Personal air pollution exposure and metals in the nasal epithelial lining fluid of COPD patients

Abstract

Background: Sampling of the nasal epithelial lining fluid (NELF) is a potential method to assess exposure to air pollution within the respiratory tract among high risk populations. We investigated associations of short- and long-term particulate matter exposure (PM) and pollution-related metals in the nasal fluid of people with COPD. Methods: This study included 20 participants with moderate-to-severe COPD from a larger study who measured long-term personal exposure to PM2.5 using portable air monitors and short-term PM2.5 and black carbon using in-home samplers for the 7 days preceding nasal fluid collection. Nasal fluid was sampled from both nares by nasosorption, and inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentration of metals with major airborne sources. Correlations of selected elements (Fe, Ba, Ni, Pb, V, Zn, Cu) were determined within the nasal fluid. Associations between personal long-term PM2.5 and 7-day home PM2.5 and black carbon (BC) exposure and nasal fluid metal concentrations were determined by linear regression. Results: Within nasal fluid samples, concentrations of vanadium and nickel (r=0.8) and lead and zinc (r=0.7) were correlated. 7-day and long-term PM2.5 exposure were both associated with higher levels of copper, lead, and vanadium in the nasal fluid. BC exposure was associated with higher levels of nickel and vanadium in the nasal fluid. Conclusion: Levels of certain metals in the nasal fluid may serve as biomarkers of air pollution exposure in the upper respiratory tract.