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USE OF EXHALED BREATH CONDENSATE IN A HUMAN EXPOSURE STUDY
Citation:
SAWYER, K., J. D. PLEIL, AND M. C. MADDEN. USE OF EXHALED BREATH CONDENSATE IN A HUMAN EXPOSURE STUDY. Presented at International Congress of Toxicology XI Meeting, Montreal, QC, CANADA, July 15 - 19, 2007.
Description:
Exhaled breath condensate (EBC) is a noninvasive, repeatable collection technique to sample biomarkers of lung inflammation, oxidative stress, and environmental exposure. It is unclear whether EBC is an effective tool in human environmental exposure studies with multi-day sampling. To assess the variability of EBC, we evaluated EBC collection volume and protein concentration across six collection time points on 4 different days, and compared them with lung physiological parameters. Ten healthy volunteers (18-40 yr old) were exposed to clean air and diesel exhaust on 2 separate days (>3 or more weeks between exposures). EBC was collected for 15 min immediately pre, immediately post, and 20 hr-post exposure on both exposure days. Repeated measures ANOVA demonstrated no differences in EBC volume (mean coefficient of variation 19%) or total protein concentrations across the six collections, suggesting reproducibility of these 2 parameters over time for individual subjects. There were statistically significant correlations (p<0.05) between EBC volume and total volume of exhaled air (r=0.82), peak expiratory force (r=0.41), tidal volume (r=0.32), minute ventilation rate (r=0.61), and breathing frequency (r=0.42). There were significant negative correlations (p<0.05) between EBC volume and airway resistance (r=-0.47) and total protein concentration (r=-0.59). These data suggest EBC collection can be used to evaluate some lung parameters via consistent EBC collection volume and protein content for at least several weeks; consequently, potential changes in EBC biomarkers induced by environmental exposures are easier to identify. [Supported by NHEERL-DESE CT826513; This abstract may not represent official EPA policy.]