Short term association between air pollution (PM₁₀, NO₂ and O₃) and secondary spontaneous pneumothorax

Secondary spontaneous pneumothorax (SSP) occurs in the context of underlying pulmonary disease. Our objectives were to estimate the relationship between SSP and short term air pollution exposure with nitrogen dioxide (NO₂), ozone (O₃) and particulate matter with a diameter ≤ 10 μm (PM₁₀). Patients with SSP were included between June 1, 2009 and May 31, 2013, in 14 Emergency Departments in France. In this case-crossover design study, PM_10, NO₂, and O₃ data were collected hourly from monitoring stations. Quantitative values, fast increase in air pollutant concentration, and air quality threshold exceedance were retained. These assessments were calculated for each of the 4 days prior to the event (Lag 1-Lag 4) for all case and control period, and for the entire exposure period. A total of 135 patients with SSP were included, with a mean age of 55.56 (SD 18.54) years. For short term exposure of PM₁₀, NO₂ and O₃, no differences were observed between case and control periods in terms of quantitative values of air pollutant exposure (P > 0.68), fast increase in concentration (P > 0.12) or air quality threshold exceedance (P > 0.68). An association between O₃ exposures cannot be ruled out, especially when considering the Lag 2 prior to the event and in warm seasons.