How Will The Gulf Oil Spill Affect Human Health?

Gerald Ingraham looks out while vacuuming oil near oiled marsh grass in Barataria Bay. i i

A cleanup worker vacuums oil near sullied marsh grass in Barataria Bay on the coast of Louisiana. Patrick Semansky/AP hide caption

itoggle caption Patrick Semansky/AP
Gerald Ingraham looks out while vacuuming oil near oiled marsh grass in Barataria Bay.

A cleanup worker vacuums oil near sullied marsh grass in Barataria Bay on the coast of Louisiana.

Patrick Semansky/AP

Medical researchers are meeting this week in New Orleans to discuss the health effects of the ongoing oil spill in the Gulf of Mexico. But most of the discussion is about what isn't known.

The workshop was pulled together in a matter of days by the Institute of Medicine, a prestigious independent body chartered by Congress. Health and Human Services Secretary Kathleen Sebelius asked for the review.

Even though oil spills are fairly common, scientists at the two-day workshop say there's surprisingly little research on how they affect human health.

Since the 1960s, one researcher notes, there have been more than 30 major oil spills, nearly all of them involving shipwrecked tankers. But only about a quarter of them have been studied for toxic effects on humans. And the studies that have been done are often small and without comparison between groups of oil-exposed and unexposed people. In addition, none has so far looked at long-term consequences of exposure, such as cancer incidence.

At the end of a long day of questions and answers on what's known about the effects of oil spills on humans, activist John Hosey pretty much summed up the situation.

"The answers that people are getting are much like the oil coming out of the floor of the ocean," Hosey told the assembled scientists. "There's a lot of it coming up, but none of it's worth very much." Hosey is a clergyman with the Mississippi Interfaith Disaster Task Force.

Concern About Long-Term Problems

None of the distinguished researchers in the audience disagreed with his assessment.

That doesn't mean there's consensus on what evidence there is. Dr. Scott Barnhart of the University of Washington is on the side that doubts there's much reason to worry.

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    A boat uses a boom and absorbent material to soak up oil in Cat Bay, near Grand Isle, La., on June 28. A tropical storm is expected to hit the Gulf and impede cleanup efforts.
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    Florida Gov. Charlie Crist and wife Carole Rome Crist (right) stand with others during a Hands Across the Sand event June 26 in Pensacola, Fla. The event was staged across the nation to protest offshore oil drilling.
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    Oil clouds the surface of Barataria Bay near Port Sulpher, La., on June 19.
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    Workers adjust piping while drilling a relief well at the site of the Deepwater Horizon oil spill.
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    A dolphin rises up out of the water near Grand Terre Island off the coast of Louisiana on June 14.
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    President Obama stands with Mississippi Gov. Haley Barbour (right) and Gulfport, Miss., Mayor George Schloegel after meeting with residents affected by the oil spill.
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    Crude oil washes ashore in Orange Beach, Ala., on June 12. Oil slicks, 4 to 6 inches thick in some parts, have washed up along the Alabama coast.
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    A volunteer uses a toothbrush to clean an oil-covered white pelican at the Fort Jackson Oiled Wildlife Rehabilitation Center in Buras, La., June 9.
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    A shrimp boat skims oil from the surface of the water just off Orange Beach, Ala., as a family enjoys the surf. Oily tar balls have started washing up on Orange Beach and beaches in the western Florida panhandle.
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    Sand from a dredge is pumped onto East Grand Terre Island, La., to provide a barrier against the Deepwater Horizon oil spill, June 8.
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    A dead turtle floats on a pool of oil from the Deepwater Horizon spill in Barataria Bay off the coast of Louisiana on June 7.
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    Workers use absorbent pads to remove oil that has washed ashore from the spill in Grand Isle, La., June 6.
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    Plaquemines Parish coastal zone director P.J. Hahn lifts an oil-covered pelican out of the water on Queen Bess Island in Plaquemines Parish, La., June 5.
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    Heavy oil pools along the side of a boom just outside Cat Island in Grand Isle, La., June 6.
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    President Obama walks alongside Grand Isle Mayor David Camardelle (from right), U.S. Coast Guard Adm. Thad Allen, who is in charge of the federal response to the spill, and Chris Camardelle after meeting with local business owners in Grand Isle, La., June 4.
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    A brown pelican sits on the beach at East Grand Terre Island along the Louisiana coast after being drenched in oil from the BP Deepwater Horizon oil spill, June 3.
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    U.S. Attorney General Eric Holder announces that the Justice Department has launched a criminal investigation into the BP oil spill. With him, from left: Stephanie Finley and Jim Letten, U.S. attorneys for the Western District of Louisiana; Ignacia Moreno, assistant attorney general for the Environment and Natural Resources Division; Tony West, assistant attorney general, Civil Division; and Don Burkhalter, U.S. attorney for the Southern District of Mississippi.
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    The oil slick off the coast of Louisiana, seen from above.
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    A worker leaves the beach in Grand Isle, La., on May 30. BP is turning to yet another mix of undersea robot maneuvers to help keep more crude oil from flowing into the Gulf.
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    Protesters cover themselves with a water and paint mixture during a demonstration at a BP gas station in New York City on May 28.
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    Workers clean up oil in Pass a Loutre, La. The latest attempt to plug the leak was unsuccessful.
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    Residents listen to a discussion with parish officials and a BP representative on May 25 in Chalmette, La. Officials now say that it may be impossible to clean the hundreds of miles of coastal wetlands affected by the massive oil spill.
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    An oil-soaked pelican takes flight after Louisiana Fish and Wildlife employees tried to corral it on an island in Barataria Bay on the coast of Louisiana. The island, which is home to hundreds of brown pelican nests as well at terns, gulls and roseate spoonbills, is impacted by oil from the Deepwater Horizon spill.
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    A sign warns the public to stay away from the beach on Grand Isle, La. Officials closed the oil-covered beaches to the public indefinitely on Saturday.
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    Pelican eggs stained with oil sit in a nest on an island in Barataria Bay on May 22.
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    A bird flies over oil that has collected on wetlands on Elmer's Island in Grand Isle, La., May 20. The oil came inland despite oil booms that were placed at the wetlands' mouth on the Gulf of Mexico.
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    Members of the Louisiana National Guard build a land bridge at the mouth of wetlands on Elmer's Island.
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    The hands of boat captain Preston Morris are covered in oil after collecting surface samples from the marsh of Pass a Loutre, La., on May 19.
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    Louisiana Gov. Bobby Jindal (center) and Plaquemines Parish President Billy Nungesser (right) tour the oil-impacted marsh of Pass a Loutre, La. "This is the heavy oil that everyone's been fearing that is here now," said Jindal.
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    BP Chairman and President Lamar McKay (left), with Transocean President and CEO Steven Newman (center) and Applied Science Associates Principal Deborah French McCay, testifies during a Senate Committee on Commerce, Science, and Transportation hearing May 18 on response efforts to the Gulf Coast oil spill.
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    This undated frame grab image received from BP and provided by the Senate Environment and Public Works Committee shows details of the oil spill in the Gulf of Mexico. BP has agreed to display a live video feed of the oil gusher on the Select Committee on Energy Independence and Global Warming Committee's website beginning Thursday evening.
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    President Obama speaks with local fishermen about how they are affected by the oil spill in Venice, La., on May 2.
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    Danene Birtell with Tri-State Bird Rescue and Research tends to a Northern Gannet in Fort Jackson, La., on April 30. The bird, normally white when full grown, is covered in oil from the oil spill.
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    Since the explosion, a third oil leak has been discovered in the blown-out well.
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    In this aerial photo taken April 21 more than 50 miles southeast of Venice, La., the Deepwater Horizon oil rig burns.
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    Tendrils of oil mar the waters of the Gulf of Mexico in this satellite image taken Monday. An estimated 5,000 barrels of oil a day are seeping into the Gulf, after an explosion last week on a drilling rig about 50 miles off the Louisiana coast.
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It's true, Barnhart says, that cleanup workers exposed to crude oil often suffer acute effects — stinging eyes, rashes, nausea, dizziness, headaches, coughs and other respiratory symptoms.

But Barnhart is not unduly concerned. "Any of these effects I don't think we would expect to be permanent," he says. "We would expect these to be reversible."

Barnhart also says there's no convincing evidence that people exposed to crude oil have more serious long-term problems, such as cancer.

"We should not have workers, volunteers, anybody exposed to significant quantities of crude oil," he says. "I mean, these [exposures] should be managed and avoided. At the same time, you know, the risk for particular carcinogens is probably quite small."

The 'Black Tides' Of Galicia

Probably the best study on that question was done by Blanca Laffon and her colleagues at the University of A Coruna in Spain, following the 2002 wreck of the tanker Prestige. The spill unleashed three "black tides" on the shores of Galicia, made up, Laffon says, of "a very complex mixture of chemicals — very viscous and water-insoluble."

The Spanish group tested several hundred cleanup workers, both professionals and volunteers, for evidence of DNA damage in the nuclei of their cells. The results were compared with similar people who were not exposed to the oil.

Laffon says exposure to oil did induce DNA damage that was greater in those with more exposure. DNA damage can be the first step along the path to cancer. However, when the research subjects were tested several months ago, the damage was repaired. "It did not become fixed as chromosomal damage," Laffon says, referring to more worrisome evidence of genetic toxicity.

The researchers are following up with more tests conducted seven years after the oil exposure.

But concern about oil toxicity goes beyond cleanup workers. In shoreline communities where spilled oil washes up, other people can get exposed, too. And Dr. Brenda Eskenazi of the University of California at Berkeley, who studies children, is far from convinced that oil spills pose no threat.

"Children are different," Eskenazi says. "They're not little adults. They're also less efficient at detoxifying and metabolizing chemicals."

Playing It Safe

Eskenazi says if she were pregnant and living in a Gulf community affected by the current oil spill, she would probably consider not eating fish – even though she acknowledges that there's been no evidence that contaminated fish has made it to market.

Her inclination, she says, "is based on a gut feeling, not data" –- and adds that she isn't recommending that pregnant women avoid eating fish.

But while there's a lot of uncertainty about the effects of the thousands of chemicals in crude oil on physical health, there's plenty of evidence about the toll it takes on mental health.

Dr. Howard Osofsky of Louisiana State University says people in the area are already showing the stresses and strains of living with the effects of the spill on their livelihoods and their way of life.

"One of our parish leaders the other day … said, 'Howard, this is the tip of the iceberg,' " Osofsky says. "We're seeing already an increase in suspiciousness, arguing, domestic violence. We're having reports from drug courts. We're already having reports of increased drinking, anxiety, anger and avoidance."

This is entirely consistent with what happened in 1989 when the Exxon Valdez tanker ran aground in Alaska. Lawrence Palinkas of the University of Southern California studied the aftereffects of that disaster on 22 communities in Alaska. He says the costs were incalculable.

Community And Individual Costs

"Fragmented families, failed marriages, community residents who no longer speak to each other or collaborate in community activities," Palinkas says. It's all part of the strong emotions generated by the disaster — including resentments over friends and family members who profited from it by working in the cleanup.

These community and individual costs "have to be taken into consideration when it comes to mitigating the consequences of oil spills," Palinkas says — although he acknowledges that in the orgy of litigation that followed the Exxon Valdez disaster, the courts ultimately rejected many such claims as "unquantifiable."

Palinkas says the Exxon Valdez aftermath showed that oil spills do affect the rate of physical illness — although not in the directly toxic way that many people imagine.

People in communities where the oil fouled the beaches had much higher incidence of post-traumatic stress disorder, depression and anxiety. And that mental stress, Palinkas says, translated into higher rates of heart attacks, high blood pressure, diabetes, respiratory disorders and other physical illnesses.

Correction June 23, 2010

The audio version of this story, as well as an earlier Web version, said oil toxins can cause mutations in mice that pass from one generation to another. The mutations in question were not caused by oil toxins, but by toxins from a different source.

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