Some chemicals contained in oil-well fire smoke, such as benzene and PAHs, are human carcinogens. As described earlier in this chapter, the amounts of these pollutants in the air were low. Hence, their contribution to excess cancer risk would be expected to be small and increased rates of cancers likely would not result. The U.S. Army used EPA's standardized methodology to estimate cancer and noncancer risks from the oil-well fire smoke.265 It concluded "the potential for significant long-term adverse health effects for the exposed DOD troop or civilian employee populations is minimal." Risks from cancers were estimated not to exceed two excess cancers per one million people exposed, a value well within EPA's acceptable range.

Noncancer risks from smoke exposure were calculated as Hazard Indices (HI). When the HI exceeds 1.0, there can be concern about potential noncarcinogenic health effects. In Saudi Arabia, the HI ranged from 0.6 to 2.0, while in Kuwait it ranged from 2.0 to 5.0. Most of this noncancer risk was contributed by inhalation of VOCs, particularly benzene. The U.S. Army concluded that risk of noncarcinogenic health effects among the U.S. service members was low since HIs are based on EPA toxicity values that are set far below levels thought to cause health effects and that also account for sensitive subpopulations such as children and the elderly. A congressional Office of Technology Assessment analysis of the U.S. Army's risk assessment methods and findings concluded "the risks to health from exposure to the smoke and the background air contaminants in the Persian Gulf are likely to be extremely small."275

Oil-well fire smoke appears not to have caused observable changes in lung tissue. Researchers at the Armed Forces Institute of Pathology found no significant differences when they compared lung tissue from autopsies of 33 U.S. service members who died after the start of the oil well fires to lung tissue from autopsies of soldiers who died before the fires.164

Information has been gathered from 110 firefighters working for private companies in the Kuwaiti oil fields in 1991. Individuals were deployed for 28-day periods, working daily at the well heads without breathing-protection equipment. Most were over 30 years old and had 10 or more years experience fighting similar well fires, many of them in Kuwait and elsewhere in Southwest Asia. No cases of illnesses resembling those reported by Gulf War veterans were reported, nor have such complaints been observed among thousands of oil-well firefighters who have spent years experiencing similar exposures.60,61

Known immediate health effects from inhaling large amounts of smoke and particulates are primarily respiratory, including coughing, wheezing, increased airway resistance, and respiratory infections. Toxic gases that can be found in oil-well fire smoke-such as hydrogen sulfide and sulfur dioxide-can cause eye and nose irritation, decreased pulmonary function, and increased airway reactivity.312,315 Nevertheless, these toxic gases were not detected at high levels during the fires.89,289,302,339 High levels of airborne particulates, which sometimes occurred in the Gulf region, are associated with increased rates of asthma and can exacerbate other chronic respiratory conditions. With chronic (months or years) exposure to particulates, there is increased risk of some loss in lung function or chronic bronchitis, especially in cigarette smokers.

Based on research on human and animal health effects of exposure to air pollutants and on currently available exposure data, the Committee concludes it is unlikely exposure to oil-well fire smoke is responsible for symptoms reported today by Gulf War veterans. Although smoke from the oil-well fires did not include levels of carcinogens that would be expected to increasecancer rates among Gulf War participants, VA mortality studies will include cancer surveillance.