Corexit Increasing Toxicity of Crude Oil

[Tutankhamun]

There's been a lot of discussion about the potential negative effects of Corexit. Not only does the dispersant itself appear to be toxic -- it makes the oil itself more toxic to marine life. BP's efforts to hide the proverbial body will only increase the REAL body count. Here are a couple of abstracts that support this: (Skip to the last sentence of each abstract if you want to avoid technical jargon and read the conclusion.)

Biochemical changes in rockfish, Sebastes schlegeli, exposed to dispersed crude oil.
Jung JH, Yim UH, Han GM, Shim WJ.

Oil and POPs Research Group, KORDI, Geoje-shi, 656-834, Republic of Korea.

Abstract
This paper describes the response of the ovoviviparous rockfish, Sebastes schlegeli, to hydrocarbons in the water-accommodated fraction (WAF) of crude oil, in the presence or absence of oil dispersants. Concentrations of cytochrome P-450 1A (CYP1A) and levels of its catalytic activity ethoxyresorufin O-de-ethylase (EROD) in rockfish exposed to WAF at concentrations of 0.1% and 1% were significantly increased by the addition of a dispersant, Corexit 9500 after 48 h exposure. After 72 h exposure, the levels of CYP1A and EROD activity were significantly increased in 0.1% and 0.01% chemically enhanced WAF (CEWAF) (Corexit 9500 and Hiclean II dispersant). Bile samples from fish exposed to WAF alone had low concentrations of hydrocarbon metabolites, exemplified by 1-hydroxypyrene. After 72 h exposure, hydrocarbon metabolites in bile from fish exposed to WAF in the presence of either Corexit 9500 or Hiclean II were significantly higher compared with fish exposed to WAF alone or control fish. These experiments confirm that the use of oil dispersants will increase the exposure of ovoviviparous fish to hydrocarbons in oil.

http://www.ncbi.nlm.nih.gov/pubmed/19410657



Ecotoxicol Environ Saf. 2004 Nov;59(3):300-8.

Oil dispersant increases PAH uptake by fish exposed to crude oil.
Ramachandran SD, Hodson PV, Khan CW, Lee K.

School of Environmental Studies, Queen's University, Kingston, Ont., Canada K7L 3N6.

Abstract
The use of oil dispersants is a controversial countermeasure in the effort to minimize the impact of oil spills. The risk of ecological effects will depend on whether oil dispersion increases or decreases the exposure of aquatic species to the toxic components of oil. To evaluate whether fish would be exposed to more polycyclic aromatic hydrocarbon (PAH) in dispersed oil relative to equivalent amounts of the water-accommodated fraction (WAF), measurements were made of CYP1A induction in trout exposed to the dispersant (Corexit 9500), WAFs, and the chemically enhanced WAF (dispersant; CEWAF) of three crude oils. The crude oils comprised the higher viscosity Mesa and Terra Nova and the less viscous Scotian Light. Total petroleum hydrocarbon and PAH concentrations in the test media were determined to relate the observed CYP1A induction in trout to dissolved fractions of the crude oil. CYP1A induction was 6- to 1100-fold higher in CEWAF treatments than in WAF treatments, with Terra Nova having the greatest increase, followed by Mesa and Scotian Light. Mesa had the highest induction potential with the lowest EC50 values for both WAF and CEWAF. The dispersant Corexit was not an inducer and it did not appear to affect the permeability of the gill surface to known inducers such as beta-napthoflavone. These experiments suggest that the use of oil dispersants will increase the exposure of fish to hydrocarbons in crude oil.

http://www.ncbi.nlm.nih.gov/pubmed/15388269

[BrklynLiberal]

1. Why was my first thought "BUT OF COURSE!!!!"

:mad: :puke: :eyes: :crazy: :silly: :spank: :grr: :nuke: :scared: :thumbsdown: :shrug: :banghead: