The National Institutes of Health began a major study today of the impact of last summer's Gulf of Mexico oil spill on the health of cleanup workers and volunteers.

The study, which will be conducted by the National Institute of Environmental Health Sciences (NIEHS), will be the largest ever conducted on an oil spill's health effects.

The Gulf Long-Term Follow-up Study, or GuLF Study, will survey 55,000 cleanup workers and is expected to last up to 10 years and cost more than $10 million.

"Over the last 50 years, there have been 40 known oil spills around the world," said NIEHS epidemiologist and study leader Dale Sandler in a statement. "Only eight of these spills have been studied for human health effects. The goal of the GuLF STUDY is to help us learn if oil spills and exposure to crude oil and dispersants affect physical and mental health."

The study will reach out to about 100,000 people who worked on the oil spill cleanup in Louisiana, Mississippi, Alabama and Florida.

Some study participants will be asked to provide information in a telephone interview, with about 20,000 people being asked to enroll in a second phase that will involve a home visit; the submission of samples of blood, urine, toenail clippings, hair and house dust; and follow-up interviews.

Local groups who began monitoring the health effects of the oil spill paved the way for the NIH study.

NIH has set aside $10 million for the study, but NIEHS Director Linda Birnbaum said last August that more money would be needed (Greenwire, Aug. 19, 2010).

BP PLC, the oil company whose ruptured well started the spill last April, has since pledged another $10 million for the study from its Gulf of Mexico Research Initiative (Greenwire, Sept. 7, 2010).

The BP effort has critics on Capitol Hill, where House Democrats have warned the company not to "muzzle scientists" through confidentiality agreements (E&E Daily, July 30, 2010).