Updated

The U.S. federal government next week will launch a massive study to determine whether workers who helped clean up last year's Gulf of Mexico oil spill are getting sick as a result of those jobs, The Wall Street Journal reported Monday.

The study was commissioned after some cleanup workers reported chest pain, headaches, breathing difficulties and other ailments that they believed were linked to the oil spill, said Dale Sandler, chief of the epidemiology branch of the National Institute of Environmental Health Sciences, the government office heading the study.

"There are people who are sick," she said. "Are they sick from the oil? Maybe, but we don't know."

The study, funded with an initial $8 million from the government and $6 million from BP PLC, aims to follow 55,000 former cleanup workers for up to a decade. It will be the biggest study ever of an oil spill's health effects, federal officials said. It will look at everything from skin rashes to respiratory problems to potential increased cancer risk.

The BP spill poured an estimated 4.1 million gallons of oil into the Gulf between late April, when the Deepwater Horizon drilling rig exploded, and mid-July, when the leaking well was capped.

At the height of the spill cleanup, in mid-July, some 47,000 people were working on it, officials said. Some shuffled paper in offices. Some shoveled oil off beaches. Some manned boats near the site of the ruptured well, skimming and burning the slick of oil off the Gulf's surface. About 7,000 people are working on the cleanup, officials said.

The BP money for the study comes from a $500 million fund the oil company set up to fund scientific research in the wake of the spill. BP did not design the study and will not help conduct it, government and BP officials said. BP wanted "an independent and credible review" of any potential link between cleanup workers' heath problems and the spill, said Richard Heron, BP's chief medical officer. The government scientists overseeing the worker health study are "very credible," he said.

The study's findings could, indirectly, raise BP's bill for the spill. Lawyers often use epidemiological studies as ammunition in lawsuits contending environmental incidents such as spills injured their clients.

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