Reilly JP, et al. Low to Moderate Air Pollutant Exposure and Acute Respiratory Distress Syndrome after Severe Trauma. Am J Respir Crit Care Med. 2018 Aug 1. [Epub ahead of print]

RATIONALE: 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 aftersevere trauma.

METHODS: We analyzed data from a prospective cohort of 996 critically ill patients presenting with acute traumaand 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.