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
Volume and extent of the Deepwater Horizon oil spill over areas of the gulf to document the scope of the disaster. Meanwhile, Phil Radford documented BP's methods of escaping liability and keeping people hired to clean the oil spill out of areas affected by the oil spill. These accusations were leveled at BP, its contractors, local law enforcement, USCG, and other government officials. Scientists also complained about prevention of access to information controlled by BP and government sources. BP stated that its policy was to allow the media and other parties as much access as possible. On 30 June 2010, the USCG put new restrictions in place across the