Controlled Diesel Exhaust Exposure Induces a Concentration-dependent Increase in Airway Inflammation: A Clinical Trial

• DOI: 10.1513/annalsats.202209-762oc
• Publication Date: 2023-03-17T18:54:10Z
• Authors: Juma Orach; Christopher Franc...; Agnes Che Yan Yuen; Carley Schwartz; Neeloffer Mookherjee; Christopher Carlsten
• Keywords: Methacholine; Crossover study

Rationale: Air pollution exposure is harmful to human airways, and its impacts are best studied using concentration–response relationships. However, most research on airway health has investigated chronic exposures, with less being known about acute effects, which can be robustly controlled exposures. Objectives: To investigate the concentration relationship between measures diesel exhaust (DE). Methods: We conducted a double-blind crossover study 17 healthy nonsmokers exposed filtered air DE standardized 20, 50, 150 μg/m3 of particulate matter ⩽2.5 μm in aerodynamic diameter for 4 hours. Before, during, up 24 hours from start, we measured lung function, responsiveness, inflammation spirometry, methacholine challenge, fractional exhaled nitric oxide (FeNO), respectively. In addition, nasal differential cell counts cytokines lavage epithelial lining fluid at assessed responses associations outcomes linear mixed effects models repeated correlations, respectively, thereafter adjusting multiple comparisons. Results: increased percentage ΔFeNO (β = 0.16 ± 0.06). Compared air, trended toward an increase concentrations 20 18.66 8.76) 50 19.33 8.92) significantly 34.43 8.92). induced trend IL-6 (percentage difference, 0.88; 95% confidence interval, 0.08, 1.70). There were no FeNO hours, or counts. Conclusions: induces concentration-dependent FeNO, indicating that it may sensitive marker inflammatory response airways. report below those previous studies, document estimates levels routinely experienced community occupational settings. Clinical trial registered www.clinicaltrials.gov (NCT 03234790).