New Orleanians LuAnn White and Patricia Williams are highly trained toxicologists, experts in food safety who agree on the lethal dangers presented by the carcinogens found in oil.
But when it comes to the safety of eating locally caught seafood since the Deepwater Horizon oil spill, they disagree completely.
“I eat the seafood and feed it to my family and I’m absolutely comfortable with that,” said White, a Tulane University professor and consultant for the state Department of Health and Hospitals.
“Since the spill I haven’t eaten the seafood and I’ve urged my children not to eat it or feed it to my grandchildren,” said Williams, who teaches at UNO and is on retainer for plaintiffs suing BP. “I consider it too risky.”
Whom to believe?
In the five months since BP’s gusher spilled as much as 200 million gallons of crude off the Louisiana coast, federal and state agencies have repeatedly proclaimed Gulf seafood safe. The state says of more than 800 seafood samples tested, 503 showed no contamination at all, and the others only tiny amounts that pose no threat. Their message: The oysters, shrimp, crabs and fish you crave are safe – dig in. Officials from President Barack Obama on down have done photo ops scarfing Louisiana seafood.
Yet people remain skeptical. Sales of locally caught seafood are down, and some restaurants still won’t serve it.
“The public remains confused and concerned,” conceded Dr. Jimmy Guidry, head of the DHH testing program. “I think it’s a combination of the size and duration of the spill, but also the media reports from other organizations that claim to have found hydrocarbons in the seafood. I think a lot of people just don’t understand the process.”
But even some of those who understand – certified toxicologists and public health advocates – remain concerned.
They charge the formula used to set allowable levels of contamination is flawed in at least four ways:
- It lowballs local seafood consumption rates.
- By assuming an average weight of 176 pounds, it leaves large populations unprotected, including children.
- The amount of seafood being tested is far too low.
- The list of toxic substances being searched for is too narrow.
In short, they think the whole process is flawed.
The seafood testing program was developed by the federal Food and Drug Administration in cooperation with Gulf states.
Like most food testing programs, it does not certify products free from contamination, or even safe for all consumers. Rather, it attempts to establish a lifetime cancer risk that “is considered appropriate by risk managers” for the FDA and the Environmental Protection Agency.
In this case, FDA and state officials said, they decided the appropriate risk was a 1-in-100,000 chance of a 176-pound person contracting cancer sometime during his 78-year life span if he eats specified portions of seafood every day for five consecutive years.
The FDA acknowledges that many hydrocarbons of concern already are abundant in the environment. So this system looks only for the worst ones – 12 polycyclic aromatic hydrocarbons, or PAHs, known to cause cancer and other serious health problems.
The formula sets a “level of concern,” or LOC, on contamination in each sample.
As of last week, the state says not a single sample has measured at or above the LOC. Test results are posted at the FDA Web page.
When the FDA and Gulf states discovered there was no valid survey of Gulf Coast seafood consumption, the agencies agreed to use data from a national survey. Acknowledging the popularity of seafood in the region, they agreed to assume locals consume it at the 90th percentile found in the national survey.
That resulted in the following monthly seafood menu determining the level of concern: 9.1 fish meals of 5.6 ounces each; 2.9 meals oyster meals of 4.2 ounces each, and 4.4 shrimp/crab meals of 3.1 ounces each.
Who eats just 4 shrimp?
Criticism of the formula was loud and immediate.
Environmental and food safety groups considered the consumption rates laughably small, pointing out that few locals sit down for one oyster or four shrimp, which their experts say is the equivalent of the portions in the FDA formula.
A recent survey by the Natural Resources Defense Council of 547 seafood eaters along the Gulf Coast supports that complaint. The median seafood consumption rate of those respondents was 20 meals a month, while those at the 90th percentile ate as many as 60 seafood meals a month. Portion sizes were also larger than those used by the FDA, especially for shrimp.
While the NRDC conceded its voluntary survey is also imperfect, it tracked EPA and World Health Organization surveys of seafood consumption rates in fishing communities.
Dr. Gina Solomon, a senior scientist with the NRDC, said her group asked the FDA to use those surveys as a baseline for the Gulf Coast “but the FDA never gave us an answer.”
Solomon said her group was “not telling people not to eat Gulf seafood, not by a long shot,” but merely pointing out that the low consumption rates in FDA protocol are unrealistic.
Of equal concern to critics was the formula’s 176-pound average weight. Critics said it leaves out children as well as some ethnic groups, specifically Vietnamese-Americans, who tend to weigh less but eat lots of seafood.
“My objection to this is that just by the body weight they are using, they’re leaving out children, so many other people — and pregnant women with fetuses,” said Williams, the toxicologist. “Yet they’re going around telling people, ‘It’s safe to eat!'”
The FDA and the state DHH stand by their formulas. While acknowledging they would prefer to have valid seafood consumption rates for Gulf communities, they say their risk assessment is extremely conservative and protects the public.
“People need to remember that this level of consumption is for every meal for every day for five consecutive years — that’s 1,825 consecutive days of eating seafood at or above the levels of concern,” said Bob Dickey, director of the FDA’s Division of Seafood Science and Technology. “And this also assumes those levels of contamination in the seafood will remain over that period, but experience (in past spills) shows the level diminishing over time.”
FDA officials said the 176-pound body weight is actually appropriate for children because it is an average weight over a 78-year life span.
Still, the FDA is developing a separate level of concern for children, said agency spokesman Don Kraemer, though the agency doesn’t expect the results to change anything.
Kraemer pointed to the negative testing results thus far. “Remember, even at these conservative levels,” he said, ‘the sampling isn’t turning up anything at the LOCs.”
But the collection process is also under question.
On May 9, with most of the coast still closed to fishing, the Department of Wildlife and Fisheries began taking water and seafood samples to establish a baseline for the presence of hydrocarbons.
When the state moved to reopen fishing in areas in late July, it used a simple protocol: If there was no oil visible in an area and if samples contained no odor of contamination, samples could be tested for safety using the FDA rules. If samples tested below the LOC, commercial fishing could resume, but testing would continue.
Samples are collected from each of seven coastal estuarine basins between the Mississippi and Texas state lines. Harry Blanchet, coordinator of coastal finfish programs, said samples were originally taken weekly, but when lab results showed little or no traces of PAHs, sampling frequency was reduced to twice monthly, then monthly.
Each sample consists of about a half-pound of tissue, collected at one spot in each basin, Blanchet said.
That means a half-pound of fish from the 5,000-plus square miles of Barataria Basin; likewise for the 10,000-square mile Pontchartrain Basin.
Critics scoff at the idea that such a small sample can be seen as representative of such a large area.
“The proper way to do this is to consider the total volume of that seafood being harvested from that area, then basing your sample size on that,” Williams said.
“Are you telling me that we’re saying all the shrimp from Barataria Basin is safe because a half-pound was collected one time that month from one spot?”
Blanchet said the answer is yes – once again pointing to the consistency of results.
“I think any scientist would tell you he would prefer to have complete coverage of all areas all the time, but based on what we saw, the consistently low results, we are comfortable with this.”
However, he noted the testing program will become much more intensive in 2011 as the state uses an $18 million check from BP to establish a long-range monitoring program 400 samples per month for 20 years.
Critics want broader tests
Critics hope the agencies use those funds to broaden tests to go beyond the 12 PAHs listed in the protocol. They want to search for traces of total petroleum hydrocarbons, or TPHs, a family of compounds found in crude oil, some of which are carcinogens.
Dickey said TPHs are not on the list because they pose little or no health risk, and many are found naturally in seafood.
Dickey and others, including Tulane’s White, say the testing protocol is conservative and the results to date give no reason for concern.
“I understand there is a tremendous distrust of government, and that probably goes back to the way the estimates of how much oil was out there kept changing,” White said. “But I know the process being used; I know we’re only allowing seafood from open areas. And I know the amounts we’re finding is five times lower than the lower limits of detection equipment.
“I know what the result means – and that’s why I have no hesitation in eating the seafood and feeding it to my family.”
But Williams, the UNO toxicologist, disagrees.
“All this test is doing is making a ‘risk assessment’, which is simply a guesstimate of your chances of contracting cancer from this small list of PAHs – if you eat the amount of seafood in the portions they say over the years they say,” she said.
“It is not based on the tenets of toxicology. It does not consider things such as peak exposures, or dose frequencies, or how these different compounds react to each other to increase or decrease the threat. And, of course, that weight they’re using doesn’t even cover children.”
Williams said the state should not be proclaiming seafood that passes its lab screening safe for all, rather that it’s safe for someone weighing 176 pounds who eats those portions at those frequencies.
“Everyone else should be warned, they are not protected by this process,” she said. “That’s what I tell my family. That’s why – even thought I love our seafood, I haven’t been eating it, and I urge my family not to eat it, either.”