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FINE PARTICLE MATTER ASSOCIATED WITH AIRWAY NEUTROPHILIA IN A SUBPOPULATION OF ADULT ASTHMATICS
Citation:
Yeatts, K. B., E. Svendsen, N. E. Alexis, R W. Williams, J Creason, W. Reed, S. Harder, P Bromberg, L Neas, R B. Devlin, AND D. B. Peden. FINE PARTICLE MATTER ASSOCIATED WITH AIRWAY NEUTROPHILIA IN A SUBPOPULATION OF ADULT ASTHMATICS. Presented at American Thoracic Society Annual Conference, San Diego, CA, March 20 - 25, 2005.
Description:
Asthmatic adults are a heterogeneous group that is sensitive to the mass concentration of ambient particulate matter (PM). However, it is not clear which components of PM are responsible for these effects, nor are the mechanisms understood. We evaluated whether increases in ambient coarse and fine PM are associated with increased markers of airway inflammation in asthmatic adults. Methods: Twelve atopic adults with mild to moderate persistent asthma living in a 30 mile radius of the clinic were followed over a six week period, each with nine clinic visits. Induced sputum samples were obtained at six of the nine clinic visits. Daily ambient coarse (PM 2.5-10) and fine (PM 2.5) PM were measured separately for each 24 hour period using a Rupprecht & Patashnick (R&P) Partisol Plus 2025D dichotomous air sampler. Sputum samples were analyzed for the percent and absolute number of eosinophils, macrophages, and neutrophils. Results: Preliminary analyses showed that for a subset of asthmatics (4 of the 12), PM 2.5 was strongly correlated with the neutrophil concentration in the induced sputum samples. (r3=.80, p=.05; r7=.828, p=.0415; r8=.77, p=.07; r10=.94, p=.004). The mean concentration for PM 2.5 was 12.4 ug/m3 (6-37 ug/m3), and PM 2.5-10 5.6 ug/m3 (0-15). No such relationship was seen for PM 2.5-10. Future multivariate analyses using mixed models will be conducted to evaluate if these associations hold when adjusted for potential confounders. Conclusion: These data provide a preliminary suggestion that exposure to ambient levels of fine PM induce an inflammatory airway response in a susceptible subpopulation of asthmatics. These effects were seen for PM 2.5 levels below the current NAAQS. These findings do not necessarily represent EPA policy. Funding: EPA Cooperative Agreement 829522, NHLBI R01HL62624