A.2  METHODOLOGY

During and after the Gulf War, military personnel reported that they had potentially been exposed to various environmental and occupational hazards. This pesticide investigation assesses the potential for exposure to veterans from US or host nation applied pesticides. In the course of this investigation, investigators identified deficiencies in various areas of pesticide management (either systematic or individual) and developed suggestions for improvements in policies, procedures, and readiness.

Medical surveillance and record-keeping practices during and after the Gulf War did not include the systematic collection, interpretation, reporting, and archival of the data and information needed to identify, assess, and respond to potential pesticides exposure incidents and events. The absence of this critical data is a significant limiting factor for retrospective investigations and analysis efforts aimed at establishing exposures (individual or collective) and associated health effects.

When DoD committed to investigating Gulf War pesticides exposures, the investigation plan identified essential information needed for a meaningful analysis; this included information on:

A.  Investigation Process

The findings and conclusions presented in this report are the result of analyses conducted on the information noted above. This information was obtained as part of several key areas of the investigation; these included: 1) a review of various databases on background issues associated with the use and application of pesticides; 2) a review of Department of Defense policies and guidelines involving the use and management of pesticides; 3) a literature review of the health effects associated with pesticide exposure; 4) a random survey of Gulf War veterans focusing on their use of and exposure to pesticides used during the Gulf War; 5) interviews with various individuals to acquire information on pesticide application and management; and 6) a health risk assessment to determine the likelihood that exposures to pesticides during the Gulf War may have caused some of the unexplained illnesses reported by some returning veterans. The following subsections discuss how and where investigators obtained information in each of these key areas.

1.  Database Searches

Much of the historical documentation from the Gulf War was available to analysts in searchable databases. Analysts searched operational guidance, command correspondence, and after action reports. Keywords were used to search both classified and unclassified databases for information about preventive medicine organizations and operations, enemy prisoner of war camps, and specific pesticides. The database of general interview data was searched for information on topics mentioned in the course of interviews such as fly baits and flea and tick collars. Personnel data was searched to identify individuals who served in the preventive medicine and pest control communities. Searches of databases available through the US Environmental Protection Agency and the National Library of Medicine yielded information on pesticide characteristics, properties, and toxicity.

2.  Department of Defense Guidelines and Policies

Military policies and procedures were contained in a variety of Department of Defense and military service directives, instructions, and regulations. These documents were reviewed to gain an understanding of policies and procedures that were in effect at the time of the Gulf War. Areas such as pesticide training and certification, application equipment, record keeping, and employment of non-preventive medicine and pest control applicators were researched.

3.  Health Effects Literature Search

The literature review conducted by RAND summarizes the existing scientific literature on the health effects of the classes of pesticides that may have affected military personnel who served in Operations Desert Shield/Desert Storm from 1990 to 1991. The study reviews the literature on 12 pesticide active ingredients believed by investigators to have been used during this time period, and reports on exposures or doses and related health outcomes. The reviews were limited to literature published or accepted for publication in peer-reviewed journals, books, government publications, and conference proceedings. Information obtained from the literature search was used to describe the acute and chronic health effects of pesticide exposure, and relate this information to the Gulf War experience.

4.  Gulf War Veteran Survey

The purpose of this area of study was to identify the pesticides used during the Gulf War and estimate the fraction of personnel deployed on the ground that were exposed to these pesticides. RAND conducted this study, which was designed to survey a cross-section of military personnel who served in the Gulf War. The participants consisted of a random sample of 2,005 officer and enlisted personnel, and addressed how pesticides were applied by either US or host nation applicators and how pesticides were acquired and applied for personal use. Information collected during the veteran surveys was used to assess the exposure to pesticides experienced by the general US military population while serving in the KTO.

5.  Personnel Interviews

Due to the limited amount of quantitative information available on pesticide quantities and application rates, information was sought from preventive medicine personnel who were involved in the general applications of pesticides (e.g., area sprays and fogging). This information, while important in helping investigators understand how pesticides were used during the Gulf War, lacks the veracity of verifiable or documented data normally sought in investigations such as this. Individuals interviewed included preventive medicine officers (physicians), entomologists, environmental science officers, preventive medicine specialists/technicians, and pesticide applicators from the Army, Navy, Marine Corps, and Air Force.

In addition to the preventive medicine interviews we also interviewed individuals involved with enemy prisoner of war delousing operations and those who were involved the handling and use of fly baits (additional information on delousing and fly baits can be found in Section B.2.A,  Exposure Data from Survey and Interviews). Collectively the information obtained during all interviews (in total approximately 900 veteran interviews were conducted) was used to provide a check on how well DoD policy and guidelines on pesticide application were followed. The information was also helpful in developing the exposure scenarios used in the health risk assessment.

6. Health Risk Assessment

In coordination with the Environmental Protection Agency, Office of Pesticide Programs (EPA/OPP), investigators prepared a health risk assessment (HRA) of the pesticides used by or around servicemembers deployed to the Gulf. The HRA follows an EPA-approved methodology that results in an estimate of the likelihood of certain specific health effects from exposures to pesticides. The HRA utilizes exposure scenarios developed from Gulf War veteran surveys and interviews with preventive medicine and other personnel to estimate whether unexplained illnesses reported by some veterans could have resulted from exposures to pesticides. The HRA was a major component of the overall investigation and is discussed in more detail in Sections A.2.B,  Health Risk Assessment; A.6,  Summary of Health Risk Assesment; and Part B.

Other groups that contributed to the investigation and the development of this report include: the United States Army Center for Health Promotion and Preventive Medicine (CHPPM); the Armed Forces Pest Management Board (AFPMB); and subject matter experts from industry and academia. Each agency or individual is identified by reference in the text and bibliography.

B.  Health Risk Assessment

Without monitoring and application rate data to accurately quantify exposures, investigators had to rely on interviews with Gulf War veterans and research into Gulf War pesticide use for sufficient background information to develop pesticide exposure scenarios. These exposure scenarios were then used to estimate potential health risks following a four-step methodology adapted from EPA/OPP (see Figure 1).

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Figure 1. Health Risk Assessment


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