A new study suggests that BP's use of dispersants during the 2010 Gulf oil spill likely allowed oil to penetrate beaches more deeply, making harmful effects last longer.
"In an attempt to deal with the 206 million gallons of light crude oil erupting from the Deepwater Horizon blowout in 2010 BP unleashed about 2.6 million gallons of Corexit dispersants (Corexit 9500A and Corexit EC9527) in surface waters and at the wellhead on the seafloor. From the beginning the wisdom of that decision was questioned. I wrote extensively about those concerns in BP's Deep Secrets.
In the short term the dispersed oil made BP's catastrophe look like less of a catastrophe since less oil made it to shore. But what about the long term?
In a new paper in PLOS ONE researchers took a closer look. They examined the effects of oil dispersed mechanically (sonication), oil dispersed by Corexit 9500A, and just plain seawater (the control). They used laboratory-column experiments to simulate the movement of dispersed and nondispersed oil through sandy beach sediments.
Their findings: Corexit 9500A allows crude oil components to penetrate faster and deeper into permeable saturated sands where the absence of oxygen may slow degradation and extend the lifespan of potentially harmful polycyclic aromatic hydrocarbons (PAHs), aka organic pollutants—aka persistently abominable hork—in the marine environment."
Julia Whitty reports for Mother Jones November 29, 2012.
