Military operations produce a great deal of trash in an environment where standard waste management practices may be subordinated to more pressing concerns. As a result, ground forces have long relied on incineration in open-air pits as a means of getting rid of refuse.
The consequences of this expediency have come to the fore in the most recent conflicts in which the U.S. military have participated. The Department of Defense (DoD) cataloged 63 open burn pit sites in Iraq as of November 2009 and another 197 in Afghanistan as of 2011 (DoD, 2011). DoD estimated that collectively the sites at the large bases alone produced approximately 60,000–85,000 pounds of solid waste per day, including plastics, wood, metal, and—according to some sources—such materials as chemicals (paints, solvents), petroleum, medical waste, munitions, and human waste (IOM, 2011). No inventories of these materials were kept, and little information besides anecdote exists regarding the burning that took place at the many small and often temporary sites used by forces.
Concerns over possible adverse effects of exposure to smoke from trash burning in the theater were first expressed in the wake of the 1990–1991 Gulf War and stimulated a series of studies that indicated that exposures to smoke from oil-well fires and from other combustion sources, including waste burning, were stressors for troops (IOM, 2005). These studies grew in number in the years that followed and resulted in a provision in the National Defense Authorization Act for Fiscal Year 2010 (Public Law 111-84, § 317; enacted October 28, 2009) that prohibited the disposal of waste in open-air burn pits by DoD and called for the department to issue appropriate regulations concerning them. At that same time, the Department of Veterans Affairs (VA) asked the National Academies of Sciences, Engineering, and Medicine (the National Academies) to convene a committee to examine the long-term health consequences of exposure to burn pits in Iraq and Afghanistan. That committee’s report (IOM, 2011) included a recommendation that an epidemiologic study be conducted to evaluate the health status of deployed service members.
Congress again took action in 2013 (Public Law 112-260, § 201; enacted January 10, 2013) when it directed VA to establish and maintain a registry for service members who may have been exposed to toxic airborne chemicals and fumes generated by open burn pits. The law also called for an independent scientific organization to prepare a report addressing issues related to the establishment and conduct of the registry and use of its data.
In late 2014 VA asked the National Academies to take on this responsibility. The full statement of task is contained in Box 1-1. In brief, it calls on the committee to analyze the initial months of data collected by the registry and offer recommendations on ways to improve the instrument and best use the information it collects. This
report, prepared by the Committee on the Assessment of the Department of Veterans Affairs Airborne Hazards and Open Burn Pit Registry, fulfills the congressional mandate and provides responses to other questions posed by VA.
FRAMEWORK AND ORGANIZATION
The committee organized its response to its statement of task into six chapters addressing the following topics:
- The motivation for and the conduct of the study, including an overview of the issues related to the health effects of exposure to emissions from open burn pits and other airborne hazards present in the Southwest Asia theater of operations, the committee’s approach to carrying out its work, and information learned from its public workshop and recent epidemiologic studies of military personnel exposed to burn pits (Chapter 1).
- The use of registries in environmental health research, with a focus on VA and DoD exposure registries; the limitations of the data they gather and of the inferences that can be drawn from them; and an overview of potential comparison populations that might be used in studies of health outcomes in Airborne Hazards and Open Burn Pit (AH&OBP) Registry respondents (Chapter 2).
- An examination of the development and implementation of the AH&OBP Registry and of the content of its key element, the self-assessment questionnaire (Chapter 3).
- The methods used and the results of the committee’s analyses of the initial months of data collected by the registry, including descriptive statistics and the demographic and military characteristics of respondents (Chapter 4); and interpretation of the exposure (Chapter 5) and the health outcomes (Chapter 6) data collected by the questionnaire that the committee believes offer the most information value.
Those chapters contain the details that build the foundation for the committee’s findings, conclusions, and recommendations presented in Chapter 7.
THE COMMITTEE’S INFORMATION-GATHERING AND ANALYSIS EFFORTS
The scientific foundation for the report’s findings, conclusions, and recommendations was developed through a number of information-gathering and data analysis activities. These included conducting a public workshop, directing the work of a consulting firm that performed analyses of registry data, and carrying out a review of relevant research literature, including previous National Academies studies on such topics as the use of military burn pits, efforts to monitor air quality in the Persian Gulf region, the state of the literature regarding the health effects of exposure to combustion products in general and burn pit emissions, and related topics.
The committee’s workshop—an element of the statement of task—was conducted in May 2015 and included presentations by professionals responsible for carrying out air emissions testing in-theater, researchers studying health outcomes in repatriated military personnel and veterans, a physician providing health care to these individuals, and veterans and veteran service organization representatives sharing their personal experiences and knowledge. Their input gave the committee great insight into the circumstances faced by service members during and after their deployment.
The analyses of the registry data were directed by the committee but carried out by a contractor that obtained the information directly from VA, and neither committee members nor National Academies staff had any access to the data. This was due to VA protocols regarding the management of data they considered to be personally identifiable information and the protection of the privacy of registrants and the security of the information they were providing. As a result of these protocols, some data were not available for analysis, and the committee was not able to fully address its charge in this area.
The committee’s literature review consisted of a targeted examination of epidemiologic studies of long-term health outcomes in military and veteran populations potentially exposed to burn pit emissions. It was limited to studies that had been published since the last National Academies review of such work in 2011 (IOM, 2011). A total of eight studies were identified and summarized.
Separately, the committee considered whether there were any population groups that might be used in comparisons of demographic or other characteristics with AH&OBP registrants. Active duty military, veteran, and general population groups were examined and their strengths and weaknesses in this application assessed, but the committee ultimately concluded that, given the nature and quality of the registry data, such comparisons were inappropriate.
ENVIRONMENTAL HEALTH REGISTRIES AS AN INFORMATION-GATHERING INSTRUMENT
Registries are structured systems for collecting and maintaining data on a group of people characterized by a specific disease, condition, exposure, or event as a means to facilitate research, monitor health, or provide information to registrants. While they are generally quicker and less expensive to establish than alternative means—such as an epidemiologic study—and while they allow for the ascertainment of several exposures and health outcomes on a defined population, they also have several inherent limitations. Registries that rely on voluntary involvement and self-reported information such as exposures and health outcomes are subject to data biases resulting from such circumstances as selective participation, faulty recall, inaccurate information, or inadvertent or intentional underestimation or exaggeration. They are thus an intrinsically poor source of information on exposures, health outcomes, and possible associations among these events. Even under the best of circumstances, there are substantial limits to the accuracy of the data and—when the respondents make up only a small, unrepresentative fraction of the eligible population—to the generalizability of analyses made with them.
THE AIRBORNE HAZARDS AND OPEN BURN PIT REGISTRY
VA was presented with a challenge when it was directed by the Congress to design, test, and implement an environmental health registry for “individuals who may have been exposed to toxic airborne chemicals and fumes caused by open burn pits” in 12 months. The questionnaire that it developed to collect information from registrants exhibits a number of problems that stem in part from the inherent weaknesses of voluntary, self-report registries but that are exacerbated by a series of flaws in the registry’s structure and operation as well as in the questions that are asked and the way they are asked. The committee’s review of the AH&OBP Registry questionnaire found that it
- inappropriately uses questions that were validated for and meant to be administered by other survey means such as a face-to-face or computer-assisted phone interview;
- asks questions that may be confusing for respondents because they are ambiguous or otherwise poorly written;
- elicits information on topics such as hobbies and places of childhood residence that do not yield information that could be productively used in any analysis that would be appropriate to undertake using registry data; • fails to ask questions (regarding non-burn-pit trash burning, for example) that could yield information related to relevant exposures;
- does not take full advantage of its Web-based format to streamline and focus questions based on previous responses;
- does not permit answers to be supplemented or updated later in time; and
- requires respondents to complete a sometimes lengthy set of repetitive questions regarding deployments before addressing core issues like health, increasing the possibility of response fatigue.
The cumulative effect of these flaws is evidenced by the high percentage of respondents who initiated but did not complete the instrument and the number of questions that had large nonresponse rates.
The issue of how to improve the questionnaire depends critically on the registry’s intended purpose(s) going forward. Even a well-designed and executed registry would have little value as a scientific tool for health-effects research compared to a well-designed epidemiologic study. The committee concludes that, given the inherent weaknesses of the instrument, the best ways to make use of the AH&OBP Registry are to
- make it a means for the eligible population to document their concerns over health problems that may have resulted from their service, bring those concerns to the attention of VA and their health care providers, and supply VA with a list of persons who are interested in burn pit exposure issues; and
- collect self-reported data on exposures and health problems in the respondents that might possibly be used to stimulate research using more sophisticated analysis means.
If VA chooses to use the registry for these purposes, then the questionnaire may be simplified as follows:
The committee recommends that VA eliminate the questionnaire sections addressing locations of previous residences (Section 4), non-military work history (5) and home environment, community, and hobbies (6), which collect data that might only be useful in epidemiologic studies of the population.
Eliminating these categories would make the questionnaire easier and faster to complete and would better focus it on the needs of the eligible population.
More generally, the AH&OBP Registry’s data collection, administration, and management efforts would be improved by taking these steps:
The committee recommends that once VA clarifies the intent and purpose of the registry, it develop a specific plan for more seamlessly integrating relevant VA and DoD data sources with the registry’s data with the goals of reducing future participant burden, increasing data quality by restructuring questions to minimize recall and other biases, and improving the usefulness of the registry database as an information source for health care professionals and researchers.
The committee recommends that alternative means of completing the questionnaire, such as a mail-in form or via a computer-assisted phone interview, be offered in order to ensure that the subset of eligible persons who do not use or are not facile with the Internet have the opportunity to participate in the registry.
The committee recommends that VA involve external survey experts experienced in Web-based instruments in any restructuring of the registry questionnaire.
ANALYSIS METHODS AND DESCRIPTIVE STATISTICS FOR THE REGISTRY DATA
VA made data from the first 13 months of the operation on the AH&OBP (June 2014–July 2015) available to the committee’s contractor. However, VA data security and participant privacy protocols precluded these data from including any items that would allow for a description of the association between respondents’ self-reported exposures and their Veterans Health Administration (VHA) health care experience as called for in the statement of task. They also circumscribed the type and level of detail of other requested analyses. The restrictions thus affect the confidence with which the committee can draw conclusions regarding the process of data acquisition and the validity of the information reported on exposure and health outcomes.
Another major limitation is that questionnaire and other data were made available only for those who finished and submitted the questionnaire. A VA report (2015) indicated that nearly 40% of those who began filling out an AH&OBP Registry questionnaire did not complete it; this is an outcome that should be followed up.
The committee recommends that VA evaluate whether and how registrants who did not complete the questionnaire differ from those who did, analyze the determinants of non-completion, and use this information to formulate strategies to encourage registrants to finish and submit their responses and improve the completion rate for future participants.
Approximately 1.0% of eligible Gulf War veterans and 1.7% of eligible post-9/11 veterans (46,404 respondents in total) are represented in the data made available for the committee’s analysis. Nearly all respondents report having encountered one or more airborne hazards in theater: 96% of all respondents reported being exposed to a burn pit on at least one deployment, and 85.6% of Gulf War era respondents reported exposure to smoke from oil-well fires, while 85.2% of all respondents reported being exposed to dust storms. The lack of data on those who were deployed and who do not believe they were exposed to burn pits precludes using the registry to compare exposed individuals with unexposed individuals. Therefore, the only means available for evaluating burn pit exposure is to examine gradations of exposure among the respondents.
Analyses of demographic data indicate that neither the Gulf War nor post-9/11 era registry respondents can be considered representative of their respective eligible non-respondent populations, although the differences are more pronounced for post-9/11 respondents and non-respondents. Thus, findings from these data—which represent the experience of a small, non-random, self-selected sample—are not generalizable to the broader, eligible population and cannot be used for making inferences concerning them.
ANALYSIS METHODS AND INTERPRETATION OF REGISTRY EXPOSURE DATA
The committee identified several problems with the way that the registry’s exposure data were collected, which were compounded by the inherent limitations of self-reported information. One issue is that response fatigue resulting from the way that the exposure questions are structured may affect the accuracy of information provided by respondents who were deployed multiple times or to multiple locations. Another is that the questions do not provide information on the intensity of exposure and are in any case limited by the great variety of chemical constituents and particulate matter characteristics that made up that exposure and the lack of the information concerning them. A high fraction of registry participants reported potential exposures to both burn pit emissions and dust, and there was a tendency for individuals who reported exposures to one type of source to report exposures to other sources as well. These issues again highlight the lack of representativeness of the data and undermine its usefulness in evaluating associations between exposures and health outcomes.
Given the charge—and a concern for over interpreting the data at hand—the committee developed a reduced set of metrics to categorize exposure potential for the purpose of analysis. Because there were many sources of airborne emissions that contributed to a service member’s exposures to particulate matter and chemical exposures and insufficient data by which to determine which sources contributed the most or pose the most harm, the committee chose to weigh each potential exposure equally and to focus on the totality of exposures.
On the basis of its evaluation, the committee concludes that the exposure data are of insufficient quality or reliability to make them useful in anything other than the most general assessments of exposure potential. Given this limitation, the committee believes that there may be some circumstances where supplementing these data with information from on-site environmental monitoring, meteorological, satellite, or other relevant measurements or observations might yield results that would suggest that some individuals or groups experienced greater or lesser exposures to specific constituents; these results might in turn stimulate more detailed assessments of health outcomes in particular populations.
ANALYSIS METHODS AND INTERPRETATION OF REGISTRY HEALTH OUTCOMES DATA
The committee took an approach analogous to that used for exposure data to characterize the health outcomes data for analysis purposes—specifically, generating variables using multiple grouped indicators of these outcomes. Health outcomes related to the symptoms, conditions, and diseases associated with the respiratory and the cardiovascular systems were identified as the best candidates for study because these are the most plausible and well-documented potential health effects of the exposures of concern. However, the limitations of the AH&OBP questionnaire and the data collected by it are still too great to allow any firm conclusions to be drawn from this analysis.
Generally speaking, the committee found that the observed prevalences of respiratory and cardiovascular outcomes appear consistent with what would be expected in a population that is predominantly male, aged 25–60,
and for whom about one-third report a current or former history of smoking. It concluded that the health data may be of sufficient quality to justify internal comparisons in which data from subsets of registrants with varying levels of potential exposure are compared with one another. An examination of multiple indices of exposure to burn pit emissions and other hazards associated with deployment showed that registrants who reported more exposures of all types also tended to report more health problems of all types.
The committee’s exposure potential variables had strong and consistent associations with self-reported asthma; any respiratory symptom; emphysema, chronic bronchitis, or chronic obstructive pulmonary disease (COPD); functional limitations due to lung or breathing problems; cardiovascular disease; and hypertension. Importantly, though, the analyses also uncovered some unexpected findings that are not consistent with currently understood scientific mechanisms of exposure and outcome, such as a statistically significant association between higher self-reported levels of asbestos exposure and a higher prevalence of neurologic, immune, or liver conditions. Such outcomes strongly suggest that the results of analyses of registry data cannot be taken at face value and that the identified associations may be an artifact of the population’s selection and the limitations of the self-reported exposure and disease data.
Again, the bottom line is that registry analyses are not generalizable and can only describe what exposures and conditions the population of registry respondents are reporting; registry data cannot be used to determine cause or to estimate prevalence in the total eligible population of service members or veterans. The committee wishes to emphasize that it would have reached this same determination had the analyses found no associations or weak associations between the exposures and health outcomes.
The strong conclusion that can be drawn is that a more rigorous and appropriate study design is needed to examine the relationship between the exposures encountered during deployment to the Southwest Asia theater of operations and health outcomes. While the registry provides a forum for collecting and recording information on those who were deployed and are motivated to participate, it cannot answer such questions.
The committee recommends that other means for evaluating the potential health effects associated with airborne hazards and open burn pit exposures be developed, such as a well designed epidemiologic study.
The 2011 report Long-Term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan (IOM, 2011) contains advice and recommendations on how such a study might be conducted.
The committee concludes that, while medically verified health outcomes information only exists for the subset of the population that uses VA health care—data that were not available to the committee but that are contained in VHA records—there is potential value in linking the registry data to health care use data and conducting analyses. Comparisons between self-reported information collected by the questionnaire and diagnoses in VA medical records for respondents who use VA health care would provide further information concerning the level of validity of self-reported health outcomes in the population of respondents.
Given this and the committee’s other findings regarding the registry,
The committee recommends that VA’s messaging be explicit about the limitations on the ability of the AH&OBP Registry to generate valid information that can be used to improve VA health and benefits programs or to inform treatment of individuals potentially exposed to burn pits or other airborne hazards in theater in order to ensure that participants and others do not form unrealistic expectations about the value of participation or the capabilities of the registry.
OTHER FINDINGS, CONCLUSIONS, AND RECOMMENDATIONS
The committee was also asked to offer observations on some additional issues surrounding the registry and the actions being taken by DoD and VA to address airborne hazards and open burn pit questions. Specifically, the legislation that directed VA to establish the registry called for
- An assessment of the effectiveness of actions taken by the [Department of Veterans Affairs and the Department of Defense] to collect and maintain information on the health effects of exposure to toxic airborne chemicals and fumes caused by open burn pits.
- Recommendations to improve the collection and maintenance of such information.
- Using established and previously published epidemiological studies, recommendations regarding the most effective and prudent means of addressing the medical needs of eligible individuals with respect to conditions that are likely to result from exposure to open burn pits (Public Law 112-260 § 201(b)(1)(A) (i–iii)).
To date, other than the AH&OBP Registry and the airborne exposures and health information collected as part of such efforts as the Gulf War Registry and Millennium Cohort Study, there are no systematic data collection or maintenance efforts focused on the effects of burn pit emissions.1 Very limited in-theater air pollution data gathering efforts have generated information that would aid in studies of those who served in the same place and at the same time as measurements were made. Two previous National Academies reports have offered recommendations on how more rigorous and useful data could be collected: Review of the Department of Defense Enhanced Particulate Matter Surveillance Program Report (NRC, 2010) and Long-Term Health Consequences of Exposure to Burn Pits in Iraq and Afghanistan (IOM, 2011). This committee concludes that the recommendations these reports offer regarding, respectively, environmental sampling in a combat theater and the conduct of a prospective study of the long-term health effects of exposure to burn-pit emissions are still salient and, if implemented, would materially improve the knowledge base concerning the health effects of past, present, and future in-theater exposures.
The committee’s review of the literature found there have been very few epidemiologic studies of service members and veterans exposed to open burn pits. The available information does not suggest any general course of action for addressing the medical needs of this population beyond the steps that health care providers should already be carrying out: taking a thorough history, including all occupational exposures, listening carefully to the patient, and structuring the clinical response accordingly. The health care provider instructions for AH&OBP Registry clinical examinations produced by VA (2016) are sound guidance on this.
The information developed by the registry has limited value for improving individual patient care. However, while these data may be inappropriate for evaluating the association between exposures and health outcomes, there are other ways in which they may be useful. As has already been mentioned, the committee believes that the registry’s primary utility is that it provides a means for veterans and service members to document their concerns about wartime exposures and the health problems that might have resulted from them and to bring these to the attention of both VA and their health care providers. The self-reported signs, symptoms, and diseases identified by registrants constitute a record that can alert providers to concerns and problems that may be forgotten about or missed during clinical encounters.
The registry questionnaire collects a number of pieces of information that would facilitate conversations between a patient and a health care provider, without regard to whether the information might be relevant to AH&OBP exposures. For example, someone who reported difficulty walking long distances or climbing stairs might be experiencing joint pain, respiratory problems, atherosclerotic vascular disease with congestive heart failure, obesity, or even anxiety. Similarly, a complaint of chest pain can have multiple causes in addition to angina and coronary artery disease, including gastroesophageal reflux disease, chest wall pain or costochondritis, and anxiety. And often these symptoms can be multi-factorial in origin. Registry questionnaire responses are already accessible to VA health care providers as part of a veteran’s electronic health record, and a complete set of responses may be downloaded and printed for a respondent to take to a clinical visit with a provider in or outside of the VA system.
The committee recommends that VA enhance the utility of the AH&OBP Registry by developing a concise version of participant’s questionnaire responses focused on information that would be most useful in a routine clinical encounter and make it available for download.
1 DoD and VA collect and analyze data on all medical conditions in the populations that participate in their health care programs, but these are not specific to airborne hazards or burn pit emissions.
Providers often have little time to get histories and patients do not always do a good job of raising concerns, so a succinct summary would greatly benefit both.
The data the registry provides on the number of respondents who report particular health problems may also be useful to VA. For example, several thousand individuals have indicated that they have diagnosed or self-reported cardiopulmonary symptoms. If these persons subsequently present for an evaluation or treatment at rates that would not otherwise have been anticipated by VA, it would indicate that the registry could be used as tool for anticipating future demand for particular provider services. However, it remains to be seen whether this would be the case, and the number of individuals who have thus far completed the questionnaire is only a tiny fraction of the overall population eligible for VA care.
Given the demonstrated concerns of respondents regarding the health effects of exposure to airborne hazards and open burn pit emissions, it is unclear why so few have yet to arrange for the optional in-person clinical evaluation by a VA provider that is made available as part of the registry.
The committee recommends that VA continue its efforts to make it easier for participants to schedule and get the optional health examination offered as part of the AH&OBP Registry—such as through targeted follow-up of respondents who indicate interest—and that it investigate the reasons why such a small percentage of respondents who indicate interest in an exam (~2.5%, to date) request one.
Adding a means of scheduling an exam as part of the questionnaire—a capability that the committee understands is being implemented—is a useful first step.
The committee recognizes the great interest that active duty military personnel and veterans who served in Iraq, Afghanistan, and the greater Southwest Asia theater of operations have in understanding potential threats to their health from airborne hazards and open burn pit exposures. As its analysis has made clear, though, there are inherent features of registries that rely on voluntary participation and self-reported information that make them fundamentally unsuitable for addressing the question of whether these exposures have, in fact, caused health problems. Addressing the issues identified by the committee would, though, improve the AH&OBP Registry’s utility as a means of
- generating a roster of concerned individuals that VA can use for targeted outreach, surveillance, and health-risk communication;
- creating, via the completed questionnaire, a record of self-reported exposures and health concerns that is recorded in the participant’s VA electronic health record; and
- allowing VA users and nonusers who take part in the optional clinical exam to articulate concerns they may have to a health care provider and, if warranted, undergo appropriate diagnostic testing or referral, and begin treatment to improve symptoms.
All parties—service members, veterans, and their families; VA; Congress; and other concerned people—would benefit from having a realistic understanding of the strengths and limitations of registry data so that they can make best use of them and, if desired, conduct the kind of investigations that might yield salient health information and improve health care for those affected.
DoD (Department of Defense). 2011. Exposure to toxins produced by burn pits: Congressional data request and studies. In Memorandum for the Assistant Secretary of Defense for Health Affairs. Washington, DC: Department of Defense.
IOM (Institute of Medicine). 2005. Gulf War and health, volume 3: Fuels, combustion products, and propellants. Washington, DC: The National Academies Press.
IOM. 2011. Long-term health consequences of exposure to burn pits in Iraq and Afghanistan. Washington, DC: The National Academies Press.
NRC (National Research Council). 2010. Review of the Department of Defense Enhanced Particulate Matter Surveillance Program report. Washington, DC: The National Academies Press.
VA (Department of Veterans Affairs). 2015. Report on data from the Airborne Hazards and Open Burn Pit (AH&OBP) Registry, June 2015. http://www.publichealth.va.gov/docs/exposures/va-ahobp-registry-data-report-june2015.pdf (accessed September 10, 2016).
VA. 2016. War Related Illness and Injury Study Center. Airborne Hazards & Open Burn Pit Registry: Introduction to airborne hazards for providers. http://www.warrelatedillness.va.gov/education/factsheets/airborne-hazards-and-open-burn-pitregistry-for-providers.asp (accessed October 18, 2016).
This page intentionally left blank.