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Review of Nasa’s Longitudinal Study of Astronaut Health 5 Recommendations for Changes in Health Care Policy Whatever the goals, design, and execution of the Longitudinal Study of Astronaut Health (LSAH), the committee believes that the National Aeronautics and Space Administration (NASA) should have a policy addressing the practical consequences of discovering that a career as an astronaut, or the experience of space travel, leaves astronauts at increased risk for an adverse health effect. Of particular concern is the case in which the effect, cataracts for example, does not become obvious during or immediately after a space flight but instead develops sometime after the astronaut leaves active duty and is no longer provided medical care by NASA. What is NASA’s ethical responsibility in this circumstance It seems evident that the federal government should take full responsibility for health care needs in the case of a disease or disorder unique to space travel or the training required for space travel. Less clear is the case in which astronauts, as a group, are shown to be at increased risk for a common disease or disorder—skin cancer, perhaps. Any individual case may or may not be attributable to space flight. This chapter describes how other federal agencies have responded to similar discoveries of suspected occupational illness in former employees and ends with a recommendation on medical care for former astronauts. DEPARTMENT OF ENERGY AND BERYLLIUM Beryllium is a hard, gray metal that occurs as a chemical component of certain rocks (bertrandite and beryl) coal and oil soil and volcanic dust. Beryllium’s light weight high tensile strength, and ability to slow neutrons have made it useful for many purposes. Pure beryllium metal is used in the manufac-
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Review of Nasa’s Longitudinal Study of Astronaut Health ture of aircraft disc brakes nuclear weapons and reactors missile parts heat shields X-ray machine parts mirrors, and spacecraft. Beryllium oxide is used in ceramics for electronics and high technology applications, but from 1945 through the mid-1990s, more than 90 percent of all beryllium was processed for use by the Departments of Defense (DOD) and Energy (DOE) (and DOE’s predecessor, the Atomic Energy Commission) to produce nuclear weapons. Workers exposed to beryllium dust are at risk of developing serious debilitating diseases. Acute (short-term) beryllium disease causes lung inflammation resembling pneumonia. Chronic beryllium disease (CBD) is a debilitating disease of the lung, apparently immunologically mediated. In severe cases both the acute and chronic conditions may be fatal. The Department of Health and Human Services Environmental Protection Agency and International Agency for Research on Cancer consider beryllium to be carcinogenic. Prevalence estimates of acute beryllium disease in Atomic Energy Commission (AEC) workers ranged as high as 7 percent in the late 1940s. An 8-hour average permissible exposure limit (PEL) of 2 micrograms/cubic meter was adopted in 1949 by the AEC, and it remained unchanged until 1999, when DOE lowered the PEL to 0.2 micrograms per 8-hour shift for its government workers and federal contractors. These standards were effective in eliminating most acute lung disease. CBD may have a latency of up to 30 years, however, and prior to the advent of current immunological tests, it frequently may have been misdiagnosed. Several studies of lung cancer in current and former beryllium workers returned the spotlight to beryllium hazards, and in 1993 Congress passed Public Law 102-484, which required the DOE to evaluate the long-range health conditions of current and former employees and contractors whose health might be at risk as a result of exposure to radioactive or other hazardous substances. In a series of pilot studies throughout the 1990s, the DOE Former Workers Program established that it would be possible to locate and contact workers who might have been exposed to hazardous substances. DOE also began medical monitoring of current employees using the beryllium lymphocyte proliferation test (BeLPT). DOE estimates that about 20,000 current and former workers were or may have been exposed to beryllium. By the end of 1999 DOE had screened 13,770 of these workers and found 149 cases of CBD and an additional 299 workers with positive beryllium BeLPT tests but no clinical manifestations of disease. In December 1999 DOE issued a rule establishing regulations to reduce beryllium exposure levels among its workforce, reduce the number of workers exposed to beryllium, and provide medical testing for exposed and potentially exposed workers. This rule on chronic beryllium disease prevention applies to federal, contractor, and subcontractor employees at 17 DOE facilities where there is actual or potential exposure to beryllium. In addition, the Secretary of Energy announced a legislative proposal reversing DOE’s past practice of op-
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Review of Nasa’s Longitudinal Study of Astronaut Health posing and litigating most worker health compensation claims and providing compensation for employees who have contracted chronic beryllium disease or beryllium sensitivity. The Energy Employees Occupational Illness Compensation Program Act of 2000 (Public Law 106-398) was enacted in October 2000, and the program went into effect on July 31, 2001. Administered by the U.S. Department of Labor, the program pays for medical monitoring of current and former DOE and DOE-contractor employees with one or more abnormal BeLPT tests. Individuals (or a surviving spouse, children, or parents) who develop CBD are eligible to receive 150,000 plus continuing coverage of costs for related medical care and treatment. DEPARTMENT OF DEFENSE AND NUCLEAR WEAPONS TESTS Between 1945 and 1963 the United States conducted more than 230 atmospheric tests of nuclear weapons. It is estimated that more than 200,000 DOD personnel, military and civilian, participated in these tests in some way. Some were merely witnesses; others set up scientific experiments and collected post-detonation data; still others participated in military exercises. Prescribed exposure limits varied as well but, as reported by Gladeck and Johnson (1996), they generally allowed maximum exposures of 3 to 5 rem (30 to 50 milliSieverts [mSv]) “per test or series.” A series averaged 12 tests, but the Defense Threat Reduction Agency (DTRA), formerly the Defense Nuclear Agency (DNA), estimates that the average dose received by a participant was about 6 mSv (DTRA, 1999). This is approximately twice the average annual natural background dose received by a person living in the United States (NCRP, 1987). The DTRA (1999) study also estimates that less than one percent of all test participants received doses in excess of 50 mSv, the current dose limit for radiation industry workers. Concerns among veterans about possible longterm effects on health persisted nonetheless, and when a veteran asserted in 1976 that his acute myelocytic leukemia was related to his participation in a 1957 nuclear test in Nevada, the Centers for Disease Control and Prevention conducted an epidemiological study of military personnel who attended that test. The study found more than the expected number of leukemia cases among them (Caldwell et al., 1980, 1983). In 1981 the Medical Follow-up Agency (MFUA) of the National Academy of Sciences began a study to evaluate the question of increased mortality among participants in other tests and at other locales. MFUA, in collaboration with DNA, studied 5 of the 19 U.S. atmospheric test series, incorporating tests over both land and sea, personnel from all branches of the armed forces (49,000 in all), and different kinds of nuclear devices. The mortality of veterans identified by DNA as having participated in at least one of the five selected test series
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Review of Nasa’s Longitudinal Study of Astronaut Health was compared to mortality rates in the U.S. male population (Robinette et al., 1985). However, in 1989 DNA informed MFUA that it had misidentified many members of the participant cohort, potentially rendering the published findings invalid. At the request of DNA, MFUA redid the study, comparing the mortality of nearly 70,000 military personnel who participated in 1 of the 5 test series selected for the original study with the mortality of both the U.S. male population and the mortality of nearly 65,000 newly identified comparable veterans (“referents”) who had not participated in any nuclear test (IOM, 2000). The study also benefited from an additional decade over which mortality could be observed. Results showed that test participants and referents had statistically similar risks of death from all causes, death from cancer, and death from leukemia. Although the difference was not statistically significant, leukemia mortality was 14 percent higher in the participant cohort (approximately 25 excess deaths). The authors chose to highlight this finding because of similar findings in two studies of military test participants in other nations, while discounting statistically significant increases in risk to participants of death from external causes (e.g., motor vehicle accidents) and nasal and prostate cancer as chance findings. The two supporting studies were on servicemen in the United Kingdom (Darby et al., 1993) and New ealand (Pearce et al., 1996, 1997). The United Kingdom study found leukemia deaths were about 75 percent higher in 22,000 test participants than in 22,000 comparison personnel. The New ealand study found leukemia mortality was elevated more than 400 percent among test participants, but it looked at only 528 test participants and 1,500 comparisons. Various public laws as codified by Title 38, Code of Federal Regulations, Part 3, (38 CFR 3) authorize the Department of Veterans Affairs (VA) to provide medical care and to pay compensation benefits to confirmed test participants and dependency and indemnity compensation to certain survivors. Confirmed participants of U.S. atmospheric nuclear testing can receive special treatment for radiogenic diseases currently covered by VA regulation (38 CFR 3.309 and 3.311). Care for these conditions is provided without regard to the veteran’s age, service-connected status, or ability to defray the cost of medical care. Additionally, no copayment by the veteran is required. Even if an eligible veteran has never filed a compensation claim or if the claim has been denied, the veteran can still receive free care for radiogenic diseases. Eligible veterans may also file a claim under either of both of the following compensation programs. VA nonpresumptive program: This program, codified in 38 CFR 3.311, provides for VA determination of service connection and benefits for about 25 specified disease categories, including any other cancer not specifically identified that are not presumed to be radiation-caused, but could be linked to radiation if the veteran’s dose was high enough. These regulations define rules for adjudicating VA claims and establish a panel of experts to address scientific issues regarding the relationship between diseases and radiation. If a claimed
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Review of Nasa’s Longitudinal Study of Astronaut Health disease is not one of the diseases listed in 38 CFR 3.311, the veteran must cite or submit competent scientific or medical evidence showing that there is a relationship between radiation exposure and the disease before consideration under this regulation may be made. To initiate a claim, veterans must submit to the VA competent medical evidence that the claimed medical condition exists. DTRA will respond to the VA’s request by providing participation and associated radiation dose information based on dosimetry data for the individual or one or more other participants in the same military unit. A medical panel then determines, using organ-specific radiological tables derived from studies of Hiroshima and Nagasaki survivors, whether odds are equal to or greater than 0.5 that the individual veteran’s condition is a result of test participation. A recent examination of DTRA’s dose reconstruction program by the National Research Council’s Board on Radiation Effects Research found that very few (in the order of 50) claims have been granted despite a number of veteran-favorable assumptions in the dose reconstruction (NRC, 2003) The report attributes this result to the fact that ionizing radiation causes cancer only at significantly higher doses than those received by all but a few veterans of atomic weapons testing. VA presumptive program Under this program, authorized by 38 CFR 3.309, the VA pays compensation for any of 21 types of cancers to eligible veterans without regard to radiation dose. To establish eligibility, veterans must submit competent medical evidence of the claimed medical condition to the VA. Upon receipt, the VA submits a request to DTRA to confirm the veteran’s participation in U.S. atmospheric testing (or the occupation forces of Hiroshima and Nagasaki). Filing a VA claim under this law does not require dose information from any source; it presumes a connection between the veteran’s participation in the test(s) and his current medical condition. DEPARTMENT OF VETERANS AFFAIRS AND AGENT ORANGE From 1962 to 1971 U.S. military forces sprayed more than 19 million gallons of herbicides over Vietnam to strip the thick jungle canopy that helped conceal opposition forces, destroy crops on which enemy forces might depend, and clear tall grass and bushes from around the perimeters of U.S. base camps and outlying fire-support bases. After a scientific report concluded that a contaminant in one of the primary chemicals used in the herbicide called Agent Orange could cause birth defects in laboratory animals, U.S. forces suspended use of the herbicide; they subsequently halted all herbicide spraying in Vietnam in 1971. During the early and mid-1970s a growing number of veterans began to suggest a linkage between a variety of their diseases or conditions and their exposure to Agent Orange in Vietnam. A class action lawsuit filed in 1979 against five chemical manufacturers was eventually settled in 1985. It established a fund of $180 million to finance cash payments to totally disabled veterans and survi-
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Review of Nasa’s Longitudinal Study of Astronaut Health vors of deceased veterans and set up an assistance foundation to help meet the medical, social, and legal assistance needs of members of the class. The federal government also took a number of initiatives in response to concerns about the possible health consequences of wartime exposure to herbicides. Scientific studies were commissioned by both the executive and legislative branches, and Congress introduced several bills focused on health care and compensation for veterans exposed to Agent Orange. Public Law 97-72, enacted in November 1981, expanded eligibility for health care services at VA medical centers to include Vietnam veterans exposed to Agent Orange. The veteran is not required to demonstrate any link with Agent Orange, only proof of service in Vietnam. Care is provided unless the condition is shown to be due to some cause other than exposure. Public Law 98-542, enacted in October 1984, addressed the issue of compensation for disabilities that may have resulted from exposure to Agent Orange in Vietnam. It provided for payment of disability and death benefits for Vietnam veterans with the skin diseases chloracne and porphyria cutanea tarda that became manifest within one year after service in Vietnam. The law also set up a mechanism for the VA to issue standards for determining disability claims based on exposure to Agent Orange. In brief, that mechanism calls for the Secretary of the Department of Veterans Affairs to presume a service connection (and provide for disability compensation where warranted) whenever there is sound scientific and medical evidence of a positive association between human exposure to an herbicidal agent and the occurrence of a disease in humans. Public Law 102-4, the Agent Orange Act of 1991, extended disability compensation payments to Vietnam veterans for non-Hodgkin’s lymphoma and several soft tissue sarcomas. This law also transferred the responsibility for determining the association between herbicide exposure and health outcomes from the VA to the National Academy of Sciences. A committee convened by the Institute of Medicine (IOM) of the National Academies conducted a major review of the scientific and medical evidence and in 1994 published a comprehensive report titled Veterans and Agent Orange Health Effects of Herbicides Used in Vietnam (IOM, 1994). Periodic updates have followed (IOM, 1996, 1999, 2000, 2002, 2003a). The original IOM committee approached its task by assigning each of the diseases and disorders under study to one of four categories on the basis of the epidemiological evidence reviewed: Sufficient evidence of an association; Limited or suggestive evidence of an association; Inadequate or insufficient evidence to determine whether an association exists; Limited/suggestive evidence that no association exists.
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Review of Nasa’s Longitudinal Study of Astronaut Health The committee’s Update 2002 (IOM, 2003a) lists four health outcomes in the first category: soft tissue sarcoma, Hodgkin’s disease, non-Hodgkin’s lymphoma, and chloracne. In the second category (limited or suggestive evidence of an association) are respiratory cancers of the lungs/bronchus, larynx, and trachea; prostate cancer; multiple myeloma acute and subacute transient peripheral neuropathy; porphyria cutanea tarda; type 2 diabetes; and spina bifida in children of veterans. Twenty-four other health outcomes have been classified as having inadequate or insufficient evidence to determine whether an association with herbicides exists, and two further outcomes (brain tumors and gastrointestinal tumors) fell in the category of limited/suggestive evidence of no association. The second element of that committee’s charge was to determine the increased risk of disease among people exposed to herbicides during service in Vietnam. The committee and its successors have reviewed numerous studies of the health of Vietnam veterans but to date have found it impossible to adequately quantify the risk to veterans, largely because of uncertainty about the nature and magnitude of exposures in Vietnam. A recent report on a modeling effort based on temporal and spatial proximity to known herbicide spraying operations encourages some additional efforts in this regard (IOM, 2003b). The result of these two products of the IOM’s Agent Orange committees has been the decision by the VA to provide compensation for Vietnam veterans for all the conditions in the first two categories listed above without requiring evidence of exposure other than service in Vietnam. CONCLUSIONS Some elements of these examples may be useful in formulating a NASA policy on its responsibilities to astronauts, despite some critical differences among them and between each of them and the situation facing NASA. Former beryllium workers with CBD or lung cancer receive treatment and compensation without evidence of a causal link in each case. The value of the beryllium case is limited by the specificity of the causal agent in the case of CBD, and the near-zero incidence of the disease outside workplaces involving beryllium. Spaceflight-specific diseases may yet emerge as the LSAH accrues more data, but at the moment it appears more likely that NASA authorities will be faced with the more difficult problem of determining whether individual cases of relatively common diseases (cataracts, for example) in former astronauts are occupation-or spaceflight-related. Vietnam veterans with a wide variety of maladies have argued that their conditions were due to exposure to Agent Orange in the course of their duties. As was the case for DOE and former beryllium workers, the VA lacked good records of exposure. Unlike the DOE case, in which there was not much question that beryllium was a necessary condition for CBD, the VA faced claims
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Review of Nasa’s Longitudinal Study of Astronaut Health from veterans with a myriad of diseases found not only in Vietnam veterans but also in individuals without known exposure to Agent Orange and similar herbicides. Considerable resources were expended establishing a short list of 11 disorders for which there is at least suggestive evidence of an association with herbicide exposure. Having established these links, the government provides compensation for Vietnam veterans without requiring further evidence of a causal link in each case. In the case of nuclear test participants, VA had more information available about exposure, in the form of radiation badges for a subset of participants, and as a result of extensive follow up of Hiroshima and Nagasaki survivors, a body of data about which cancers were radiation-related and a dose-response curve that described that relationship. For some of these cancers and other health problems, compensation is provided only if the test participant’s documented dose meets a liberal but nevertheless specified threshold. In most cases, however, documentation of one of 15 different cancers and participation in a nuclear test is sufficient for compensation. In each of the three examples, Congress has authored legislation to ensure that the federal government errs on the side of finding too many of its former employees eligible for care and compensation. Given the high profile of the NASA astronaut corps, it is hard to imagine a radical change in that approach should the LSAH reveal that former astronauts have an elevated risk for certain medical problems. Given the small size of the astronaut corps and their unique service to the country, the committee believes that NASA should take a page from military retirement policy and assume responsibility for the lifelong health care of former astronauts. Not only would it be the right thing to do, but it would preempt both adverse public opinion and Congressional intervention. An associated benefit to NASA might be increased participation in the LSAH. The committee’s final recommendation, therefore, reiterates a suggestion of their predecessors on the committee that authored Safe Passage (IOM, 2001c). Recommendation 4 NASA should assume responsibility for the lifelong health care of its active and former astronauts.
Representative terms from entire chapter: