May 17, 2010: Markey to EPA on Oil Dispersants: How Toxic, How Effective?

Questions Arise on Chemicals Used in Gulf Spill, Including Link to Giant Undersea Oil Plumes

WASHINGTON (May 17, 2010) -- Rep. Edward J. Markey (D-Mass.) today queried the U.S. Environmental Protection Agency on the dangers of applying oil-dispersing chemicals deep underwater as an effort to mitigate the Gulf of Mexico oil spill. In the letter sent to EPA Administrator Lisa Jackson, Rep. Markey raises questions about the potential toxicity of the trademarked formulation, called Corexit, 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.

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.”

A copy of the letter can be found here:http://markey.house.gov/docs/ejmdispersant51710.pdf

On the first question of the levels of toxicity of the dispersant chemicals,  Rep. Markey notes that some formulations of Corexit, the substances being used in the Gulf of Mexico, were banned in Britain more than a decade ago due to their tested harmful effects to sea life. Rep. Markey also asks for information on the 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.

Recent reports from independent scientists have told of large, undersea oil “plumes.” Instead of rising to the surface, large clouds of oil are currently suspended thousands of feet below the ocean and are found at various depths within the water column, making the issue of quantifying the spill much more difficult.

Citing concerns of scientists that the formation of these plumes may be linked to the use of dispersants, Rep. Markey asks whether EPA considered this scenario for the interaction of the dispersants with the oil plume when applied at the depth of the Deepwater Horizon leak.

Finally, Rep. Markey asks EPA whether these chemicals could accumulate in marine life over time, and what human health impacts could result from eating Gulf seafood.

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