Doctors reported that behavioral and mental health issues spurred by last year's BP PLC oil spill may have a deeper impact on Gulf Coast residents than adverse health effects from oil and chemical exposure.

The review, published yesterday in the New England Journal of Medicine, used data from past oil spills as well as the Gulf of Mexico spill.

Emotional effects that may stem from oil spills are headaches, pains and insomnia -- symptoms associated with stress and anxiety, said Howard Osofsky, one of the authors of the review.

The authors acknowledged uncertainty about the true effects of the spill and that the federal government's delay in studying the spill's health effects would limit experts' full understanding of those issues.

Waiting to study the effects could cause confusion, the authors of the review said. Some health markers fade after a certain amount of time has passed while more persistent effects "are likely to be confounded by other types of exposures."

Other less-understood factors are the health effects for children and oil cleanup workers.

"There have been few studies of longer term health consequences" in the population of workers who were exposed to the spill at its freshest, the study said.

Another problem the authors faced was drawing connections between previous spills and the one in the Gulf, which stands alone as the most severe in U.S. history.

"The intensity of exposure as well as the duration of exposure in this scenario, due to its ongoing release as opposed to an acute oil spill, are different," said William Sawyer, a toxicologist who has been tracking the effects of the spill on the Gulf Coast. "We may find that we have a higher percentage of long-term effects than published in the other studies."

Further complicating the findings is the fact that it is difficult to isolate the spill's direct health effects. Residents of the Gulf states already suffer from significant health problems such as higher mortality rates from cancer and cardiovascular disease.

Pinpointing the exact health effects of the spill is important because it will allow medical professionals to begin helping people who have been affected, said Wilma Subra, a chemist who provides technical assistance to the Louisiana Environmental Action Network.

"Not only are we not prepared to handle the amount of crude that was spilled into the Gulf and not prepared to handle the environmental impact, but clearly the human health impacts are not being addressed," she said (Campbell Robertson, New York Times, April 6). -- PK