GIS/EM4 Using Modeled Data and Geographic Informations System (GIS) Technology for the Investigation of Gulf War Veterans' Environmental Exposures and Illnesses

Using Modeled Data and Geographic Informations System (GIS) Technology for the Investigation of Gulf War Veterans' Environmental Exposures and Illnesses

GIS/EM4 No. 171

Jack M. Heller, Ph.D.
Warren J. Wortman
J. Christopher Weir

Abstract

The United States Army Center for Health Promotion and Preventive Medicine (USACHPPM), with the United States Naval Health Research Center (NHRC) and Uniformed Services University of the Health Sciences, compared possible associations between exposure to oil well smoke from Kuwaiti Oil field fires and increased risk of hospitalization among veterans of the Persian Gulf War. This study required the integration of many technologies including air modeling, health risk assessments, remote sensing and GIS. The following chronological outline gives an overview of the project from 1991 to the present.

Following Operation Desert Storm (ODS) the USACHPPM was assigned the task of assessing troop exposures to emissions from burning oil wells. To assess the environment, and subsequent risk to troops caused by the oil fires, approximately 4,000 environmental samples were collected at 10 major troop locations throughout Kuwait and Saudi Arabia. The exposure data were then used to support a health risk assessment (HRA) that indicated only a small potential for adverse health effects in the exposed population. However, following the conflict, troops began experiencing health problems upon their return to the United States. This situation prompted the Congress to pass two laws that required the Department of Defense (DOD) and the Department of Veterans Affairs to set up a registry of all Desert Storm veterans. The registry was to be used, among other things, to determine the oil fire smoke exposure of all ODS veterans. To accomplish this mandate, the United States Armed Services Center for Unit Research Records (CURR) was given the mission of determining troop locations on a daily basis and the USACHPPM was assigned the task of determining daily troop exposures to oil fire emissions. Because the USACHPPM’s environmental sample data only covered a limited geographic area and time period, modeled exposure data were required. The USACHPPM enlisted the aid of the National Oceanic and Atmospheric Administration (NOAA) Air Resources Laboratory to assist in the modeling effort. The USACHPPM used the output from the NOAA model, in conjunction with satellite images, to determine where the oil fire plume impacted troops on a daily basis and at what levels. The exposure data is based on a published, validated model. Additional strengths come from the use of satellite image data, ground based sampling results, plume transect flights, crude oil composition data, and oil fire extinguishments chronology and emission rates used as model inputs. The CURR was at the same time constructing the troop unit movement database from all existing records that could be located following the war. This effort continues to this day to improve and complete the database as new records are located and individuals are interviewed who have knowledge of troop locations. The USACHPPM selected geographic information system (GIS) technology to integrate the massive amount of data required to support this effort. The GIS can integrate daily troop location data, oil fire plume data, and satellite images to calculate an individual service member’s daily exposure and resultant potential health risks using standard USEPA exposure and toxicity factors. The exposure data is used to support an epidemiological investigation by comparing exposed and non-exposed populations and studying hospitalization history.

Keywords

Gulf War, Oil Well Smoke, Epidemiology, Database, Exposures

Introduction

The exposure of United States Department of Defense (DOD) and Allied personnel to more than 700 burning and gushing oil wells during the conflict in the Persian Gulf region raised concerns about potential health effects. These concerns and the Congressional mandate of Public Laws 102-190 (oil fires exposure registry) and 102-585 (Veterans’ health status) prompted this investigation of Gulf War veterans’ environmental exposures. The effort to measure exposures uses GIS as the mechanism to incorporate data from environmental samples, daily troop locations, personnel demographic data, air dispersion models and satellite images.

Problem statement

The Army Surgeon General tasked the United States Army Center for Health Promotion and Preventive Medicine (USACHPPM) to measure the exposure and assess the potential for adverse health effects from the Kuwait oil well fires. In addition, the United States Congress enacted laws requiring the characterization of every individual United States Gulf War veteran’s exposure to oil fire smoke, showing both duration and intensity.

The challenges of the USACHPPM to measure each veteran’s daily exposure and risk were many. Nearly 700,000 mobile U.S. troops occupied an extensive region -- approximately 880,000 square miles within Kuwait, Saudi Arabia, and Iraq. Daily troop locations were not consistently documented, nor were those existing records readily available. Also, the USACHPPM environmental samples had several limitations for this application. First, USACHPPM used only 10 static sampling locations, although troops moved throughout the region. Second, the sampling period had a three-month gap. Samples were collected starting in May, yet the oil well fires began in February. Third, the 4,000 environmental and industrial hygiene samples did not distinguish between compounds originating from the oil fires and those originating from other sources.

Background

In the summer of 1990, Iraqi forces invaded and occupied the country of Kuwait. In response to that invasion, United States forces began deploying to the region in August of that same year. After opportunities for a peaceful agreement had failed, the United Nations began an aerial assault on Iraq in January 1991. Iraq, in an unconventional and desperate act of war, began setting fire to Kuwait oil wells beginning on 3 February 1991. By the end of February 1991, there were a total of 605 oil wells on fire and 46 gushing oil. These fires continued to generate enormous environmental hazards until November 1991 (See Figure 1). The conflict ended after the five-day ground war of 24 - 28 February when the United Nations forces drove the Iraqi army out of Kuwait.

Figure 1. Oil Fire Chronology. (USACHPPM).

The concern with potential long-term health effects to DOD military and civilian personnel from the Kuwaiti oil well fires prompted the DOD to initiate an investigation. As part of the effort, a team from the USACHPPM, formerly the United States Army Environmental Hygiene Agency (USAEHA), was dispatched on 1 May 1991 to collect samples and monitor the health effects in Southwest Asia. Permanent ambient air monitoring stations were established at four locations in Saudi Arabia and six locations in Kuwait. Approximately 4,000 environmental and industrial hygiene samples were collected at these locations. With 558 oil wells on fire, the environmental monitoring effort by the USACHPPM began on 5 May 1991 and continued until 3 December 1991. Although the fires were all extinguished by approximately 6 November 1991, monitoring continued until 3 December 1991 to obtain one month of background data. The background data would assist the USACHPPM in identifying the contaminants that exist naturally in the environment and those that are from the oil well fire smoke. The exposure data was then used to support a typical United States Environmental Protection Agency (USEPA) “Superfund” health risk assessment (HRA). However, following the conflict in the Persian Gulf, troops began experiencing health problems upon their return to the United States. This situation prompted the Congress to pass two laws, PL102-190 and PL102-585, requiring the DOD to set up a registry of all Desert Storm veterans. The registry was to be used to determine the oil fire smoke exposure of all Operation Desert Storm (ODS) veterans and to also conduct scientific research.

To comply with the public laws, additional data concerning the locations of the deployed personnel and their respective duration in the theater of operations was To comply with the public laws, additional data concerning the locations of the deployed personnel and their respective duration in the theater of operations was needed. The United States Armed Services Center for Unit Records Research (CURR) was tasked to develop a database that contained daily troop unit geographic locations for the theater of operations. For the troop unit movement database, the CURR gathered all the unit history data archives, such as log reports, after action reports, and other pertinent information. This amounted to over 5 million pieces of paper from which 800,000-unit grid coordinates were created. With the CURR troop unit movement database, the USACHPPM is capable of locating daily company level unit identification code (UIC) locations. Typically, 75 to 150 personnel belong to a company. The USACHPPM also obtained a copy of the Defense Manpower Data Center (DMDC) Desert Shield/Desert Storm Personnel File. This data provides the USACHPPM dates when each deployed person entered and exited the theater of operations and their unit of assignment.

To augment the fixed location sampling, air modeling was conducted in conjunction with National Oceanic and Atmospheric Administration’s Air Resources Laboratory (NOAA/ARL), to predict pollutant concentrations at locations and times when no sampling was being conducted. Moreover, because the sampling data contained contaminants from the surrounding industry as well as those naturally occurring in the environment, the air modeling would provide exposure data only from the emissions of the burning oil wells. The combined set of modeled and sampled exposure data would then be applied temporally and spatially to the approximately 700,000 deployed personnel.

The USACHPPM elected to develop a GIS for calculating exposure and risk for each veteran. This GIS, know as the Troop Exposure Assessment Model (TEAM) uses the environmental sampling data, CURR troop locations, DMDC personnel data, NOAA air dispersion models and NOAA satellite images of the oil well fires.

Approach

The development and organization of the TEAM was first tested with a pilot project. The pilot project administers and analyzes the data is the same manner as the TEAM and upon successful testing, leaves a template available to complete the mandated exposure assessments for every veteran. To limit the time needed to setup and analyze the data, only a small subset is used to proof the process. Specifically, the dates selected for use in the pilot project were 19 – 24 May 1991. The pilot project also enables the USACHPPM to evaluate the hardware and software chosen for the TEAM. Operating on a UNIX based platform, Intergraph Corporation’s Modular GIS Environment (MGE) and Informix relational database management system software were the two primary software packages used. After the pilot project proved successful, the development of the TEAM began by transferring the data to an Oracle relational database management system on a Microsoft Windows NT platform. The MGE software was still maintained as the primary GIS media. Several custom programs to calculate exposure and health risks were also converted and enhanced for the NT platform.

Six primary data sets were gathered and loaded for use in the pilot project and subsequently the TEAM. The data sets are spatially and temporally associated to derive daily exposure estimates of the troop units in theater. The first set of data is the sampled concentration data gathered from the ten sites in Kuwait and Saudi Arabia. Again, these sites sampled ambient air and soil media during 5 May - 3 December 1991 and represented primary troop staging locations. The second data set is the model simulations of the fire emissions generated by the NOAA/ARL. The model output is used to determine the location, extent and concentration of the oil fire smoke. The output also supplements the sampling data, since the sampling effort missed the first three months of the fires. The third set of data is the satellite images of the oil fires combined smoke plumes (i.e., super plumes), obtained from the National Center for Atmospheric Research. The images were captured using the NOAA Advanced Very High Resolution Radiometer (AVHRR) and were used to supplement and validate the spatial aspect of the NOAA/ARL model results. The fourth set of data is the troop unit locations provided by the CURR. The data provides the daily locations of company sized units in theater. The fifth set of data is the personnel data from the DMDC. It provides the veteran’s unit during their time in theater as well as the dates they entered and exited the theater. The final data are the toxicity values used to evaluate the health of the oil well fire exposures. This information was obtained from standard USEPA data sources.

Methods

To administer and apply the sampled and modeled data for potential health risks to approximately 700,000 personnel, across approximately 880,000 square miles, the USACHPPM employed the use of GIS technology. GIS technology provides the capability of analyzing and displaying large quantities of spatially and temporally referenced environmental/exposure, health outcome, demographic, and troop location data.

In augmenting the fixed location, 1991 air sampling data, the USACHPPM contracted with the NOAA/ARL to predict daily pollutant concentrations at geographic locations impacted by the oil well fires. The NOAA/ARL had been involved since 1991 with the Department of Commerce Arabian Gulf Program Office in an international effort to determine the atmospheric effects of the Kuwait oil well fires. The original NOAA/ARL model simulations of the Kuwait oil fires, conducted for the USACHPPM in 1993, used data from the NOAA/National Center for Environmental Predictions (NCEP) Medium Range Forecast (MRF) global spectral model. These simulations include archive fields that defined meteorological transport winds and boundary layer turbulence parameters (USEHA 1991, Draxler et. al. 1994, McQueen and Draxler 1994). The meteorological fields were then used in the NOAA/ARL Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) dispersion model to derive daily super plume boundaries from the Kuwait oil fires for 2 February – 31 October 91 (Draxler and Hess 1997). The USACHPPM consulted with the NOAA/ARL in 1996 to reproduce the daily, modeled derived super plume boundaries for 2 February – 15 May 1991 using the high-resolution reanalysis meteorological fields from the European Center for Medium-Range Weather Forecasting (ECMWF) (ECMWF 1995). This effort was undertaken to improve the model results for this time period. The USACHPPM coordinated with NOAA/ARL to provide 24-hour predicted unit emission concentration values on a 15- X 15- kilometer grid encompassing the Desert Storm Theater of Operations.

For each day the fires were burning, daily grid locations of the smoke were created with the MGE software. Each daily grid set was then used to digitize the outer most boundary of the smoke for that day (See Figure 2). Each modeled grid point contains data regarding the composition of the oil well fire smoke. HYSPLIT predicts the concentrations and composition of each grid point by factoring in the oil fire’s extinguishment rate, emission rates, plume transects and ground data.

Figure 2. Oil Fire Super Plume Boundary Modeled Data. (USACHPPM).

Similarly, the satellite images were geo-referenced to the theater of operations and the outer-most boundary of the satellite super plume boundary was also manually digitized (See Figure 3).

Figure 3. Oil Fire Super Plume Boundary Satellite Data. (USACHPPM).

Then, the MGE software merges the modeled and satellite boundaries together creating the outer-most union of the two boundaries. The software then adds a fifteen-kilometer buffer around the merged boundary to help compensate for any user digitizing errors and to have a more conservative estimate of the super plume on each day (See Figure 4).

Figure 4. Oil Fire Super Plume Boundary Merged Data. (USACHPPM).

Once a daily boundary is created then, the troop unit locations provided by CURR are placed at their geo-locations within the theater to determine if they are within the super plume boundary. Units within a daily super plume boundary are run through a custom program generating exposure levels. A unit’s associated exposure level is determined from the closet modeled grid point on that day. Each grid point contains the concentrations of the smoke compounds at the breathing zone (2 meter height). These compounds and concentrations are used to derive associated health risk factors. This routine continues for the unit’s entire duration in the theater. The program is complete when every unit in theater has been evaluated to see if it is within the super plume boundary and those that are, have a daily health risk factor assigned.

Another program assigns risk levels to individual personnel. The program assigns risk to a veteran based upon his/her corresponding UIC’s risk. The program factors in the veteran’s theater entrance and exit dates. For example, if a unit operated in the theater from January – June 1991 but the veteran was in theater during February – May 1991, then the person’s risk is generated only for his/her tenure in theater.

Findings and Discussion

The original NOAA/ARL model simulations of the Kuwait oil fires, conducted for the USACHPPM/USAEHA in 1993, used data from the NCEP/MRF global spectral model. The daily-modeled superplume boundaries derived from these meteorological fields for the Kuwait oil fires (2 February – 31 October 91) did not produce results consistent with satellite images for certain time periods. The USACHPPM consulted with the NOAA/ARL in 1996 to reproduce the daily, modeled derived superplume boundaries for this inconsistent time period (2 February – 15 May 1991) using the high-resolution reanalysis meteorological fields from the ECMWF (ECMWF 1995). This effort greatly improved the model results for this time period and there was good agreement between model and satellite superplume boundaries for the entire oil fire model time period. Individual troop exposures could then be accurately determined on a daily basis to modeled concentrations (oil fire emissions) based on geographic location. The GIS could then calculate risk levels based on exposure to oil fires. This operation is accomplished for each day of exposure and the risk summed for all days of exposure.

Modeled exposure point concentrations (chemical and particulate) were small when compared to sampled data, which represented exposures from all sources, not just oil fire emissions. To help validate the model predictions and determine the particulate contributions originating from sand (silicon/calcium-rich particles) versus the oil fires (elemental carbon/soot and carbon chain agglomerates), a study analyzing sand, industrial hygiene, and PM10 (particulate matter < 10 microns) air samples was conducted (USAEHA 1991). Methods used included electron microscopy (computer controlled scanning and transmission), thermal/optical analysis, and standard heavy metal analytical techniques (inductively coupled plasma spectroscopy, atomic absorption, and ion chromatography). Results of this work indicated that soot (elemental carbon) and carbon chain agglomerates from the oil fire plumes were, in general, only a minor component of the PM10 sample mass. Data indicated that sand-based particles accounted for the majority of the particle mass on most samples.

Another study that helped validate the accuracy of the predicted model results was the Association Between Asthma and Modeled Exposure to Oil Fire Smoke. A case-controlled epidemiological study was conducted of Comprehensive Clinical Evaluation Program (CCEP is the DOD Gulf War Health Registry) participants, using GIS technology, to determine if there was an association between asthma diagnosis and modeled exposure to oil fire smoke (Cowan et. al. 1998). Statistically significant associations were found between model oil fire exposures (intensity and duration) and asthma, although additional study is required before this association can be considered to be etiologic. Additional epidemiological studies assessing modeled oil fire exposure and adverse health outcomes in Gulf War veterans are currently underway to further assess the validity of the modeled exposure and risk data.

One of the difficulties in trying to determine modeled oil fire exposure levels of individual service members is good troop unit location data. Although extensive efforts have gone into the development of the Troop Movement Database by the U.S. Joint Services Center for Research of Unit Records, the database resolution is only at the company level. To identify individuals the Defense Manpower Data Center’s Desert Shield/Desert Storm personnel file must be queried to determine individuals’ troop units. Some issues that may make individual versus site exposure evaluations difficult are; multiple troop unit locations per day, where it can’t be determined to which part of the unit the individual is attached, individuals who may temporarily not be with their unit, and missing unit location data, either for certain days or no data at all is available for the unit. This situation also makes epidemiological investigations of environmental exposures more difficult. Figure 8 demonstrates the available troop location data for a particular investigation of oil fire exposure for regular army troops.

During the eight years since the end of the Gulf War, some veterans of Operations Desert Shield and Desert Storm reported a diversity of non-specific, physical (somatic) symptoms. The most commonly reported symptoms have been fatigue, headaches, joint pains, skin rash, shortness of breath, sleep disturbances, difficulty concentrating, and forgetfulness (DeFraites et. al. 1992, Milner et. al. 1994, PGVCB 1995).

In addition to non-specific symptoms, there have been reports of possible increased rates of various medical and psychological illnesses among Gulf War veterans (PGVCB 1995). For medical conditions, attention has focused on neurological diseases like amyotrophic lateral sclerosis (ALS), various benign and malignant cancers, connective tissue diseases, and immunologic abnormalities (Knoke et. al. 1998, Hanchette and Brewer 1998). There also has been concern about possible increased rates of birth defects among children born after the war to both male and female Gulf War veterans (Penman et. al. 1996).

Diverse factors related to the Gulf War experience have been postulated as causes of chronic symptoms and other health problems (PGVCB 1995, Joseph et. al. 1998). Potential health hazards include: biological warfare, chemical warfare, pesticides and insect repellents, pyridostigmine bromide, oil well fire smoke, anthrax and botulinum vaccinations, infectious diseases, depleted uranium, psychological stress, sand, other types of exposures, and combinations of exposures.

The exposures U.S. Troops received from oil fire emissions was one of the most completely characterized of all the possible exposures they encountered in the Persian Gulf. There is however, still continuing controversy over the impact this exposure, and others, had on veteran’s health since their return from the Gulf.

Conclusion

Current available data supports the conclusion that the oil well fires did not have a significant impact on the overall environmental exposures most U.S. Forces received in the Persian Gulf during Operation Desert Storm. However, there were time periods and localized areas where significant ground level plume impacts occurred. The AEHA/USACHPPM studies and the monitoring activities other groups conducted immediately after hostilities ceased substantiate this fact (WMO 1992, USEPA 1991, AirParif 1991, USGAO 1992). These facts not withstanding, the most significant environmental exposure U.S. Forces received was from particulate matter, predominantly from wind-blown sand, although the oil fire smoke did contribute to this at certain times and locations. Specific conclusions that can be drawn from our current work efforts include:

The USACHPPM GIS is capable of modeling individual troop exposures to oil fire smoke and determining the length and intensity of exposure and the health risk.
Modeled and satellite oil fire smoke plumes are generally in good agreement with respect to direction, size, and intensity.
Sample and modeled exposure levels are generally in good agreement based on actual sampling data from several researchers and other scientific studies.
The first epidemiological study assessing modeled oil fire particulate exposure and incidence of asthma among participants in the DOD clinical Gulf War registry correlates well.

Recommendations for future research

Future research in the area of oil fire exposure effects should concentrate on the impact of the particulate component from the oil fires and include sand base contributions. Also, based on sampling results, less emphasis should be placed on the chemical component of oil fire exposure. Therefore, research emphasis should target the most biologically plausible areas of particulate impact -- pulmonary effects. Specific areas of research should include:

Modifying the HYSPLIT model to determine sand based particulate exposures of Gulf War veterans.
Continuing epidemiological studies to investigate the relationship between particulate exposure in the Persian Gulf and respiratory or other plausible health events.
Continuing database updates and improvements as new or improved data becomes available.

One of the key components in determining a service member’s exposure is individual troop location data. This proved to be a source of uncertainty in determining exposure values for Gulf War veterans and it remains a problem today in assessing the exposures of troops in Bosnia and Kosovo. DOD must improve its method of tracking individual troop locations in order to more acurately determine their deployment exposures and the potential for adverse health outcomes.

References used

AirParif, “Main Results of The French Air Pollution Monitoring”, 1991.

Cowan, D. N., Lange, J., Heller, J., Kirkpatrick, J., Howard, J., Weir, C., and Wortman, W. Using Geographic Information System (GIS) Technology to Evaluate Asthma and Exposure to Oil Fire Smoke Among Gulf War (GW) Veterans, AEP, Vol. 8, No. 7: 445-478, October 1998.

DeFraites RF, Wanat ER, Norwood AE, Williams S, Cowan D, Callahan T. Report, Investigation of a suspected outbreak of an unknown disease among veterans of Operation Desert Shield/Storm, 123d Army Reserve Command, Fort Benjamin Harrison, Indiana, April, 1992. Epidemiology Consultant Service (EPICON), Division of Preventive Medicine, Walter Reed Army Institute of Research, Washington, DC 20307; June 15, 1992.

Draxler, R.R. and Hess, G.D., “Description of the HYSPLIT_4 Modeling System,” NOAA Technical Memorandum ERL ARL-224, Air Resources Laboratory, Silver Spring, Maryland, December 1997.

Draxler, R.R., McQueen, J.T., and Stunder, B.J.B., “An Evaluation of Air Pollutant Exposures Due to the 1991 Kuwait Oil Fires Using a Lagrangian Model,” Atmospheric Environment, Vol. 28, No. 13, pp. 2197-2210, 1994.

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Authors

Jack M. Heller, Ph.D., Senior Scientist, United States Army Center for Health Promotion and Preventive Medicine,
Deployment Environmental Exposure Program
MCHB-TS-EES, Bldg E-1675, APG-EA, Maryland 21010-5403 USA.
Email:jack.heller@apg.amedd.army.mil, Tel: +1-401-436-5243, Fax: +1-401-436-2407.

Warren J. Wortman, Research Environmental Geographer, Henry M. Jackson Foundation
USACHPPM, MCHB-TS-EES, Bldg E-1675, APG-EA, Maryland 21010-5403 USA.
Email:warren.wortman@apg.amedd.army.mil, Tel: +1-401-436-2475, Fax: +1-401-436-2407.

J. Christopher Weir Research Environmental Geographer, Henry M. Jackson Foundation
USACHPPM, MCHB-TS-EES, Bldg E-1675, APG-EA, Maryland 21010-5403 USA.
Email:chris.weir@apg.amedd.army.mil, Tel: +1-401-436-7712, Fax: +1-401-436-2407