Beginning in January and continuing into February 1991, Iraq ignited or otherwise damaged more than 750 oil wells in Kuwait. This destruction released numerous pollutants into the atmosphere, some of which, in sufficient concentrations, could have endangered human health.
Several national and international organizations conducted air quality monitoring studies from March to December 1991 to characterize this threat. Generally, the contaminant concentrations observed during these monitoring programs were below US levels and fell within ambient and occupational air quality standards, the one exception being the levels of particulate matter (PM10) measured during this period. The average concentration for particulate matter was 354 m g/m3, more than twice the US EPA ambient air quality standard of 150 m g/m3.
The RAND Corporation reviewed the existing scientific literature on oil fires health effects. Based on animal and human exposure studies and epidemiological data, RAND and the USIAAT Team led by the US EPA concluded the concentrations of volatile organic hydrocarbons, polycyclic aromatic hydrocarbons, metals, and criteria pollutants (e.g., sulfur dioxide, nitrogen dioxide, ozone, and lead) were much lower than the levels currently known to cause short- or long-term health effects. Even under a very conservative exposure scenario that assumed all troops in the Kuwait theater of operations were exposed for an extended time to the concentrations observed, the cumulative contaminant dose, except for particulates (i.e., PM10), fell below the levels known to cause health effects.
The question about long-term health effects associated with PM10 is of primary interest. As noted above, PM10 levels were high, typically exceeding US EPA ambient standards. These levels were largely the result of natural and man-made regional sources, not solely the result of the oil fires. Furthermore, ambient standards are designed to protect all populations, including the sensitive (e.g., the sick, elderly, and children), from disease. Therefore, one could argue that the degree of protection these standards provided could be overstated for Gulf War veterans.
RAND cites the peer-reviewed literature as lacking epidemiological studies on health effects due to particulate matter exposures in the indigenous population as well as US troops. In an occupational setting, however, exposure to high levels of particulate matter for months to decades has resulted in several respiratory complaints, including silicosis. A determination of whether short-term PM10 exposure could have a long-term health impact on US troops is fundamental to this overall investigation and the subject of a recent OSAGWI report.
Some troops experienced short, intense exposures to oil fire fall-out and debris (e.g., various combustion solid by-products and unburned crude oil), sometimes called "oil rain," whose principal routes of exposure are the skin and lungs. Other than minor skin rashes, dermal problems associated with crude oil exposure do not appear to be a major concern. Self-reported symptoms from inhalation exposure include eye, nose, and throat irritations; and shortness of breath. Health screening, medical evaluations, and diagnoses are not available for those troops so exposed; however, physician directed health screening studies have been completed on firefighters deployed to Kuwait who experienced more severe, longer exposures. These studies indicate these firefighters generally are in good health and have not experienced any of the symptoms the troops have reported. Nevertheless, exposures to "oil rain" remain an issue of concern on which a future investigation will focus (see Section VIII).
Finally, USACHPPM has completed health risk assessments to estimate the potential for excess cancers and non-cancer diseases from oil fire smoke exposures. That is, estimates were made of the likelihood that exposed troops would experience the onset of disease, including cancers, due to their exposure to oil fires. An integral part of the overall methodology employed to assess possible adverse health effects, these assessments complement the health effects studys findings.
USACHPPM calculated risk levels for all US troops, ranked the risks from highest to lowest, and then compared them to US EPA-determined acceptable levels. The assessment results indicated that in all cases troop unit excess cancer and non-cancer disease risks were below their respective US EPA acceptable risk level ranges. However, these estimates, based as they were on a subset of the total number of contaminants of concern, likely were understated. If the risk is adjusted upward by 20% (assuming the current health risk assessment accounts for 80-90% of the risk) to account for the excluded contaminants, then the revised cancer risk may remain below the US EPA acceptable risk range and the non-cancer disease risks may increase to a point where it will be approximately equal to the USETA standard. Verifying this hypothesis will require additional research and analysis, developing toxicity factors for the contaminants USACHPPMs assessment did not include, and re-calculating the risk numbers.
VIII. AREAS REQUIRING ADDITIONAL RESEARCH
As noted previously, there are several areas of this investigation that could benefit from additional research and analysis that in turn would improve our understanding of the health issues associated with exposures to oil fire smoke. Three areas requiring additional emphasis include: 1) particulate matter exposures and related health effects; 2) health risks associated with dermal and inhalation exposures to "oil rain;" and 3) cancer and non-cancer disease health risks incorporating all contaminants of concern.
OSAGWI completed an investigation to determine whether a causal relationship exists between the exposures to particulates and long-term unexplained illnesses some Gulf War veterans report and released an interim report on the subject on "GulfLINK" in July 2000. The reports findings suggest reversible, short-term or acute effects attributable to high levels of particulates found in the KTO may have occurred, but do not support the likelihood these exposures lead to chronic or long-term illnesses.
In on-going research, USACHPPM is investigating "oil rain" exposures to compare those troop units and individuals potentially in the oil fields when damaged oil wells sprayed and gushed crude oil to another cohort of troops not exposed the "oil rain." USACHPPM will examine health records in DoDs hospitalization database and the Comprehensive Clinical Evaluation Program (CCEP) database to determine whether exposure to "oil rain" adversely affected the exposed troops health. Their report is expected in late 2000.
USACHPPM is also revising its risk assessments to reflect exposures to all oil well fire emissions. In this analysis USACHPPM will develop toxicity factors for the oil fire contaminants currently lacking them and revise the oil fire risk assessment to incorporate the new factors. This report also is expected in late 2000.
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