Mayak Worker Study Project 2.4

Volume III

Internal Dosimetry Dose Reconstruction Methods

Used in Preparation of Doses-2005 Database

Project 2.4: Southern Urals Biophysics Institute

V. Khokhriakov V. Khokhriakov, Jr. N. Koshurnikova N. Shilnikova P. Okatenko V. Kreslov M. Bolotnikova M. Sokolnikov K. Suslova S. Romanov

Mayak Production Association:

Е. K. Vasilenko

University of Utah: S. C. Miller

Melinda Krahenbuhl

Oak Ridge National Laboratory: K. F. Eckerman

Project 2.2: Southern Urals Biophysics Institute

N. Koshurnikova U.S. National Cancer Institute

E. Gilbert

March 15, 2007

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Abstract The Doses-2005 database was prepared by Project 2.4 researchers for use in epidemiologic analyses of Mayak Production Association (MPA) workers. The database includes external dose as described in Volume I and II, and internal dose as described herein.

The MPA Enterprise is the first industrial nuclear complex in Russia and its construction in the late-1940s involved many first-of-a-kind facilities, equipment, and processes that were later found to be inadequate, and this situation resulted in comparably high exposures to workers.

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Contents

Section Page

Acronyms and Abbreviations ....................................................................................................................... 6

1.0 Overview............................................................................................................................................. 7

2.0 History and Background of SUBI Center of Radiation Medicine and Archives on Medical and Dosimetric Records of Mayak Production Association Workers................................... 8

3.0 Progression and Development of Internal Dosimetry Systems for Plutonium: FIB-1, Doses-1999, Doses-2000, Doses-2005 ............................................................................................. 12

4.0 Doses-2005 Model for Internal Doses for Plutonium Exposures...................................................... 14 4.1 Use of biophysical measurement data ..................................................................................... 14 4.2 Use of measurements of plutonium content at autopsy........................................................... 14 4.3 Reevaluation of early (pre-1972) radiochemical methods ...................................................... 15 4.4 Determination of the ratio of feces/urine for workers at later periods after

intake could be used to improve the systemic and lung clearance models for plutonium?......................................................................................................................... 15

4.5 Development of typical Worker Exposure Profiles for different work locations, events, and times..................................................................................................... 16

4.6 Documentation of accidents and incidents .............................................................................. 16 4.7 Determination of influence of health status on biokinetics, deposition, and

subsequent dosimetry calculations .......................................................................................... 16 4.8 Determination of effect of smoking on plutonium biokinetics and

resultant dosimetry .................................................................................................................. 17 4.9 Documentation of the use of DTPA and utilize this information to

improve the dosimetry data in existing cohort. ....................................................................... 17 4.10 Determination of physical, chemical, and biological behavior

(“transportability”) of industrial aerosols characteristic of different industrial work locations ......................................................................................................... 18

4.11 Improvement and extension of internal dosimetry cohorts with new data obtained by whole-body counting methods ............................................................................ 18

4.12 Improvement and adaptation of “Leggett systemic model” (ICRP Publication 67) for Doses-2005 .............................................................................................. 19

4.13 Creation of combined biokinetic plutonium model of systemic retention and lung clearance and development of new internal dosimetry algorithm for dose calculation: Doses-2005. ........................................................................................... 20

5.0 References ......................................................................................................................................... 25

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Tables Table Page 3.1 Characteristics of internal plutonium dosimetry models; Doses 1999 and Doses

2000 ............................................................................................................................................... 12 3.2 Reliability groups 1-V.................................................................................................................... 13 3.3 Number of workers with internal dose and occupational records and with or

without external dose and occupational records sorted by dose reliability categories ....................................................................................................................................... 13

4.1 Example of original data for a bioassay measurement .................................................................. 14 4.2 Organs used for determinations of 239Pu concentrations found in autopsy database ..................... 15 4.3 Registered contingency radionuclide intakes in nuclear workers .................................................. 16 4.4 Parameters used in lung component of the model ......................................................................... 17 4.5 IDs of plutonium production sites with determined transportability coefficients.......................... 19 4.6 General characteristic of workers for whom plutonium exposures were estimated

by 241Am gamma-radiation measurements..................................................................................... 19 4.7 Transfer coefficients used in the Doses 2005 model ..................................................................... 22

Figures Figure Page 4.1 Doses-2005 model ......................................................................................................................... 21

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Acronyms and Abbreviations DOE U.S. Department of Energy DTPA diethylenetriaminepentaacetic acid

FIB-1 Branch 1 of the First Institute of Biophysics

JCCRER Joint Coordinating Committee for Radiation Effects Research

MINATOM Ministry of Atomic Energy MPA Mayak Production Association

SUBI Southern Urals Biophysics Institute

USTUR U.S. Transuranium and Uranium Registries UU University of Utah

WBC whole-body counter

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1.0 Overview This volume describes the history of the Southern Urals Biophysics Institute (SUBI), formerly Branch 1 of the First Institute of Biophysics (FIB-1), and the development of the archive of medical and dosimetric records from the Mayak Production Association (MPA). The task for internal dosimetry was to develop an updated dosimetry system such that organ doses from internal exposures to plutonium could be calculated, estimated, or extrapolated. The initial dosimetry system employed the FIB-1 model, which was replaced in sequence by the Doses-1999 and Doses-2000 models. The details, development, and progression of these internal plutonium dosimetry models have been well documented in the peer-reviewed, public-domain literature listed at the end of this report.

The Doses-2000 model has been used from 2000 to the present, but is being replaced by an updated model, Doses-2005. The new model was developed using data sets that were unique to Mayak workers and other sources such as the International Commission on Radiological Protection (ICRP). This model consists of two major parts: a lung model and a systemic model. Both parts were described in detail in recent manuscript publications. The combined model (Doses-2005) with the various transfer coefficients will be summarized in this report, but the reader is referred to the published literature for technological details.

Throughout this report, the reader will be referred to supporting published literature, when available. Publications that were derived specifically from the Internal Dosimetry Team during the course of these studies are listed in the Project 2.4 Internal Dosimetry Bibliography.

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2.0 History and Background of SUBI Center of Radiation Medicine and Archives on Medical and Dosimetric Records of Mayak Production Association Workers

Construction on the MPA began in the summer of 1946. The first spent fuel elements were dissolved in December 1948, with the first separation of plutonium product completed by February 1949, and the finished product completed later that year. During the period from 1948 to 1955, six nuclear reactors and two radiochemical plants entered into production. Of the six reactors, five were graphite-moderated while the sixth was originally a heavy-water reactor.

In the early years of MPA operation, a number of workers were exposed to significant amounts of radiation and radioactive materials, largely due to unfamiliarity with this emerging technology and a series of incidents and accidents. To address some of the health-related issues associated with these radiation exposures, a scientific/medical division was created in May 1953. This division was originally part of the MPA Central Laboratory and Medical Sanitary Department-71, and later became FIB-1 and more recently SUBI. The initial function of the Division was to accumulate primary dosimetry and medical information on MPA workers to address occupational and work-related issues that would protect worker health by decreasing harmful radiation exposures.

The Division was initially led by G. D. Baysogolov and A. K. Guskova and within the first 5 yr of operation provided unique information on the health consequences of acute and chronic radiation exposures. Of particular interest were effects on the hematopoietic system and other clinical indicators of exposures. These early data were used to help control worker exposures by occupational and/or leave assignments and to also implement medical monitoring and intervention, when needed. It was the results of these early studies that led the central Soviet Ministry Research Council to establish a more formal branch at the MPA, thus FIB-1. This provided an improved infrastructure to accumulate primary medical and dosimetry monitoring information and provide medical care and support.

There was considerable emphasis in the period from 1953 to the 1960s to implement monitoring for plutonium exposures. The early monitoring approaches were elementary by today’s standards, but were implemented to address the significant problem of inhalation exposures by the workers. In the mid-1950s, the need to implement biophysical examinations was apparent and some early data on plutonium uptake, retention, and metabolism in humans were obtained from autopsy materials.

Some of the exposures to plutonium in the initial years of plant operations were so high that affected individuals appeared to have chronic radiation sickness. The recognition of this radiation-related illness prompted the initiation of some basic science and clinical research studies at FIB-1. These included radiobiology studies on the dosimetry, metabolism, and toxicity of alpha-emitting radionuclides in biological systems. Various animal models were developed to study these scientific issues.

Inhalation of contaminated aerosols was recognized as the main route of internal contamination and, beginning in about 1957, use of the “Lepestok” respirator was introduced. This helped reduce occupational exposures, along with other improvements in personnel protection, such that there has been a gradual decline in exposures from 1958 to the present.

The Internal Dosimetry Laboratory was created at the FIB-1 in 1967 to study plutonium metabolism with the goal of reducing worker exposures and improving worker health. The laboratory began to accumulate data on radionuclide metabolism in the workers and to develop and improve detection and measurement methods. From the initial data that were accumulated from early Mayak workers, attempts were made to

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begin to estimate the longer term accumulation and retention of plutonium in the human and to estimate radiation doses to organs and tissues.

Due to the now well-known concept of latency (the time from exposure to clinical manifestation), many of the first clinical symptoms of early respiratory exposures began to become apparent in the 1960s. For example, a number of cases (about 123) of “plutonium pneumosclerosis” were diagnosed. Additionally, cancers that were suspected of having a radiation etiology from earlier exposures began to appear. Thus, the longer term (stochastic) effects of radiation exposures (internal and external) on morbidity and mortality started to become evident.

In the following decade (1970s), research into the various exposure situations, including metabolism, dosimetry, and the resulting health consequences began to intensify. During this period, very unique data obtained at autopsy and from urine bioassays were used to develop some of the early radiation guidelines for the former Soviet Union. The first Directive Guidelines (IMU-72) were issued by FIB-1 in about 1972 and were used to provide dosimetry estimates for cohorts used in some of the initial epidemiological studies conducted on these workers. These early epidemiological studies were some of the first to explore relationships between human exposures to significant internal and external radiation exposures and the incidence of oncological diseases and other pathologies. Some of the results from these early studies were published in the Soviet literature and one monograph, in particular, was published in 1971 and translated into English in 1973 in the United States and distributed through the U.S. Library of Congress.

In the mid-1970s, more advanced radiochemical methods and techniques for the analysis of plutonium and americium in biological materials are introduced at the Biophysics Laboratory at FIB-1. This greatly increased the capabilities of the laboratory to detect and measure plutonium and americium in biological samples.

In the early 1980s, a whole-body counter (WBC) installed at the Biophysics Laboratory greatly increased the capability to detect and measure the whole-body content of 241Am in the individual. Individuals with higher than background levels of 241Am were suspected of being exposed to greater amounts of plutonium. These individuals were used for bioassay measurements of plutonium. Thus, the use of the WBC became, and continues to be, a valuable worker screening tool and collaboration effort between FIB-1 and the Radiological Protection Service at the MPA. In the late 1980s, new guidelines, similar to those of the ICRP (ICRP Publication 30; ICRP 1979) for plutonium dosimetry were developed (Directive Guidelines IMU-88). These guidelines remain in use today for dosimetry control at Ministry of Atomic Energy (MINATOM) enterprises.

During the 1970s and 1980s, medical and dosimetry studies were significantly expanded to consider environmental exposures. This was particularly important for areas contaminated by the tank explosion in 1957 (the “Kystym Explosion”) that contaminated a large area extending from the plant to the northeast (the East Ural Radioactive Track, or EURT) and exposed about one quarter of a million people to radiation. An estimated 2 million curies of radiation were expelled into the atmosphere. Of interest to the investigators at FIB-1 was to reconstruct the cumulative dose from all sources of radiation. This was done using data from autopsies, in vivo measurements, bioassays, and information on environmental exposures and other sources of information, such as film badge dosimetric data obtained from the MPA.

From the 1950s through the 1990s, the medical and dosimetry records were largely contained in paper records. In the early 1990s, computerization and creation of electronic databases of some of these records began and continue to the present. The various databases included information on autopsy data (about 1,200 cases), bioassay measurements, chelation records, and other important information on plutonium and americium exposures. These records were used and continue to be used by statisticians and epidemiologists to study the health consequences of the radiation exposures.

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In the late 1980s, more direct contacts and collaborations between scientists at FIB-1 and foreign scientists were initiated. Some of the motivation for these collaborations was perhaps driven by the political expediency of dealing with the Chernobyl accident at the international level. With time, the unique dosimetric and medical records contained at the FIB-1 and MPA became recognized, and there was a growing interest to initiate formal international collaborations. On January 14, 1994, an agreement on cooperation to study the health consequences of radiation exposures at the MPA was signed between the Russian Federation and the United States. Thus, the Joint Coordinating Committee for Radiation Effects Research (JCCRER) was formally established. The U.S. Department of Energy (DOE) is the managing agency of the program for the United States, but incorporates other participating Federal agencies including the U.S. Nuclear Regulatory Commission, U.S. Department of Defense, and the U.S. Department of Health and Human Services. On the Russian side, the participating agencies were the Ministry for Civil Defense Affairs, Emergencies and Elimination of Consequences of Natural Disasters, MINATOM, and Ministry of Health.

Since the inception of the JCCRER, numerous collaborative studies have been initiated between scientists from SUBI and foreign investigators. Under the JCCRER, the initial collaborative studies were with investigators from the U.S. Transuranium and Uranium Registries (USTUR) at the University of Washington and investigators from the University of Utah (UU). With USTUR, techniques for the radiochemical and spectroscopic analyses of alpha-emitting isotopes were modernized and standardized between the USTUR and SUBI. Additionally, improvements in the detection of soft-gamma radiation were made, and are useful for routine and emergency examination of personnel.

With investigators from UU and later with Oak Ridge National Laboratory, a series of improvements was made in the internal dosimetry system for plutonium (the topic of this report). This included a sequential improvement of models used to calculate internal doses to organs that began with the FIB-1 model, then the Doses-1999 model, the Doses-2000 model, and now the Doses-2005 model (summarized later in this report). With the development of these models were sequential improvements in the database that contains the dosimetric records of the Mayak worker cohort (about 18,600 in the original cohort).

With investigators from the USTUR and later with DOE, the Radiological Department at SUBI created an archive of biological materials and tissue samples obtained from Mayak workers. Materials in this archive are being used to support studies that include the molecular and cell biology of radiation-induced cancers and studies on the organ, tissue, and cellular localization of plutonium in human tissues determined by various autoradiographic methods.

Perhaps one of the most important activities of the joint Russian-U.S. study is the creating of a large database that contains health and medical records, dosimetry and other exposure information, and occupational and work history information on the Mayak workers. Comparing the information in this data base with registries in other countries, there are some unique aspects of the database and the Mayak worker cohort. Some of these include:

• A large and well-documented cohort

• Documented exposures to plutonium in a significant population of workers

• Higher radiation exposures permitting a broad range of dose-effects studies

• Ability to distinguish external and internal exposures in much of the cohort

• The potential to study the effects of exposures to other radionuclides including 241Am and uranium fission products

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Khokhryakov and Vasilenko (2003) published additional unique characteristics and features of the Mayak worker database and dosimetry system.

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3.0 Progression and Development of Internal Dosimetry Systems for Plutonium: FIB-1, Doses-1999, Doses-2000, Doses-2005

The model used to calculate annual organ doses from plutonium exposures was called the FIB-1 model and was based on the so-called “Durbin Model.” In 1999, the FIB-1 model was updated and referred to as Doses-1999 and in the following year as Doses 2000. Details on the development and application of these models have been published (Khokhryakov et al. 2000a; Khokhryakov et al. 2000b; Khokhryakov et al. 2002a; Krahenbuhl et al. 2002; Khokhryakov 2004).

The distinguishing features of the model are listed in Table 3.1. Both models, as well as the new Doses-2005 model have two major components: a pulmonary clearance model and a systemic model.

Table 3.1. Characteristics of internal plutonium dosimetry models; Doses 1999 and Doses 2000.* Attribute Doses-1999 Doses-2000

Worker database Period of employment, work location, and trade

Period of employment, work location, and trade

Aerosol characteristics

Particle size not addressed. Solubility characterized in physiological saline. Three transportability groups defined.

Large particles assumed. Solubility characterized in physiological saline. Three transportability groups defined.

Respiratory tract model

Simple model considering long-term dynamics

Structure of respiratory model of ICRP-66 with absorption based on transportability groups

Systemic model Systemic burden estimated from modified Durbin excretion function. Fixed systemic distribution estimated from autopsy data.

Systemic burden estimated from modified Durbin excretion function. Fixed systemic distribution estimated from autopsy data.

Dosimetry model Absorbed dose averaged over entire organ Absorbed dose averaged over entire organ *From Table 2 in: Leggett et al. 2005.

The uncertainties associated with the Internal Doses 2000 Dosimetry Model were recently published (Krahenbuhl et al. 2005).

The method to estimate uncertainties associated with total body doses derived from the Doses-2000 model includes errors generated by both detection and modeling methods. The approach used standard statistics, Monte Carlo, perturbation, and reliability groups. Using an approach that was previously used in the Sellafield worker studies, we sorted members of the cohort into “reliability” groups. This approach has several advantages including a better characterization of the entire cohort and statistical uncertainties estimated for each of these reliability groups. We identified five uncertainty categories based on how and when plutonium content was determined (e.g. autopsy, bioassay, nonmeasured) and transportability (transport to the systemic circulation) characteristics (e.g. fast, medium, and slow). The transportability (identified as “S” in our manuscripts) correlates with the characteristics of the various industrial aerosols to which the workers were exposed. For example, the less soluble plutonium dioxide compounds were found to have a solubility of 0.3%, the mixed compounds of 1.0%, and the more insoluble plutonium nitrate compounds of 3.0%. The solubility directly correlates with the transport of the plutonium out of the lung into the systemic circulation; more recent nomenclature (ICRP) identifies these as S (slow), M (medium), and F (fast). The five reliability categories are listed in Table 3.2.

Of concern to the epidemiologists and others who use or might use these data are the relative numbers of workers who fall into these categories. Clearly, autopsy data provides the best direct measure of terminal organ plutonium content, but relatively few autopsies have been performed (about 1,200 total in the total worker cohort). Bioassays are less able to predict total body and organ plutonium content, but in many

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Table 3.2. Reliability groups 1-V. Group Characteristics

I Individuals with only one transportability and autopsy II Individuals with more than one transportability and autopsy III Individuals with only one transportability and bioassay IV Individuals with more than one transportability and bioassay V Individuals who were not monitored for plutonium exposure

cases represent the only data available for these workers. The majority of workers who worked on locations where they could have been exposed to plutonium compounds, however, had neither a bioassay nor an autopsy. This is summarized in Table 3.3.

Table 3.3. Number of workers with internal dose and occupational records and with or without external dose and occupational records sorted by dose reliability categories.*

Category Internal dose records only External dose and

internal dose records Total cases I 72 733 805 II 10 175 185 III 710 4,043 4,753 IV 92 1,636 1,728 V 3,084 11,751 14,835

*Taken from Figure 9 and Table 6 in Krahenbuhl et al. 2005.

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4.0 Doses-2005 Model for Internal Doses for Plutonium Exposures

The Doses-2005 model for calculating doses to various organs from plutonium exposures is comprised of a respiratory tract model and a systemic model. The details on these two components have been recently published. Details on the respiratory (pulmonary) tract portion of Doses-2005 were recently published in Khokhryakov et al. 2005. The systemic portion of the Doses-2005 model have been recently published in Leggett at al. 2005.

The development of the Doses-2005 model required a number of studies on various components of the model. The following summarizes some of these studies and the resultant publications that described the results. Supplementary references can be found in the publications resulting from these studies.

4.1 Use of biophysical measurement data

Direct measurements of the plutonium content in the body are derived from autopsy and urine bioassay data. In these studies the internal dosimetry database was expanded and improved by the inclusion of new bioassay data obtained from current and former workers of the MPA. This task continued through the duration of the project and will continue into the future as part of the ongoing worker health program at Mayak and SUBI. The bioassay (urinalysis) data were used in the dosimetry models to calculate organ doses. This, naturally, required a number of assumptions, which are detailed in the publications that were derived from this project. The methods, procedures and data obtained from the studies conducted under this task were published by the Project 2.4 Internal Dosimetry Team (see Khokhryakov et al. 2003a; Khokhryakov et al. 2004a).

An example of the bioassay data that is found in the original records and transferred into the Bioassay data base is found in the following Table 4.1.

Table 4.1. Example of original data for a bioassay measurement (translated from Russian). (This example was taken from Journal 637, Page 66, ID 63766.)* Date of collection: 20/11/75 (date urine was collected from the worker for the assay) Amount of urine: 1,300 ml (24-hr collection while worker was in Health Center) Volume of sample used in assay: 200 ml Aliquot used for counting: 10 ml Background counts: 3 Counting efficiency: 13 PMT Identifier: 626 Sample counts: 40 Calculated dpm/g: 48 Final dpm/g: 48

* Other information on this individual found in the original notebook records includes name (by unique identifier), date of birth, employment dates, other sampling dates, death record (if deceased), weight at last exam, use of DTPA in the bioassay, employment and plant work history, and other information on the dates of the bioassays relative to work at the plant.

4.2 Use of measurements of plutonium content at autopsy

The data obtained from the autopsy materials (e.g. organ content of alpha emitters) was considered to be the most reliable and highest quality data for calculation of organ doses. There were more than 1,200 autopsy cases from the Mayak worker cohort. The autopsy program has been completed and no further

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autopsies will be performed except on a very limited basis. A special “autopsy database” created for this important and unique dataset is maintained in the biophysics laboratory at SUBI. The data are used to calculate organ doses using the new Doses 2005 model and were used in the models to estimate organ doses from the bioassay (urinalysis) measurements.

The autopsy data have provided new insights in the effects of various diseases and lifestyle issues (e.g. smoking) on plutonium biokinetics. The use of these data for understanding the effects of smoking are presented later in this report. The effects of various late-in-life diseases, such as cancers and liver disease, are also presented later in this report. The autopsy database at SUBI complements the DOE-databases maintained in USTUR.

The autopsy database contains data on the concentrations of 239Pu in a number of organ systems. These are listed in Table 4.2.

Table 4.2. Organs used for determinations of 239Pu concentrations found in autopsy database. Liver Skeleton Skeletal muscle Spleen Kidneys Heart Thyroid gland Gonads Pancreas Gall bladder Adrenal glands Stomach Esophagus Bladder Intestine and colon Mammary gland Skin Blood Red bone marrow Lymph nodes (axillar, mesenteric, inguinal) Lung and pulmonary tree

4.3 Reevaluation of early (pre-1972) radiochemical methods

Methodological and instrumentation sensitivity and error are a source of uncertainty in dosimetry calculations. In these series of studies, the early radiochemical methods were characterized and the various changes in methodology, equipment, and measurement sensitivity for the bioassay data were documented. The methodological aspects of this task were accomplished under the original Project 2.1. This included equipment and methodological improvements in the bioassay technologies and comparisons with related technologies in use in the United States. Some of the results of this work were published by Project 2.1 investigators and one paper with Project 2.4 investigators (see Khokhryakov et al. 2000c; Khokhryakov et al. 2002a; Kathren 2004).

4.4 Determination of the ratio of feces/urine for workers at later periods after intake could be used to improve the systemic and lung clearance models for plutonium?

Plutonium excretion occurs via fecal and urinary routes, and is influenced by the route and pattern of plutonium exposures. For example, at early times after an inhalation exposure, the relative excretion of plutonium in the feces is greatly increased due to clearance from the lungs into the gastrointestinal tract. Later, however, the relative amount of urinary excretion will increase as plutonium enters the systemic circulation. There are, however, few data on this topic, particularly in humans. It was of interest to determine if the relative fecal/urinary ratios would be influenced by type of industrial aerosol and age and sex of the workers. It was the goal of this task to determine if these new data on human plutonium kinetics could be used to improve the dosimetric models. Indeed, the findings of this study indicated that the Doses-2000 model and the ICRP-66 model (ICRP 1994) overestimated the feces/urine ratio by about an order of magnitude. The results from these studies have been published and were utilized in the development of the Doses-2005 Internal Dosimetry Model. See Khokhryakov et al. 2003a; Khokhryakov et al. 2004b; Khokhryakov et al. undated.

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4.5 Development of typical Worker Exposure Profiles for different work locations, events, and times

Soon after Project 2.4 started, it became evident that much more information about the nature of the worker exposures would be needed to obtain more reliable dose estimates and to identify workers who might have been exposed, but dosimetry data was sparse or nonexistent. Then the occupational histories of the workers were obtained from the MPA and systematically entered into the database. These occupational data helped identify when and where workers might have been exposed and, if so, to what types of industrial compounds (e.g., nitrates, oxides, mixed). All of these data were then used to develop the new dosimetry models (Doses-2000 and Doses-2005). These “worker exposure profiles” have also been used to obtain “surrogate doses” when doses based on actual measurements (e.g., bioassay and autopsy) were not available. These surrogate doses can be used by the epidemiologists, and are used for specific groups of workers with the similar labor conditions given their occupation, working time, means of individual protection, air contamination, and physical-chemical properties of alpha-active aerosols.

The worker exposure profiles have already been used in the initial epidemiological evaluations of both liver and bone cancers and more recently lung cancers in the Mayak worker cohort. The exposure profiles permitted the epidemiologists to segregate and identify individual workers based on location of work (e.g., reactor, plutonium plant, radiochemical plant), work period, and dates. The following publications include authors from Project 2.4 (U.S. and/or Russian): Gilbert et al. 2000; Koshurnikova et al. 2000; Shilnokova et al. 2003; Gilbert at al. 2004; and Kreisheimer et al. 2003.

4.6 Documentation of accidents and incidents

The purpose of these studies was to document the occurrence, dates, and nature of accidents and incidents that might have resulted in acute exposures. This information is important to understand when exposures occurred and to distinguish acute vs. chronic exposures for dosimetry calculations. A database was developed that contains available information on incidents and accidental exposures to radionuclides among MPA workers. These have been obtained from records in the SUBI archives and continue to be updated as new information is obtained.

Table 4.3 summarizes the information in the accidents and incidents database. Currently, the database contains information on accidental intakes of radionuclides for 653 workers. Of these, 367 workers were from cohorts of epidemiological projects on stochastic risk estimation (Project 2.2) and deterministic effects (former Project 2.3; now supported by the U.S. National Institute of Health). In total, the database contains 833 incident cases for the period from 1949 (beginning of plant operations) to March 2005.

Table 4.3. Registered contingency radionuclide intakes in nuclear workers. Nuclear workers

Stab wounds, cuts, scratches

Skin surface contamination

Acute inhalation intakes

Chemical burns Other Total

Cohorts I-V* 271 (1)** 74 (0) 87 (3) 29 (0) 40 (0) 501 (4) Other 116 (2) 75 (0) 89 (7) 23 (0) 29 (0) 332 (10) Total 387 (3) 149(0) 176 (10) 52 (0) 69 (0) 833 (14)

* Cohorts I-V include workers of the plutonium production and radiochemical plants employed during 1948–1982. ** Number of female workers

4.7 Determination of influence of health status on biokinetics, deposition, and subsequent dosimetry calculations

The purpose of these studies was to determine the influence of health status on the distribution of plutonium and perhaps other actinides among organs. If differences were observed, this would influence how organ doses were calculated for the individual. The studies found that certain diseases, particularly

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those that occur late in life, will influence the redistribution of plutonium among the organs. These data resulted in a reevaluation and reconsideration of historical data often obtained from individuals with various late-in-life diseases. From these data, new corrections in the dosimetry calculations were made. It is important to note that the presence of disease factors that would influence the assays of plutonium content (e.g., autopsy and bioassay) can now be taken into consideration in the new Doses-2005 dosimetry system. We should also note that these findings illuminated some deficiencies in dosimetry assumptions and calculations derived from other (non-Russian) populations. The results from the following studies have been published or are in press: Suslova et al. 2000; Suslova et al. 2002; Suslova et al. 2003; Suslova et al. in press; Suslova et al. submitted.

4.8 Determination of effect of smoking on plutonium biokinetics and resultant dosimetry

Smoking history can influence the plutonium lung clearance model given the modifying effect(s) of smoking and other modifiers on the retention of various nuclide compounds in the respiratory tract. Additionally, smoking is the primary confounder in the interpretation of the epidemiological data, particularly considering the prevalence of smoking among Mayak workers. Information on an individual’s smoking history is found in the clinical records and has now been entered into a database in the biophysics laboratory at SUBI. These smoking history data have and are being used in the epidemiological analyses of cancer risk, as indicated in the following publications from investigators who are using this database: Tokarskaya et al. 2002; Kreisheimer et al. 2003; and Gilbert et al. 2004.

The influence of smoking on plutonium biokinetics has been studied and the modifying factors involved with smoking or nonsmoking can now be used in the Doses-2005 Internal Dosimetry system. Thus, the influence of smoking on plutonium biokinetics can be taken into account when individual organ doses are calculated. These modifying factors were obtained from analyses of several hundred autopsy cases in which smoking history was confirmed. We found that smoking increased the retention of plutonium in the lungs, particularly with less soluble plutonium compounds. There were no significant differences observed in lung retention in the smokers vs. the nonsmokers exposed to the more soluble industrial compounds. A similar relationship was found in pulmonary lymph nodes. Much of the data derived from these studies have been published or are in press; see Khokhryakov et al. 2005; Suslova et al. submitted; and Kudryavtseva and Sokolova submitted.

The parameters used in the lung component of the model are listed in the Table 4.4. S = “solubility” of the aerosols and the less soluble plutonium (0.3%) represents dioxides and metallic compounds; moderate soluble plutonium (3.0%) represents nitrates; and the intermediate solubility forms of plutonium (1.0%) represent mixtures of moderately soluble and insoluble compounds.

Table 4.4. Parameters used in lung component of the model (after Khokhryakov et al. 2005). Smokers Nonsmokers

S, % fr f1 N fb ss, d-1 N fb ss, d-1 0.3 0.003 10-5 50 0.193 3.22 × 10-4 8 0.147 3.61 × 10-4 1.0 0.01 3 × 10-5 188 0.0657 1.17 × 10-3 69 0.0332 4.75 × 10-4 3.0 0.03 10-4 157 0.0203 7.11 × 10-3 58 0.0226 1.77 × 10-3

Assumes an AMAD of 5 µm.

4.9 Documentation of the use of DTPA and utilize this information to improve the dosimetry data in existing cohort.

DTPA was frequently used to temporarily increase the urinary output of plutonium to improve the sensitivity of the bioassay measurements. DTPA was also used, in a very few cases, to reduce the body burden of plutonium. In these studies, the use of DTPA for bioassay measurements was documented and

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reviewed. This was important because a large number of the bioassays were from individuals who were taking DTPA for short periods prior to the bioassay. These data are then used to correct, adjust, and standardize the bioassay results.

The records of 1,179 workers were obtained. Some of these workers were chelated more than once, resulting in 1,237 analyzed cases. The majority (about 80%) of these workers were males and most (about 75%) were exposed to plutonium prior to 1961. Most of the chelation-enhanced bioassay measurements were made from 1961 to 1974. The typical protocol was that Ca-DTPA was injected intravenously at a dose of 0.25 g/d for 3 d. Urine was collected over this 3-d period. Typically, this was done after 20–60 d of vacation away from the production plant. This was done to minimize the effects of more acute exposures. The results indicate that this procedure would enhance plutonium excretion by a factor of about 62.3 during the injection period. After concurrent administration of Ca-DTPA, the enhancement factor decreased exponentially with a halftime of 3.7 d. This project became a Ph.D. dissertation topic for one of the younger scientists at SUBI; some of the results have been presented in Khokhryakov et al. 2003, and two articles by Schadilov et al. submitted for publication (included in the references list).

4.10 Determination of physical, chemical, and biological behavior (“transportability”) of industrial aerosols characteristic of different industrial work locations

These studies were designed to determine the “solubility” characteristics that would influence transport (transportability) or translocation from the lung to other tissues of the industrial aerosols that workers encountered at the Mayak complex. These data were used to derive the revised lung component of the Doses-2005 model; the results were published in the following manuscripts: Khokhryakov et al. 2000; Khokhryakov et al. 2002a; Khokhryakov et al. 2002b; Khokhryakov et al. 2005.

Table 4.5 summarize the sites, work period, technological processes, and the associated “solubility” of the industrial compounds. These data were used to develop the “Doses 2005” model.

4.11 Improvement and extension of internal dosimetry cohorts with new data obtained by whole-body counting methods

The Rocky Flats Plant WBC was installed at the Biophysics Laboratory at SUBI and became operational in 2000. These studies determined if 241Am data obtained from the WBC could be used to screen for plutonium exposures. This was important because most of the workers were not routinely screened for plutonium exposures. In addition, the data from the WBC will provide completely new data on 241Am in the human, but these americium data were not part of Project 2.4.

The overall approach was to estimate the whole body plutonium content by measuring 241Am by whole body counting. Measuring 241Am by WBC is much more economical than measuring plutonium in bioassays and then having to estimate the total body content from the models. To date, 6,798 whole-body measurements have been made on 4,328 Mayak workers. Of these, 2,137 belong to the Project 2.2 cohort. At present, 256 workers from the Project 2.2 cohort have synchronous and reliable results from both biophysical assays and WBC measurements. From this group, algorithms have been developed to permit the estimation of plutonium content based on their exposure scenarios (e.g., the types of industrial compounds to which they were exposed). Some of these data have been derived from the autopsy database discussed earlier. The workers for whom plutonium exposures were estimated by 241Am measurements are summarized in Table 4.6.

19

Table 4.5. IDs of plutonium production sites with determined transportability coefficients.

Site ID of

workplace Work period Technological process Substrate S, %

Chemical-metallurgical

49 1949-1960 Refining Nitrate solution, Oxide, chloride

1.0

50 1949-1960 Oxalate precipitation Nitrate solution, oxalate

1.0

51 1949-1960 Filtration Oxalate 1.0 Metallurgical 55 1949-1962 Calcination, chlorination reducting fusion Chloride

Oxide

0.3 52-54 1971-present Fuel element production Mixed aerosols 1.0 Waste treatment 56 1955-1962 Dissolution, precipitation, filtration Nitrate solution 3.0 57 1949-1970 Oxalate precipitation Oxalate 1.0 Chemical 58 1962-1970 Sorption on VP-AP resin Nitrate solution 3.0 59 1967-1968 Extraction Nitrate solution,

extract 3.0

Plutonium production

74 1950-1980 Part blank Pu metal 0.3

74 1950-1980 Mechanical cutting Pu metal 0.3 75 1950-1980 Defectoscopy Mixed aerosols 1.0 81 1950-1980 Capsulation Pu metal 0.3 86 1950-present Foundry-pressing Pu metal 0.3

Table 4.6. General characteristic of workers for whom plutonium exposures were estimated by 241Am gamma-radiation measurements.

Solubility Characteristics S = 0.3% S = 1.0% S = 3.0%

Number of workers 28 135 99 Working at time of examination 25 41 50 Year of initial contact, (at average ± years) 1967 ± 8 1959 ± 6 1961 ± 9 Contact duration (average ± years) 33 ± 9 31 ± 13 25 ± 14

To date, the Pu + 241Am body burden was calculated by the Doses-2000 model and according to the WBC measurement results - total 241Am body burden. It should be noted that the bioassay measurements of the urine do not distinguish alpha particles derived from plutonium or americium using current techniques at SUBI. Further work on 241Am exposures in Mayak workers might be proposed in the future.

Several papers (Khokhryakov et al. 2003c; Khokhryakov and Efimov 2004) describe the initial experience with the use of the whole body counter to measure 241Am and to monitor the Mayak workers.

4.12 Improvement and adaptation of “Leggett systemic model” (ICRP Publication 67) for Doses-2005

The systemic portion of the Doses-2005 uses a revision of the ICRP Publication 67 model. Data for these studies were obtained mostly from autopsy cases. Parameters of plutonium metabolism in the skeleton, liver, and blood were revised. A manuscript that describes in detail the development and application of this systemic portion of the Doses 2005 model was recently published (Leggett et al. 2005). The overview of the entire Doses 2005 model is presented later.

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4.13 Creation of combined biokinetic plutonium model of systemic retention and lung clearance and development of new internal dosimetry algorithm for dose calculation: Doses-2005.

The Doses-2005 model combines the lung clearance model with the new systemic component. Both of these individual components of the Doses-2005 model have recently been published; see Khokhryakov et al. 2005 and Leggett et al. 2005.

The final model is presented in Fig. 4.1 and the derivations and conditions placed on the components of the model are discussed in detail in the published references.

21

Fig. 4.1. Doses-2005 model.

Trabecular volume

Trabecular surface

Trabecular marrow

Cortical marrow

Cortical surface

Cortical volume

Skeleton

İPu

Blood 0

Gonads

Feces

Urinary bladder contents

Urine

Blood 2

Blood 1

AI2 AI3AI1

bb1

BB1

ET2

bbseq

BB2

bb2

BBseq

ETseq LNET

LNTH

Lung fast dissolution AI2 AI3AI1

bb1

BB1

ET2

bbseq

BB2

bb2

BBseq

ETseqLNET

LNTH

Lung slow dissolution

AI2 AI3AI1

bb1

BB1

ET2

bbseq

BB2

bb2

BBseq

ETseq LNET

LNTH

Lung bound material

Intermediate turnover

(ST1)

Rapid turnover

(ST0)

Slow turnover

(ST2)

Other soft

tissue

Lower large intestine

Upper large intestine

Small Intestine

Stomach

GI tract

Liver 0

Liver 1

Liver 2

Liver

Renal tubules Other kidney

Kidneys

22

The individual transfer coefficients currently used in the model are listed in Table 4.7. The source of the information, data, or publication used to derive the specific transfer functions are also listed.

Table 4.7. Transfer coefficients used in the Doses 2005 model. Symbol Definition -s Input +s Units Source

IDL3 Worker identification number -- ##### -- -- Data S Transportability coefficient -- 0.3, 1, 3 -- -- Data sm Smoking coefficient -- 0, 1 -- -- Data

year Yearly markers -- 1948...2006 -- Year Data GNK Year started working -- 1948...2006 -- Year Data GKK Year finished working -- 1948...2006 -- Year Data GP Year of analysis or death -- 1948...2006 -- Year Data ti Time indexing -- 0.001…365 -- Day Data

V0 Maximum intake rhythm -- 100 -- Day-1 Constant g Intake exponent index (S=0.3) 0.024 0.068 0.024 Year-1 Project 2.4 Intake exponent index (S=1.0) 0.03 0.165 0.03 Year-1 Project 2.4 Intake exponent index (S=3.0) 0.011 0.129 0.011 Year-1 Project 2.4

Um Urine bioassay for Pu 100% assay 120% dpm Krah 2005 MDA Minimum detectable activity of Pu 70% assay 150% dpm Krah 2005 MU Urine bioassay performed? -- 0, 1 -- -- Data Qaut Pu body content via autopsy 5% assay 5% nCi Krah 2005 MQ Autopsy performed? -- 0, 1 -- -- Data mave Average worker mass 10 70 10 kg Data Km Shaping factor Calculated 0…1 calculated -- Calculated VI Shaped intake rhythm Calculated 0...100 calculated Day-1 Calculated

√-box Bypass autopsy for urine Km value -- 0, 1 -- -- Data Symbol Definition -s Model +s Units Source

fr Fraction dissolved rapidly (S=0.3) Monte Carlo 0.003 Monte Carlo -- Khok 2005 Fraction dissolved rapidly (S=1.0) Monte Carlo 0.01 Monte Carlo -- Khok 2005 Fraction dissolved rapidly (S=3.0) Monte Carlo 0.03 Monte Carlo -- Khok 2005

fb Fraction to bound state (S=0.3, sm=0) Monte Carlo 0.147 Monte Carlo -- Khok 2005 Fraction to bound state (S=0.3, sm=1) Monte Carlo 0.193 Monte Carlo -- Khok 2005 Fraction to bound state (S=1.0, sm=0) Monte Carlo 0.0332 Monte Carlo -- Khok 2005 Fraction to bound state (S=1.0, sm=1) Monte Carlo 0.0657 Monte Carlo -- Khok 2005 Fraction to bound state (S=3.0, sm=0) Monte Carlo 0.0226 Monte Carlo -- Khok 2005 Fraction to bound state (S=3.0, sm=1) Monte Carlo 0.0203 Monte Carlo -- Khok 2005

ss Slow dissolution rate (S=0.3, sm=0) Monte Carlo 3.61E-04 Monte Carlo Day-1 Khok 2005 Slow dissolution rate (S=0.3, sm=1) Monte Carlo 3.22E-04 Monte Carlo Day-1 Khok 2005 Slow dissolution rate (S=1.0, sm=0) Monte Carlo 4.75E-04 Monte Carlo Day-1 Khok 2005 Slow dissolution rate (S=1.0, sm=1) Monte Carlo 1.17E-03 Monte Carlo Day-1 Khok 2005 Slow dissolution rate (S=3.0, sm=0) Monte Carlo 1.77E-03 Monte Carlo Day-1 Khok 2005 Slow dissolution rate (S=3.0, sm=1) Monte Carlo 7.11E-03 Monte Carlo Day-1 Khok 2005

sr Rapid dissolution rate Monte Carlo 100 Monte Carlo Day-1 ICRP 66 fd1 Fraction deposited in AI1 (sm=0) Monte Carlo 0.3 Monte Carlo -- ICRP 66 Fraction deposited in AI1 (sm=1) Monte Carlo 0.3*0.3 Monte Carlo -- ICRP 66

fd2 Fraction deposited in AI2 -- 1-fd1-fd3 -- -- ICRP 66 fd3 Fraction deposited in AI3 Monte Carlo 0.1 Monte Carlo -- ICRP 66 fd4 Fraction deposited in bb1 -- 1-fd5-fd6 -- -- ICRP 66 fd5 Fraction deposited in bb2 Monte Carlo 0.398 Monte Carlo -- ICRP 66 fd6 Fraction deposited in bbseq Monte Carlo 0.007 Monte Carlo -- ICRP 66 fd7 Fraction deposited in BB1 -- 1-fd8-fd9 -- -- ICRP 66 fd8 Fraction deposited in BB2 Monte Carlo 0.333 Monte Carlo -- ICRP 66 fd9 Fraction deposited in BBseq Monte Carlo 0.007 Monte Carlo -- ICRP 66 fd10 Fraction deposited in ET2 -- 1-fd11 -- -- ICRP 66 fd11 Fraction deposited in ETseq Monte Carlo 0.0005 Monte Carlo -- ICRP 66 cr1 Mech. clearance from AI1 to bb1 Monte Carlo 0.02 Monte Carlo Day-1 ICRP 66

23

Table 4.7 (Continued). Transfer coefficients used in the Doses 2005 model. Symbol Definition -s Model +s Units Source

cr2 Mech. clearance from AI2 to bb1 (sm=0) Monte Carlo 0.001 Monte Carlo Day-1 ICRP 66 Mech. clearance from AI2 to bb1 (sm=1) Monte Carlo 0.001*0.7 Monte Carlo Day-1 ICRP 66

cr3 Mech. clearance from AI3 to bb1 (sm=0) Monte Carlo 0.0001 Monte Carlo Day-1 ICRP 66 Mech. clearance from AI3 to bb1 (sm=1) Monte Carlo 0.0001*0.7 Monte Carlo Day-1 ICRP 66

cr4 Mech. clearance from AI3 to LNTH Monte Carlo 0.00002 Monte Carlo Day-1 ICRP 66 cr5 Mech. clearance from bb1 to BB1 Monte Carlo 2 Monte Carlo Day-1 ICRP 66 cr6 Mech. clearance from bb2 to BB1 Monte Carlo 0.03 Monte Carlo Day-1 ICRP 66 cr7 Mech. clearance from bbseq to LNTH Monte Carlo 0.01 Monte Carlo Day-1 ICRP 66 cr8 Mech. clearance from BB1 to ET2

(sm=0) Monte Carlo 10 Monte Carlo Day-1 ICRP 66

Mech. clearance from BB1 to ET2 (sm=1)

Monte Carlo 10*0.5 Monte Carlo Day-1 ICRP 66

cr9 Mech. clearance from BB2 to ET2 Monte Carlo 0.03 Monte Carlo Day-1 ICRP 66 cr10 Mech. clearance from BBseq to LNTH Monte Carlo 0.01 Monte Carlo Day-1 ICRP 66 cr11 Mech. clearance from ET2 to GIT Monte Carlo 100 Monte Carlo Day-1 ICRP 66 cr12 Mech. clearance from ETseq to LNET Monte Carlo 0.001 Monte Carlo Day-1 ICRP 66 fdr1 Regional deposition fraction, AI Monte Carlo 0.0532 Monte Carlo -- ICRP 66 fdr2 Regional deposition fraction, bb Monte Carlo 0.011 Monte Carlo -- ICRP 66 fdr3 Regional deposition fraction, BB Monte Carlo 0.0177 Monte Carlo -- ICRP 66 fdr4 Regional deposition fraction, ET2 Monte Carlo 0.3991 Monte Carlo -- ICRP 66 f1 Fraction to body from GIT (S=0.3) Monte Carlo 1.00E-05 Monte Carlo -- ICRP 30 Fraction to body from GIT (S=1.0) Monte Carlo 3.00E-05 Monte Carlo -- ICRP 30 Fraction to body from GIT (S=3.0) Monte Carlo 1.00E-04 Monte Carlo -- ICRP 30

l1 Transfer stomach to small intestine Monte Carlo 24 Monte Carlo Day-1 ICRP 30 l2 Transfer small to upper large intestine Monte Carlo 6 Monte Carlo Day-1 ICRP 30 l3 Transfer upper to lower large intestine Monte Carlo 1.8 Monte Carlo Day-1 ICRP 30 l4 Transfer lower large intestine to feces Monte Carlo 1 Monte Carlo Day-1 ICRP 30 l5 Transfer small intestine to blood -- l2*f1/(1-f1) -- Day-1 ICRP 30

l6 Transfer blood 1 to upper large intestine Monte Carlo 1.0500E-02 Monte Carlo Day-1

l7 Transfer 30% blood to soft tissue 0 Monte Carlo 3.0000E+02 Monte Carlo Day-1 Legg 2005 l8 Transfer 70% blood to blood 1 Monte Carlo 7.0000E+02 Monte Carlo Day-1 Legg 2005 l9 Transfer blood 1 to liver 0 Monte Carlo 4.2000E-01 Monte Carlo Day-1 l10 Transfer blood 1 to cortical surface Monte Carlo 7.9800E-02 Monte Carlo Day-1 l11 Transfer blood 1 to cortical volume Monte Carlo 4.2000E-03 Monte Carlo Day-1 l12 Transfer blood 1 to travecular surface Monte Carlo 1.1340E-01 Monte Carlo Day-1 l13 Transfer blood 1 to travecular volume Monte Carlo 1.2600E-02 Monte Carlo Day-1 l14 Transfer blood 1 to urinary bladder Monte Carlo 1.4000E-02 Monte Carlo Day-1 l15 Transfer blood 1 to kidney 1 (renal) Monte Carlo 7.0000E-03 Monte Carlo Day-1 l16 Transfer blood 1 to kidney 2 (other) Monte Carlo 3.5000E-04 Monte Carlo Day-1 l17 Transfer blood 1 to testes Monte Carlo 2.4500E-04 Monte Carlo Day-1 -- Transfer blood 1 to ovaries NA NA NA Day-1 Legg 2005 l18 Transfer blood 1 to soft tissue 1 Monte Carlo 1.6828E-02 Monte Carlo Day-1 l19 Transfer blood 1 to soft tissue 2 Monte Carlo 2.1000E-02 Monte Carlo Day-1 l20 Transfer soft tissue 0 to blood 1 Monte Carlo 9.9000E-02 Monte Carlo Day-1 Legg 2005 l21 Transfer blood 2 to urinary bladder Monte Carlo 4.0000E+00 Monte Carlo Day-1 l22 Transfer blood 2 to blood 1 Monte Carlo 6.6000E+01 Monte Carlo Day-1 l23 Transfer blood 2 to soft tissue 0 Monte Carlo 3.0000E+01 Monte Carlo Day-1 l24 Transfer kidney 1 to urinary bladder Monte Carlo 1.7329E-02 Monte Carlo Day-1 Legg 2005 l25 Transfer kidney 2 to blood 2 Monte Carlo 1.2660E-04 Monte Carlo Day-1 Legg 2005 l26 Transfer soft tissue 1 to blood 2 Monte Carlo 1.3860E-03 Monte Carlo Day-1 Legg 2005 l27 Transfer soft tissue 2 to blood 2 Monte Carlo 1.2660E-04 Monte Carlo Day-1 Legg 2005 l28 Transfer liver 0 to small intestine Monte Carlo 4.6210E-04 Monte Carlo Day-1 Legg 2005 l29 Transfer liver 0 to liver 1 Monte Carlo 2.2643E-02 Monte Carlo Day-1 Legg 2005

24

Table 4.7 (Continued). Transfer coefficients used in the Doses 2005 model. Symbol Definition -s Model +s Units Source

l30 Transfer liver 1 to blood 2 Monte Carlo 1.5200E-03 Monte Carlo Day-1 Legg 2005 l31 Transfer liver 1 to liver 2 Monte Carlo 3.8000E-04 Monte Carlo Day-1 Legg 2005 l32 Transfer liver 2 to blood 2 Monte Carlo 1.2660E-04 Monte Carlo Day-1 Legg 2005 l33 Transfer gonads to blood 2 Monte Carlo 3.8000E-04 Monte Carlo Day-1 Legg 2005 l34 Transfer cortical surface to marrow Monte Carlo 8.2100E-05 Monte Carlo Day-1 Legg 2005 l35 Transfer cortical surface to volume Monte Carlo 2.0500E-05 Monte Carlo Day-1 Legg 2005 l36 Transfer cortical volume to marrow Monte Carlo 8.2100E-05 Monte Carlo Day-1 Legg 2005 l37 Transfer trabecular surface to marrow Monte Carlo 4.9300E-04 Monte Carlo Day-1 Legg 2005 l38 Transfer trabecular surface to volume Monte Carlo 1.2300E-04 Monte Carlo Day-1 Legg 2005 l39 Transfer trabecular volume to marrow Monte Carlo 4.9300E-04 Monte Carlo Day-1 Legg 2005 l40 Transfer cortical marrow to blood 2 Monte Carlo 7.6000E-03 Monte Carlo Day-1 Legg 2005 l41 Transfer trabecular marrow to blood 2 Monte Carlo 7.6000E-03 Monte Carlo Day-1 Legg 2005 l42 Transfer urinary bladder to urine Monte Carlo 12 Monte Carlo Day-1 lPu Decay constant for Pu-239 -- ln(2)/8.8E6 -- Day-1 Constant

k0,eff SEE conversion constant -- 0.00725 -- -- Constant -- Joules per MeV -- 1.60E-13 -- J/MeV Constant -- Grams per kilogram -- 1000 -- g/kg Constant -- MeV per decay of Pu-239 -- 5.2445 -- MeV/Bq Constant -- Rads per gray -- 100 -- rad/Gy Constant -- Energy deposition -- 1 -- Gy/(J/kg) Constant -- Seconds per hour -- 3,600 -- s/hr Constant -- Hours per day -- 24 -- hr/day Constant m1 Mass of reference man 10 70 10 kg ICRP 23 m2 Lung mass 200 1,000 200 g ICRP 23 m3 Liver mass 378 1,800 450 g ICRP 23 m4 Bone surface mass 24 120 24 g ICRP 23 m5 Red bone marrow mass 750 1500 750 g ICRP 23 Q0 Environmental Pu-239 burden -- 1.00E+10 -- Bq -- Ux ?? 13% 0.83 13% -- VU Volume of urine sample? 200 1000 1000 mL/day

Symbol Definition -s Output +s Units Source Q Compartmental Pu content -- f(input,t) -- Bq Model U Compartmental Pu transformations -- f(input,t) -- Bq Model

Qlung Lung Pu content TBA f(input, t) TBA nCi Model Qln Lymph node Pu content TBA f(input, t) TBA nCi Model

Qsys Systemic Pu content TBA f(input, t) TBA nCi Model Qorg Total body Pu content TBA f(input, t) TBA nCi Model Dlung Lung dose from Pu TBA f(SEE, U, t) TBA rad Model Dliv Liver dose from Pu TBA f(SEE, U, t) TBA rad Model

Dbsurf Bone surface dose from Pu TBA f(SEE, U, t) TBA rad Model Drbm Red bone marrow dose from Pu TBA f(SEE, U, t) TBA rad Model

The uncertainties associated with this model are currently being calculated using the method published for Doses-2000. Associated with this will be the indexing of groups of workers into “reliability” categories based on the “quality” of their dosimetry. See Leggett 2003 and Krahenbuhl et al. 2005.

25

5.0 References Gilbert ES, Koshurnikova NA, Sokolnikov M, Khokhryakov VF, Miller S, Preston DL, Romanov SA, Shilnikova NS, Suslova KG, Vostrotin VV. Liver tumors in Mayak workers. Radiat. Res. 154:246-252, 2000.

Gilbert ES, Koshurnikova NA, Sokolnikov ME, Shilnikova NS, Preston DL, Ron E., Khokhryakov VF, Vasilenko EK, Miller S, Eckerman K, Romanov SA. Lung cancers in Mayak workers. Radiat. Res. 162:505-516, 2004.

ICRP (International Commission on Radiological Protection). Limits for intakes of radionuclides by workers. Oxford: Pergamon Press; ICRP Publication 30; Ann ICRP 2(3-4), 1979.

ICRP (International Commission on Radiological Protection). Human Respiratory Tract Model for Radiological Protection. Oxford: Pergamon Press; ICRP Publication 66; Ann ICRP 24(1-3), 1994.

International Commission on Radiological Protection. Age dependent doses to members of the public from intake of radionuclides. Part 2. Oxford: Pergamon Press; ICRP Publication 67; 1993.

Kathren RL. A review of contributions of human tissue studies to biokinetics, bioeffects and dosimetry of plutonium in man. Radiat Prot Dosimetry. 109(4):399-407, 2004. Review.

Khokhryakov, VF. “Doses-1999, 2000” are serial improvements of plutonium dosimetry for Mayak PA workers. Radiation Safety Problems 1:71- 82, 2004. [In Russian]

Khokhryakov VF. Graphical method for assessment of doses and level accumulation based on urine excretion data. Submitted to Medical Radiology and Radiation Safety. (In Russian)

Khokhryakov, VV, Efimov AV. Experience in application of whole body counting technique to control 241Am body burden in the Mayak PA workers. Radiation Safety Problems, 1: 57-70, 2004. [In Russian]

Khokhryakov VF, Vasilenko EK. Dosimetry register of Mayak PA personnel – one of the major world information sources for solution of fundamental radiation safety problems. Radiation Safety Problems (Special Issue), pp. 36-40, 2003. (In Russian)

Khokhryakov V, Suslova K, Aladova E, Vasilenko E, Miller SC, Slaughter DM, and Krahenbuhl MP. Development of an improved dosimetry system for the workers at the Mayak Production Association. Health Phys. 79:72-76, 2000a.

Khokhryakov V., Suslova, K, Romanov, S, Vostrotin, V. Pulmonary clearance of industrial plutonium compounds in remote period after the beginning of inhalation. Medical Radiology and Radiation Protection 2: 28-34, 2000b.

Khokhryakov VF, Suslova KG, Filipy RE, Alldredge JR, Aladova EE, Glover SE, Vostrotin VV. Metabolism and dosimetry of actinide elements in occupationally-exposed personnel of Russia and the United States: a summary progress report. Health Phys. 2000 Jul;79(1):63-71, 2000c.

Khokhryakov VF, Suslova KG, Vostrotin VV, Romanov SA, Menshikh ZS, Kudryavtseva TI, Miller SC, Krahenbuhl MP, Filipy RE The development of the plutonium lung clearance model for exposure estimation of the Mayak PA, nuclear plant workers. Health Physics 82:425-431, 2002a.

26

Khokhryakov, VF, Suslova KG, Vostrotin VV, Romanov SA, Eckerman KF, Miller SC. Adaptation of the ICRP-66 model to the data on plutonium metabolism for “Mayak.” Proceedings of an International Workshop, Internal Dosimetry of Radionuclides, 9–12 September 2002. Oxford: 2002b.

Khokhryakov VF, Suslova KG, Kudryavtseva TI Schadilov AE, Vostrotin VV, Barabanschikova AU, Lagunova NU. Relative role of plutonium urinary and fecal excretion from the human body. Medical Radiology and Radiation Safety, 2003a. (In Russian)

Khokhryakov VF, Kudryavtseva TI, Schadilov AE, Shalaginov AI. Successful DTPA therapy in the case of 239Pu penetration via injured skin exposed to nitric acid. Radiat. Prot. Dosim. 105:499-502, 2003b.

Khokhryakov VF, Chernikov VI, Efimov AE. The use of scintillation body counter for monitoring of actinide accumulation among Mayak PA personnel. Radiation Safety (Special issue) 64-70, 2003c. [In Russian]

Khokhryakov VF, Suslova KG, Kudryavtseva TI, Schadilov AE, Vostrotin VV. Relative role of urinary and fecal excretions of plutonium from the human body. Health Physics 86:523-527, 2004.

Khokhryakov VF, Suslova KG, Kudravtseva TI, Schadilov AE, Vostrotin VV, Yu A, Lagounova NY, Barabanshchikova AY. Precision of equations for systemic Pu excretion based on new data on nuclide removing with urine and feces at late times after inhalation. Medical Radiology and Radiation Safety 4:12-20, 2004b.

Khokhryakov VF, Suslova KG, Vostrotin VV, Romanov SA, Eckerman KF, Krahenbuhl MP, and Miller SC. Adaptation of the ICRP Publication 66 respiratory tract model to data on plutonium biokinetics for Mayak workers. Health Phys. 88:125-132, 2005.

Khokhryakov VF, Suslova KG, Kudryavtseva TI, Schadilov AE, Vostrotin VV, Lagounova NY, Barabanshchikova A. Precision of equations for systemic Pu excretion based on new data on nuclide removing with urine and feces at late times after inhalation. Submitted to Medical Radiology and Radiation Safety. (In Russian)

Koshurnikova NA, Gilbert, ES, Sokolnikov, Khokhryakov, MVF, Miller, S, Preston, DL, Romanov, SA, Shilnikova, NS, Suslova, KG, Vostrotin, VV. Bone tumors in Mayak workers. Radiat. Res. 154:237-245, 2000.

Krahenbuhl MP, Slaughter DM, Wilde JL Bess JD, Miller SC, Khokhryakov VK, Suslova KG, Vostrotin VV, Romonov SA, Menshikh ZS, Kudryavtseva TI. The historical and current application of the FIB-1 model to assess organ dose from plutonium intakes in Mayak workers. Health Physics 82:445-454, 2002.

Krahenbuhl MP, Bess JD, Wilde JL, Vostrotin VV, Suslova KG, Khokhryakov VF, Slaughter DM, Miller SC. Uncertainties analysis of doses resulting from chronic inhalation of plutonium at the Mayak Production Association. Health Physics 89:33-45, 2005.

Kreisheimer M, Sokolnikov ME, Koshurnikova NA, Khokhryakov VF, Romanov SA, Shilnikova NS, Okatenko PV, Nekolla EA, Kellerer AM. Lung cancer mortality among nuclear workers of the Mayak facilities in the former Soviet Union. An updated analysis considering smoking as the main confounding factor. Radiat Environ Biophys. 42:129-135, 2003.

Kudryavtseva TI, Sokolova AB. Macrodistribution of Pu industrial compounds in human lung. Submitted to Radiation Safety Issues (The Mayak Production Association Journal). [In Russian].

27

Leggett RW. Reliability of the ICRP’s dose coefficients for members of the public. III. Plutonium as a case study of uncertainties in the systemic biokinetics of radionuclides. Radiation Protection Dosimetry 106:103-120, 2003.

Leggett RW, Eckerman KF, Khokhryakov VF, Suslova KG, Krahenbuhl MP, Miller SC. Mayak worker study: An improved biokinetic model for reconstructing doses from internally deposited plutonium. Radiat. Res. 164:111-122, 2005.

Schadilov AE, Khokhryakov VF, Kudravtseva TI, Vostrotin VV. DTPA effects on plutonium excretion from human body. Submitted to Radiation Safety Problems. (In Russian)

Schadilov AE, Khokhryakov VF, Kudryavtseva TI, Vostrotin VV. Ca-DTPA effects on plutonium excretion from the human body. Submitted to Health Physics

Shilnikova NS, Preston DL, Ron E, Gilbert ES, Vassilenko EK, Romanov SA, Kuznetsova IS, Sokolnikov ME, Okatenko PV, Kreslov VV, Koshurnikova NA. Cancer mortality risk among workers at the Mayak nuclear complex. Radiat Res 159:787-98, 2003.

Suslova K, Khokhryakov V, Tokarskaya Z, Kudryavtseva T, Nifatov A. Distribution of plutonium in organs of extrapulmonary pool in remote periods after the beginning of inhalation in workers of Radiochemical Plant. Medical Radiology and Radiation Protection 1: 17-25, 2000.

Suslova KG, Khokhryakov VF, Tokarskaya ZB, Nifatov AP, Krahenbuhl MP, Miller SC. Extrapulmonary organ distribution of plutonium in healthy workers exposed by chronic inhalation at the Mayak Production Association. Health Physics 82:432-444, 2002.

Suslova KG, Khokhryakov VF, Tokarskaya ZB, Nifatov AP, Sokolova AB, Kudryavtseva TI,. Miller SC, Krahenbuhl MP. The effect of state of health on the distribution and excretion of systemic plutonium in occupational workers. Radiat. Prot. Dosim. 105:229-233, 2003.

Suslova K., Khokhryakov VF, Tokarskaya ZB, Nifatov AP, Sokolova AB, Miller SC, Krahenbuhl MP. Modifying effects of health status, and some physiological and dosimetry factors on extrapulmonary organ distribution and excretion of inhaled plutonium in workers at the Mayak Production Association. Health Physics (in press).

Suslova KG, Khokhryakov VF, Nifatov AP, Sokolova AB. Smoking and lung diseases as the modifying factors of plutonium distribution in the respiratory tract at the late times of clearance in workers at the radiochemical plant. Submitted to Medical Radiology and Radiation Safety. (In Russian)

Tokarskaya ZB, Scott BR, Zhuntova GV, Okladnikova ND, Belyaeva ZD, Khokhryakov VF, Schollnberger H, Vasilenko EK. Interaction of radiation and smoking in lung cancer induction among workers at the Mayak nuclear enterprise. Health Phys. 83:833-846, 2002.

DOCUMENTS UNCITED IN THE TEXT BUT APPLICABLE TO THIS REPORT

Alexandrova ON, Vasilenko EK, Krahenbuhl MP, Slaughter DM. The statistical analysis of occupational radiation dose caused by professional exposure to external gamma-radiation. In: Proceedings of the International Data Analysis Conference. Innsbruck: 2000.

Bailey BR, Eckerman KF, Townsend, LW. An analysis of a puncture wound case with medical intervention. Radiat. Prot. Dosim. 105(1-4):509-512, 2003.

28

Choe, DO, Shelkey BN, Wilde JL, Walk HA, Slaughter DA. Calculated organ doses for Mayak production association central hall using ICRP and MCNP. Health Physics 84:317-321, 2003.

Khokhryakov, VF. “Doses-1999, 2000” are serial improvements of plutonium dosimetry for Mayak PA workers. Radiation Safety Problems 1: 71- 82, 2004. [In Russian]

Khokhryakov VF, Kellerer AM, Kreisheimer M, Romanov SA. Lung cancer in nuclear workers of Mayak. A comparison of numerical procedures. Radiat Environ Biophys 37: 11-17, 1998.

Khokhryakov V, Suslova K, Aladova E, Vasilenko E, Miller SC, Slaughter DM, and Krahenbuhl MP. Development of an improved dosimetry system for the workers at the Mayak Production Association. Health Phys. 79:72-76, 2000.

Khokhryakov V, Suslova K, Romanov S, Vostrotin V. Pulmonary clearance of industrial plutonium compounds in remote period after the beginning of inhalation. Medical Radiology and Radiation Protection 2: 28-34, 2000.

Khokhryakov VV, Khokhryakov VF, Suslova KG, Efimov AV, Vostrotin VV, Schadilov AE. Status and prospects of internal dosimetry for the Mayak workers. (Submitted to International Journal of Low Radiation)

Khokhryakov VV, Lagunova NY, Sypko SA, Rumyantseva EY. Investigation on Effects of the dispersed composition of industrial aerosols on plutonium dialysis kinetics. Submitted to Siberian Medical Journal. (In Russian)

Krahenbuhl MP, Slaughter DM, Wilde JL Bess JD, Miller SC, Khokhryakov VK, Suslova KG, Vostrotin VV, Romonov SA, Menshikh ZS, Kudryavtseva TI The historical and current application of the FIB-1 model to assess organ dose from plutonium intakes in Mayak workers. Health Physics 82:445-454, 2002.

Miller SC, Lloyd RD, Bruenger FW, Krahenbuhl MP, Polig E, Romanov SA. Comparisons of the skeletal locations of putative plutonium-induced osteosarcomas in humans with those in Beagle dogs and with naturally-occurring tumors in both species. Radiation Research 160:517-523, 2003.

Romanov SA, Vasilenko EK, Khokhryakov VF, Jacob P. Studies on the Mayak nuclear workers: dosimetry. Radiat Environ Biophys 41:23-28, 2002.

Schadilov AE. Sypko SA. Application of the Monte Carlo methods to determine 239Pu and 241Am content in the wound. Health Physics Society 48th Annual Meeting. July 20-24, 2003 San Diego, CA, Health Phys. vol. 84, No. 6, June 2003, supplement.

Vasilenko EK, Smetanin MY, Miller SC, Slaughter M, Jacob P, Feherbaher G. Approach to retrospective reconstruction of the photon exposure spectra distribution at technological sites of the Mayak Production Association. Radiation Safety Problems (Russian Federal Ministry of Atomic Energy) 3:42-50, 2000. (In Russian).