Two days ago, BP received authorization from the EPA and the US Coast Guard to use oil-dispersing chemicals from a product line called Corexit, according to Rep. Edward J. Markey (D-Mass.), who wrote the U.S. Environmental Protection Agency today to express concern. Markey reminds that some formulations of Corexit had their approval rescinded in Britain more than a decade
ago because, he wrote, "laboratory tests found them harmful to sea life that
inhabits rocky shores."
Here at Discovery News, we've been discussing the dispersants, and how they could be changing public perception of the spill's affect on wildlife in the Gulf region.
(Before and After: Oiled Brown Pelican washed at the Fort Jackson, LA
Oiled Wildlife Center. May 14, 2010
Credit: International Bird Rescue Research Center, http://www.ibrrc.org)
According to Rep. Markey's letter, BP can now apply Corexit dispersants at the site of the Gulf oil leak, over one mile below the surface. He claims the practice has never been authorized before.
Markey also raises questions about the potential toxicity of the trademarked formulation, and whether the chemical could be contributing to new reports of large undersea “plumes” of oil suspended thousands of feet below the water's surface.
(NASA's Terra satellite captured a visible satellite image of the Gulf
oil spill on May 17 from the Moderate
Resolution Imaging Spectroradiometer Instrument on-board. The oil slick
appears as a dull gray on the water's surface and stretches south from
the Mississippi Delta with what looks like a tail. Credit: NASA Goddard / MODIS Rapid Response Team / Rob Gutro)
“The release of hundreds of thousands of gallons of chemicals into the Gulf of Mexico could be an unprecedented, large and aggressive experiment on our oceans,” said Rep. Markey, chair of the Energy and Environment Subcommittee in the Energy and Commerce Committee, which is conducting an extensive investigation into the spill. “The information regarding the chemical composition, efficacy and toxicity of the dispersants currently being used is scarce.”
The letter calls for information on all eighteen dispersants EPA has approved for use, including a ranking of their efficacy and toxicity.
The letter also asks about the effects of water temperature and pressure on the chemicals, as they are currently, and for the first time, being used at 5,000 feet where the temperature is near freezing and the pressure of the water is extremely high.
Rep. Markey additionally asks the EPA whether the oil dispersant chemicals could accumulate in marine life over time, and what human health impacts could result from eating Gulf seafood.