Departments of Raritan Valley Community College (of New Jersey).

Dr. Lewis is a Diplomate of the American Board of Toxicology (certified in 1980, recertified in 1985, 1990, 1995, 2000, 2005).  He has served on the editorial boards of 4 scientific journals and is currently Associate Editor of Dose-Response (formerly, Nonlinearity in Biology, Toxicology and Medicine).  Dr. Lewis is very active in a variety of professional societies, including the Society for Risk Analysis (past-member of the governing Council and nominee for the office of President), the International Society for Regulatory Toxicology and Pharmacology (elected to governing Council in 2002; re-elected in 2006), and the Society of Toxicology.

Dr. Lewis has served as a Consultant to the U.S. EPA Science Advisory Board, and as a Member of the Risk Communication Subcommittee of the EPA Board of Scientific Counselors (of the Office of Research and Development).  He frequently provides comments on scientific and regulatory issues before U.S., state and international agencies and has repeatedly served as a selected peer reviewer for toxicological profiles, summaries and risk assessments.  He is a Past-Chair of the American Petroleum Institute’s Toxicology Committee, and a former member of the Board of Directors of the Toxicology Forum, past Chair of the American Industrial Health Council’s Science Policy Committee, and a former member of the Science Program Committee of the Chemical Industry Institute of Toxicology.  Dr. Lewis served as a member and Chairman of the Board of Trustees of TERA/ITER (a not-for-profit organization specializing in the assessment of health and environmental risks).  He is continuing his association with TERA in the role of collaborative Fellow. Dr. Lewis recently completed his term as a member of the U.S. National Research Council’s panel on "Public Participation in Environmental Decision-Making."

Dr. Lewis retains the title of Senior Fellow (Cecil and Ida Green Center for the Study of Science & Society, University of Texas at Dallas), where he was a Visiting Scholar in 1995.  Dr. Lewis has published and presented the results of his work widely, and has delivered numerous invited seminars and other presentations.

Charles Anthony Pittinger, Ph.D., TERA Fellow

6547 Edwood Avenue
Cincinnati, OH  USA  45224

Work: 513-218-9897
Alt: 513-729-4280


Dr. Pittinger is an environmental scientist with broad experience in ecotoxicology, environmental fate, and ecological risk assessments of organic chemicals, metals and mining products.  He provides leadership and success to multi-national corporations in meeting global product stewardship needs of their chemical products.  He has worked broadly in public (e.g., SETAC, the EPA’s Science Advisory Board) and private venues to provide technical insight and advancement in health and environmental fate and effects, regulatory compliance (e.g., GHS, REACH, HPV), technical external relations, and product sustainability (e.g., life-cycle analysis).

Dr. Pittinger has 27 years of experience in chemical safety and regulatory compliance, including 17 years with The Procter & Gamble Company and 10 years in environmental consulting with multiple industry sectors such as industrial and specialty chemicals, metals and mining, consumer goods, and pharmaceuticals.  Recently, he has also led projects for trade associations including the American Cleaning Institute, the International Council on Mining and Metals, and the Water Environment Research Foundation (WERF).  He brings technical, regulatory, and external relations experience to enable the freedom to market safe and sustainable products in highly dynamic global markets. 

As a Fellow, Dr. Pittinger and TERA have successfully leveraged their respective strengths in human health toxicology and industrial hygiene, and in ecotoxicology and environmental fate, to offer our project sponsors the full range of product stewardship services described below.  They assemble and manage multi-disciplinary staff at senior and junior levels to support project teams efficiently and cost-effectively, with excellent communications with clients.  Some examples include:

    • For WERF, a TERA team compiled and analyzed complex chemical fate, health and environmental effects data for trace organic substances in biosolids and sludge-amended soils.

      For mining firms and local, provincial and national regulatory agencies, Dr. Pittinger chaired a peer review coordinated by TERA, of long-term soil amendment programs to restore lands near Sudbury Ontario impacted by historical mine smelting operations.

      For a private paint manufacturer, TERA developed and applied hazard prioritization scoring to product ingredients to evaluate substances of special concern and opportunities for product improvement in green chemistry.

      Dr. Pittinger and TERA have actively developed regulatory submissions including REACH dossiers and Chemical Safety Reports, CLP notifications, and High Production Volume Chemical Summaries and Test Plans.

      For a number of private firms preparing GHS-compliant Material Safety Data Sheets (GHS = Globally Harmonized System for Classification and Labeling of Chemicals), Dr. Pittinger has developed environmental hazard classifications and sound, weight-of-evidence justifications for organic and inorganic substances and mixtures.

      Dr. Pittinger has conducted chemical and product life-cycle sustainability evaluations, including verification of green certification criteria and product use consumption of water and energy.

Pamela R. D. Williams, Sc.D., TERA Fellow

4647 Carter Trail Boulder, Colorado 80301

phone: 303-284-1935


Dr. Williams' areas of expertise include retrospective exposure assessment, exposure modeling, health risk assessment, decision analysis, and risk communication.  Dr. Williams recently served as a Senior Science and Policy Advisor in the Office of Research and Development at the U.S. Environmental Protection Agency (EPA).  Her past projects include conducting scientific literature reviews and analyses of various chemicals (e.g., benzene, MTBE, asbestos), characterizing human exposures and health risks in occupational and community settings, designing and implementing indoor air exchange rate and exposure simulation studies, and designing environmental health education materials.  Most of this work has been published in the peer-reviewed literature and presented at technical and scientific conferences nationally and internationally.  

Dr. Williams is the 2007 recipient of the Joan M. Daisey Outstanding Young Scientist Award, granted in recognition of outstanding contribution to the science of human exposure analysis by a young scientist.  Dr. Williams received her MS in Health and Social Behavior and her ScD in Environmental Science and Risk Management from the Harvard School of Public Health.

Raymond York, Ph.D., DABT, ATS, ERT., TERA Fellow

(315) 692-4854


Dr. York is a board-certified toxicologist with almost 30 years of experience in the field of toxicology, specializing in reproductive and developmental toxicology.  He has served as a study director on over 700 GLP safety evaluation studies, and published over a 100 manuscripts, review articles, book chapters and abstracts, and has been an invited speaker at international conferences.  Dr. York earned his Ph.D. in Toxicology at the University of Cincinnati Medical Center, Kettering Laboratory and completed a two-year postdoctoral fellowship at the Children's Hospital Research Foundation in Cincinnati, in the area of developmental toxicology.


Dr. York has directed or participated in studies to evaluate safety exposure to chemicals from consumer products and pharmaceuticals to pesticides and water contaminates to assess compliance with USEPA (TSCA, FIFRA), FDA, ICH, and OECD requirements.  He has designed numerous acute, subchronic and chronic toxicology, teratology, and carcinogenicity studies in mice, rats, rabbits, dogs and primates.  Dr. York has planned, analyzed, interpreted and summarized toxicity data for the endocrine disruptor screening program (EDSP), multi-generational, development neurotox- and immunotoxicity studies, and is familiar with sperm morphology, vaginal cytology, fetal visceral and skeletal evaluation techniques.   


Dr. York has been a member of the Teratology Society since 1984, and has been a member and served as the President for both Midwest Teratology Association (MTA; 1989) and the Middle Atlantic Reproduction and Teratology Association (MARTA; 2004).  He has also been a member of the Society of Toxicology since 1985, and the American College of Toxicology since 1998.  As a member of the Reproductive and Developmental Toxicology Specialty Section of SOT, he served on its Nominating Committee in 2006 and currently the President for SOT's Mid-Atlantic Regional section (MASOT).  Dr. York has served as a reviewer for Toxicology and Applied Pharmacology and International Journal of Toxicology and as a member of the Editorial Board of Fundamental and Applied Toxicology.  He was the reproductive toxicologist reviewer for the USEPA Biodiesel Program and on the peer consultation panel for assessment of the potential risk of health effects from exposure to tertiary-butyl acetate (TBAC).