Immunological Effects of Gulf Oil Spill: Crude Oil, COREXIT® EC9500A Dispersant and Oil/Dispersant Mixtures

Abstract

Workers involved in the gulf oil spill containment and cleanup efforts have reported health concerns including pulmonary distress, dermatological problems, and an increased incidence of infection. These concerns have prompted toxicological evaluation of samples recovered from the gulf oil spill including: COREXIT® EC9500A (CR), crude oil and crude oil/CR mixtures. Potential for hypersensitivity and immune suppression were evaluated in dermal exposure murine models. Dermal exposure to 50 μl of CR for 3 days induced irritation and significant increases in lymphocyte proliferation at concentrations of 10% and greater, while exposure to oil induced significant elevations in lymphocyte proliferation at concentrations of ≥50%. No alterations in serum IgE were observed after exposure to either test article. Exposure to crude oil was also found to be immunosuppressive. The spleen IgM response to sheep red blood cells was significantly inhibited when mice were exposed to 50 μl at concentrations of ≥25% crude oil for 14‐days. Increased liver and decreased spleen weights were also documented. Mixtures of crude oil and CR did not enhance either effect. Consistent with these results, CR did not enhance in vitro epidermal penetration of naphthalene. These studies suggest potential immunological effects from dermal exposure to crude oil and CR.