http://www.guardian.co.uk/environment/2010/may/16/louisiana-oil-spill-toxic-chemical-bpsnip-
Approval by the US Environment Protection Agency (EPA) for the pumping of tens of thousands of litres of the chemical Corexit 9500 deep on to the seabed early yesterday comes despite warnings from Louisiana state health officials, scientists and fishermen that the technique is untested and potentially hazardous to marine life and the wider ecosystem. Louisiana officials claim BP and the EPA ignored their concerns about how the chemicals may harm the sea floor.
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But it is the use of the chemical dispersant in such depths that has become the increasing focus of concern. Until now, Corexit 9500 has been approved for surface use only.
Corexit 9500 has been identified as a "moderate" human health hazard that can cause eye, skin or respiratory irritation with prolonged exposure. Its makers also warn that it has the tendency to "bioconcentrate" in the environment.
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Another toxiciology expert, Dr William Sawyer, who has made a presentation to the US lawyers representing environmental and other interests after the spill has added to the concern: "The dispersants used in the BP clean-up efforts, known as Corexit 9500 and Corexit EC9527A, are also known as deodorized kerosene," he told the group. "With respect to marine toxicity and potential human health risks, studies of kerosene exposures strongly indicate potential health risks to volunteers, workers, sea turtles, dolphins, breathing reptiles and all species which need to surface for air exchanges, as well as birds and all other mammals. Additionally, I have considered marine species which surface for atmospheric inhalation such as sea turtles, dolphins and other species which are especially vulnerable to aspiration toxicity of Corexit 9500 into the lung while surfacing."
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