In efforts to mitigate the devastating underwater petroleum leak caused by the explosion of the Deepwater Horizon oil rig in 2010, BP used controversial oil-dispersing chemicals that have long been suspected to do more harm than good. The clean-up—in which two million gallons of dispersant were combined with crude oil—created a mixture that could be 52-times more toxic than oil alone, according to new research from the Georgia Institute of Technology and Universidad Autonoma de Aguascalientes (UAA), Mexico.
The dispersants break up oil floating atop the sea into tiny droplets that dilute with water just beneath the surface. Although beneficial to various species such as sea turtles, birds and mammals, the process is highly damaging to microscopic organisms that regulate entire aquatic ecosystems. Lab tests have proved that the mixture’s effects increased mortality of rotifers, microscopic plankton-like organisms at the base of the Gulf’s food chain. The rotifer egg hatching was inhibited by 50 percent, when affected by as little as 2.6 percent of the oil-dispersant mixture.
“Dispersants are preapproved to help clean up oil spills and are widely used during disasters… But we have a poor understanding of their toxicity. Our study indicates the increase in toxicity may have been greatly underestimated following the Macondo well explosion,” said UAA’s Roberto-Rico Martinez, who led the study.
The research, released online, will also be published in print, in the February 2013 issue of the scientific journal Environmental Pollution.
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