Air pollutants and atmospheric pressure increased risk of ED visit for spontaneous pneumothorax

Objective: To investigate the impact of short-term exposure to air pollutants and meteorological variation on ED visits for primary spontaneous pneumothorax (PSP). Material and methods: We retrospectively identified PSP cases that presented at the ED of our tertiary center between January 2015 and September 2016. We classified the days into three types: no PSP day (0 case/day), sporadic days (1–2 cases/day), and cluster days (PSP, ≥3 cases/day). Association between the daily incidence of PSP with air pollutants and meteorological data were determined using Poisson generalized-linear-model to calculate incidence rate ratio (IRRs) and the use of time-series (lag-1 [the cumulative air pollution level on the previous day of PSP], lag-2 [two days ago], and lag-3 [three days ago]). Results: Using multivariate logistic regression analysis, O₃ (p = 0.010), NO₂ (p = 0.047), particulate matters (PM)₁₀ (p = 0.021), and PM_2.5 (p = 0.008) were significant factors of PSP occurrence. When the concentration of O₃, NO₂, PM₁₀, and PM_2.5 were increased, PSP IRRs increased approximately 15, 16, 3, and 5-fold, respectively. With the time-series analyses, atmospheric pressure in lag-3 was significantly lower and in lag-2, was significantly higher in PSP days compared with no PSP days. Among air pollutant concentrations, O₃ in lag-1 (p = 0.017) and lag-2 (p = 0.038), NO₂ in lag-1 (p = 0.015) and lag-2 (p = 0.009), PM₁₀ in lag-1 (p = 0.012), and PM_2.5 in lag-1 (p = 0.021) and lag-2 (p = 0.032) were significantly different between no PSP and PSP days. Conclusion: Increased concentrations of air pollutants and abrupt change in atmospheric pressure were significantly associated with increased IRR of PSP.