From the AP:
Federal regulators have approved the use of a technique to fight the ballooning oil spill in the Gulf of Mexico by shooting chemical dispersants 5,000 feet beneath the sea.
Sounds promising, right?
Breaking up the oil at its source would prevent further damage, right?
Um...
As jamess described in exquisite detail in It's basically a giant Experiment: Corexit 9500, Oil, just Add Water Column, Corexit, the most widely-used oil dispersant, is poisonous.
Which means that any fish or shrimp that are still edible won't be for long.
A little more about dispersants:
Dispersants, which help break up the oil by binding it to water molecules, have been sprayed from airplanes onto the Gulf surface, and injected with tubes at the site of the broken well on the seafloor.
Yet despite the mass deployment of the chemical - and BP's desire to use more underwater - scientists know little about the potential ecological dangers and health risks posed by prolonged use of dispersants, particularly underwater.
The U.S. Coast Guard and the Environmental Protection Agency have authorized BP to use dispersant on the surface of the Gulf, but the oil company has been required to conduct tests for using the chemical underwater at the source of the leak. EPA approved use of dispersants underwater on a temporary basis Friday, despite state of Louisiana's objections.
A final decision is expected this weekend on whether dispersants can continue to be used underwater to help break up the oil.
OK, because this hasn't been done before, the government is allowing BP to test the method not in a lab, but in the gulf. Whatever works, right? This is an emergency and expediency is important.
Although the diary by jamess focused on Corexit 9500, the current generation product, it turns out that one of the chemicals BP has been using is an older-generation product that's been discontinued:
the government's Deepwater Horizon Response website confirmed the use of two dispersants: Corexit 9500 and Corexit 9527A...
Corexit 9527A is the older product, and considered more toxic. According to its Material Safety Data Sheet, it contains a chemical called 2-butoxyethanol -- at a level of between 30 percent and 60 percent by weight (the public information on these products is maddeningly inexact). Since writing the post last week, I've come upon the entry for 2-butoxyethanol on the website of Haz-Map, a service of the National Library of Medicine that provides "information about the health effects of exposure to chemicals."
This is not charming stuff, according to Haz-Map:
Severe hemoglobinuria and changes in the lungs, kidneys, and liver are seen in mice after 7-hour lethal concentration studies. Volunteers showed no evidence of adverse effects other than mucous membrane irritation after 8 hour exposures to 200 ppm. ... For ethylene glycol ethers, there is limited positive evidence of spontaneous abortions and decreased sperm counts in humans and strong positive evidence of birth defects and testicular damage in animals.
(Source) (Emphasis added)
Nasty stuff. Poison, really. Good thing it's not in use anymore.
Except in the Gulf Coast. From the same article:
Rather than discuss the toxicity of 2-butoxyethanol, Anastas sought to assure us it was no longer in use -- because the Gulf cleanup crew had already dumped all of the Corexit 9527A it had in hand into the Gulf, and were now using only Corexit 9500.
...
He went on to say that "9527 was being used originally, but due to supply, the 9500 is now being used at the current time."
So they got rid of toxic stores of an older chemical known to cause all sorts of maladies, both temporary and permanent, by dumping all the remaining Corexit 9527 into the Gulf.
What will happen? A Biologist's View of the Spill by Crashing Vor provides some partial answers (all emphasis is mine):
I asked which was the greater danger to marine life, the oil or the dispersants. True to his tribe, he responded, "That's not a simple question. The dispersants are much more toxic, but they break down much more quickly." He said that the use of dispersants was probably excessive, driven by PR considerations. "Oily beaches make great TV, but not for BP."
He told me to hold on and leaned out of his office to call to a colleague.
...
"Dr. A" ... said that, if we see a die-off in the oyster population, it could last as little as 3-5 years if the dispersants stay in the water. "If they get into the sediment, long-term toxicity will be a problem."
DB concurred, adding, "Probably the same time scale with the brown shrimp. Two years, maybe three or four." He added the caveat that the brown shrimp are so important in the food chain that it will be hard to predict what effects the oil and dispersants will have. "You could get concentrations too small to kill the shrimp, but then they get out in the tuna feeding grounds. High-lipid fish like tuna concentrate toxins. They're in some danger of buildup."
"Dr. A" also confirmed that "they're pulling a lot of stock that hasn't been used in years, anything they can get their hands on right now."
That doesn't sound like a well thought-out strategy. Perhaps this is why they've chosen to use that particular product:
BP PLC continues to stockpile and deploy oil-dispersing chemicals manufactured by a company with which it shares close ties, even though other U.S. EPA-approved alternatives have been shown to be far less toxic and, in some cases, nearly twice as effective.
...
So far, BP has told federal agencies that it has applied more than 400,000 gallons of a dispersant sold under the trade name Corexit and manufactured by Nalco Co., a company that was once part of Exxon Mobil Corp. and whose current leadership includes executives at both BP and Exxon. And another 805,000 gallons of Corexit are on order, the company said, with the possibility that hundreds of thousands of more gallons may be needed if the well continues spewing oil for weeks or months.
But according to EPA data, Corexit ranks far above dispersants made by competitors in toxicity and far below them in effectiveness in handling southern Louisiana crude.
Of 18 dispersants whose use EPA has approved, 12 were found to be more effective on southern Louisiana crude than Corexit, EPA data show. Two of the 12 were found to be 100 percent effective on Gulf of Mexico crude, while the two Corexit products rated 56 percent and 63 percent effective, respectively. The toxicity of the 12 was shown to be either comparable to the Corexit line or, in some cases, 10 or 20 times less, according to EPA.
EPA has not taken a stance on whether one dispersant should be used over another, leaving that up to BP. (Source) (Emphasis added)
So the government has approved the use of an unproven method of injecting dispersants, some of which are known to be highly toxic and less effective than competing products, into deep water, with the concomitant risk of them contaminating the sea floor. All to keep the "slick" under the surface, where it can't be seen.
If they are able to deliver the dispersant to the correct locations, and if the dispersant breaks up the oil before it reaches the surface, I expect that within three weeks, BP will announce that it has done its duty to "clean up" the "spill."
Wildlife? You never saw anything that lived down there anyway.
Fisherfolk? Eh, they'll have to survive a bad season. Maybe the gubmint will provide some socialist handouts.
People who like to eat seafood? The dispersants "melted" all the oil - what's the fuss? Of course it's safe!
For BP, poisoning the gulf with gushing oil has an easy answer: poison it with dispersants that "disappear" the oil.
They should be tried for crimes against humanity.
UPDATE: The Houston Chronicle has more on this story. I found this statement alarming (emphasis added):
Environmentalists worry that the newly approved dispersant approach may just move environmental damage to the seabed where it may be harder to track than on shore. So far, planes have dropped more than 500,000 gallons of chemicals on the surface slick.
U.S. Coast Guard Rear Adm. Mary Landry said scientists with the Environmental Protection Agency and the National Oceanic and Atmospheric Administration had approved the use of the detergent-like substance following analysis of three tests.
"This was not a decision that was made lightly. It's a series of trade-offs. You're really trying to minimize the impact on the environment as much as possible," Landry said.
Somehow, using an experimental technique that operates in water so deep that it requires ROVs to see what's going on down there isn't my idea of "minimizing the impact on the environment." But maybe that's just me :-|