Ed, you’ve come here from Louisiana and, of course, this amazing oil spill from Deepwater Horizon. A terrible disaster, you’re the expert on it as Louisiana State University man, but what has this got to do with cancer?

Well the oil spill was not simply oil going into the water, there was this massive spill of five million barrels which is substantially larger than any other accidental spill ever. The truth is nobody knows the long-term effects but the oil, number one, some of it was on the surface and burnt off, so some of it was vaporised. There is natural gas that came up and, of course, that went into the atmosphere. Then the oil company, to diminish the effects, added something called a dispersant and the dispersant is controversial in and of itself. Petroleum contains benzene, polycyclic aromatic hydrocarbons, a number of heavy metals and the Corexit, which is the name of the dispersant, there were two kinds of dispersants used but they were both called Corexit with different numbers after them, that contains a carcinogen as well. So there are known carcinogens in the petroleum, there are known carcinogens in the dispersant and people were exposed to these.

OK, so there’s been exposure. What are the data about how big the risk might have been?

The answer is we really don’t know yet and the reason we don’t know is because nobody has ever followed a cohort of people who have been exposed to an oil spill beyond four years and that was only for mental health effects. So there were some immediate effects of what you would imagine – respiratory problems, skin rashes, there were some palsies that people reported – and then there were a weird variety of symptoms. Part of the problem is clinicians don’t know what to look for.

So you’re on an awareness raising campaign.

That’s part of it and part of it is we know some of the workers, some of the clean-up workers, there were seventeen people who were killed but of the other clean-up workers… they were killed by the explosion. Of the other clean-up workers they had varying degrees of exposure: some of them were touching it, some of them were trying to clean it off the surface and their clothes became soaked with the oil. It was too hot to wear protective gear so if the clean-up workers put on protective gear they would pass out due to heat exhaustion so that quickly went out the window.

So some of the main exposure was from workers dispersing this oil spill?

Absolutely, workers who were assigned to clean up the spill.

But oil spills have happened before so what’s special about this one, then? I know it was big, you said.

It was big, it was a lighter type of oil so more evaporated quickly which is good for the surrounding community but very bad for the people who were working in the area because they had much more inhalation. We know that cancer is a disease of long latency and so if somebody claims now they have cancer from the oil spill I’m sceptical. But we do anticipate that there will be some hematologic cancers occurring, a possibility of lung cancer, a possibility of any of the major systems that were affected. The other important piece is that the Gulf of Mexico is a great source of fish and shellfish so the oil that did not evaporate and was not cleaned up sank. So you have shrimp, you have fish, you have all kinds of sea-life swimming through that.

So we’re going to end up eating it?

Right, so it’s in the food chain and it’s in the marshes where the babies start developing. It’s in plankton and so as it goes up the food chain people who eat this on a daily basis, which does happen in New Orleans…

Right, New Orleans seafood is one of the reasons people come to New Orleans and so eating the seafood that’s containing incorporated benzene may be a problem, that’s incorporating any of the petrochemicals that are carcinogenic may be a problem.

So finally, then, your interim assessment because it’s now a couple of years down the line, two or three years down the line, what is your interim assessment of the cancer risks from Deepwater Horizon?

It’s still too early to tell. What we do know is that there is one other important pathway that I need to mention and that is degree of emotional stress. This is a highly stressed population to begin with; they went through Hurricane Katrina, they lost their homes. They went through an economic downturn. They had two more hurricanes and then the oil spill. The oil spill made them lose their income and so we have much more depression and anxiety, an increase in smoking and alcohol use and so we know, from a variety of other studies, that chronic stress increases inflammation and increased inflammation is related to both metabolic syndrome and a variety of cancers.

Smoking and drinking doesn’t help either.

That’s right. So right now I would be very surprised if anybody claiming they had cancer could say it was due to the exposure from this oil spill. However, we’ve established a cohort of women and children, some of the women are wives of the clean-up workers, the children are the children of these families, because nobody knows what happens to susceptible populations.

And you’re keeping a close watch on these?

We’re keeping a close watch. We’re interviewing them, we’re collecting biological samples and we need to be able to follow people over the course of time.

So what’s the take home message, then, for cancer specialists, cancer clinicians generally and patients in other parts of the world, the lessons that can be learned from this event?

The first lesson is protect yourself if this ever happens again. The second thing is that probably moderate your seafood consumption if this happens in an area where that’s a common source of food. The third thing for clinicians is to be on the look-out for changes in lung function, for changes in skin rashes or potentially skin cancers and then in the long-term there won’t be enough cases to justify screening everybody for lymphoma or leukaemia but it is a possibility. So there’s a lot we don’t know but if nobody starts and studies it we will never know.

Well thank you for starting us on that path, Ed. Thanks for joining us on ecancer.tv.