Pulmonary Effects after Acute Inhalation of Oil Dispersant (COREXIT EC9500A) in Rats

Abstract

COREXIT EC9500A (COREXIT) was used to disperse crude oil during the 2010 Deepwater Horizon oil spill. While the environmental impact of COREXIT has been examined, the pulmonary effects are unknown. Investigations were undertaken to determine whether inhaled COREXIT elicits airway inflammation, alters pulmonary function or airway reactivity, or exerts pharmacological effects. Male rats were exposed to COREXIT (mean 27 mg/m(3), 5 h). Bronchoalveolar lavage was performed on d 1 and 7 postexposure. Lactate dehydrogenase (LDH) and albumin were measured as indices of lung injury; macrophages, neutrophils, lymphocytes, and eosinophils were quantified to evaluate inflammation; and oxidant production by macrophages and neutrophils was measured. There were no significant effects of COREXIT on LDH, albumin, inflammatory cell levels or oxidant production at either time point. In conscious animals, neither breathing frequency nor specific airway resistance were altered at 1 hr, 1 d and 7 d postexposure. Airway resistance responses to methacholine (MCh) aerosol in anesthetized animals were unaffected at 1 and 7 d postexposure, while dynamic compliance responses were decreased after 1 d but not 7 d. In tracheal strips, in the presence or absence of MCh, low concentrations of COREXIT (0.001% v/v) elicited relaxation; contraction occurred at 0.003-0.1% v/v. In isolated, perfused trachea, intraluminally applied COREXIT produced similar effects but at higher concentrations. COREXIT inhibited neurogenic contractile responses of strips to electrical field stimulation. Our findings suggest that COREXIT inhalation did not initiate lung inflammation, but may transiently increase the difficulty of breathing.

The Deepwater Horizon Oil Spill Through the Lens of Human Health and the Ecosystem

“…Chemical oil dispersants used in DWH oil spill response efforts were COREXIT 9500A and COREXIT 9527A representing mixtures of surfactants and solvents containing propylene glycol, dioctyl sodium sulfosuccinate (DSS), hydro-treated light petroleum distillates, and ethoxylated alcohols [20]. Animal studies have examined effects of dispersant exposure on pulmonary and immunologic endpoints [20–22].…”

“…Chemical oil dispersants used in DWH oil spill response efforts were COREXIT 9500A and COREXIT 9527A representing mixtures of surfactants and solvents containing propylene glycol, dioctyl sodium sulfosuccinate (DSS), hydro-treated light petroleum distillates, and ethoxylated alcohols [20]. Animal studies have examined effects of dispersant exposure on pulmonary and immunologic endpoints [20–22]. Acute inhalation of COREXIT EC9500A was found to induce a transient decrease in dynamic compliance 1 day after exposure, but was reversed after 7 days, and no differences in lung neutrophils and phagocyte oxidant production, or lung function were found [20].…”

“…Animal studies have examined effects of dispersant exposure on pulmonary and immunologic endpoints [20–22]. Acute inhalation of COREXIT EC9500A was found to induce a transient decrease in dynamic compliance 1 day after exposure, but was reversed after 7 days, and no differences in lung neutrophils and phagocyte oxidant production, or lung function were found [20]. Another study found transient chronotropic effects on cardiac function in rats 1 day post-acute exposure to COREXIT EC9500A exposure [21].…”

The Gulf Long-Term Follow-Up Study (GuLF STUDY): Biospecimen collection at enrollment

“…The dispersants Corexit 9500 and Corexit 9527, used to break up the oil in the water, contain various respiratory irritants, including 2-butoxyethanol, propylene glycol, and dioctyl sodium sulfosuccinate (Roberts et al 2011; EPA 2011). Evidence from rat models suggests possible neurological (Sriram et al 2011), immunological (Anderson et al 2011), and cardiovascular (Krajnak et al 2011) effects of Corexit 9500.…”

Effects of Corexit Dispersants on Cytotoxicity Parameters in a Cultured Human Bronchial Airway Cells, BEAS-2B

“…Judson et al (2010) examined the cytotoxic effects of COREXIT 9500A dispersant in aquatic species and cultured mammalian cells and found a median LC50 value of approximately 100 ppm. A comprehensive examination on the effects of COREXIT 9500A on the immune, cardiovascular, and pulmonary systems in rats was conducted by the National Institute for Occupational Safety and Health (NIOSH; Anderson et al, 2011; Krajnak et al, 2011; Roberts et al, 2011; Sriram et al, 2011). COREXIT 9500A did not induce marked alterations in peripheral and pulmonary immune parameters but transiently increased breathing difficulties (Anderson et al, 2011; Roberts et al, 2011).…”