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Overview of the Toxicity of the Oil Dispersant Corexit++
Citation:
DEMARINI, D. M. Overview of the Toxicity of the Oil Dispersant Corexit++. Presented at Environmental Mutagen Society Meeting, Montreal, QC, CANADA, October 15 - 19, 2011.
Impact/Purpose:
Talk summarizes the 4 long-term, low-dose carcinogenicity studies ever done, as well as several low-dose rodent cancer biomarker studies.
Description:
The anionic surfactant dioctyl sodium sulfosuccinate (DOSS) is in the oil dispersant Corexit 9500A, which was used in the Deepwater Horizon Oil Spill. Analysis of water from the area of Deepwater Horizon showed that DOSS biodegraded little or at a slow rate several months after application of Corexit. Corexit did not alter the biodegradation rate of oil in lab studies. Corexit is not mutagenic to Salmonella and does not cause mutagenic urine in rats exposed orally to it or oil + Corexit. Corexit was not an endocrine disruptor in vitro. Corexit results in greater exposure of marine organisms to hydrocarbons (PAHs) from oil in waters where the salinity is low, such as in coastal waters. Although Corexit or Corexit + oil are generally more toxic to early-life stages than to adults, species differences complicate this generalization. Corexit is less toxic than oil alone, and the toxicity ofoil or oil + Corexit to aquatic organisms is similar when based on measured water-column values and the concentration ofnon-volatile hydrocarbons. The concentrations of dissolved hydrocarbons in the water column are similar for oil or Corexit + oil, and most toxicity appears to be due to the concentration of the dissolved (soluble) hydrocarbons. Corexit also puts some portion of the hydrocarbons into colloidal suspension, and these are less associated with toxicity than the dissolved (soluble) hydrocarbons. [Abstract does not necessarily reflect the views or policies of the US EPA.]