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
Deepwater Horizon oil spill figure, saying that the government overestimated the volume. Internal emails released in 2013 showed that one BP employee had estimates that matched those of the FRTG, and shared the data with supervisors, but BP continued with their lower number. The company argued that government figures do not reflect over of oil that was collected or burned before it could enter the Gulf waters. According to the satellite images, the spill directly affected of ocean, which is comparable to the size of Oklahoma. By early June 2010, oil had washed up on of Louisiana's coast and along the Mississippi, Florida, and