Who's making sure Gulf seafood safe to eat?

The shopper stood staring at the large, ice-covered shrimp in the chiller case of the high-end Seattle grocery.

"Fresh. Wild Gulf Shrimp. Never Frozen. $16.99 lb." read the sign.

"They're my favorites, but are they safe?" the woman asked the fishmonger.

"We couldn't and wouldn't sell them if they weren't," he answered, adding quickly that someone is testing the hell out of everything coming from the Gulf of Mexico.

He was telling the truth, but several questions remain to be answered for consumers:

• Petroleum contamination is known to cause cancer and brain damage. But how much oil and gas does it take to make seafood dangerous?

• Who's in charge of determining how safe is safe?

• The Food and Drug Administration (FDA) is supposedly the nation's food protector. What exactly is FDA's role in this process?

AOL News spent the past two weeks chasing down precisely who is doing that testing and how they decide what is safe to eat. Public-health experts say they are not concerned about E. coli or salmonella coming from seafood heavily tainted with oil. What they fear is the possibility of cancer or neurological impact.

Analyzing whether dangerous contaminants are in the seafood is an intricate process that uses a complex array of CSI-like instruments that can find bad things down to the parts per billion level.

But these are everyday tasks for marine biologists, toxicologists and other technical wizards in Louisiana state laboratories in Baton Rouge and in the National Oceanic and Atmospheric Administration's (NOAA) Northwest Fisheries Science Center in Seattle. These are the two primary sites scrutinizing thousands of samples of shrimp, crab and fin fish gathered from the Gulf.

The multiple chemical analyses have detected no harmful level of contaminants, both labs say. But the scientific determination of whether the seafood is tainted from the still-flowing oil is only half the battle.

The decision to declare food safe or unsafe appears to be a thornier debate, sometimes fraught with political implications, finger-pointing and, occasionally, debilitating fear of saying or doing the wrong thing.

"Government decisions on what should or should not be done with potentially contaminated food are often influenced by everyone who has a stake in the outcome," said Jay Shimshack, an assistant professor of environmental economics at Tulane University.

"In this case, we might reasonably expect the oil industry or its lobbying organizations to represent their own interests during the relevant policymaking process."

This is how the concerns among the players appear to break down:

• BP and other oil interests want the food declared safe to limit its liability and to halt further erosion of the industry's reputation.

Crabbers, shrimpers, fishermen and processors want to continue selling the oil-free seafood they're harvesting and keep longtime commercial customers — some better restaurants and persnickety shoppers — from fleeing to foreign suppliers.

Public-health experts just want to ensure the safety of what's being sold.

However, the wording of the public advisories is crucial.

Shimshack, the Tulane professor, an expert on risks and benefits of seafood consumption, cautions that consumers tend to overreact to negative information. He says health officials need to manage the risk trade-offs of potential contamination from fish consumption versus the loss of health benefits from reduction in fish consumption.

Often, he says, those who rely on seafood for their subsistence because of its availability will switch to a diet of often less-healthy ground meat and macaroni and cheese.

He warns that it's difficult to match the significant health benefits of fish and shellfish: rich in protein, low in undesirable fats and high in nutrients and healthful Omega 3 fatty acids. The professor urges that potentially contaminated seafood be kept out of the food chain and then the public be advised that the remaining available seafood is safe to eat, which is what several government agencies are attempting to do.

Who's in charge?

State officials and seafood sellers from Louisiana, Mississippi and Alabama say inspectors from the Environmental Protection Agency (EPA) and NOAA are all over the place.

The FDA has told Congress and issued press releases proclaiming it has "implemented a surveillance-sampling program of seafood products at Gulf Coast-area primary-processing plants" and "this sampling will provide verification that seafood being harvested is safe to eat."

The FDA is sending lots of e-mail — including the often indecipherable Hazard Analysis Critical Control Point safety plan. But most officials and business owners say they haven't seen FDA personnel on shrimp or crabbing boats, on docks or in processing plants.

FDA's media controllers were asked repeatedly where their "surveillance" people are working, and how many samples FDA has collected and analyzed. Seven people, 11 calls or e-mails. No answer.

However, only hours after this article was posted on the Internet on Tuesday, the FDA issued a press release assuring it was working with NOAA, the National Marine Fisheries Service and Gulf Coast state officials to ensure the safety of Gulf seafood.

And Vice President Joseph Biden, speaking to shrimpers, crabbers and fishermen in the region, later said the federal government had reached an agreement with Gulf Coast states to set safety levels for Gulf seafood. "We want one single standard so you all don't have to worry about where you fish, if you can fish and if the waters are open," Biden said.

How it's tested

This type of analysis is not new to the NOAA team. Identical testing of seafood was performed after other major oil spills, including the Exxon Valdez, other spills in the Gulf, on both U.S. coasts and even in the Persian Gulf in 1991, when fleeing Iraqi forces opened the pipes of several oil tankers and the valves at the huge Sea Island Oil Terminal.

NOAA reports that petroleum oils are composed of complex and variable mixtures of hundreds of hydrocarbon compounds. Of these, polycyclic aromatic hydrocarbons typically are of greatest concern with regard to health effects.

The agency still is very proud of its fish sniffers, who perform "blind nose sensory evaluation" to detect the scent of chemicals that are not normal to fish. But the chemical analysis is the definitive test.

Depending on the day and weather, NOAA has two to eight vessels actively collecting seafood samples in the Gulf and brought to the NOAA lab in Pascagoula, Miss., where the seafood is labeled, numbered and logged in.

The fin fish, shrimp, oysters and crab arrive in Seattle frozen in small blue-top jars, said Walton Dickhoff, a research scientist and division director at NOAA's National Marine Fisheries Service lab. Eighteen to 30 research chemists and other marine specialists move the samples though equipment and work stations spread over two floors. Once Jon Buzitis removes and logs in the carefully numbered jars from the storage freezer, analysis of the samples can take three days, but they can and do run multiple samples.

Dickhoff says samples are thawed, homogenized and dried with a sodium or magnesium sulfate. To remove bones or connective tissue, samples then are mixed with a dichloromethane, similar to the commercial dry-cleaning fluid.

They then are moved into a high-performance liquid chromatograph that, over eight or nine hours, removes a lot of compounds that could interfere with the analysis.

Finally, Dickhoff says, the samples spend 28 hours running through a chromatograph mass spec machine, which cranks out a detailed chart with separate peaks showing the level of each of the 19 polyaromatic hydrocarbons found in the samples.

What it means

What those numbers mean is what determines the safety of the Gulf seafood.

But is it safe?

"We've got the science of detection down," Dickhoff said. "The discussions that we have been having with EPA and FDA is to determine what's an appropriate level of (seafood) consumption and risk?"

The bible that most risk assessors seem to be relying on is a lengthy 2002 NOAA report issued after the Valdez spill. The report explains that the acceptable cancer-risk assessment is derived from how much seafood a person eats, over what period of time and the level of contamination found.

The seafood is deemed safe if it doesn't increase a person's lifetime cancer rate by more than one additional case in 1 million people. Some states use higher risk levels, such as a lifetime cancer risk of no greater than 1 in 100,000 people, NOAA says.

Patrick Banks, a marine fisheries biologist for the state of Louisiana, is responsible for ensuring the quality and accuracy of the testing of market-bound Gulf seafood. The state has tested more than 10,000 samples of fish, crab and shrimp. None has levels of oil contamination that raised health concerns.

"Determining how safe is safe can be a painful process," Banks said. "NOAA has a number, the level of contamination at which a closed fishing ground can be reopened for commerce or sport. That's the level that we test for. Make sense?"