On April 20, 2010, a major explosion occurred on the Deepwater Horizon oil rig in the Gulf of Mexico. A fire ensued, 11 lives were lost, and thousands and thousands of gallons of oil starting pouring out from broken risers into the Gulf. Many attempts to contain the oil have failed. The resulting oil sheen and emulsified crude slick that contaminate the Gulf and have settled along the coastline and marshes of Alabama, Louisiana and Florida constitute the worst oil spill in U.S. history. In his testimony before the Senate Subcommittee on Health, Committee on Energy and Commerce on June 15, 2010, the NIH Director pledged support from the Office of the Director and the NIH Common Fund for research to be led by the National Institutes of Environmental Health Sciences (NIEHS) into the environmental health hazards posed by the Gulf oil spill. Current plans are for NIEHS intramural researchers to launch the Gulf Long-term Follow-up (GuLF) prospective study of clean-up workers, and for toxicological studies to be conducted through the National Toxicology Program. The efforts will complement and be coordinated with response efforts of other agencies and institutions working in the Gulf region.