Health consequences of the Deepwater Horizon oil spill effects, while even very low doses can cause mutagenic effects, with cancer of particular concern. The carcinogens of concern in crude oil are benzene and polycyclic aromatic hydrocarbons (PAHs), which are present in oil and in the air as a result of offshore controlled burning of crude oil. During the 2010 BP/Deepwater Horizon Gulf oil spill, an estimated one of every 20 barrels of spilled oil was deliberately burned off. Routes of exposure include contact and inhalation. The EPA obtained hundreds of air samples during the spill and a review showed that none of the samples showed concentrations of benzene
Gulf of Mexico Coast Guard Rear Adm. Sally Brice O'Hare stated that the U.S. government will be "employing booms, skimmers, chemical dispersants and controlled burns" to combat the oil spill. By May 1, 2010, the oil spill cleanup efforts were underway, but hampered by rough seas and the "tea like" consistency of the oil. Cleanup operations were resumed after conditions became favorable. On May 27, 2010, The USGS had revised the estimate of the leak from to 12,000– an increase from earlier estimates. On July 15, 2010, BP announced that the leak stopped for the first time in 88 days. In July 2015