Exposure to air pollution has molecular and physiologic effects on the lung that may increase the risk of Acute Respiratory Distress Syndrome (ARDS) after injury.Objective:
To determine the association of short and long-term air pollutant exposures and ARDS risk after severe trauma.Methods:
We analyzed data from a prospective cohort of 996 critically ill patients presenting with acute trauma and an injury severity score >15. Exposures to ozone, nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and particulate matter <2.5 μm (PM2.5) were assessed by weighted averages of daily levels from all monitors within 50 km of the geocoded location of a patient's residence. Patients were followed for 6 days for the development of ARDS according to Berlin Criteria. The association between each exposure and ARDS was determined via multivariable logistic regression adjusting for potential confounders.Measurements and Main Results:
ARDS developed in 243 (24%) patients. None of the short-term exposures averaged over the 3 days prior to presentation were associated with ARDS, except SO2, which demonstrated a non-linear association. NO2, SO2, and PM2.5 exposure over the 6-weeks prior to presentation were significantly associated with ARDS (p<0.05). All long-term exposures (3-years) were associated with ARDS (p<0.01) in adjusted models, despite exposure levels largely below United States and European Union air quality standards.Conclusions:
Long-term low to moderate-level air pollutant exposure is associated with a greater risk of developing ARDS after severe trauma, and represents a novel and potentially modifiable environmental risk factor for ARDS.