Background: Non-allergic rhinitis (NAR) is one of the most prevalent sinonasal inflammatory processes, yet its etiology remains unclear. The fine particulate matter (PM2.5) component of air pollution may contribute to the development of NAR, but has not been well studied. Our objective was to investigate the association between NAR and PM2.5 exposure.
Methods: Under IRB approval, adult patients with newly diagnosed NAR by rhinologists across a single health system were identified. Data from 191 patients with NAR, without comorbid allergy testing or chronic rhinosinusitis (CRS), were compared to 764 age and gender-matched, healthy controls without rhinitis or CRS (1:4 Ratio of Cases to Controls). Cumulative PM2.5 exposure was estimated by a novel technique incorporating patients’ residential zip codes into a deep learning neural networks model and conditional logistic regression was performed.
Results: Exposure levels to PM2.5 were significantly higher in patients with NAR as compared to healthy controls at all measured time points at 1, 2, 3, and 5 years preceding diagnosis. An increased odds of developing NAR was associated with a 5 µg/m3 increase of PM2.5 concentrations over all measured time points prior to diagnosis: one year (aOR=1.99,95% CI:1.12-3.54), two years (aOR=2.16,95% CI:1.23-3.80), three years (aOR=2.18, 95% CI:1.27-3.76), and five years (aOR=2.47, 95% CI:1.42-4.29).
Conclusions: This powered case-control study is one of the first to demonstrate that long-term exposure to PM2.5 is associated with increased odds of developing NAR. Ambient PM2.5 represents a potentially ubiquitous and modifiable risk factor for NAR and warrants further prospective studies to determine potential mechanisms.