through systematic investigation. Health-effects research typically uses the scientific method, which involves the formulation and testing of hypotheses and the collection of data through observation and experimentation. Results of research can lead to the initiation of surveillance and vice versa, but the two activities are not synonymous.
After the first Persian Gulf War in 1991, many veterans who had been deployed to that military theater complained of persistent respiratory symptoms. Multiple reports in the published literature have shown associations between deployment to the gulf region during the war and increases in various respiratory outcomes (Richards et al. 1993; Iowa Persian Gulf Study Group 1997; Proctor et al. 1998; Gray et al. 1999; Petruccelli et al. 1999; Gray et al. 2000; Lange et al. 2002; Kelsall et al. 2004). Because the ambient environment during and immediately after the 1991 Gulf War was characterized by high concentrations of particulate matter and other pollutants due to windblown dust and smoke from oil fires, exposure to PM has been suggested to be responsible for the reported increase in respiratory symptoms among veterans (Richards et al. 1993; Petruccelli et al. 1999; Cowan et al. 2002; Kelsall et al. 2004). The health risks of PM generated in the Gulf War may not be confined to veterans of the conflict. A risk assessment of civilian mortality in Saudi Arabia estimated that over 1,000 excess deaths during 1991-1992 could be attributed to increases in PM due to the war (White et al. 2008).
With the renewed U.S. military activity in the Middle East (Afghanistan and Iraq) over the last 9 years, deployed military personnel are again experiencing exposure to high concentrations of wind-blown dust. They are also exposed to other types of PM, including diesel-exhaust particles and smoke from open-pit burning that has been used at military bases to dispose of various waste materials. A cross-sectional survey of personnel deployed in the Middle East during 2003 and 2004 found that respiratory illness was the second-most common condition to result in short-term disability and hospitalization of deployed troops (Sanders et al. 2005).
Air pollution in the Middle East is characterized by episodes of resuspended windblown dust from desert regions, which increase particle concentrations to levels above the Military Exposure Guidelines (MEGs) many times each year. As noted above, high concentrations of both coarse particles (PM10-2.5) and fine particles (PM2.5) have been measured by the military during both the Afghanistan and Iraq conflicts. A recent study of PM in Kuwait also documented