Persistent Respiratory Conditions among Coast Guard Responders to the Deepwater Horizon Oil Spill, Five Years of Follow-up

Abstract

Background: This year marks the 10th anniversary of the Deepwater Horizon oil spill. To date, little is understood about persistent respiratory conditions associated with oil spill response exposures. We conducted a longitudinal study of incident chronic respiratory conditions in a cohort of U.S. Coast Guard (USCG) responders enrolled in an equal access medical system.Methods: For all active-duty cohort members (N=45,193) we obtained medical encounter data, 10/01/2007-10/1/2015, representing ~2.5 years pre- and ~5.5 years post-spill. We queried incident respiratory conditions classified by International Classification of Diseases, 9th Edition. We used adjusted Cox Proportional Hazards regressions to compare responders to non-responders, responders reporting any crude oil exposure vs. none, and responders reporting any inhalation of crude oil fumes vs. none for earlier (2010-2012) and later (2013-2015) periods. We also evaluated joint effects of self-reported crude oil and oil dispersant exposures. Within-responder comparisons were adjusted for age, sex, and smoking.Results: Responders compared with non-responders were at increased risk in the later period for asthma (HR=1.48), dyspnea (HR=1.23), shortness of breath (HR=1.33), and cough (HR=1.27), in age- and sex-adjusted analyses. Oil exposed responders were at increased risk for asthma in the earlier period (HR=1.60) and for dyspnea (HR=1.52) and shortness of breath (HR=1.88) in the later period. Inhalation exposure was associated with increased risk of many respiratory conditions, including a two-fold elevated risk for shortness of breath in the later period (HR=2.11). Self-reported dispersant exposure further increased this association (HR=2.24). Most HRs were statistically significant.Conclusions: Our study, among a population with equal healthcare access, indicates the potential for crude oil exposures during a spill response to increase the risk for longer-term respiratory conditions.Disclaimer: The contents, views or opinions expressed here are those of the authors and do not reflect official policy or position of USU, the DoD, or the USCG.