Study looks at concentrations of oil and dispersant in ‘sand patties’ found along the Gulf Coast
Read more Summit Voice stories about dispersants and the aftermath of the Deepwater Horizon spill here.
By Summit Voice
FRISCO — Fossil fuel companies involved in offshore oil drilling may have to rethink their emergency response plans for oil spills after a new study showed that dispersant used to prevent large slicks persists in the environment much longer than previously thought.
Scientists at Haverford College and Woods Hole Oceanographic Institution (WHOI) has found that the dispersant compound DOSS, which decreases the size of oil droplets and hampers the formation of large oil slicks, remains associated with oil and can persist in the environment for up to four years.
The EPA approved the use of massive quantities of dispersant after the 2010 Deepwater Horizon oil disaster in hopes of preventing oil from fouling beaches, reasoning that the chemicals degrade rapidly. The Deepwater oil spill was the largest ever, releasing at least 210 million gallons of oil. BP applied almost 2 million gallons of dispersant, much of it deep beneath the surface.
But it’s far from clear that the use of dispersant is an overall environmental benefit. Ongoing studies have shown that the mixture of dispersant and oil is far more toxic to many marine organisms than either substance on its own. For example, a study by scientists with the Georgia Institute of Technology and Universidad Autonoma de Aguascalientes, Mexico showed that the oil-dispersant mix was up to 52 times more toxic to tiny rotifers, microscopic grazers at the base of the Gulf’s food chain. Continue reading