Biomarkers of kidney injury among Deepwater Horizon oil spill workers

Abstract

Background: Individuals who participated in oil spill response and cleanup following the 2010 Deepwater Horizon (DWH) disaster were exposed to a range of chemicals from fresh and burning oil. These included benzene, toluene, ethylbenzene, and xylenes (BTEX), which have shown nephrotoxicity in animal and/or human studies. We examined biomarkers of kidney injury among participants in the GuLF Study, a prospective study of health effects among DWH oil spill workers.Methods: We analyzed data and biospecimens collected at baseline (1-3 years after the spill) from 924 male workers randomly sampled on the basis of exposures estimated in the GuLF Study using detailed DWH work histories collected at baseline and extensive air monitoring data collected during the spill response. Fourteen urinary biomarkers of kidney injury were measured via multiplex immunoassay. We used linear regression to examine both maximum and cumulative exposures to BTEX and hexane in relation to creatinine-adjusted biomarker concentrations, adjusting for age, race, BMI, smoking status, binge drinking, and pre-spill physician-diagnosed diabetes.Results: Maximum exposures to benzene, toluene, xylene, and hexane were associated with higher levels of GST-α, a marker of proximal tubule damage, and osteoactivin, a marker of distal tubule damage. Cumulative exposures to benzene, toluene, and ethylbenzene were associated with higher levels of osteoactivin, while cumulative exposures to toluene and xylene were associated with higher levels of EGF, another marker of proximal tubule damage. Results were similar among never smokers, non-binge drinkers, and individuals without pre-spill diabetes.Conclusions: Exposure to BTEX and hexane among oil spill workers is associated with elevated levels of urinary biomarkers of kidney injury, including of the proximal and distal tubules. Mixtures analysis will allow us to tease apart the relative contributions of these correlated exposures and follow-up of the cohort will shed light on whether these exposures are also associated with kidney disease.