Insights into the Public Health Legacy of the Cold War Era

By
F. Owen Hoffman

and

Ecological Risk Assessment: Reconciling Theory and Practice

By
Igor Linkov

4:05-4:30 PM Social gathering, light snacks
4:30–6:30 PM Program

Conference Room, CDM
One Cambridge Place, 50 Hampshire Street,
Cambridge, MA

RSVP Required to Korin Scheible at CDM, ScheibleKA@cdm.com by noon the day of the meeting to facilitate security sign in.

Insights into the Public Health Legacy of the Cold War Era

F. Owen Hoffman
President
SENES
Oak Ridge, TN

Summary: Exposures to the American public occurred nationwide from the testing of nuclear weapons in the U.S., the Pacific, and the former U.S.S.R. After decades of diminished public awareness on the subject of health risks resulting from exposure to fallout, the release of the National Cancer Institute's 1997 report on nationwide exposure to 131I from the Nevada Test Site has led to renewed interest. Public requests for information are focused on individual and family health problems, the right to credible and full disclosure of information, and the need for medical care and assistance for exposure-related health problems. To some extent, public concerns are rooted in the legacy of government secrecy surrounding the development and testing of nuclear weapons, distrust of government sources of information about radiation exposures and health risks, and the fact that past exposures were imposed without informed consent.

Members of the public participating in the oversight of dose reconstruction projects and epidemiologic studies have requested information on the total impact from all relevant sources of exposure that might contribute significantly to an individual's risk, including exposure to local releases and to NTS and global fallout. Information has been requested on individual doses and risks from these cumulative exposures, as well as the possibility that a person's diagnosed disease was caused by past exposure (i.e., the probability of causation).

In the attempt to address some of these concerns, it can be demonstrated that many individuals, who today have a diagnosed thyroid carcinoma and who were exposed in childhood during the 1950s to 131I in fallout from nuclear weapons production and testing, would qualify for compensation and medical care, if the present rules for the adjudication of claims for atomic veterans and radiation workers at DOE sites were to be extended to the public.

Biography: Dr. F. Owen Hoffman, President and Director of SENES Oak Ridge, Inc., Center for Risk Analysis, has more than 30 years of experience in the evaluation of doses to humans from the release and transport of radionuclides and chemicals in terrestrial and aquatic systems. He is currently a member of the National Council on Radiation Protection and Measurements (NCRP) and a corresponding member of the International Commission on Radiological Protection. He is a member of the Society for Risk Analysis and is their liaison to the NCRP. He is a past member of the Radiation Advisory Committee of EPA's Science Advisory Board. He has served as an advisor to dose reconstruction projects managed by the States of Tennessee and Colorado, the National Cancer Institute, and the Centers for Disease Control and Prevention.

Ecological Risk Assessment: Reconciling Theory and Practice

Igor Linkov
Senior Risk Assessor
ICF Consulting

Summary: Statistical analyses play a crucial role in ecological risk assessments. The characterization of risk, the establishment of remedial goals, and the determination of liability are all significantly influenced by the selection of statistical methods. Even though EPA guidance on the subject is currently available, the selection of appropriate tools and methods still requires a great deal of expert judgment and the incorporation of site-specific considerations. An additional complication is the incorporation of spatial and temporal factors, for which very little regulatory guidance is available.

The first part of this presentation will describe the development and application of statistical methodology to the deterministic and probabilistic phases of an ecological risk assessment recently conducted by ICF Consulting at a Superfund site. Among other objectives, the assessment sought to determine if the risk posed to a representative range of ecological receptors at a portion of a contaminated lake influenced by the PRP's activities was greater than that at other areas of the same lake. Although an extensive sampling program was designed and conducted at the site, ecological modeling of the receptors' foraging ranges required the parceling of this data into relatively small exposure units. We will present the design of an adaptive sampling program developed under site and cost constraints. We will discuss the application of statistical tests to compare site and background concentrations as well as to determine optimal sample sizes. This paper will also describe management options that arose in the application of EPA guidance to the site risk assessment when faced with a conflict between statistical conservatism and ecological modeling integrity, and uncertainty characterization using probabilistic modeling.

The selection of appropriate remedial, abatement and land-use policies for contaminated sites involves multiple criteria such as cost, benefit, environmental impact, safety, and risk. The second part of this presentation will summarize considerable research in the area of multi criteria decision analysis (MCDA) that could be used to supplement risk assessment and to apply scientific decision theoretical approaches to multi-criteria problem of remedial policy selection. A framework specifically tailored to deal with decision-making at contaminated sites developed for the US Army Corps of Engineers will be presented.

Biography: Dr. Linkov is a Senior Risk Assessor and Team Leader with ICF Consulting. He has more than 13 years of experience in performing cutting edge ecological and human health risk assessments and environmental investigations for contaminated sites in the U.S.A and worldwide. Dr. Linkov's skills include ecological and human health risk assessment, project management, study of contaminated sites, probabilistic modeling, risk assessment for biowarfare agents and emerging threats, toxicology and biostatistics. He is also developing software for environmental modeling, decision support and risk assessment. His current research interests include probabilistic modeling, multi criteria decision analysis, and risk assessment as well as developing risk-based approaches to environmental decision making. Prior to joining ICF Consulting (former Arthur D. Little, Global Environment and Risk Division.), Dr. Linkov was a Senior Scientist at Menzie-Cura & Associates, Inc., where he conducted environmental risk assessments in support of government and commercial clients. He also worked at Harvard University where he researched carcinogenic potencies of chemicals for risk-based regulatory policies and applied Bayesian updating methodology for environmental modeling. Dr. Linkov chairs the Ecological Risk Assessment Specialty group for the Society for Risk Analysis and is President-Elect for its New-England Chapter. He serves as a Scientific Advisor to the Massachusetts Toxic Use Reduction Institute. Dr. Linkov has published four books and more than sixty peer-reviewed publications and book chapters.