DESTIN -- The oil is inescapable to the people of the Gulf Coast. Cleanup workers burn it at sea, skim it in boats. Residents smell its sheen, pick up its puddles
and tar balls with shovels. Tourists sometimes let their kids swim in
it.

What is the oil doing to human health? What about the chemicals used to disperse it?

Health officials don't know yet.

Even Jimmy Guidry, director of the Louisiana Department of Health, who says 108 workers and 35 residents have reported ailments they believe
are related to oil or dispersants, admits he can't prove the connection.

``It's hard to understand if nausea or dizziness or headache is related to the oil or to working in 100-degree heat in a [protective] suit,''
he said.

The lack of certainty led the U.S. Institute of Medicine, health arm of the National Academy of Sciences, to hastily convene a symposium of experts in New Orleans on Tuesday and Wednesday
seeking better understanding.

``Some scientists say there's little or no toxicity from the oil,'' U.S. Surgeon General Regina Benjamin told the group. ``Others express serious concerns.''

So far, most health problems among oil spill workers have been relatively mild, involving heat stress, respiratory problems, headaches and throat
irritations, U.S. Department of Health and Human Services spokeswoman
Lisa Kaplowitz told a U.S. Senate subcommittee last week.

Since then, 11 oil spill workers have been hospitalized briefly with nausea, dizziness and chest pains amid debate over whether they were caused by
a dock cleaning chemical, the oil dispersant Corexit, heat and fatigue
or a combination.

NO BOTHER

The oil doesn't bother Jamie Clayton of Atlanta. She brought her husband, Cameron, their 3-year-old son, Colby, and 17-month-old
daughter, Lottie, to the beaches at Seaside in Florida's Walton County
this week despite local tar ball sightings.

``We were actually picking it up and touching it to see how it felt. It didn't seem like a big deal,'' she said.

And when her children emerged from the surf with light brown tar specks on their feet, she stayed cool: ``Honestly, it wasn't anything a baby
wipe couldn't get rid of. If it was really dangerous, I'm sure they
would have posted a health advisory.''

In Louisiana, Guidry's department is posting advisories warning residents not to touch the oil in any form. One says: ``Skin contact with oil may cause irritation.
Oil particles in the air may also cause irritation of the eyes, nose,
throat and lungs.''

But the experts in New Orleans only underlined the lack of certainty about health effects of the oil.

``We have very scant information about oil spills from a few studies of oil tankers that have run aground,'' said John Howard, director of the
National Institute of Occupational Safety and Health.

Workers nearest the spill, burning the oil at sea, operating skimming boats, have the greatest exposure.

``Close to the plume, where vessels are working in fresh crude, the volatile compounds are not totally gone, including methane, vapors and
concentrated dispersants,'' Howard said.

And exposure to irritants such as hydrocarbons ``can have very serious effects. Carcinogens may be present,'' said Scott Barnhart, professor of
medicine at University of Washington.

By the time sheen, puddles or tar balls reach shore, more than 50 percent of the oil has evaporated. The remaining, weathered oil contains some, but fewer,
toxins, noted Edward Overton, professor of chemistry at Louisiana State
University.

Most residents who have breathed fumes from oil near the shore have suffered nothing worse than dizziness, nausea and vomiting, Kaplowitz said. And Guidry, Louisiana's health department
director, said hospital reports so far show no increase in asthma or
other respiratory ailments.

The safety of the dispersant, Corexit, that BP is using to break up the oil and keep it from reaching shores, also is being debated. Several cleanup workers have said they
developed nausea, dizziness and throat irritation from Corexit, but
officials said they couldn't prove the dispersant was the cause.

On May 20, the EPA, which earlier had approved BP's use of Corexit, ordered BP to find a less toxic substitute. BP wrote back that it would
continue using it: ``Corexit appears to have fewer long-term effects
than the other dispersants evaluated.''

Nalco, the dispersant's manufacturer, said on its website that Corexit falls within EPA toxicity guidelines: ``All of the ingredients are safe and found in
common household products such as food, hand and body lotion,
packaging, cosmetics and household cleaners.''

The EPA countered by ordering BP to stop spraying any dispersant on the surface of Gulf waters, and limited it to 15,000 gallons a day underwater, near the
blown-out well.

LOOKING INTO FUTURE

Long-term effects of oil exposure are even less well-understood.

``How do you separate today's oil in the environment from genetics, lifestyle choices and ongoing stresses if something happens 20 years
from now?'' asked Guidry.

Studies of intense, long-term exposure to heavy crude oil have shown an association with peripheral neuropathy, or damage to nerves in feet and hands, said Peter Spencer,
professor of neurology at Oregon Health and Science University.

``But that's very different from the oil in the Gulf,'' which is lighter, he said.

One chilling note at the New Orleans symposium was the discussion of a Spanish study after the Prestige oil tanker spill of 2002, which left
more than 100,000 tons of oil on the North Atlantic coast of Galicia.
The study said volunteers cleaning birds and rocky shores experienced
damage to their DNA.

The damage tended to repair itself over time, and did not turn into health-threatening alterations of their chromosomes, said Blanca Laffon, a toxicologist at Spain's University
of A Coruna. .

Still, the DNA damage worried government officials. And National Institutes of Health director Francis Collins last week set aside $10 million for more research into the Spanish
incident.

Psychologically, Gulf Coast residents have been holding up relatively well, officials said. But Thursday, CNN and other news outlets reported that the captain of an Alabama fishing boat had
committed suicide, and friends said he was despondent about losing his
way of life because of the oil spill.

Long-term, psychological problems could be a problem, said Lawrence Palinkas, professor of social policy at University of Southern California. He took part in a
study of 22 Alaskan communities a year after the 1989 Exxon Valdez oil
spill.

``There were increased rates of drinking, drug use, fighting among family and friends, declines in social relationships,'' he said.