Blood tests on Gulf residents show ethylbenzene and other hydrocarbons , page 1

Ethylbenzene @ wikipedia:

Ethylbenzene is an organic compound with the formula C6H5CH2CH3. This aromatic hydrocarbon is important in the petrochemical industry as an intermediate in the production of styrene, which in turn is used for making polystyrene, a commonly used plastic material. Although often present in small amounts in crude oil, ethylbenzene is produced in bulk quantities by combining benzene and ethylene in an acid-catalyzed chemical reaction:
C6H6 + C2H4 → C6H5CH2CH3

CDC info about ethylbenzene:

What is Ethylbenzene?
Ethylbenzene is a colorless, flammable liquid that smells like gasoline.

It is naturally found in coal tar and petroleum and is also found in manufactured products such as inks, pesticides, and paints.

Ethylbenzene is used primarily to make another chemical, styrene. Other uses include as a solvent, in fuels, and to make other chemicals.

also

What happens to ethylbenzene when it enters the environment?
•Ethylbenzene moves easily into the air from water and soil.
•It takes about 3 days for ethylbenzene to be broken down in air into other chemicals.
•In surface water, ethylbenzene breaks down by reacting with other chemicals found naturally in water.
•Ethylbenzene can move through soil into groundwater
•In soil, it is broken down by bacteria.

Toxic profile PDF's for ethylbenzene from CDC.

I think directly linking ethylbenzene to Corexit is a presumptuous stretch of the imagination as the chemical occurs in a lot of other things. Granted, the oil spill itself would contribute a portion of the chemical to the environment but in air, it breaks down in approximately 3 days, though no indication is given of its decomposition rate in other media. Additionally, a cursory google of styrene producing / using / recycling companies shows many in the gulf and mid-west regions, as well as oil refineries and such so take that for what it's worth.

[edit on 9/4/2010 by abecedarian]