- Renee Dufault
Former Food and Drug Administration (FDA) environmental health officer Renee Dufault published a study on trace mercury levels in high fructose corn syrup in the January 2009 edition of the journal Environmental Health. Dufault’s research team claimed that a minority of high fructose corn syrup samples obtained from production facilities contained trace amounts of mercury. Their study proposed that caustic soda (also known as lye) used in the sweetener’s refining process contributed mercury to the finished product.
But Dufault’s study suffered from serious shortcomings. One peer reviewer of the study noted that it relied on a very small number of samples and failed to put her data in a useful context. Indeed, Dufault based her conclusions on just 20 samples of high fructose corn syrup. More recent laboratory testing has called her entire line of reasoning into question.
Comprehensive testing by the independent Eurofins Central Analytical Laboratory found no quantifiable mercury in 119 samples from all 22 U.S. high fructose corn syrup production facilities. The Eurofins testing was funded by the Corn Refiners Association, a trade group representing producers of high fructose corn syrup. It was independently evaluated by a widely published mercury expert at the Duke University Medical Center, who reviewed and approved the study’s methodology.
Caustic soda used in the corn refining process is sourced from chlor-alkali plants. Dufault’s study (and a follow-up report from the Institute for Agriculture and Trade Policy) suggested that these facilities are responsible for adding mercury to caustic soda, and for passing it along to finished high fructose corn syrup.
The Chlorine Institute (a trade group representing the chlor-alkali industry) disputes this suggestion, writing to Environmental Health that “it is neither physically nor chemically possible for caustic soda to be the source of the mercury levels identified in this study.” And the Corn Refiners Association has added that in any event, “no mercury or mercury-based technology is used in the production of high fructose corn syrup in North America.”
Unsettling questions remain about how Dufault, a former FDA employee, acquired the data she used as the basis for her study. In a letter accompanying the study’s submission for publication, Dufault indicated that she did not want anyone affiliated with the FDA to have an opportunity to peer-review her work prior to publication. “Please,” she wrote, “do NOT send this manuscript to anyone affiliated with the US Food and Drug Administration.”
It’s clear that Dufault requested the high fructose corn syrup samples in her study in 2005, for FDA review. But it’s unclear whether she obtained permission to use the government-owned data after she left her FDA position. At the time of the Environmental Health study’s publication, she worked in the Online Education department at the United Tribes Technical College in Bismarck, North Dakota.
- Dr. Phillippe Grandjean
Odense University (Denmark) professor and Harvard School of Public Health adjunct faculty member Dr. Phillippe Grandjean argued in early 2005 that the Environmental Protection Agency should consider cutting its already conservative mercury Reference Dose in half, a move that would essentially place about a dozen fish species outside the boundaries of government advisories for most Americans.
The rationale for Grandjean's suggestion comes from a large study, which he led, of an isolated population in the Faroe Islands that eats a lot of whale meat. Grandjean's team claims to have documented neurological damage among children in the Faroes, and their study formed the backbone for the EPA's Reference Dose calculations in the first place. Despite the prominence given to Grandjean's work by regulators at the EPA and elsewhere, he has consistently refused to release the raw data from his study to outside scientists for review.
In addition to high levels of methyl mercury, pilot whale meat contains large concentrations of "polychlorinated biphenyls" (PCBs), which some scientists have suggested might have interfered with Grandjean's analysis. But since he won't release his data, we may never know for sure. Drs. Kenneth Poirier and Michael Dourson, both former EPA Reference Dose Work Group co-chairs, outlined this concern in a November 2000 letter to the EPA:
"The Faroe Island studies are not the proper choice for the critical study for a methyl mercury RfD [Reference Dose] … It is also important to note that the Faroe Islands researchers are the ones who performed the statistical analyses for PCB confounding. They have never made the raw data from their testing available to other scientists and statisticians to verify that the results were not affected by PCB confounding."
Grandjean's work has other shortcomings, not the least of which is his team's reliance on something called the Boston Naming Test to diagnose what he has called "subtle and small neuropsychological changes" in 7-year-old Faroese children. Speaking to an FDA Committee in 2002, Grandjean admitted that testing children's development proved too "complicated to do the same way every time." For instance, while one neuropsychologist might report a subtle effect from the mercury in a child's diet, the effect would frequently disappear when a different examiner repeated the test.
The Boston Naming Test was developed specifically to help diagnose language disorders in elderly adults after they suffer strokes or other brain traumas. The test's inventors noted serious problems applying it to children, but that's exactly the age group Grandjean's team tested.
Even so, the worst Grandjean's team could say about their Faroe Islands results from the Boston Naming Test was that there was a 0.25 percent difference (translating to about one-tenth of an IQ point) between children whose mothers had no mercury exposure at all and those with the highest exposure. Grandjean ominously told the FDA that if these kids' exposure were doubled, the results might translate to a loss of about 1.5 IQ points (well within the margin of error). And the test's designers specified that "normal" test results could sway as much as 12 percent in either direction.
Then there's the problem of pilot whale meat. Faroese kids and adults eat lots of it, and it contains far more mercury than any ocean-going fish. While Grandjean has acknowledged this fact, he hasn't let it temper his enthusiasm for the view that the fish are the major source of mercury exposure in the Faroese diet. The principal problem with this is that Faroe Islanders citizens don't eat whale meat every day, but they consume it in very large amounts when it's available. Grandjean's study didn't pay attention to this fact. If his measurements were taken shortly after the big whale feast, that would be a big problem.
In a February 2004 letter to The Boston Herald, Grandjean's colleague Dr. Pal Weihe (the Faroe study's chief physician) wrote:
"Faroe Islands women do not eat mercury-tainted fish and fish consumption does not harm Faroese children … The Faroese children are not exposed to methyl mercury by eating fish. They are exposed to mercury by the traditional consumption of pilot whale meat. Fish normally consumed in the Faroes, e.g. cod and haddock, are low in mercury and do not, to my opinion constitute any threat to the health of the Faroese children. In the contrary [sic], the fish consumption most likely is beneficial to their health."
- Dr. Jane Hightower
San Francisco physician Jane Hightower's name became synonymous with the fish-mercury scare in April 2003, when she published a study in the online journal Environmental Health Perspectives claiming that 89 percent of the patients tested in her own medical practice had blood-mercury levels exceeding the EPA's "Reference Dose." The mass media interpreted this finding as the end of fish as we know it.
But Hightower herself admitted to The Mobile Register: "It's important not to get too hung up on the [mercury] levels. We've found that the absolute mercury level does not correspond to the number of symptoms or their severity. Backpedaling in USA Today, she admitted that "there were some [patients] with elevated levels who had no symptoms."
And one scientist pointed out in a very critical follow-up letter to Environmental Health Perspectives that Hightower's study only looked at the connection between high-fish diets and blood-mercury levels -- "not the relationship between methyl mercury and health effects."
Reading Hightower's magnum opus, this critic appears to be correct. The study was essentially an inventory of a hand-picked group (only 123 out of 720) of Hightower's patients. She conceded in the study's text that "because only mercury was tested in these individuals, other contaminants responsible for symptoms cannot be ruled out." In other words (her words): "Cause and effect regarding symptoms was not fully addressed in this study."
Another thing Hightower didn't fully address is the potential differences among the various outside laboratories she used to analyze the blood samples in her study. Her patients' blood was collected at twelve different locations and analyzed by seven different labs, based largely on which facilities their various health insurance plans preferred.
And although Hightower asked her chosen test subjects to describe their diets and health symptoms during the previous year, she failed to do the same thing for the patients whom she chose not to include in the study. "A chart review," Hightower wrote, "on all patients presenting to the office in the 1-year period of the study was not done. Therefore, a comparative analysis for the purpose of controls is not available." So although some of her test subjects reported symptoms like fatigue, headaches, muscle pains, and hair loss, there's no way to know how many of her other patients had the same symptoms.
A medical experiment without a control group should raise huge red flags for serious scientists. (Even the EPA's Dr. Kathryn Mahaffey hedged her bets, telling The Oakland Tribune: "I'm not at the point of saying these health effects are caused by mercury.") But activist groups haven't been nearly as judicious. A glowing profile of Hightower appears on the mercury policy website of the Natural Resources Defense Council. The Mercury Policy Project (a minor group run by an activist with no science background) has featured fresh quotes from Hightower in its press releases. And Physicians for Social Responsibility has enlisted her to give newspaper interviews critical of federal government's pollution-control plans that would impact mercury emissions.
Hightower continues her one-doctor crusade to save the world (or at least the San Francisco Bay Area) from fish. In 2003 she told United Press International -- without providing any evidence -- that "you shouldn't have more than half a can of tuna a week." And the Gannett News Service describes her point of view in these words: "No fish containing any level of mercury is entirely safe to eat."
Dig a bit deeper, and Hightower's social-activist leanings shout down her medical credentials. She told one reporter in 2004 that mercury in fish is just one "poison" in American food. "We've had a large assault on our food supply," Hightower complained. "We genetically alter it, we put chemicals on it, we wrap it in plastic, we put it on Teflon, we microwave it."
- Dr. Kathryn Mahaffey
To the extent that the U.S. Environmental Protection Agency's mercury policy is seen as hyper-conservative and difficult to defend scientifically, Dr. Kathryn Mahaffey bears a good deal of the blame. Mahaffey is the EPA's most visible mercury "expert," and her influence has led to nutrition policy (and an accompanying activist bandwagon) that turns common sense on its head. This is doubly odd when you consider that her controversial positions on mercury in fish aren't even endorsed by the EPA itself.
Mahaffey's involvement in the mercury-in-fish saga parallels the federal government's escalation of estimates of just how many U.S. children are born "at risk" of mercury poisoning. Keep in mind that the real number is likely zero.
At the request of the EPA, the National Research Council (a division of the National Academy of Sciences) issued a July 2000 report about the health impacts of methyl mercury. This NRC report claimed that "60,000 newborns annually are born at risk due to methyl mercury," but it provided no documentation to back up this claim. The NRC arrived at this "60,000" number by assuming that women who eat the most fish (those in the top five percent) are risking their babies' health. At a 2002 government hearing on the matter, former USDA Human Nutrition Information Service Administrator Dr. James Heimbach told the EPA: "This '60,000 newborns annually at risk' [figure] has become sort of an urban legend."
But at that same meeting, Kathryn Mahaffey upped the ante, insisting that data from the Centers for Disease Control and Prevention showed nearly eight percent of mothers had mercury levels "higher than the value that EPA believes to be safe. So, we don't think the 60,000 is too high. If anything, the data suggest it is comparatively low." Mahaffey concluded by dropping a bombshell: The real number of annual at-risk births, she claimed, "would be about 320,000." A half-hour later, the Environmental Working Group chimed in, with the group's Richard Wiles claiming that mercury in U.S. fish endangers "a huge number of pregnancies, as many as 400,000 per year."
By this time, Mahaffey's mathematical gymnastics were seemingly irreversible. The following year, she released a report claiming: "Over 300,000 newborns each year in the United States may have been exposed in utero to methyl mercury concentrations higher than those considered to be without increased risk of adverse neurodevelopmental effects." Mahaffey acknowledges that her calculations are all based on the assumption that the EPA's "Reference Dose" is a hard-and-fast danger line. But as a scientist, she should know that it's just one-tenth of the level that represents a hypothetical danger.
Mahaffey's transformation from reputable scientist to activist appeared to be complete in 2004, when she announced at an EPA "National Forum on Contaminants in Fish" that the number of newborns "at risk" from mercury would have to be revised upward again. She announced that since mercury is 70 percent more concentrated in the umbilical cord than it is in a mother's bloodstream, the latest numbers would have to be multiplied by 1.7 to account for the "added danger" to a newborn. Mahaffey was quick to note that her new claim of "630,000 newborns each year" born at risk for mercury poisoning, was "preliminary in nature," but the damage was done.
Within a month, more than ten national environmental groups were using this new number in their advertising and on their websites. The media ran with it as well. The Canadian Press wrote that Mahaffey "estimates that one in six pregnant women in the United States had blood mercury high enough to damage her child, meaning approximately 630,000 U.S. newborns are at risk."
But when the EPA calculated its mercury "Reference Dose," it had already accounted for the differences between the way mothers and babies store mercury in the blood. Mahaffey continues to cling to a contrary illusion that goes against the grain of her own agency's positions.
During the EPA's 2005 fish forum, Mahaffey acknowledged that the number of women who exceed the Reference Dose for mercury had fallen between 2000 and 2004, but insisted that the same formula should be used to calculate the "risk." She now claims that 410,000 American babies are threatened by mercury every year from the fish their mothers ate while they were in utero. But since the Reference Dose includes a ten-fold safety cushion, none of these women ate enough mercury to harm their unborn children. Mahaffey's refusal to acknowledge this is a considerable black eye for the EPA, and is ultimately the source for most of America's paranoia about mercury in fish.
- Dr. Urvashi Rangan
As a senior scientist at the Consumers Union of the United States (the publisher of Consumer Reports), Urvashi Rangan is the primary public proponent of the magazine’s controversial June 2006 advisory that pregnant women should not eat any canned tuna because of mercury’s effects on developing fetuses. Rangan claims data collected by the Food and Drug Administration indicates that the threat posed by a higher-mercury-than-average piece of tuna is enough to justify complete avoidance.
The scientific establishment has been quick to point out that this abstinence-only approach belies a misunderstanding of how chemicals in food affect the body. Dr. David Acheson, chief medical officer at the FDA’s Center for Food Safety and Applied Nutrition, told WebMD that he was “not aware of any science that would indicate that having an occasional meal at [an elevated mercury] level would cause any harm, and if that science is out there, I would love to see it.”
Dr. Joshua Cohen, the Harvard University author of a well-regarded study on the risks and benefits of fish consumption, says Rangan’s approach overstates the implications of some tuna having above-average mercury content. “What your body sees is the average [mercury dose] over several weeks,” says Cohen. “The idea that the departure above the average on one day is going to mean a bad health outcome is like saying that two slices of apple pie at Thanksgiving is going to lead to obesity.”
The former secretary of the U.S. Department of Health and Human Services, Dr. Louis Sullivan, offered an even harsher rebuke. “I don’t know of any science that supports what they're saying,” Sullivan told the Chicago Tribune. “For all we know they could be relying on high school science students to come up with this.”
The faulty logic that these experts are bemoaning -- that a single piece of tuna can contain enough mercury to endanger a child in the womb -- has proved to be the linchpin of Rangan’s campaign. In an interview with National Public Radio, Rangan claimed that "any risk is too great” for pregnant women, so they should take “every step [they] can to avoid exposure.” And in remarks to the media following the Consumer Reports piece, she said that “for pregnant women in particular where you are talking about potential fetal exposure -- and it’s an avoidable risk -- we’re saying go ahead and take some extra measures to reduce your Hg [mercury] exposure at all costs.”
Everything we do -- crossing the street, driving a car, reading Consumer Reports (those darn paper cuts!) -- involves some risk. The important question is, just how much risk is associated with a given activity, relative to the benefits? In the case of driving, reading, and walking, the risks are infinitesimally small and the benefits -- seeing family and friends, learning something new about the world, enjoying a summer’s day -- are large. The same goes for tuna, an excellent and affordable source of omega-3 fatty acids, which are integral to a healthy pregnancy.
This isn’t the first time Rangan has exaggerated the risks associated with food contaminants. In May 2004, when the food scare of the day was mad cow disease, she claimed that there are only “two types of beef that offer a reasonable assurance of safety”: “organic” and “biodynamic.” The U.S. Department of Agriculture, however, says differently and advises that these are merely marketing labels, not safety guarantees.
- Dr. Deborah Rice
A onetime Environmental Protection Agency toxicologist, Dr. Deborah Rics now works for the Maine Bureau of Health. While at the EPA, she was one of three scientists responsible for determining the agency’s mercury “Reference Dose” -- a hyper-precautionary standard with a built-in tenfold safety factor. In 2005 she was hired as an “expert witness” by the losing side in a landmark California court case which ultimately ruled that the state’s Attorney General could not mandate public mercury warnings wherever canned tuna is sold.
During the trial, Dr. Rice argued in favor of setting the state’s Maximum Allowable Dose Limit (MADL) for mercury in fish so low that (in the words of Judge Robert Dondero) “all servings of fish and shellfish larger than literally a grain of rice would require a warning.” Given Rice’s questionable credentials -- she “had never calculated an MADL” and was “not Board Certified” -- the Judge was understandably skeptical of her “expert” opinion.
In addition to lacking the experience necessary to calculate mercury dosage limits, Dr. Rice appears to have mistaken a theoretical harm for an actual harm while on the witness stand. Judge Dondero wrote that she “claimed that the World Health Organization had ‘observed’ paresthesia [prickling sensations] in persons poisoned [by mercury] ... at a daily dose of 50 and 200 micrograms. She was specifically asked, and testified under penalty of perjury that the paresthesias were ‘observed not modeled.’” In other words, according to Dr. Rice, the WHO has evidence that a tiny daily intake of mercury has caused neurological damage in actual people, not just computer simulations.
But the judge later noted that “Dr. Rice misstated the WHO’s analysis ... Only when confronted with the WHO report did Dr. Rice acknowledge that the 50 and 200 micrograms per day levels were [computer] modeled, not observed.”
Later in her testimony, Dr. Rice admitted that her calculations were based on a study of Denmark’s Faroe Islands. As the judge readily noted, the Faroe Islands study is an inappropriate basis for a mercury consumption standard because it “did not identify and quantify confounding factors and did not have complete follow-up of all children in the study.” Once the Faroe Island researchers accounted for other toxins in the whale meat eaten by the Faroese, Judge Dondero added, “there was no statistically significant correlation between methylmercury and performance [on developmental tests].
Odder still, Dr. Rice had previously co-authored an article acknowledging the shortcomings of the Faroe Islands study -- yet chose to rely on it for her calculations anyway. When this inconsistency was pointed out, the judge wrote, “Dr. Rice initially denied that she had ever written a paper stating [this]” but “when she was shown her article stating this precise conclusion, she first tried to distance herself from its authorship, but then admitted to reviewing and approving it, and that the article was published under her name.”
Ultimately, the judge dismissed Dr. Rice’s testimony as “misleading” as well as “unreliable” and “biased.”
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