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
Deepwater Horizon oil spill leaked oil had been greatly exaggerated. However, biogeochemist Chris Reddy, said natural microorganisms are a big reason why the oil spill in the Gulf of Mexico was not far worse. Genetically modified "Alcanivorax borkumensis" was added to the waters to speed digestion. The delivery method of microbes to oil patches was proposed by the Russian Research and Development Institute of Ecology and the Sustainable Use of Natural Resources. On 18 May 2010, BP was designated the lead "Responsible Party" under the Oil Pollution Act of 1990, which meant that BP had operational authority in coordinating the response. The first video