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Defense > 2. DOD's Storage of Occupational and Environmental Health Surveillance Data

Inconsistencies among the policies of the Department of Defense and the military services have contributed to fragmented and duplicative efforts to store occupational and environmental health surveillance data needed to track and assess service-related health conditions of returning servicemembers and veterans.

Why This Area Is Important

Since the end of the 1991 Persian Gulf War, servicemembers’ and veterans’ reports of unexplained illnesses that they attributed to service-related occupational and environmental exposures have led to increasing interest in health effects related to military deployments. In 1997, the Department of Defense (DOD) developed a military-wide health surveillance framework that includes occupational and environmental health surveillance (OEHS)—the regular collection and reporting of occupational and environmental health hazard data by the military services during deployments that can be used to help prevent, treat, or control disease or injury. Despite these efforts, attempts to research and investigate whether post-deployment health conditions are the result of military service continue to be problematic. This is of particular concern for those servicemembers and veterans returning from more recent conflicts, who have health concerns they believe are related to their deployment, such as conditions related to smoke inhalation from open-air burn pits—used for waste disposal—on military bases in Iraq and Afghanistan.

Establishing a service connection for health conditions is important because federal law generally entitles veterans with service-connected disabilities (i.e., injuries or diseases incurred or aggravated while on active military duty) to Department of Veterans Affairs disability compensation benefits.[1] However, establishing a relationship between occupational and environmental exposures and health issues can be difficult. In light of such difficulties, Congress has, on several occasions, legislated “presumptive service connections,” which allow veterans to receive compensation for certain conditions without having to prove cause.[2]

In July 2005, GAO reported that improvements were needed with OEHS during deployments to address immediate and long-term health issues. Specifically, GAO recommended that DOD improve deployment OEHS data collection and reporting, including the development of cross-service guidance to facilitate more consistent implementation of OEHS policy, which DOD developed in 2007. From the July 2005 report through December 31, 2014, there have been about 2.1 million servicemember deployments to Iraq and Afghanistan, involving about 1.4 million individual servicemembers.[3]

[1] 38 U.S.C. §§ 1110 and 1131. Service-connected disability status does not include disabilities caused by a veteran’s own “willful misconduct or abuse of alcohol or drugs.”

[2] A presumptive service connection relieves veterans of the burden to prove that a disability or illness was caused by a specific exposure that occurred during service in the Armed Forces, and instead shifts the burden of proof concerning whether a disease or disability was caused or aggravated due to service from the veteran to the Department of Veterans Affairs.

[3] Of these approximately 1.4 million individual servicemembers, about 470,000 were deployed more than once—potentially multiple times—to Iraq and Afghanistan during this period.

What GAO Found

In May 2015, GAO found that inconsistencies among the policies of DOD and the military services regarding OEHS data storage had led to fragmentation and duplication of OEHS data between the department’s two information technology systems—the Military Exposure Surveillance Library (MESL) and the Defense Occupational and Environmental Health Readiness System (DOEHRS):

  • MESL, originally implemented in 2003, contains both classified and unclassified documents that have been scanned and uploaded into the system.[1]
  • DOEHRS—which DOD began implementing in 2006—only contains unclassified data, but incorporates additional functionalities, including OEHS data collection, management, and assessment, into a single system.

DOD officials told GAO that DOD is transitioning from the use of MESL to DOEHRS, which has greater functionality, and that this transition would eventually include the transfer of all unclassified documents currently in MESL to DOEHRS (once DOEHRS had been sufficiently upgraded) while classified data would remain in MESL. However, departmental policy last updated in 2011 states that all classified and unclassified OEHS data should be stored in MESL even though DOEHRS was implemented more recently.[2] DOD officials told GAO that the policy DOD currently has in place does not reflect the potential transition from MESL to DOEHRS because developing the functionality of DOEHRS in archiving data from deployments was still under way when the policy was last updated in 2011—about 5 years after DOEHRS was implemented. These officials also told GAO that the policy was being revised to require the storage of unclassified OEHS data in DOEHRS, and they expected the updated policy to be released in 2016.

Further, when GAO reviewed all of DOD’s relevant OEHS policies as well as corresponding policies developed by each of the military services—all dated after 2006—GAO identified additional inconsistencies about which system should be used to store OEHS data.[3] Specifically, only 3 of the 14 policies GAO reviewed instructed officials to store OEHS data in DOEHRS, while 4 others instruct officials to store OEHS data in MESL. In addition, 6 of the policies instruct the use of both systems as appropriate, depending on the type of document being submitted and the availability of DOEHRS during a deployment. One of the policies does not specifically mention DOEHRS or MESL, although it notes that databases are necessary for OEHS data storage. The table below shows the list of 14 policies related to OEHS data storage that GAO reviewed.

Policies That Direct the Storage of Occupational and Environmental Health Surveillance Data to the Defense Occupational and Environmental Health Readiness System (DOEHRS) or the Military Exposure Surveillance Library (MESL)





Department of Defense Instruction 6490.03 (2011)




Department of Defense Instruction 6055.05 (2008)




Joint Chiefs of Staff Memorandum MCM 0017-12 (2012)




Central Command Regulation 40-2 (2014)




Army Regulation 11-35 (2007)




U.S. Army Public Health Command Technical Guidance 230 (2013)




Air Force Instruction 48-145 (2014)




U.S. Air Force Central Command Public Health Guide(2014)




U.S. Air Force Central Command Special Instruction 13-04 (2014)




U.S. Air Force Central Command Bioenvironmental Engineering Deployment Guide(2014)




Air Force Manual 48-146 (2012)




Secretary of the Navy Instruction 6200.1 (2014)




Occupational and Environmental Health Site Assessment Guide(2012)c




Technical Bulletin: Sanitary Control and Surveillance of Field Water Supplies(2010)d




Source: GAO analysis of DOD information. │ GAO-16-375SP

aAlthough DOD Instruction 6055.05 does not directly reference MESL in the policy, it does reference the “DOEHRS data portal,” a prior name for MESL.

bArmy Regulation 11-35 (May 2007) highlights the importance of collecting and storing OEHS data, but does not specifically mention DOERHS or MESL. According to DOD officials, the regulation is currently under revision.

cThe Army, the Air Force, and the Navy jointly developed this guide on occupational and environmental health site assessments for all officials to follow, and each of the military services has its own reference for it (NTRP 4-02.9, AFTTP 3-2.82_IP, and ATP 4-02.82).

dThe Army, the Air Force, and the Navy jointly developed this technical bulletin regarding the sanitation and safety of water during deployments for all officials to follow, and each of the military services has its own reference for it (TB MED 577, AFMAN 48-138_IP, and NAVMED P-5010-10).

Inconsistent policies are contrary to federal standards for internal control, which state that management should have policies in place that are both appropriate and clear.[4] Without consistent policies on which system should be used to store unclassified OEHS data, officials’ efforts to store these data are inefficient and have resulted in both fragmentation and duplication. Specifically, in some cases, similar types of unclassified OEHS data have been submitted to both MESL and DOEHRS, and in other cases, identical unclassified OEHS data have been submitted to both systems. A DOD official who has technical expertise in both systems confirmed that there is duplication of stored OEHS data, but told GAO that there was no reasonable way to determine the extent because only DOEHRS has specific data level querying abilities. As neither system serves as a central repository for OEHS data, it is difficult to identify complete and comprehensive data sets for specific types of OEHS data, which may impede future efforts to identify and fully assess service-related health conditions, or in conducting other important research.

[1] MESL was originally established by DOD as the OEHS Document Archival Portal and went through several name changes before being renamed the MESL in October 2011.

[2] See DOD Instruction 6490.03, Deployment Health (Aug. 11, 2006; certified current as of Sept. 30, 2011).

[3] All but one of these policies referenced DOD Instruction 6490.03, which reflects the departmental policy on OEHS storage. The only policy that did not directly reference DOD Instruction 6490.03 referenced another policy, which refers to DOD Instruction 6490.03.

Actions Needed

GAO recommended in its May 2015 report that to eliminate the fragmentation and duplication in the storage of unclassified OEHS data, the Secretary of Defense should

  • determine which information technology system—MESL or DOEHRS—should be used to store specific types of unclassified OEHS data and clarify the department’s policy accordingly; and
  • require all other departmental and military-service-specific policies to be likewise amended and implemented to ensure consistency.

Because GAO found that DOD cannot readily determine the extent to which identical unclassified OEHS data are stored repetitively in both MESL and DOEHRS, the potential costs associated with the fragmented and duplicative data storage efforts, such as any additional administrative costs expended in uploading data into both systems, could not be determined. However, taking these actions should help ensure that the storage of OEHS data does not compromise the future ability of officials to use the data in determining service connections for specific health conditions, or in conducting other important research.

How GAO Conducted Its Work

The information contained in this analysis is based on the findings from products listed in the related GAO products section. To conduct this work, GAO reviewed and analyzed DOD and military-service-specific policies that describe OEHS data storage.[1] GAO also obtained information on the functionalities and capabilities of DOD’s two information technology systems used to store OEHS data: MESL and DOEHRS. GAO reviewed the numbers and types of OESH data entries in each system to better understand how OEHS data were being stored. In addition, GAO interviewed DOD and military service officials about their practices for storing OEHS data.

[1] In total, GAO reviewed 64 DOD and military service policies to determine which policies described how OEHS data should be stored. GAO also confirmed with officials that these policies were still current as of May 2015. GAO found that 14 of those policies described the storage of OEHS data. For the purposes of the May 2015 report and this report section, “policies” include directives, instructions, technical guides, and memorandums.

Agency Comments & GAO Contact

In commenting on the May 2015 report on which this analysis is based, DOD concurred with GAO’s recommendations. DOD noted that it plans to clarify DOD Instruction 6490.03 in a subsequent version and issue appropriate guidance on the use of MESL and DOEHRS. Additionally, DOD noted that once a new instruction is published, the entire department, including the military services, is to revise related policies accordingly. However, while this may be the case, GAO found that not all of the departmental and military services’ policies were revised to reflect the main DOD instruction regarding which system to use for storing OEHS data. As a result, GAO maintains that it is important for the department to ensure that the appropriate revisions are made to all related policies.

GAO provided a draft of this report section to DOD for review and comment. In an email received in March 2016, the Executive Officer to the Deputy Assistant Secretary of Defense for Health Readiness Policy and Oversight stated that a draft version of the revised DOD Instruction 6490.03 is under review within the department. In addition, the Executive Officer stated that once DOD Instruction 6490.03 is published, military service and combatant command policy and guidance documents will be revised to ensure consistency.

For additional information about this area, contact Debra A. Draper at (202) 512-7114 or

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