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
Oil spill volume is a limited measure of damage or impact. Smaller spills have already proven to have a great impact on ecosystems, such as the "Exxon Valdez" oil spill because of the remoteness of the site or the difficulty of an emergency environmental response. Since 2004, between 300 and 700 barrels of oil per day have been leaking from the site of an oil-production platform 12 miles off the Louisiana coast which sank in the aftermath of Hurricane Ivan. The oil spill, which officials estimate could continue throughout the 21st century, will eventually overtake the 2010 BP Deepwater Horizion disaster as