Figure 4.3 shows the time distribution of U.S. troops from August 1990 to August 1991, when most troops were re-deployed from the Gulf, together with the monthly mean PM 10 measured in 1991 and 1994. These results, together with the data in Figure 4.1, suggest that most of the exposures due to inhaled contaminants that had a potential for health risk were less likely to have come from the burning oil wells than to have come from the amount of very fine sand in the air. A significant number of Gulf War veterans were smokers. Smokers, even young smokers, may react differently than nonsmokers to inhaled pollutants regardless of exposure levels. Also, a percentage of the veterans may have had some underlying predisposition to pulmonary disease that might have been triggered by exposure to high levels of PM 10 .
Further research is needed on the health effects of exposure to multiple pollutants.