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Important Notice: The Hanford Health Information Network (HHIN) closed in May, 2000. HHIN Web pages are provided as archived information only, and are not currently maintained. Information contained on the HHIN Web pages may be out-of-date.

Current information is available through the Hanford Community Health Project, which is updated by the Agency for Toxic Substances and Disease Registry of the U.S. Centers for Disease Control and Prevention.

The Newsletter of the Hanford Health Information Network

Vol. 4, No. 2Summer/Fall 1998

Inside this
issue

Genetic Sensitivity to Radiation

Hanford Former
Workers Programs

Public Health
Assessments

Archives
Update

Multiple
Myeloma Study

Nevada Test
Site Doses
and Risk

Project and
Study Updates

Connections is published quarterly by the Hanford Health Information Network. Opinions expressed in this newsletter are those of the author, not necessarily of the Network.

The Hanford Health Information Network is a collaboration among three states and nine Indian Nations. Our work is based on respect for the dignity of individuals and their right to make personal decisions with the most complete information currently available.

Important Notice: The Hanford Health Information Network (HHIN) closed in May, 2000. HHIN Web pages are provided as archived information only, and are not currently maintained. Information contained on the HHIN Web pages may be out-of-date.

Current information is available through the Hanford Community Health Project, which is updated by the Agency for Toxic Substances and Disease Registry of the U.S. Centers for Disease Control and Prevention.

Radiation Science Update:
Chornobyl and Health - A Review of the Recent Literature

by Jim Ruttenber, M.D., Ph.D.

In the 12 years since the accident at the Chornobyl (or Chernobyl) nuclear power plant in Ukraine, scientists from many countries have been following the health effects on workers and the public. A search of the National Library of Medicine’s MEDLINE database lists 1,824 articles on Chornobyl: 218 published in the past year, 342 in the past two years, and 877 within the past five years.

Most of these reports describe health effects for adults and children in the comparatively high exposure areas of Belarus and Ukraine, and parts of the Russian Federation. Some articles report on Chornobyl-related health effects in Europe and North America. There are also reports on diseases among the 600,000 liquidators – workers who helped to decontaminate the damaged reactor and highly contaminated areas nearby.

Articles about effects among members of the public describe increased rates of a number of types of cancer in both children and adults. Other health effects are thyroid disease, genetic effects, adverse pregnancy outcomes, immune system disorders and psychological effects. Articles about the liquidators describe similar effects as well as acute radiation sickness and suicide.

Most of the evidence for increases in various diseases comes from studies comparing disease rates in particular areas before and after the Chornobyl disaster, or from comparisons of regions receiving high amounts of fallout and regions of low fallout. However, many of the reports are based on data for diseases that may not have been collected with good epidemiologic techniques. For this reason, it is difficult to draw many conclusions at this time.

It is clear, however, that there has been a dramatic increase in thyroid cancer in children who lived in the highly exposed areas. This increase was first reported in 1992. These early reports were met with skepticism by the scientific community. However, after the publication of a number of reports of increased incidence of thyroid cancer among children in the high-fallout regions, most scientists no longer question this finding. To date, there are over 280 scientific articles published on thyroid disease, and over 60 on thyroid cancer in children. The most likely cause for the increase in thyroid cancer is exposure to iodine-131 through consuming fresh dairy products during the weeks following the explosion.

One of the most interesting areas of research has been the relation between a diet low in iodine and thyroid disease. Ordinarily, iodine deficiency can lead to goiter, an enlargement of the thyroid gland causing it to protrude at the front of the neck. Many papers have described below-normal iodine in the diet and the goiter that was common in areas receiving high amounts of iodine-131. Other studies speculate that the thyroid gland of a person with below-normal dietary iodine would absorb more iodine-131 during exposure to fallout from Chornobyl. This would result in a higher iodine-131 dose than if levels of dietary iodine had been higher.

There is conflicting evidence, however, for increased prevalence of goiter in areas that received high amounts of iodine-131. It is also not clear whether areas with a high prevalence of goiter also have a high prevalence of thyroid cancer in children who were exposed to fallout from Chornobyl.

A number of papers note an increase in concentrations of autoantibodies to thyroid proteins in children in high exposure areas. At least one study has suggested that poor iodine intake coupled with low-level radiation exposure might increase the risk for autoimmune thyroid disease.

The studies of thyroid disease that have been reported have not estimated individual radiation doses for subjects. Dose estimates are desirable from a scientific standpoint and usually are required to argue that radiation is the cause of a particular disease. However, the evidence for increases in thyroid cancer among children is substantial enough to have convinced most scientists.

This points to the importance of analyzing data from health surveillance programs, even simple ones. At the time of the Chornobyl accident, the prevailing scientific theory was that iodine-131 did not cause cancer. If scientists had assumed that this theory was true instead of considering the surveillance data, they would not have made the connection between exposure to Chornobyl’s fallout and thyroid cancer among children.

Data on thyroid diseases were not routinely collected around Hanford during the years following the large releases of iodine-131. Although there is evidence that some scientists were concerned, the majority believed there was no problem. Because the HTDS will determine individual radiation doses for all subjects of the study (which has not been done in Chornobyl studies to date), its results will help improve our scientific understanding of the relation between iodine-131 and diseases of the thyroid and parathyroid glands.

Genetic Sensitivity to Radiation
by Sandy Rock, M.D., Public Health Physician, HHIN Washington Program

A question that callers to HHIN often ask is why certain families seem to have more cases of cancer than others who were apparently exposed to similar amounts of radioactive materials. Health educators respond that there is probably a wide range of sensitivity or resistance to the effects of radiation exposure, just as there seems to be for illnesses caused by microorganisms (e.g., viruses, bacteria) and by toxins (e.g., industrial chemicals, biologic products, tobacco smoke). In addition, most cancers can be initiated by a variety of physical and chemical exposures. This poses a further challenge to those who try to link diseases to their causes. Indirect evidence, such as statistical association and animal studies, has been the source of most understanding about the causes of cancer. For more information, see the HHIN publication, Epidemiology: Understanding Health Studies.

Some researchers working with victims of the Chornobyl disaster in Ukraine have wondered why there seems to be such a high level and early onset of cancers – especially thyroid cancer – within the exposed population. One explanation is that there may be a group within this population that is genetically more sensitive to the effects of radiation.

New Material Available from HHIN

New HHIN Information Sheet
Using Health Studies: A Guide to Risk Estimates and Statistics (to be issued Winter 1998) - An introduction to the basic concepts and terms scientists use to describe the risk from radiation exposure. Also describes information to come out in 1998 and 1999 about the risk from exposure to iodine-131.

Now a team at the Virginia Mason Research Center in Seattle has found evidence that there is genetic control of the human cell’s response to radiation. The research points to a gene that may regulate the manner in which human cells are protected from damage by radiation exposure. Cell technology that was unavailable until just a few years ago allowed the team to identify and pinpoint the location of the gene. The lack of one of the usual two copies of this gene may result in failure to repair DNA – the substance in a cell that controls all of its metabolic and replicating activity. This can lead to an increased likelihood of cancer from exposure to radiation, chemicals and even sunlight.

The study focuses on a rare disorder which includes an increased risk of cancer (mostly of the lymph glands) from radiation exposure: the Nijmegen Breakage Syndrome (NBS). In this genetic illness, there is instability of chromosomes (the material in cell nuclei that is made up of DNA and carries all the genetic information), making them more likely to break when subjected to chemical or physical stress. (Varon, Raymonda, et al. “Nibrin, a Novel DNA Double- Strand Break Repair Protein, Is Mutated in Nijmegen Breakage Syndrome,” Cell 93:467-476 [May 1, 1998])

Medical scientists and the public have long hoped for a test that not only could detect increased sensitivity to radiation and other physical and chemical agents but could also determine if such exposures had caused disease. To reach the goal of identifying the cause of diseases, researchers will need to focus on events that occur in the cell after different types of exposures. If it is possible to identify distinguishable features of damage from radiation and other agents for most people (a sizeable portion of the population), it should take a relatively small amount of laboratory work to develop tests for these changes in cancer cells taken from a person during evaluation or treatment. If tests can accurately predict risk for cancer in a large portion of the population and the tests can be made readily available, they will revolutionize the prevention and care for most cancers and possibly many other illnesses as well.

At this time, there is no test that identifies the cause of most cancers. But the technology applied in the NBS study suggests that such tests can be developed. To Hanford downwinders, this may mean getting closer to answering the question: “Did my or my family member’s disease come from exposure to radiation released from Hanford?” Until then, medical scientists will continue to rely on indirect evidence to determine cancer causation.

ATSDR to Revise Hanford Public Health Assessments

by Hanford Health Effects Subcommittee – Outreach Working Group

The Agency for Toxic Substances and Disease Registry (ATSDR) plans to revise and rework the Hanford public health assessments as a result of the recommendations made to ATSDR by the Hanford Health Effects Subcommittee. The revised public health assessment will include new information about the Columbia River, and will combine the 200 and 300 areas at the Hanford Nuclear Reservation into one public health assessment.

ATSDR is required to evaluate whether communities located near or around hazardous waste sites have been exposed to contaminants at levels that could affect the health of residents. Three types of information are used to evaluate the health concerns and issues at these sites:

(1) environmental data (e.g., concentrations of radionuclides in groundwater);

(2) expressed community health concerns (e.g., is it safe to eat fish from the Columbia River?); and

(3) positive or negative health results (e.g., iodine-131 causing thyroid diseases).

Archives Update:
Nearly 2,700 Collections Now Available

The Hanford Health Information Archives (HHIA) collections now include information from nearly 2,700 people. This material, donated by Hanford-exposed people, is open for public use. The number of individual collections increases as more people realize that their old pictures, journal writings and medical records, as well as health questionnaires they can fill out now, are useful to others.

Recollections, the newsletter of the HHIA, is one tool the Archives is using to help Hanford-exposed people know that their information is valuable to others. Please call the Archives at 1-800-799-4442 to request a copy of Recollections or to ask about the Radiation Health Effects Archives – a separate nonprofit organization set up to maintain the HHIA through private funding and grants.

At Gonzaga University’s Foley Center Library in Spokane, Wash., Archives staff sort through boxes of materials carefully packed by people who want to share their experiences. Information has been donated by farmers who lived in the exposed area, children of Hanford workers, U.S. military veterans who were stationed in the area, and people who grew up or lived in the Hanford exposure area in cities such as Richland, Wash., Lewiston, Idaho, and Pendleton, Ore. Additionally, there are collections donated by relatives and friends of Hanford-exposed people who now live across the United States and in other countries.

Each new donation provides a different perspective.“We have records from people who have experienced no health problems, as well as information from people who have been very ill and who associate their illnesses with Hanford exposure,” said Archives Administrator Tom Carter.

Results Released from Study of Multiple Myeloma at Four DOE Sites

Results of an epidemiological study of multiple myeloma among U.S. Department of Energy (DOE) workers at four sites were released to the public this summer. The study found that although total radiation doses for workers who died of multiple myeloma were similar to doses for workers who did not die from this disease, there was an increased risk of multiple myeloma for workers who received radiation doses at older ages. Multiple myeloma is a cancer of the blood-forming tissues that affects primarily older people. Although it is highly treatable, it is rarely curable.

For information about this or other studies on occupational health:

National Institute for Occupational Safety and Health (NIOSH), 1-800-35-NIOSH (356-4674)

About multiple myeloma or other cancers:

Cancer Information Service, 1-800-4-CANCER (422-6237) or the American Cancer Society, 1-800-227-2345

The study, which began in October 1993, was conducted by Dr. Steven Wing of the University of North Carolina at Chapel Hill, Department of Epidemiology. The final report was submitted to the funding agency, the National Institute for Occupational Safety and Health (NIOSH), in March 1997. Current workers and managers at the sites were notified of the results before the study results were made public.

Following is a summary of the study provided by Dr. Wing and NIOSH.

Purpose of the Study

Ionizing radiation has been associated with certain types of cancer, including multiple myeloma. NIOSH requested this study because of previous reports of associations of multiple myeloma with radiation exposure of workers at the Hanford site. This new study was intended to include more cases of the disease and provide a better evaluation of radiation doses.

Study Methods

Facilities were chosen for this study based on their age, size, type of operations and availability of basic records assembled for past epidemiological studies. Those records included employee rosters and information on causes of death. These data formed the basis for choosing “cases” (workers who died with multiple myeloma) and a random sample of “controls” (workers who lived to be as old as the cases). Because multiple myeloma is rare, four facilities were chosen in order to identify a sufficient number of cases for statistical analysis.

The study team identified 98 multiple myeloma cases (deaths) and 391 age-matched controls selected from a combined roster of 115,143 workers hired before 1979 at Hanford, Los Alamos National Laboratory, Oak Ridge National Laboratory, and the Savannah River site. These workers’ vital statistics were determined through 1990 (1986 for Hanford). Information on prior work history, smoking, medical X-rays, and exposure to physical and chemical agents, using personnel, medical, industrial hygiene and health physics records were gathered and used in the analysis.

. . . . there was an increased risk of multiple myeloma for workers who received radiation doses at older ages.

The study team attempted to determine whether workers had been exposed to a variety of chemical and physical agents that might be causes of multiple myeloma. These included solvents, metals, welding fumes, asbestos, and ionizing and non-ionizing radiation. Most long-term workers had at least some badge data on exposures from external penetrating radiation. However, for exposures to specific chemical and physical agents, there was not enough information to be able to assign a quantitative estimate of exposure or even to determine with a high degree of certainty whether or not a worker was exposed. The only exposure that appeared to make a significant difference between cases and controls was ionizing radiation.

Findings and Conclusions

Total cumulative radiation doses were similar between cases and controls. However, for workers who received radiation doses when they were age 45 or above, the risk for multiple myeloma increased by 7 percent for each additional rem of dose. [Note: A rem is a unit of dose that measures the damage to a human from radiation exposure.] This result is adjusted for age, race, sex, facility, period of hire, birth cohort, monitoring for internal radionuclide contamination and external radiation received prior to age 45.

The association of multiple myeloma with radiation doses at older ages is consistent with findings from epidemiological studies of cancer among workers and theoretical expectations that older people are more sensitive to a variety of carcinogens. These findings and other studies of nuclear workers have implications for radiation protection standards for workers and the general public.

Review Progresses on Nevada Test Site Doses and Risk

The National Academy of Sciences (NAS) and the Institute of Medicine (IOM) are completing their assessment of the National Cancer Institute (NCI) study of the releases of iodine-131 from the Nevada Test Site from 1951 through 1962. The NCI study included thyroid dose estimates and estimates of cancer risks.

The NAS/IOM combined what originally was going to be two reports into one report. It will include an assessment of the NCI dose estimates, discussion of the implications for public health strategies, and identification of key areas of research needed for refining risk estimates. This report is now undergoing the Academy’s exacting external review process. When the review is completed, the NAS/IOM report will be delivered to the Department of Health and Human Services and be made public. The NAS expects the report to be available in the fall of 1998.

Published September 1998

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