“This is the largest, most comprehensive spill response mounted in the history of the United States and the oil and gas industry,” BP chief executive Tony Hayward said. Is it the correct response? BP is using chemicals, known as dispersants, to thin out the oil. These agents break up and “disperse” the oil. Sounds like a good idea, right?
Not really. Propublica says using dispersants means that “instead of having the oil collect at the surface, dispersed droplets of oil can spread more quickly and in more directions.” The dispersed droplets “linger longer in the water, collecting on the seabed and harming the ecosystem offshore.”
Toxicology experts agree that dispersants cause great harm to marine life and anyone exposed to them. Dr. William Sawyer, toxicology expert, said the dispersants being used in the Gulf of Mexico, Corexit 9500 and Corexit EC9527A, are “also known as deodorized kerosene.” He went on to say that 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.”
A report on oil dispersants by the National Academy of Sciences said that the use of dispersants “represents a conscious decision to increase the hydrocarbon load (resulting from a spill) on one component of the ecosystem (e.g., the water column) while reducing the load on another (e.g., coastal wetland).”
“One of the most difficult decisions that oil spill responders and natural resource managers face during a spill is evaluating the trade-offs associated with dispersant use,” said the Academy report. “There is insufficient understanding of the fate of dispersed oil in aquatic ecosystems.”
Carys Mitchelmore, assistant professor at the University of Maryland’s Chesapeake Biological Laboratory, told McClatchy, “There’s research out there that shows that dispersed oil is more toxic than the oil itself, and then there are studies that say it’s the same. The big questions are what are the long-term or delayed effects, and how will the different routes of oil exposure due to dispersant use affect exposed organisms?”
Given what experts are saying about dispersants, why did the Environmental Protection Agency (EPA) authorize their use? The EPA’s website claims that the authorization “included specific conditions to ensure the protection of the environment and the health of residents in affected areas.” BP can only use dispersants on the surface of the water, and the EPA says it is “monitoring air quality in the Gulf area through air monitoring air craft, and fixed and mobile air stations.” In other words, dispersants are toxic, but don’t worry, the EPA is monitoring their use.
David Pettit of the Natural Resources Defense Council said using dispersants is a trade-off. Dispersants help stop oil from making it to the shore, but are “toxic to marine life.” Pettit added, “And just because humans can’t see oil on the surface doesn’t mean it’s not still in the water column, affecting marine life from plankton to whales.”