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
Environmental impact of the Deepwater Horizon oil spill that the damage from the spill would rapidly resolve, three years into the recovery dolphins continue to die, fish are showing strange lesions, corals in the gulf have died and oil still remains in some marsh areas. Due to both its size and the way it was handled, there is little previous research to predict long-term effects. At the 2013 "Gulf of Mexico Oil Spill and Ecosystem Science Conference", oceanographer David Hollander presented data that showed as much as one-third of the oil released during the spill may still be in the gulf. Researchers described a phenomenon called "dirty blizzard":