Overview

The Deepwater Horizon oil spill (also referred to as the BP Oil Spill, the Gulf of Mexico oil spill, or the Macondo blowout) is a massive ongoing oil spill stemming from a sea floor oil gusher in the Gulf of Mexico that started with an oil well blowout on April 20, 2010. The blowout caused a catastrophic explosion on the Deepwater Horizon offshore oil drilling platform that was situated about 40 miles (64 km) southeast of the Louisiana coast. Eleven platform workers are missing and presumed dead; the explosion also injured 17 others. The gusher originates from a deepwater oil well 5,000 feet (1,500 m) below the ocean surface. Estimates of the amount of oil being discharged range from BP's current estimate of over 5,000 barrels (210,000 US gallons; 790,000 litres) to as much as 100,000 barrels (4,200,000 US gallons; 16,000,000 litres) of crude oil per day. The exact spill flow rate is uncertain - in part because BP has refused to allow independent scientists to perform accurate measurements - and is a matter of ongoing debate. The resulting oil slick covers a surface area of at least 2,500 square miles (6,500 km2), with the exact size and location of the slick fluctuating from day to day depending on weather conditions. Scientists have also discovered immense underwater plumes of oil not visible from the surface. (wikipedia)

Oil dispersants are a common tool used after oil spills to remove oil slicks from the water surface and increase the oil's rate of biodegradation. By removing large slicks, oil dispersants are intended to reduce harmful oil exposures of birds, fish, and other wildlife in proximity to spills. Two oil dispersant products have been in heavy use during the current BP oil leak: COREXIT 9500 and 9527, both produced by Nalco. BP has used over 800,000 gallons of dispersant since the start of the oil leak (Buchanan).

Human and environmental health concerns

• BP's Oil Spill - A Health Disaster for Generations to Come by Jessica Marie Little in Healthy Child Healthy World

• The Oil Spill's Effects on Life Underwater NY Times
  

References

• Deepwater Horizon oil spill - wikipedia
• Encyclopedia of Earth - Ocean-Oil