PART A – ENVIRONMENTAL EXPOSURE REPORT

A.1  SUMMARY [1]

For many years the United States has formulated and used chemical products to control insects and other animal populations that serve as vectors for various diseases. Over the past 20 years, pesticides used according to label directions have posed a minimal health threat to healthy adults. However, there are numerous reports of health problems resulting from overexposures due to misuse or accidents. Of particular note are reports documenting the potential for organophosphate and carbamate pesticides to cause adverse neurological effects in humans. It is because of this potential that some veterans and some within the medical and scientific communities have expressed concern over the possible long-term health consequences of pesticide use during the Gulf War. Indeed, some Gulf War veterans have reported a wide array of unexplained illnesses that some suspect may be related to their use of and exposure to pesticides, alone or in combination with other health stressors that were present during the war.

Given the experience of past campaigns fought in the region, preventive medicine personnel expected pests in the Gulf—especially sand flies, mosquitoes, and fleas. These insects carry several infectious diseases, including leishmaniasis, sand fly fever, and malaria. However, of the 697,000 US servicemen and women deployed during the Gulf War, medical personnel identified only 40 cases of infectious diseases transmitted by insects. Military analysts attributed this low incidence of insect-borne infectious diseases to the establishment of a comprehensive preventive medicine structure, favorable weather, dry desert locations for most units, and the use of pesticides.

We know from information received during veteran interviews (see Tab C-4) and from Department of Defense (DoD) guidance and policy documents that US forces used pesticides in areas where they worked, slept, and ate throughout the Kuwait Theater of Operations (KTO). Troops used pesticides for a number of reasons, including personal use on the skin and uniforms as an insect repellent, as area sprays and fogs to kill flying insects, in pest strips and fly baits to attract and kill flying insects, and as delousing agents applied to enemy prisoners of war. These widespread, commonly reported uses further supported the decision to investigate pesticide exposures.

In general, the pesticides of potential concern used by US personnel in the KTO can be divided into five major classes or categories: 1) organophosphorus pesticides, such as malathion and chlorpyrifos; 2) carbamate pesticides, such as bendiocarb; 3) the organochlorine, lindane; 4) pyrethroid pesticides, such as permethrin; and 5) the insect repellent DEET. These or similar pesticide products are available for purchase by the general public at local garden and hardware supply stores and, when used during the Gulf War, were approved by the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) for general use by the US public. Some pesticide products, such as the fly bait Snip, were purchased in-theater by authorized personnel for unit use or by individuals for their personal use. Some of these locally purchased products were not registered with the EPA.

The purpose of this investigation is to report on the use of pesticides[2] during the Gulf War and to describe what is known regarding the medical implications that may be attributed to that exposure. In reporting on these issues, the objective of the Office of the Special Assistant for Gulf War Illnesses, Medical Readiness, and Military Deployments (OSA) is to determine the extent to which pesticide exposures may have played a role in the undiagnosed illnesses reported by some Gulf War veterans. Secondary objectives are: to provide an accounting of the issues surrounding pesticide use during the Gulf War; and to support DoD’s continued effort to advance force health protection issues. By reporting on related events that support the development of lessons learned, DoD can make changes in policy and procedures on how future deployed forces meet challenges from environmental factors.

This report documents a number of cases of apparent misuse of pesticides. It is important to note that in a majority of the cases where chemicals were improperly used, personnel involved in the incidents did not follow the clear instructions on the product label. Other personnel apparently exposed themselves and those around them unnecessarily by ignoring published guidance on pesticide use provided by the services or by choosing not to wear appropriate personal protective equipment. Some deficiencies are identified however, and many of those present at the time of the Gulf War, for example guidance on local purchases of pesticides and accurate recordkeeping, have been addressed by the services in the interim since the war. A key element still not addressed is the lack of training in the use of personal protective measures against pests of military significance (including use of personal pesticides to combat these pests). Inclusion of such training at a basic training level and during refresher training will raise the awareness of all personnel and their leaders on the proper use of pesticides.

Information contained in this report references the results of two studies prepared by RAND. The first study presents the results of a medical and scientific literature review on the health effects associated with pesticide exposure[3] ; and the second study presents the results of information obtained from surveys of Gulf War veterans, focusing on how pesticides were used during the Gulf War.[4] The literature review reports on the health effects of 12 active ingredients contained in pesticide products used during the Gulf War. The report summarizes the relevant scientific literature and focuses on reports of known pesticide exposures or doses and related health outcomes where available. Results of the literature review indicate the following:

Absorption through the skin is considered to be the most frequent means of pesticide exposure, although pesticides can also enter the body through inhalation or ingestion, that is, through breathing or eating. As noted, Gulf War records document only one case of acute health problems during or immediately after pesticide exposures. In this case symptoms were what preventive medicine (PM) personnel would have expected for acute exposures, the most noticeable being slight nausea, mild headaches, and some throat irritation.

Regarding organophosphate and carbamate pesticides, one important question is: if individuals had no signs or symptoms at the time of exposure, how likely is it that such exposures could result in adverse health effects months or years later? There is no simple answer that we can give with a high level of confidence as there is conflicting information in the literature on this subject. The relevant information comes mainly from published studies of civilian pesticide handlers in the US and foreign countries. There are reports in the literature that suggest unless individuals had signs and symptoms of serious pesticide poisoning or toxicity at the time of the initial exposure, health effects months or years later are unlikely. However, according to the RAND literature review for pesticides, there is also evidence of modest long-term effects following asymptomatic exposures (i.e., no symptoms). This issue can only be resolved by further research.

The veteran survey report was designed and conducted by RAND for the purpose of obtaining detailed data both on pesticides personally used by individuals and pesticides used or observed in the field. The data were obtained from telephone interviews with 2,005 veterans who were randomly selected to be statistically representative of the entire Gulf War ground population. The RAND survey results suggest that some symptomatic exposures may have occurred during the deployment and that those exposures may have been severe, especially for those assigned to apply organophosphate pesticides. However, the majority of symptomatic exposures, due for example to DEET, permethrin, and lindane, most likely resulted in mild and localized reactions of short duration.

Collectively, the RAND reports add to the body of knowledge on pesticide use and exposures during the Gulf War, and complement the data and information collected by this office to determine whether there is a causal relationship between pesticide use and the unexplained adverse health effects reported by some Gulf War veterans.

While most US personnel who participated in Operations Desert Shield/Desert Storm were potentially exposed to pesticides, there were select groups who were potentially at greater risk. The Army, the Navy (which supported the Marine Corps), and the Air Force each had specially trained and certified personnel (applicators) to apply pesticides. In addition to these certified applicators, the military assigned two groups of Army personnel to temporary duty as pesticide applicators during all or part of their deployment; field sanitation teams and military police. To reduce disease and non-battle injury, and to assist unit commanders in protecting their units’ health, the field sanitation teams provided individual Army units with limited PM capabilities. To prevent the outbreak of typhus, the military police conducted delousing operations in enemy prisoner of war camps using the insecticide lindane. Lindane was also authorized for use by the general military population to control body lice on an as needed basis.   Three other groups who were potentially over exposed included those in the general military population who were exposed to pest strips, those who were exposed to fly baits; and those who were exposed to pesticides during area spraying operations.

OSA prepared a peer-reviewed health risk assessment (HRA) as part of this investigation. The HRA’s purpose is to identify those military population who may have been at higher risk to pesticide exposure and to provide an estimate of the likelihood of certain specific effects from those exposures. Such effects would have been limited to the time of deployment, and may or may not have implications for long-term health effects.

The conduct of the HRA was hampered by the lack of quantitative data on the amount of pesticides used during the Gulf War, and the levels of pesticides present in the air and on surfaces to which US troops were exposed.  For example, during the Gulf War, military personnel may have used 37 different types of pesticide active ingredients, but the amounts used are undocumented. Because the military kept no records on what pesticides it dispensed, it was impossible for investigators to determine the total quantity of pesticides used in the Gulf. In addition, the non-specialized personnel who applied many of these pesticides were not adequately trained and monitored, raising concerns that they may have improperly applied the pesticides and thereby created unsafe conditions. In combination, the lack of information in a number of key areas regarding use and application has resulted in a fairly high level of uncertainty with respect to the results of the HRA.

As a result, the HRA relies on exposure scenarios to estimate the likelihood and magnitude of health effects. Exposure scenarios are based on commonly known application procedures and deployment-specific data (e.g., area spraying by certified applicators and enemy prisoner of war delousing by military police), however, the application rates and doses received by the applicators are unknown. Therefore some estimate of the range of exposure is required to complete the HRA. Since the HRA relies on many assumptions and varying levels of uncertainty, the risk estimates may indicate areas of potential concern for large groups (e.g., areas sprayers or field sanitation teams) but cannot be used with any certainty to predict the hazards and risks to individuals.

The results of the HRA alone do not prove either that overexposures occurred during deployment, or that any connection exists between pesticide exposures and chronic health effects months or years after exposure. The HRA contends, however, that some groups may have been exposed to concentrations of pesticides that exceeded conservatively derived risk-based levels of concern. Moreover, as a result of an overall lack of data with which to base a rigorous analysis, there is insufficient evidence to completely rule out possible long-term effects resulting from exposures to pesticides during the Gulf War.

This report is organized into three parts. Part A is the Environmental Exposure Report and contains information on the background issues associated with pesticide use during the Gulf War. Part A also includes a discussion of the health effects associated with exposure to pesticides and a non-technical summary of the health risk assessment. Part B is the complete health risk assessment, which is a highly technical report. Part C contains information used to support or expand the discussion of selected topics presented in Parts A and B, including a description of DoD guidance on the use, application, and management of pesticides; additional information on fly baits and delousing operations; procurement, storage, and distribution practices used in handling pesticides during the Gulf War; and benchmark toxicological data on selected pesticides.


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