AdvertisementLasting Impact Of Dispersants Unclear, Senate ToldAugust 04, 2010Christopher JoycefacebookEmailAlmost 2 million gallons of oil dispersants were used to dilute the oil spill in the Gulf of Mexico, and though testing indicates the toxic chemical has largely dissipated in the water, scientists warn that the long-term effects are still unknown. Above, a dispersant plane passes over an oil skimmer in the Gulf of Mexico. (AP)