Impact of Oil Dispersants Still Unknown, EPA Says
WASHINGTON (CN) - The impact on wildlife and seafood after more than 1.8 million gallons of chemical dispersants were applied to the BP oil spill in the Gulf of Mexico is "largely unknown," government officials said Thursday.
"We remain concerned about the volume of dispersants used to date," Environmental Protection Agency Administrator Lisa Jackson said at a Senate appropriations subcommittee hearing.
Since the BP drilling rig Deepwater Horizon exploded April 20, starting the worst oil spill in U.S. history, the oil giant has unloaded nearly 1.8 million gallons of dispersant on the spill: more than 1 million gallons on the ocean's surface and 735,000 gallons underwater.
Chemical dispersants had never been applied underwater before the Gulf spill, where they have been sprayed directly at the gushing wellhead.
The sheer volume of dispersants used in the Gulf is unprecedented. At one point, BP applied 700,000 gallons in a single day.
"That was an alarming number," Jackson said.
BP has regularly been applying dispersants to the Gulf spill at rates of 35,000 to 65,000 barrels per day. In contrast, 250,000 barrels of dispersants total were used in the aftermath of the Exxon Valdez disaster in Alaska in 1989.
Jackson said she did not know of any research focused on the heavy use of chemical dispersants or underwater application of the chemicals.
"You're suggesting to me that we haven't done that research anywhere?" Sen. Lisa Murkowski, R-Ala., asked.
"That's correct senator," Jackson said. When asked about how much study had been done of chemical dispersants since the Exxon Valdez disaster, Jackson said, "There has been significant research, but let me say at the outset, I don't think there has been enough."
Dispersants, which are made with a petroleum base and chemical additives, work to degrade oil before it impacts wildlife on the ocean's surface or before the oil hits the shore. The dispersants break up into small droplets, which sink in the water and are eaten by tiny microbes.
"Should we ban them?" subcommittee chair Sen. Barbara Mikulski, D-Md., asked. "I don't want dispersants to be the Agent Orange of this oil spill."
"Every single thing done at sea has some cost," Jackson said. "There is good news. We have not seen signs of environmental impact from the use of dispersants so far," she said, though she acknowledged that the long-term affects on aquatic life are "largely unknown."
So far, EPA testing of water and sediment close to the shore has yielded no evidence of dispersants on or near the shoreline.
"So why did you tell them to limit it?" Mikulski asked Jackson, referring to a May 26 order issued by the EPA for BP to scale back the use of dispersants.
"Because there were scientific unknowns," Jackson said. She said she had a choice between banning dispersants altogether or letting BP use them in moderation, and she let the company use them in moderation in hopes that the dispersants would help.
"[The dispersants] are much less toxic and the chemicals added to them are much less toxic than the oil itself," Jackson said.
"U.K. has banned dispersants," Mikulski said. "If the U.K. banned it, a nation surrounded by water, why weren't we banning it?"
Jackson said the U.K. banned Corexit not due to its toxicity or lethality, but because it caused to lose their ability to cling to rocky shores, a problem the United States doesn't have because it only allows dispersants to be applied at least 30 miles offshore.
Currently, federal agencies are not testing seafood coming out of the Gulf for traces of chemical dispersants, a fact that aroused concern in senators.
Jackson explained that by the time the dispersants break down the oil, the only thing left are the oil byproducts.
"They don't stick around," Jackson said of chemicals in the dispersants. "The thing that sticks around is the oil."
Under the current seafood testing protocol for the Gulf, the National Oceanic and Atmospheric Administration tests seafood collected from the contaminated area more than 3 miles offshore, and states monitor seafood collected less than 3 miles offshore with the help of the Food and Drug Administration.
Murkowski complained that seafood sales in her state of Alaska have been affected by the Gulf spill because consumers, especially in the Midwest, may not know where their seafood is coming from, and out of fear that it is polluted, do not buy any.
"Those shrimp might be absolutely perfectly safe," Murkowski said, "but as long as market perceives that they are not, then no one is going to buy them.
"NOAA and FDA need to come out and unequivocally state, 'Things are safe,'" Murkowski said. "We need to get that word out."