Potential Immunotoxicological Health Effects Following Exposure to COREXIT 9500A during Cleanup of the Deepwater Horizon Oil Spill

• Published in: Journal of Toxicology and Environmental Health, Part A Vol. 74; no. 21; pp. 1419 - 1430
• Main Authors: Anderson, Stacey E., Franko, Jennifer, Lukomska, Ewa, Meade, B. J.
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01-01-2011; Taylor & Francis Ltd
• Subjects: Animals; Assaying; Cleaning; Cytokines - metabolism; Dioctyl Sulfosuccinic Acid - toxicity; Ear; Emulsifying Agents - toxicity; Environmental Exposure - adverse effects; Environmental Restoration and Remediation - adverse effects; Female; Genotype & phenotype; Gulf of Mexico; Health; Hypersensitivity - etiology; Immune System Phenomena - drug effects; Immune Tolerance - drug effects; Immunoglobulin E - blood; Immunologic Tests; Lipids - toxicity; Lymph; Lymph Nodes - drug effects; Lymphatic system; Lymphocytes - drug effects; Mice; Mice, Inbred BALB C; Oil spills; Petroleum Pollution; Rodents; Serums; Swelling; Toxicity; Gulf of Mexico
• ISSN: 1528-7394; 1087-2620; 2381-3504
• DOI: 10.1080/15287394.2011.606797

Workers involved in the Deepwater Horizon oil spill cleanup efforts reported acute pulmonary and dermatological adverse health effects. These studies were undertaken to assess the immunotoxicity of COREXIT 9500A, the primary dispersant used in cleanup efforts, as a potential causative agent. COREXIT 9500A and one of its active ingredients, dioctyl sodium sulfosuccinate (DSS), were evaluated using murine models for hypersensitivity and immune suppression, including the local lymph node assay (LLNA), phenotypic analysis of draining lymph node cells (DLN), mouse ear swelling test (MEST), total serum immunoglobulin E (IgE), and the plaque-forming cell (PFC) assay. Dermal exposure to COREXIT 9500A and DSS induced dose-responsive increases in dermal irritation and lymphocyte proliferation. The EC3 values for COREXIT 9500A and DSS were 0.4% and 3.9%, respectively, resulting in a classification of COREXIT 9500A as a potent sensitizer and DSS as a moderate sensitizer. A T-cell-mediated mechanism underlying the LLNA was supported by positive responses in the MEST assay for COREXIT and DSS, indicated by a significant increase in ear swelling 48 h post challenge. There were no marked alterations in total serum IgE or B220+/IgE+ lymph-node cell populations following exposure to COREXIT 9500A. Significant elevations in interferon (IFN)-γ but not interleukin (IL)-4 protein were also observed in stimulated lymph node cells. The absence of increases in IgE and IL-4 in the presence of enhanced lymphocyte proliferation, positive MEST responses, and elevations in IFN-γ suggest a T-cell-mediated mechanism. COREXIT 9500A did not induce immunosuppression in the murine model.