deployed veterans than among 1588 nondeployed veterans. Self-reported physician diagnosis of respiratory diseases such as asthma, chronic bronchitis, and emphysema was also higher in deployed veterans but not significant except for chronic bronchitis (OR 1.9, 95% CI 1.2-3.1), and pulmonary function were similar between the two groups. Danish peacekeepers, both military and nonmilitary, deployed to the gulf after the end of the conflict were studied by Ishoy and colleagues (1999b). They found that that the respiratory symptom of shortness of breath were more common among 686 deployed personnel when compared to a 231 professionally matched group of nondeployed subjects (14% vs 3.5%, p < 0.001). However, no significant difference was found on pulmonary function testing (FVC, FEV1, peak flow) between the two groups.
Several primary studies examined the association between exposure to smoke from the Kuwaiti oil-well fires and respiratory outcomes. Cowan et al. (2002) conducted a case-control study examining the effect of exposure to oil-well fire smoke using exposure estimates based on troop locations and National Oceanographic and Atmospheric Administration (NOAA) modeling. They found that the risk of physician-diagnosed asthma increased with increasing exposure categories after controlling for sex, age, race, rank, smoking history, and self-reported exposure. They did not use pulmonary function tests and did not distinguish preexisting asthma from new onset asthma. A large population-based study of 1560 Iowa veterans found no association between modeled oil-well fire exposure and the risk of asthma or bronchitis as defined by interview questions about wheezing and chest tightness and cough (Lange et al., 2002). However, when the risk of asthma or bronchitis was compared to self-reports of exposure to oil-well fires a significant association was found with increasing self-reported exposure.
Smith and colleagues (2002) studied post war hospitalizations and estimates of exposure to oil-well fire smoke based on troop location and NOAA modeling. Among 405,142 active-duty veterans, no association was found between modeled exposures and hospitalizations for asthma or acute or chronic bronchitis. A modest but non significant increase in risk for hospitalizations for emphysema was associated with exposure (RR 1.36, 95% CI 0.62-2.98).
The Volume 4 committee reviewed numerous multiple secondary studies, most of which relied on self-reported respiratory symptoms. Most of the studies consistently found increased self-reports of respiratory symptoms and illness among Gulf Was veterans compared with nondeployed counterparts. This finding was true both for US studies (Eisen et al., 2005; Gray et al., 2002; Iowa Persian Gulf Study Group, 1997; Kang et al., 2000; Kroenke et al., 1998; Petruccelli et al., 1999; Steele, 2000) as well as studies of veterans from the United Kingdom (Cherry et al., 2001b; Nisenbaum et al., 2004; Simmons et al., 2004; Unwin et al., 1999), Denmark (Ishoy et al., 1999b), Australia (Kelsall et al., 2004b), and Canada (Goss Gilroy, 1998).
Secondary studies that focused on exposure to oil-well fires were relatively few. One found an increase in respiratory symptoms associated with self-reports of exposure to oil-well fire smoke (Proctor et al., 1998). A prospective study of British veterans deployed to Kuwait found no significant changes in FEF25%-75%3 across across a period of presumed oil-well fire smoke exposure; however, the exposure appears to have been low (Coombe and Drysdale, 1993). Two ecological studies of asthma hospitalizations among Kuwaiti residents found no significant difference after the conflict (Abul et al., 2001; Al-Khalaf, 1998).