MNeagle
1st September 2010, 07:24 PM
Scientists: Dispersants May Delay Recovery of the Gulf By Years ... Or Decades
The government and BP claim that the combination of Corexit and crude oil is less toxic than crude oil by itself.
Is that true?
Well, EPA's tests used a combination of Corexit with Louisiana light crude oil. However, the oil coming out of BP's leaking well contains an unusually high concentration of methane. As CBS notes:
The oil emanating from the seafloor contains about 40 percent methane, compared with about 5 percent found in typical oil deposits, said John Kessler, a Texas A&M University oceanographer who is studying the impact of methane from the spill.
It is doubtful that the EPA used such unusually methane-rich oil in their testing.
More importantly, EPA toxicity tests on the dispersant-oil mixture were conducted at sea level pressures (in other words, the pressure at the surface of the ocean). But enormous quantities of Corexit have been applied 5,000 feet under the ocean at the leaking wellhead.
As the New York Times noted in May:
There has been significant research in response to spills over the past few decades, especially the Exxon-Valdez spill in Alaska in 1989 and the Prestige spill in 2002 off the coast of Spain.
But all of the scientific precedent is from spills from tankers or near shore.
"We are working with reliable knowledge from that science," Plumb said, "but it is limited and not across the scale or scope of the ecosystem we are in now."
Scientists and responders are prepared to deal with oiled birds and shoreline effects, because those are the usual problems. An ongoing oil spill a mile under water is unchartered ground.
"We've never dealt with this kind of deep water, we've never dealt with this amount of dispersants, we've never dealt with the Gulf," [Roger Helm, chief of the contaminants division of the Fish and Wildlife Service] said. "We're in a very early phase of the science here; there is not a lot of experimental work or practical work upon which to base the work we're doing."
Marine biologist and toxicologist Dr. Chris Pincetich - who has an extensive background in testing the effects of chemicals on fish - told me yesterday that scientists have no idea what compounds will be formed when Corexit dispersant and oil interact under the high pressures present at BP's deepwater spill site (Dr. Pincetich directed environmental toxicity testing as a consultant and lab supervisor for many years, and now works to protect endangered sea turtles at the Sea Turtle Restoration Project, http://www.seaturtles.org).
And as Scientific American notes, breakdown products from the dispersant might be toxic as well:
For example, more testing will be needed to determine if the breakdown of Corexit 9500 - either into other chemicals or when metabolized by animals - produces toxic products of its own. "In toxicology, it's quite often not the original compound that's the toxic entity," [toxicologist Cary Mitchelmore of the University of Maryland, who co-authored a National Research Council report on dispersants in 2005] notes.
Indeed, even Sergio Alex Villalobos, toxicologist for Nalco - maker of the Corexit dispersant - says:
Once it’s mixed with oil, that’s where you get the most impact, that’s where you see most of the toxicity.
Government Testing is "Embarassing"
more (http://www.zerohedge.com/article/scientists-dispersants-may-delay-recovery-gulf-years-or-decades?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+zerohedge%2Ffeed+%28zero+hedg e+-+on+a+long+enough+timeline%2C+the+survival+rate+fo r+everyone+drops+to+zero%29)
The government and BP claim that the combination of Corexit and crude oil is less toxic than crude oil by itself.
Is that true?
Well, EPA's tests used a combination of Corexit with Louisiana light crude oil. However, the oil coming out of BP's leaking well contains an unusually high concentration of methane. As CBS notes:
The oil emanating from the seafloor contains about 40 percent methane, compared with about 5 percent found in typical oil deposits, said John Kessler, a Texas A&M University oceanographer who is studying the impact of methane from the spill.
It is doubtful that the EPA used such unusually methane-rich oil in their testing.
More importantly, EPA toxicity tests on the dispersant-oil mixture were conducted at sea level pressures (in other words, the pressure at the surface of the ocean). But enormous quantities of Corexit have been applied 5,000 feet under the ocean at the leaking wellhead.
As the New York Times noted in May:
There has been significant research in response to spills over the past few decades, especially the Exxon-Valdez spill in Alaska in 1989 and the Prestige spill in 2002 off the coast of Spain.
But all of the scientific precedent is from spills from tankers or near shore.
"We are working with reliable knowledge from that science," Plumb said, "but it is limited and not across the scale or scope of the ecosystem we are in now."
Scientists and responders are prepared to deal with oiled birds and shoreline effects, because those are the usual problems. An ongoing oil spill a mile under water is unchartered ground.
"We've never dealt with this kind of deep water, we've never dealt with this amount of dispersants, we've never dealt with the Gulf," [Roger Helm, chief of the contaminants division of the Fish and Wildlife Service] said. "We're in a very early phase of the science here; there is not a lot of experimental work or practical work upon which to base the work we're doing."
Marine biologist and toxicologist Dr. Chris Pincetich - who has an extensive background in testing the effects of chemicals on fish - told me yesterday that scientists have no idea what compounds will be formed when Corexit dispersant and oil interact under the high pressures present at BP's deepwater spill site (Dr. Pincetich directed environmental toxicity testing as a consultant and lab supervisor for many years, and now works to protect endangered sea turtles at the Sea Turtle Restoration Project, http://www.seaturtles.org).
And as Scientific American notes, breakdown products from the dispersant might be toxic as well:
For example, more testing will be needed to determine if the breakdown of Corexit 9500 - either into other chemicals or when metabolized by animals - produces toxic products of its own. "In toxicology, it's quite often not the original compound that's the toxic entity," [toxicologist Cary Mitchelmore of the University of Maryland, who co-authored a National Research Council report on dispersants in 2005] notes.
Indeed, even Sergio Alex Villalobos, toxicologist for Nalco - maker of the Corexit dispersant - says:
Once it’s mixed with oil, that’s where you get the most impact, that’s where you see most of the toxicity.
Government Testing is "Embarassing"
more (http://www.zerohedge.com/article/scientists-dispersants-may-delay-recovery-gulf-years-or-decades?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+zerohedge%2Ffeed+%28zero+hedg e+-+on+a+long+enough+timeline%2C+the+survival+rate+fo r+everyone+drops+to+zero%29)