In Gulf of Mexico, Chemicals Under Scrutiny
Elizabeth Rosenthal
The New York Times
05/05/2010
As they struggle to plug a leak from a ruptured oil well in the Gulf of Mexico, BP and federal officials are also engaging in one of the largest and most aggressive experiments with chemical dispersants in the history of the country, and perhaps the world.
With oil continuing to gush from the deep well, they have sprayed 160,000 gallons of chemical dispersant on the water’s surface and pumped an additional 6,000 gallons directly onto the leak, a mile beneath the surface.
John Curry, director of external affairs at BP, said the company was encouraged by the results so far. But some environmental groups are deeply nervous.
“I understand it’s the only thing they can do,” said Paul Orr of the group Lower Mississippi Riverkeeper. “But I think it’s vital afterwards to really monitor what’s happening with aquatic life, with oil on the sea floor and things like oyster beds.”
Even in the best cases, dispersants are applied in what might be termed a lose-lose strategy. Scientists make the calculation that it is better to have the ocean filled with low concentrations of the dispersant chemicals — which are in themselves mild to moderate poisons — than to have dense oil on the surface or washing up onshore, places where it is most likely to harm wildlife.
And while most environmentalists support the application of dispersants as a necessary evil to limit the damage, some have assailed an industry policy that guards their chemical makeup. Keeping the exact mix secret makes it harder to evaluate the risks to marine ecosystems and to know what side effects to look for as the crisis unfolds.
What is more, the main dispersants applied so far, from a product line called Corexit, had their approval rescinded in Britain a decade ago because laboratory tests found them harmful to sea life that inhabits rocky shores, like limpets, said Mark Kirby, a scientific adviser to the British government on the testing, use and approval of oil spill treatment options.
But Mr. Kirby added that the finding might have little to no relevance to the current situation, where the product is being applied in the open ocean. While Corexit failed the British government’s limpet test, it passed its offshore safety tests, Mr. Kirby said. (The dispersant had to pass both tests for British waters.)
Still, as the molecules from the 160,000 gallons of dispersant bind with the oil from Deepwater Horizon, the oil drilling rig that exploded on April 20, and fan out across the gulf, some groups are fighting for more information about the product’s composition. That amount of dispersant is greater than the entire stockpile kept by oil-producing nations like Norway.
