Sickness response symptoms among healthy volunteers after controlled exposures to diesel exhaust and XXXX .

@entity14469 @entity2704 @entity701 @entity544 @entity1642
BACKGROUND: Interactions between acute exposures to environmental chemical contaminants and @entity1642 may be important in situations where they are likely to co-occur, ranging in intensity from daily urban living to participation in war. Modification of symptomatic responses by stress may play a role in medically unexplained symptoms attributed to low-level chemical exposures. OBJECTIVES: We hypothesized that the combination of exposure to diesel exhaust (DE) and @entity14469 would cause @entity2704 responses in healthy volunteers. Moreover, these responses would be greater in individuals with self-reported prior chemical odor intolerance. METHODS: One hundred adult subjects underwent 1-hr exposures to diluted DE and clean air control. Half of the subjects performed a public-speaking stressor task during the exposures. Subjects completed questionnaires to determine their Chemical Odor Intolerance Index score. Plasma @entity701 , end-tidal @entity544 , and the severity of 35 symptoms were measured at time points before and after the exposures. RESULTS: Subjects exposed to DE demonstrated small but statistically significant increases in severity for several symptom categories, including @entity2704 response and upper respiratory, central nervous system, and total symptoms. The psychological stressor did not increase symptom severity independently or via interaction with DE. Subjects with prior self-reported chemical intolerance had more severe @entity2704 response symptoms from DE. CONCLUSIONS: These results suggest that exposure to DE can cause acute @entity2704 response symptoms and that these symptoms are also associated with increased levels of self-reported chemical intolerance. The results did not confirm our hypothesis that an acute stressor would increase @entity2704 response symptom severity during the exposure.
