Characterization of a portable method for the collection of exhaled breath condensate and subsequent analysis of metal content.
Fox-JR; Spannhake-EW; Macri-KK; Torrey-CM; Mihalic-JN; Eftim-SE; Lees-PSJ; Geyh-AS
Environ Sci Process Impacts 2013 Apr; 15(4):721-729
Using exhaled breath condensate (EBC) as a biological media for analysis of biomarkers of exposure may facilitate the understanding of inhalation exposures. In this study, we present method validation for the collection of EBC and analysis of metals in EBC. The collection method was designed for use in a small scale longitudinal study with the goal of improving reproducibility while maintaining economic feasibility. We incorporated the use of an Rtube with additional components as an assembly, and trained subjects to breathe into the apparatus. EBC was collected from 8 healthy adult subjects with no known elevated exposures to Mn, Cr, Ni, and Cd repeatedly (10 times) within 7 days and analyzed for these metals via ICP-MS. Method detection limits were obtained by mimicking the process of EBC collection with ultrapure water, and resulted in 46-62% of samples falling in a range less than the method detection limit. EBC metal concentrations were found to be statistically significantly associated (p < 0.05) with room temperature and relative humidity during collection, as well as with the gender of the subject. The geometric mean EBC metal concentrations in our unexposed subjects were 0.57 µg Mn per L, 0.25 µg Cr per L, 0.87 µg Ni per L, and 0.14 µg Cd per L. The overall standard deviation was greater than the mean estimate, and the major source in EBC metals concentrations was due to fluctuations in subjects' measurements over time rather than to the differences between separate subjects. These results suggest that measurement and control of EBC collection and analytical parameters are critical to the interpretation of EBC metals measurements. In particular, rigorous estimation of method detection limits of metals in EBC provides a more thorough evaluation of accuracy.
Inhalation-studies; Breathing; Biomarkers; Metal-compounds; Heavy-metals; Respiration; Manganese-compounds; Nickel-compounds; Cadmium-compounds; Chromium-compounds; Biological-agents; Exposure-assessment; Analytical-processes; Analytical-methods; Humans; Exposure-limits; Equipment-design
Julie R. Fox, University of Washington, Department of Environmental & Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE Suite 100, Box 354695, Seattle, WA 98105, USA
7439-96-5; 7440-02-0; 7440-43-9; 7440-47-3
Environmental Science: Processes & Impacts
Johns Hopkins University