GuLF Study Environmental Health Sciences (NIEHS), part of the National Institutes of Health, and aims to recruit 55,000 of the 150,000 workers who volunteered or were employed to help clean up the spill. It is led by Dale Sandler, head of the NIEHS's epidemiology branch. The "Deepwater Horizon" oil spill was the world's largest accidental marine oil spill. It began on 20 April 2010 after an explosion on the "Deepwater Horizon", a drilling rig leased by BP to drill an exploratory well. Between then and 15 July, when the well was capped, over four million barrels of oil (around 170 million US
Reactions to the Deepwater Horizon oil spill this spill with everything we've got for as long as it takes. We will make BP pay for the damage their company has caused. And we will do whatever's necessary to help the Gulf Coast and its people recover from this tragedy." The President was later reported to have said that "his frustration over the mammoth oil spill in the Gulf of Mexico is not an attack on Britain" and that he had "no interest in undermining BP's value", as the two leaders tried to soothe trans-Atlantic tensions over the disaster. On 4 July 2010, the federal government announced that