Active Projects

Russian Health Studies Program

Studies on the health effects of radiation exposure are conducted jointly by U.S. and Russian scientists at Mayak and the Southern Urals Biophysics Institute in Ozersk and at the Urals Research Center for Radiation Medicine in Chelyabinsk. U.S. organizations currently involved in the studies are:

  • Georgetown University;
  • Pacific Northwest National Laboratory;
  • University of Florida;
  • Oak Ridge Institute for Science and Education;
  • Oak Ridge National Laboratory;
  • University of Southern California; and
  • University of Utah.

Also involved is the U.K. organization Nuvia, Ltd.

Russian organizations leading the studies are:

  • Mayak Production Association;
  • Southern Urals Biophysics Institute; and
  • Urals Research Center for Radiation Medicine.

The program is organized into three directions: community, worker, and emergency response.

Direction 1: Community Health Effects Research

The major goal under this Direction is to analyze the carcinogenic risk of radiation from environmental exposures. For this purpose, 2 projects are being conducted:

  • Project 1.1, Techa River Population Dosimetry; and
  • Project 1.2b, Techa River Population Cancer Morbidity and Mortality.

Project 1.1: Techa River Population Dosimetry

Principal Investigators:

R.F.: Marina Degteva, Urals Research Center for Radiation Medicine
U.S.: Bruce Napier, Pacific Northwest National Laboratory

Brief Description: This dose reconstruction project is to provide accurately reconstructed radiation doses to individual members of the public that resulted from releases of radio active material from the Mayak Production Association (Mayak). The researchers are developing improvements in doses for members of the Techa River Cohort (TRC) by reducing the uncertainty of the doses, validating the doses, determining the feasibility of reconstructing doses from medical exposures, reconstructing doses from other sources of radiation exposure, such as the East Urals Radioactive Trace and resuspension from deposits in Lake Karachai, and including an expression of uncertainty. The specific goal of this project is to update the reconstruction of external and internal radiation doses for approximately 30,000 individuals in the TRC for use in companion epidemiologic studies of radiogenic leukemia and solid cancers (see below Project 1.2b, Techa River Population Cancer Morbidity and Mortality).

Results to date: Phase III of Project 1.1 concluded on September 30, 2018. Researchers completed the deterministic and stochastic versions of the Techa River Dosimetry System (TRDS) - 2016 to improve the quality at the TRDS-based estimates of internal and external doses. This includes both central point estimates and full uncertainty distributions of annual absorbed dose calculated for up to 23 organs and tissues of the TRC members for defined periods of time. In addition, in FY2018 researchers completed the doses for the East Urals Radioactive Trace Cohort (EURTC).

Projected end date: September 2021.

Project 1.2b: Techa River Population Cancer Morbidity and Mortality

Principal Investigators:

R.F.: Alexander Akleyev and Ludmila Krestinina, Urals Research Center for Radiation Medicine
U.S.: Daniel Stram, University of Southern California

Brief Description: This epidemiologic study is designed to assess carcinogenic effects among populations exposed to offsite releases of radioactive materials from the Mayak nuclear facility. Discharges of radioactive wastes into the Techa River during the period 1950-1956 resulted in radiation exposures of the inhabitants of the riverside villages for whom the river was the principal source of water. This is the first study of cancer morbidity in the Techa River Cohort (TRC). It is a companion study to Project 1.1, Techa River Population Dosimetry, and to Techa River Population Cancer Mortality, formerly sponsored by the U.S. National Cancer Institute, and now sponsored by DOE.

The TRC consists of 28,102 exposed permanent residents of villages on the Techa River born before the start of contamination in 1950 and who lived in one of 41 riverside villages up to 120 miles downstream at anytime between 1950 and 1960. Vital status is known through 2016. The aim of Phase III is to extend the follow-up of cancer incidence among the members of the TRC and use new epidemiological and dosimetric data from Project 1.1 to assess radiogenic cancer risk taking into account the effects of medical exposures on cancer risks and potential confounding with environmental radiation effects. Researchers also will analyze the effects of non-radiation factors, such as smoking and alcohol consumption and potential confounding with environmental radiation effects.

Results to date: Results from this study indicate statistically significant increases in solid cancer mortality, solid cancer incidence adjusted for smoking, and non-Chronic Lymphocytic Leukemia (non-CLL) incidence in the exposed population.

Projected end date: September 2023.

Direction 2: Worker Health Effects Research

The major goal under this direction is to analyze the carcinogenic risk of radiation from occupational exposures. For this purpose, 3 projects are being conducted:

  • Project 2.2, Mayak Worker Cancer Mortality;
  • Project 2.4, Mayak Worker Dosimetry; and
  • Project 2.8, Mayak Worker Tissue Repository.

Project 2.2: Mayak Worker Cancer Mortality

Principal Investigators:

R.F.: Mikhail Sokolnikov, Southern Urals Biophysics Institute
U.S.: Daniel Stram, University of Southern California

Brief Description: This epidemiologic study is designed to obtain quantitative estimates of carcinogenic risks from both protracted external exposure and from internal exposure to plutonium based on analyses of data from the Mayak Worker Cohort (MWC). The cohort consists of 25,757 workers, 25% of whom were women, first employed at any time between 1948 and 1982 in the reactor, radiochemical, plutonium production, or auxiliary plants. This is the largest plutonium-exposed cohort in the world. Vital status is known through 2016. Risks of cancers of the lung, liver, and bone are being expressed as functions of doses to these organs and of potential modifying factors such as sex, time since exposure, and age at exposure. In addition, researchers will investigate whether risks of cancers of sites other than lung, liver, and bone are related to external dose and to plutonium exposure. Uncertainties in risk estimates that are developed will be quantified. In order to meet these objectives, further improvements in the data are being implemented. These include the continual updating of follow-up and the collection of further data on smoking from medical records. The results of this study are likely to enhance our understanding of protracted radiation exposure risks to humans and provide definitive data for the improvement and validation of radiation protection standards.

Results to date: This is the first study to demonstrate in humans a statistically significant association between occupational exposure to plutonium and bone, lung, and liver cancer. These analyses were performed using the Mayak worker Doses 2005, the Mayak Worker Dosimetry System (MWDS)-2008, and MWDS-2016. Next, Project 2.2 researchers will analyze the data using the most recent dose estimates from MWDS-2019 and compute new cancer risk estimates linked to radiation dose. Results from this study, based on the improved dosimetry, will provide data to better understand the risks of protected exposure to plutonium, assess the contributions of uncertainties in dosimetry to uncertainties in risk, and improve the scientific basis for radiation protection standards, especially with regard to plutonium-239.

Projected end date: September 2023.

Project 2.4: Mayak Worker Dosimetry

Principal Investigators:

R.F.: Mikhail Gorelov (External Dosimetry Team Leader), Mayak and Alexander Efimov (Internal Dosimetry Team Leader), Southern Urals Biophysics Institute
U.S.: Bruce Napier (External Dosimetry Team Leader), Pacific Northwest National Laboratory, and Richard Bull (Internal Dosimetry Team Leader), Nuvia, Ltd.

Brief Description: This dose reconstruction project is to establish a computerized database of individual internal and external radiation doses and uncertainty about those doses for each member of the 25,757 Mayak worker cohort under study in Project 2.2, Mayak Worker Cancer Mortality. The work product is an electronic database containing updated individual dose estimates by year called Mayak Worker Dosimetry System (MWDS)-2019. As a result, improved doses for risk assessment analysis of causes of health effects from radiation exposure will be available. These data are also being used for other projects in Direction 2. This project is perhaps one of the most important of the 5 current projects within the Russian Health Studies Program. Without good dosimetry data, epidemiologists and biostatisticians will not be able to assess radiation-induced cancer risks from exposure to gamma, neutron, and alpha radiation. The Mayak worker cohort under study has the largest number of individuals and the highest chronic radiation exposures of any known population on earth. Approximately one-fourth of the exposed workers were women. Detailed health and exposure records are available at Mayak, thereby facilitating radiation health effects research.

Results to date: In addition to providing the dosimetric data for Project 2.2, Mayak Worker Cancer Mortality, this project has enhanced the understanding of plutonium metabolism in the human body and improved the biokinetic models for assessing dose from plutonium uptakes. These outcomes will be of direct benefit to DOE in improving the determination of dose to DOE workers from plutonium exposure. Improved doses have been calculated for a fraction of the group of workers. Dose calculations and uncertainty analysis of the doses continues. The Mayak worker dosimetry database "Doses 2005" was completed in 2005. MWDS-2008 was completed in September 2010. MWDS-2013 was completed in September 2014. MWDS-2016 will be completed in 2019. Project 2.2 researchers will analyze the data using the most recent dose estimates and are producing revised radiation cancer risk estimates. The next iteration of the dosimetry system will be called MWDS-2023 and will include worker doses from both internal and external radiation exposure based on a comprehensive Job Exposure Matrix (JEM). The purpose of the JEM is to complete internal dose estimates for members of the MWC without urine bioassay or autopsy data and for periods before the date of initial monitoring based on data for workers with urine bioassay or autopsy data in the same workplaces. As a result, a uniform and consistent system of internal dose estimation could be developed that would include both monitored and unmonitored workers, i.e., the entire cohort. In addition, a synthetic cohort of hypothetical workers will be prepared to allow exploration of the various dosimetric approaches.

Projected end date: September 2023.

Project 2.8: Mayak Worker Tissue Repository

Principal Investigators:

R.F.: Evgenia Kirillova, Southern Urals Biophysics Institute
U.S.: Christopher Loffredo, Georgetown University

Brief Description: The aim of this project is to establish and maintain a state-of-the-art tissue repository designed to serve as a resource for studies of the effects of protracted internal and external radiation exposure on human health. The repository is located at the Southern Urals Biophysics Institute in Ozersk. It includes samples of archival autopsy tissues from 1,017 individuals (840 Mayak workers and 177 unexposed controls), samples of surgical tissues from 977 individuals (532 workers and 445 controls), samples of blood and its components from about 8,348 individuals (7,268 workers and 1,080 controls), and isolated DNA from the blood of 423 parental-offspring trios from 299 families in which one or both parents is a Mayak worker and 23 control families. In addition, buccal epithelial cells, bone marrow, lymphoid tissue, and cells from sputum from 1,811 individuals (1,667 workers and 144 controls) have been collected and stored. The storage conditions of the biosamples in the repository were designed to provide optimal long-term preservation of tissue samples. In conjunction with medical, occupational, and dosimetry information, data collected in the repository are used in molecular epidemiology studies. Such studies can be used to establish an association between disease and radiation exposure in individuals.

Results to date: Samples of tumor and other tissues for 155 registrants were delivered to the U.S. researchers who worked on several projects in the Russian Health Studies Program, i.e., Project 2.5, Plutonium Microdosimetry in the Lung, Project 2.6, Molecular Markers of Lung Cancer, and Project 2.7, Radiation Biomarkers. Without these samples, completion of Projects 2.5, 2.6, and 2.7 would not have been possible. Methods of transportation of tissue samples from Russia to other countries by international air mail have been tested and implemented. A website in both Russian and English describes the contents of the repository and the procedures for researcher access to the contents. Further collection and storage of tissue samples in optimal conditions and intensification of efforts to inform scientists worldwide on the established repository and its biosamples are underway.

Recently, the tissue repository database structure and website were updated to facilitate the tasks of specimen bar coding, metadata development with linkage to the web site, and tissue sample inventory.

Projected end date: September 2023.

FOR ADDITIONAL INFORMATION:

Dr. Joey Zhou
(301) 903-3602