Dispersants: Part II

(9 am. – promoted by ek hornbeck)

From Climate Progress.org

Chemically dispersing oil spills “solves the political problem of visible oil but not the environmental problem,” Robert Brulle, a 20-year Coast Guard veteran and an affiliate professor of public health at Drexel University, told me. These dispersants “do not actually reduce the total amount of oil entering the environment,” as a 2005 National Academy of Sciences report on the subject put it.


I spoke to Carys Mitchelmore, one of the writers of the toxicity chapter for the NAS report. She explained that dispersants are “a molecule that looks like a snake. The head part likes water and the tail part likes oil.” The dispersant “pulls the oil into the water in the form of tiny droplets.”

And that means subsurface creatures – from oysters to coral to larval eggs – that might never have had significant exposure to the oil are now going to get a double whammy, getting hit by the oil and by the dispersants. Worse, the oil droplets are now in a form that looks like food (e.g., the same size as algae) to filter feeders like oysters, which otherwise may only have been exposed to the far lower levels of dissolved oil components found under a typical oil slick. The droplets can also clog up fish gills.


Why is BP using Corexit, one of the most toxic dispersants of all?

BP “shares close ties” with Nalco. A BP board member who served as an executive at the company for 43 years also sits on Nalco’s board, and critics suggest there may be a conflict of interest in BP’s choice of Corexit. “It’s a chemical that the oil industry makes to sell to itself, basically,” said Defenders of Wildlife’s Richard Charter.


And, from Salon:

ProPublica has reported that BP has bought up more than a third of the global supply of dispersants. Nalco Holding Co. has provided its entire inventory of one dispersant, Corexit 9500, to BP and the Coast Guard. Nalco’s chief technology office, Mani Ramesh, has claimed that “Corexit’s active ingredient is an emulsifier also found in ice cream,” and that it is not harmful to marine life.

Mitchelmore, however, has extensively studied the impact of Corexit 9500, and found the chemical to be “pretty toxic to soft corals.” It was “acutely toxic” to corals at low levels, 30 parts per million.  It “affected physiological parameters at levels as low as 10ppm and also low ppm (20ppm) 8 hour exposures lead to reduced growth compared to controls even 32 days after being placed in clean seawater.”


So, Corexit destroys corals and all other life, spreads oil droplets to organisms that would not have been affected, is a know human carcinogen, and they kill the very microbes that can break up oil.

see part 1:


And from Scientific American :

Ultimately, it is only microbes that can remove the oil from the ocean. “In the long run, it’s biodegradation that removes most of the oil from the environment in these situations,” Lee says. Or, as Joye puts it, “They’re clever, they’re tough, they can basically eat nails…. The microbes have to save us again.”


830,000 gallons of dispersants have now been sprayed on the gulf.


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  1. And, we’re killing him.  

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