A New Database for Potential Use in Radiation Risk Assessment By Neil Wald, Ph.D.

and

The USGS National Geochemical Database and Its Use in Determining "Background" Concentrations of Trace Elements in Surficial Materials By David B. Smith, Ph.D.

Wednesday, October 9, 2002

Neil Wald, Ph.D.
Professor of Radiation Health, Environmental and Occupational Health, and Human Genetics and Radiology,
University of Pittsburgh Graduate School of Public Health

Summary: Over the past 50 years, defense-related activities in the Russian Federation have resulted in significant occupational radiation exposures to tens of thousands of nuclear workers. Information has recently become available about the Mayak production facility in the South Urals. The Mayak facility, which started operations on 1 January 1948, was the first nuclear production site in the Soviet Union and included a reactor plant, a radio-chemical plant, and plutonium processing plant. In the first decade of its existence (1948-1958), inexperience with production techniques, combined with an emphasis on urgency of political priorities, resulted in at least 8,000 workers receiving cumulative exposures to relatively high levels of external gamma radiation (1-10 Gy) and, in many cases, to acute accidental gamma exposure, as well as to internal alpha radiation from inhaled plutonium aerosols. A number of these workers, including about one third females, developed early deterministic health impairments diagnosed by their physicians at Branch No. 1 of the Institute of Biophysics FIB-1, now the Southern Urals Biophysics Institute, SUBI, as the Acute Radiation Syndrome (ARS), Plutonium Pneumosclerosis (PPn), or Chronic Radiation Sickness (CRS).

These detailed longitudinal data on human occupational (internal and external) exposures to ionizing radiation and their resulting clinical outcomes represent an important addition to the currently available data that can be used for research and regulatory purposes. For example, these new data hold the potential for:

1. significantly improved estimates of the human dose thresholds and dose-response relationships for the deterministic effects of acute and prolonged exposure to ionizing radiation, particularly in females who make up a significant proportion of all the diagnostic categories included the current database;
2. the development of more precise prognostic models to predict the long and short-term consequences of prolonged and intermittent radiation exposures ranging from the sub-lethal to the sub-clinical;
3. the clinical description and dose-response modeling of possible radiation-related deterministic effects in human beings (e.g., plutonium pneumosclerosis, chronic radiation sickness) that have not been encountered by Western scientists and physicians, as well as,
4. the impact of high levels of pre-accident chronic occupational exposure on the post-accident ARS response.

Biography: Dr. Niel Wald received a medical degree from the New York University School of Medicine. He served in the US Air Force as a Flight Surgeon and Research Radiobiologist, was Senior Hematologist at the National Academy of Sciences Atomic Bomb Casualty Commission in Hiroshima, and Head Biologist at the Health Physics Division at Oak Ridge National Laboratory. Since 1958, Dr. Wald has worked at the University of Pittsburgh Graduate School of Public Health . Currently he is Professor of Radiation Health, Professor of Environmental and Occupational Health, and Professor of Human Genetics and Radiology. He has served as an editor or officer for several professional societies: the Health Physics Society, the Radiation Research Society, the Society of Nuclear Medicine, and the American Public Health Association. He has been honored with a British Royal Society of Medicine Visiting American Professorship; a U.S. Department of Energy Health Physics Faculty Research Award; and the American Medical Association Award for 50 Years Service to Medicine.

Research interests include the effects of radiation on populations and chromosome changes associated with cancer. Some recent publications relevant to the upcoming talk include background information on radiation effects as well as information on the database:

• Wald, N. Acute Radiation Injury and its Medical Management, in "The Biological Basis of Radiation Protection Practice". Mossman, K. L. and Mills, W. A., Eds., Williams and Wilkins, Baltimore, MD, 1992, pp. 184-201.

• Upton AC, Marshall CH and Wald N. Ionizing Radiation, in "Clinical,Occupational and Environmental Medicine", Rosenstock L and Cullen M, Editors. Saunders, New York 1994; pp. 633-645

• Claycamp, H.G., Okladnikova, N.D., Azizova. T.V., Belyaeva, Z.D., Boecker, B.B., Pesternikova, V.S., Scott, B.R., Shekhter-Levin, S., Sumina, M.V., Sussman, N.B., Teplyakov, I.I. and Wald, N. Deterministic Effects from Occupational Exposures in a Cohort of Mayak PA Workers: Data Base Description.Health Physics, 79:48-54, 2000.

• Okladnikova, N.D., Claycamp, H.G., Azizova, T.V., Belyaeva, Z.D., Pesternikova, V.S., Scott, B.R., Sumina, M.V., Teplyakov, I.I., Boecker, B.B., Vasilenko, E.K., Khokhryakov, A.M, Fevralov, A.M., Shekhter-Levin, S., Wald, N. Deterministic Effects of Occupational Radiation Exposures for Workers of the First Russian Nuclear Plant (Medical-Dosimetric Database) Medical Radiology and Radiation Safety, Vol. 46, No.6, Pp.84-93,2001. (In Russian)

• Azizova, T.V., Sumina, M.V., Pesternikova, V.S., Osovets, S.V. and Wald, N. Acute Radiation Syndrome among Nuclear Workers of Mayak Production Association. Health Physics 82:S164, 2002.

The USGS National Geochemical Database and Its Use in Determining "Background" Concentrations of Trace Elements in Surficial Materials

David B. Smith, Ph.D.
Research geochemist with the USGS in Denver, Colorado

Dr. Smith is organizing a meeting to identify the properties of soil that are useful in risk assessment. The meeting will be in Colorado in early March. Contact him at dsmith@usgs.gov if you are interested.

Summary: An initial step in the risk-based assessment of contaminated land generally involves establishing the "background" concentration for the stressor(s) in question (assuming, of course, that the stressor(s) occur in nature). A tool that has proven useful to the risk-assessment community in estimating "background" values for potentially toxic trace elements is the U.S. Geological Survey's (USGS) National Geochemical Database (NGDB). The NGDB contains inorganic chemical analyses for approximately 2 million samples of geologic material collected since the late 1960s. The primary sample media represented in the database are unconsolidated sediments (from streams and lakes), rocks, and soils. Also represented in the database are analyses of plants, water, and organic fuels (primarily coal). This presentation will involve a short summary of the evolution of the NGDB, discussion of regional- and national-scale data sets within the NGDB, examples from New England of how the database has been used to determine and map geochemical baselines, and a summary of current efforts to collect new samples and generate new data to improve the usefulness of the NGDB.

The NGDB, in reality, consists of three separate databases. Two of these databases consist of data generated by the analytical laboratories of the USGS Geologic Division since the late 1960s and the third consists of data generated during the Department of Energy's National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) Program conducted from the mid-1970s through the early 1980s. Approximately 70-75 percent of the land surface of the United States currently has some degree of sample coverage represented in the NGDB. Even though the samples within the databases were collected and analyzed by a variety of protocols to address many different issues in the earth sciences, the NGDB still represents a potentially valuable resource for anyone involved in risk assessment of contaminated land. For those areas where sample type, sample density, and elements analyzed are appropriate, the NGDB may be used to establish the abundance and spatial distribution of stressors. The USGS has archival splits of most of the samples making up the NGDB, thus affording the opportunity for reanalysis to determine elements not originally analyzed or to determine elements by improved analytical techniques. Efforts are currently underway in the USGS Mineral Resources Program to improve national coverage for both soils and stream sediments based on data generated from newly collected samples as well as archival samples.

Biography: David B. Smith is a research geochemist with the U.S. Geological Survey (USGS) in Denver, Colorado. Dr. Smith received B.A. and M.S. degrees in geology from Vanderbilt University and a Ph.D. in geochemistry from the Colorado School of Mines. During his 26-year career with the USGS, he has conducted geochemical field studies throughout the western US and in the Xinjiang-Uygur Autonomous Region of China. From 1990-1995, he served as the Chief of the USGS Branch of Geochemistry. He is currently in charge of the USGS National Geochemical Database and is co-leader of the International Union of Geological Sciences Working Group on Global Geochemical Baselines. Dr. Smith is also the leader of a new USGS project titled "Geochemical Landscapes". This project focuses on upgrading the soil geochemical data for the US as well as understanding the processes that led to the current soil geochemical baseline.