BELTSVILLE, Md., July
23 — Pregnant women are urged not to eat four types of fish that could
contain enough mercury to hurt an unborn baby’s developing brain. But should
tuna or other species be on the do-not-eat list
THE FOOD and Drug Administration says a few servings a week of most fish is
safe. But critics charge the FDA watered down its tuna advice after seafood
industry lobbying — and should have considered other worrisome fish — and
thus left tens of thousands of babies at risk of learning disabilities. The
FDA insists its advice wasn’t tainted, but asked its independent scientific
advisers to judge whether it erred and if American women need stronger fish
“It was our genuine belief that if women consciously followed this advice
... these women would be protecting their unborn children,” FDA food safety
chief Joseph Levitt said Tuesday as the advisers opened the three-day
inquiry, an inquiry taken so seriously that FDA acting commissioner Lester
Crawford attended. “It is an emotionally charged issue,” Levitt
acknowledged. “We are truly open and want your best advice, whether you
agree with us or not.” The panel will issue a decision on Thursday. Fish
is very nutritious; certain types contain high levels of heart-healthy fats,
plus fats important for fetal brain development. But different types also
harbor different amounts of toxic mercury. Typically, the largest fish
contain the most mercury.
Based on loose figures about U.S. fish consumption, some 60,000 newborns a
year might be at risk of neurologic damage because of mercury their mothers
absorbed during pregnancy, the National Academy of Sciences says. RISKY
MERCURY LEVELS About 8 percent of U.S. women of childbearing age have
enough mercury in their blood, based on the academy’s levels, to be at risk,
says the Centers for Disease Control and Prevention. Those who eat three or
more servings of fish a week had the highest levels.
Last year, the FDA advised:
Pregnant women, and those wishing to become pregnant, should not eat shark,
swordfish, king mackerel or tilefish (also called golden snapper) because
they contain high mercury levels. Those women can safely eat up to 12 ounces
of any other cooked fish a week —from canned tuna to shellfish to smaller
ocean fish. Critics immediately attacked the FDA for not including tuna
steaks, which contain somewhat less mercury than swordfish.
Some groups also urge pregnant women to curtail canned tuna consumption,
although canned tuna is made from small tuna fish that contain far less
mercury. And some advise pregnant women to avoid other species, such as sea
bass and marlin. The result is mass confusion — women don’t know what to
believe, consumer advocate Caroline Smith DeWaal of the Center for Science
in the Public Interest told the FDA advisory panel.
NO WARNING LABELS
Worse, she said, the FDA doesn’t prevent the most heavily contaminated fish
from being sold. Nor does it require warning labels on the fish pregnant
women aren’t supposed to eat, making it difficult for consumers to know the
advice. “It truly is a toothless tiger,” she said. Another advocacy
organization, the Environmental Working Group, says it created a model of
what would happen if pregnant women followed FDA’s advice, and concluded
that up to 1 million a year could be exposed to worrisome mercury levels.
The FDA strongly disagrees, saying it can’t validate the activists' model.
A seafood industry consultant argued Tuesday that the risk has been inflated
mostly because women eat far less fish than has been estimated. The FDA
deems fish safe if they contain less than 1 part per million of
methylmercury; the four types on its do-not-eat list exceed that level.
Critics charge large tuna steaks can contain more, too, and certain other
species contain only slightly less. One of FDA’s own advisers said Tuesday
that he bought 11 cans of tuna fish at his grocery store, and independent
testing showed one of them contained 1.2 ppm of mercury.
How much mercury exposure is too much is controversial. There are two
competing studies: Babies born in the Faroe Islands in the North Atlantic,
where people eat lots of highly contaminated whale meat, have a higher risk
of certain defects in memory and learning. Babies in the Indian Ocean’s
Seychelles Islands seem to suffer little effect. Women there eat mostly the
same fish Americans do, but so much that their bodies contain 10 to 20 times
more mercury than Americans’.
Infertility linked to mercury in seafood
Raised levels of mercury in the blood, from high seafood consumption, are
linked to infertility, researchers have found. The study was carried out in
Hong Kong, where people eat a large amount of seafood, and where seas have
high levels of pollution. In the UK, people eat less seafood and there is
less pollution. But UK experts say the Hong Kong findings show the effect
environmental pollutants can have on fertility. Mercury is one toxin thought
to have an impact on fertility. Researchers from The Chinese University of
Hong Kong studied 150 infertile couples undergoing IVF, and 26 fertile
Blood tests were used to assess the level of mercury in the men and women's
system. A dietician also asked infertile couples about their seafood
consumption. Other potential sources of mercury, such as fish pill
supplements or the use of skin-lightening cosmetic creams were also
recorded. Overall, the infertile group had significantly higher blood
mercury concentrations than the fertile group. Over a third of infertile men
had abnormally high concentrations, as did 23% of infertile women.
The researchers point out that women who are exposed to mercury through
their jobs can have irregular periods. Writing in the British Journal of
Obstetrics and Gynaecology, the researchers led by Dr Christine Choy, said:
"While comparing infertile subjects having abnormally high blood mercury
concentrations, seafood consumption was the only different source of
exposure to mercury among various other sources." They add that
contamination of the waters around Hong Kong with heavy metals is common.
A recent study in Thailand which looked at 10 samples of shark's fin found
six had concentrations of mercury above the upper safety limit for human
consumption. Tuna and swordfish, which are predatory fish, may also
accumulate high concentrations of mercury. The researchers add: "Reduction
in dietary consumption of seafood is a measure that may be effective in
controlling the accumulation of mercury. "However, this should be balanced
against the beneficial effects of other components of fish, such as those of
3-omega fatty acids and selenium."
Bill Ledger, professor of obstetrics and gynaecology at the Royal
Hallamshire Hospital, Sheffield, said though the Hong Kong findings did not
apply to the UK, there were lessons in terms of the effect of environmental
pollutants. "It's different in Hong Kong, where they eat a huge amount of
seafoods and the seas there are highly polluted. "People in the UK just
don't eat as much seafood. "You would have to have seafood at least three or
four times a week." But he said it did show how environmental pollutants
could affect fertility and the impact of long-term exposure. "For example,
working in Sheffield, I see a number of males with low sperm counts because
they are working every day with pollutants, such as solvents. "They are
exposed all day every day. People doing some DIY, that's not a problem."
Doctor links ailments to consumption of mercury laden fish Internal medicine
specialist and her patients say they see direct relationship between fish
consumption, high mercury levels and bizarre ailments by Ben Rrines, Mobile
Register, Staff Reporter Jane Hightower, one of San Francisco's leading
internal medicine specialists, a physician to rock stars, actors and
writers, was at a loss to explain the unusual ailments afflicting her most
health-conscious patients. Heart tests, CAT scans, spinal taps and blood
work showed only that the patients took good care of themselves.
Yet clearly they were sick.
A surgeon had tremors so bad she was afraid she'd have to give up
operating. A geophysicist said he couldn't think anymore and was unable to
do even simple subtraction. A mother, father and child living on a ranch in
the rolling hills of wine country were losing their hair. Ultimately, there
were about 200 patients, dotted all over the hills around San Francisco,
most enjoying the good life complete with nannies and private yoga
instructors and sweeping views of the Golden Gate Bridge.
They were scientists, surgeons, CEOs, psychiatrists, wine-makers,
writers and children, and the only thing they seemed to have in common were
the persistent symptoms – including severe memory loss, depression and a
strange metallic taste in their mouths – that might have a hundred causes
but would not respond to any treatment. Now, in a diagnosis rattling
experts in San Francisco's medical community and beyond, Hightower has
determined that all of those patients were suffering from mercury poisoning,
and the mercury came from the fancy fish they ate.
She was set to present a paper describing her findings at a Vermont
conference called “Methylmercury Contamination in Fish: Human Exposures and
Case Reports,” sponsored by the US Environmental Protection Agency, the U.S.
Centers for Disease Control and the American Academy of Pediatrics, among
others. The paper has been reviewed by her scientific peers and will be
published in Environmental Health Perspectives, a medical journal produced
by the National Institutes of Health.
Last year, Mobile Register-sponsored testing of 65 fish consumers on the
Gulf Coast revealed that many
had mercury levels some five to 10 times higher that the EPA's safe level.
But would people with such mercury concentrations actually suffer ill
effects? The scientific data was not definitive. Hightower believes her work
cuts through many of the ambiguities, and should cause concern anywhere that
people eat large predator fish such as grouper, tuna, amberjack and
“Jane's patient base is quite convincing in terms of exposure,” said
Kate Mahaffey, the EPA's top official regarding mercury, who has visited
Hightower's clinic. “Now, it's time for scientists and physicians to study
the effects she describes. In the exposure range she describes, we simply
don't have a lot of published medical evaluations.” Hightower and her
colleagues have linked sometimes devastating health problems to the
consumption of tuna, Chilean sea bass, grouper and other popular fish known
to have high levels of mercury in their flesh. Some women were found to have
transferred excessive mercury to their infants solely through their breast
Treating patients with elevated mercury levels since 1999, Hightower and
doctors working with her observed a suite of health effects including
depression, loss of scalp hair, metallic taste, headaches, arthritic pain in
joints, irritability, tremors, and numbness and tingling in hands and feet.
She also described cognitive problems such as pronounced memory loss,
confusion and difficulties in talking. In some cases, those problems were so
severe they interfered with the ability to earn a living or attend school.
In every case, the doctors say there have been dramatic improvements in
the health of patients within a few months of cutting fish from their diets.
“The symptoms my patients were reporting are consistent with symptoms
reported in medical literature from around the world when it comes to
mercury poisoning,” Hightower said. “I'm just a doctor that happened onto
this, but it's so clear. When we pulled fish out of the diet, the mercury
levels came down and the symptoms went away. In medicine, that's about as
good as it gets for proving something is the culprit. And we've seen it over
and over again.”
Alan Stern, a New Jersey researcher, noted mercury authority and a
member of the National Academy of Sciences, said he would have a “healthy
skepticism” when looking at Hightower's clinical findings at this weekend's
conference. He also warned that the satellite of symptoms described by
Hightower's patients could have a number of causes. Still, he said of
Hightower's findings, “I believe this is possible, but we don't have a lot
of data. I'm not aware of any data that addresses the effects of low level
adult exposure, so I'm very curious.”
Hunting for symptoms “'You're crazy,' that was the most common diagnosis of
these people before their mercury levels were known,” Hightower said. “They
had all these symptoms and it looked like they were making it up because no
one could find a reason.” Hightower admits that she stumbled onto the fish
and mercury connection after the ranch family members losing their hair were
referred to her by Dr. Kathy Fields, a dermatologist who works in
Hightower's medical group.
“I had heard on National Public Radio that heavy metals could make your
hair fall out, so I ran a metals test on them,” Fields said. “I called Jane
and said, 'I've got this wild mercury level, see what you can do.'” The
family had extensive environmental testing performed on their property,
searching for a mercury source in their well water, on their land and in
their home. There was no mercury to be found. On a hunch, Hightower asked
about their diet and discovered they ate a lot of seafood, particularly big
fish such as tuna and swordfish.
The wheels turned and Hightower picked up the phone and started calling
some of her patients. “I'm driving down the freeway and Hightower calls me
and says, 'How much fish do you eat?' It was the weirdest thing,” said Will
Smith, the geophysicist forced to quit work when his symptoms were at their
worst. “I was eating tuna all the time, for lunches, business dinners. I was
eating sushi a lot and canned tuna several days a week as a snack. I told
her and she said, 'I think it's mercury.'”
Among patients who showed mercury-related symptoms, Smith's situation
was the most extreme. But a few ailments were common to all. “The metallic
taste, that was ever present,” said Smith. “My speech was severely impacted,
slurred, so was my memory, my balance. I couldn't watch TV because I became
dizzy. I was always losing my car. I had tremors. I was always tired. I
couldn't concentrate.” Hightower told Smith to cut fish out of his diet and
he started getting better almost immediately, though it has been a long,
slow process. Neurological testing has revealed that he suffered permanent
damage to the parts of his brain that control executive functions. Doctors
said the type of brain damage Smith has is almost exclusively associated
with heavy metal exposure.
Doug Anderson, the San Francisco psychiatrist who treated Smith for
depression, said Smith routinely left his keys or jacket at his office after
their sessions and frequently got lost in a city he has lived in for
decades. Anderson noted that Smith got progressively better as the mercury
left his system. “That is the most logical culprit,” Anderson said as a
cable car clanged past his row house office. “The fish seems to be the most
likely agent.” He has treated a number of Hightower's patients.
“For someone to come in with major cognitive problems like Will had, we
always look for treatable causes. At the bottom of a long list of potential
things are pesticides and heavy metals,” Anderson said. “At this point, if
people eat significant amounts of fish, they should be tested – if you have
a depression that doesn't clear up quickly with traditional treatment like
Prozac, if there are cognitive deficiencies. Some people just feel low. They
may not be melancholic, tearful or suicidal, but they have a pervasive sense
that they can't function.”
A plastic surgeon, who spoke to the Register on condition of anonymity,
had symptoms similar to Smith's, though she rarely ate fish. In fact, her
seafood diet was limited to fresh tuna steaks two or three times a month,
she said. Yet her mercury level was six to seven times the EPA's safe level.
“My hair was just falling out,” said the surgeon, who described herself as
a “meat and chicken kind of girl. I had tremors and numbness and tingling in
my hands and feet. And I had serious memory problems. I've always had an
excellent memory, that's what got me through medical school. But all of a
sudden, I couldn't remember who I had operated on the week before.
Hightower made her give up the tuna, and the mercury level came down
within months. The surgeon said the symptoms just disappeared. Not all of
the patients were adults, and Hightower and Fields said the effects in
children may be the most long-lasting. “In an adult, you can have a
recovery, because the brain is already formed. But in a child, mercury
affects the migration of nerve cells, and it kills them. It's tragic. We're
talking about permanent damage,” Fields said.
Recently, articles in national publications have noted an increase in
autism among children, an increase some have linked to mercury contamination
of a preservative – Thimerosal – commonly used in vaccines. Hightower said
that among the children she has treated, Thimerosal was ruled out as a
possible source of mercury, either because the kids had never received it,
or because it had been several years since their vaccinations. All of the
children, however, had been exposed to fish known to be contaminated with
A 7-year-old boy who ate canned tuna, fresh tuna and king mackerel
regularly from the age of 3 was found to have a mercury level 15 times the
EPA's safe level. After eight months without fish, his mercury
level had dropped to within the normal range, but it was too late. Hightower
said extensive neuropsychiatric testing confirmed that he suffered some
degree of permanent brain damage. After passing all normal developmental
milestones up to around age 3, when he began eating fish, the boy showed a
severe decline in mental development. His mother said he quit socializing
with others, was no longer able to express complete thoughts and couldn't
remember classmates' names.
“Up until we stopped the fish, he was just completely in a fog. He would
sit there, all by himself, totally lost,” said his mother, who did not want
to be named in order to protect him. “It's just horrifying, because with
better information from the government, we could have prevented this. I was
even eating fresh tuna when I was pregnant, you know. My son's improved,
steadily and markedly, since we got him off of fish, but he's not fully
recovered and I don't know that he ever will be. Still, he can communicate
now, and he can make friends again.”
Four-year-old Sophie Waldman lives in Berkeley with her parents,
novelists Ayelet Waldman and Michael Chabon, a Pulitzer Prize winner.
Sophie, her mother said, loves canned tuna and used to eat tuna sandwiches a
couple of days a week. “Sophie was an early walker and an early talker,”
Ayelet said, curled up on a couch in her dark and woody Berkeley bungalow.
“Then she sort of slowed down. She was starting to tie her own shoes and
then all of a sudden, she couldn't do it anymore. And she was sounding out
words, then she couldn't do it anymore. And her hair was really weird. It
wouldn't really grow and felt strange.”
When Hightower pulled her off of fish, she got better. “When her mercury
level came down, she could tie her shoes again and was suddenly able to
read. She had this huge developmental upsurge, after a year of being sort of
stagnant,” said Waldman, a Harvard-educated former public defender. “I'm not
some Berkeley-mom-food-Nazi. My kids live off sugar, you know. But, I saw a
difference in my kid. Simple as that.”
Multiple forms of exposure Fields and Hightower said they found that their
patients were exposed to mercury in three major ways: Adults and children
ate popular fish such as fresh tuna. Fetuses were exposed as a result of
the mother's fish consumption. Infants nursed from mothers with high
mercury levels. In the case of one patient, the only apparent source of
exposure was fish oil supplement pills. Hightower said symptoms can occur
in patients with high mercury levels as well as in patients whose mercury
levels fall within the “safe” range set by some federal agencies. Although
all patients with symptoms had mercury concentrations in excess of the EPA's
safe level, many showed effects when their mercury concentrations were below
the US Food and Drug Administration's safe level, which is four times higher
than the EPA's.
She said some patients with highly elevated mercury levels were
symptom-free. Hightower suggested that people may have different thresholds
for mercury in their bodies. “It's important not to get too hung up on the
levels. We've found the absolute mercury level does not correspond to the
number of symptoms or their severity. The symptoms are what's important, and
they can occur at any level,” she said. “Think of mercury like a bee sting.
You know, some people will die from one bee sting. Others can handle 40
stings or 100 stings, but everybody has a threshold where the bee stings
will kill them. What kills you isn't the bee sting. What kills you is your
body's reaction to the bee sting. I think that's the way mercury works.”
Fields said that as more doctors learn of Hightower's work, it's likely
they will begin to diagnose mercury poisoning in patients who eat a lot of
fish and have similar symptoms that cannot otherwise be explained. “Our
mercury is no different than anyone else's,”said Hightower. “I'm just a
doctor who happened to discover these mercury levels in my patients.”
Similar levels have been documented in research literature in places as
diverse as Washington state, Wisconsin, Maryland, New Jersey and California.
“This is afflicting the people who are doing what they are supposed to
do, eating a lot of fish to get those Omega-3 fatty acids that are good for
your heart. The problem is, it turns out these big popular predator fish
have a contaminant in them: mercury,” Hightower said. “It's not how much
fish you eat that's the problem, it's what kind of fish you eat. If you are
eating a fish that is bigger than the pot you are cooking it in, get a
smaller fish, not a bigger pot.” She continued, “People are buying steaks of
tuna or swordfish or amberjack or whatever these days. The steaks have no
bones, they are easy to prepare and the fish taste good. The problem is they
have so much mercury...
“I've seen in my patients that mercury levels can fluctuate up and down
weekly based on what they ate and what day of the week they ate it. And
guess what? Their symptoms can come and go like clockwork based on when they
ate fish.” Several women in the group were found to have transferred
excessive amounts of mercury to their infants solely through breast milk.
One breast-fed baby had three times the EPA's safe level for mercury by the
time he was 4 months old.
Jeanine Harmon breast-fed her child twice a day and fed him salmon and
sole frequently. By the time he was 19 months old, he was found to have four
times the EPA's safe level for mercury. Harmon, whose son is one of
Hightower's patients, said she ate canned tuna a couple of times a week
during and after pregnancy and worries she may have caused her son permanent
brain damage. “He seems fine now, but I'm an elementary school teacher. If
he's going to have cognitive problems, they may not even show up until third
grade,” Harmon said. “It was horrifying, knowing I couldn't get it out of my
baby's body. It's unnerving knowing he had such a high mercury level for so
long as he was growing, when his brain was building.”
Dr. Leslie Kardos, an obstetrician who works in the same building as
Hightower, was tested for mercury five months after her baby was born. She
had mercury concentrations more than three times the EPA's safe level. Her
infant daughter was twice the safe level, her sole exposure through her
mother's breast milk. “I'm terrified because I know mercury exposure is
linked to a lessening of the IQ, and here I was feeding it to my baby in my
breast milk,” Kardos said. “I had to pump and dump my milk for three months
because I didn't want mercury in my milk. You know, I'm buying fish in good
places, it looks good, and yet it's poisoning me. Clearly the government is
not doing its job here.”
Her fellow obstetrician, Heidi Wittenberg, discovered a number of her
pregnant patients had excessive mercury levels and agrees with Kardos that
the government has let the public down. “When my patients ask me if canned
tuna is OK, I tell them no. If they want to get pregnant, I tell them to eat
fish once every two weeks. No more,” Wittenberg said. “They say we're
scaring people unnecessarily but the truth is the government has no idea.
Where is the FDA? Why hasn't the NIH funded a study? If you're finding these
levels in average Americans, how can you not address it?
“Here I am, I'm not drinking wine, I'm not doing drugs, I'm not eating
cheeseburgers and yet I'm hurting my baby. These are smart people, doing
heart-healthy things and they are hurting themselves or their babies,”
Fields said. “This is life-changing stuff.” Hightower said that in her view
the government can't afford to duck the mercury problem any longer.
“All I can say is I saw this in the field. I'm in the trenches with the
patients. Now, it's time for the scientists to do the big studies and see if
there are correlations,” Hightower said. “It's really sad and distressing.
We don't want to lose our tuna, but if people get ill for a long time and
they cut it out and feel better than they have in years, they'll quit eating
fish. Especially if they go back and eat some and feel sick again.”
FDA changes course on mercury policy
Sea change likely to affect fish-consumption advisories nationwide
By BEN RAINES
In what leading scientists describe as a landmark change in the government's
regulation of mercury, a senior U.S. Food and Drug Administration official
says his agency now uses the U.S. Environmental Protection Agency's much
lower safe level for mercury in the human body.
Previously, the FDA had maintained there was no danger in having four times
more mercury in the human body than the safe level set by EPA. The reversal,
along with other policy shifts described by the FDA in an inteview this week
with the Mobile Register, will likely affect the mercury advisories issued
by states for recreationally caught fish. It will almost certainly lead to
significant changes in the ad vice the FDA gives to women and children about
what fish are safe to eat.
Some regulators say the FDA's stance also may indicate that the agency plans
to provide fish-consumption advice for men, who are not included in the
agency's current warning, which targets only women and children. A paper in
this month's Journal of the American Medical Association represented the
first outward sign of the FDA's new position. The paper was written by top
officials from the FDA, the EPA, the Centers for Disease Control and
Prevention, and the National Oceanic and Atmospheric Administration.
"This is really a landmark paper," said the EPA's Kate Mahaffey, who helped
author the article. "It's really a consensus on what we know about mercury."
Both the FDA and the EPA have a role in protecting the public from ingesting
too much mercury from contaminated fish. The EPA, which has a larger mission
of protecting the nation's natural resources, investigates and regulates
various contaminants, including mercury, in recreationally caught fish.
The FDA is charged with protecting the nation's food supply, including
regulating how much mercury is allowed in commercially sold seafood. The
FDA's former position regarding the safe level of mercury is well-documented
in official publications and has caused longstanding disagreement between
that agency and the EPA. In fact, during a public meeting discussing the
FDA's mercury policy last July, the EPA's Mahaffey and the FDA's Mike
Bolger, whose name appears with Mahaffey's on the new paper, got into a
terse and heated argument while discussing the science behind the safe level
or "reference dose."
During that meeting, an internal FDA panel challenged the agency to publish
a scientific rationale for its higher safe level. That has not happened, and
now the FDA is taking pains to distance itself from its old position. "Right
now, the FDA is not making that statement," said Dr. David Acheson, the
newly appointed chief medical officer in the FDA's science office. "Whether
they did in the past, I don't know. That may have been based on past
thinking." Leading mercury researchers around the nation expressed surprise
when told of the FDA's change.
"If the FDA is now cooperating closely with the EPA and they are on the same
page, this makes a very big difference not only in terms of government
policy for commercial seafood, but it provides great clarity for states on
how they should handle their mercury advisories," said Alan Stern, who
coordinates mercury research for the state of New Jersey and who served on
the National Academy of Sciences panel that studied and endorsed the EPA's
"This is really like a sea change at FDA," Stern said. Acheson did not
equivocate when asked if the FDA endorsed the EPA's safe level. "The FDA is
basing its advisory on the EPA's reference dose," Acheson said. "Are we
formally endorsing it? I'm not aware, but we are certainly using it and pay
attention to it." The new thinking appears to extend to some other
contentious topics the agency has been wrestling with. Acheson indicated
that the FDA plans to add more fish to its so-called "Do Not Consume" list
if new mercury testing reveals that a species tends to have a high level of
mercury. Now, there are only four fish on the list: swordfish, shark,
tilefish and king mackerel. Environmental groups have accused the agency of
caving in to pressure from the fishing industry instead of listing
additional fish that scientists believe have high mercury levels.
Mercury tests of fish by the Mobile Register in the last two years revealed
that a number of species -- including grouper, amberjack, redfish, cobia and
yellowfin tuna -- may contain so much mercury they would qualify for the
FDA's list. Also, the Register has shown that the mercury databases used by
the FDA for selecting the fish on its list are fun damentally flawed. EPA
scientists have described the FDA data as essentially useless for
determining whether a species is safe to eat.
As a result, the agency may have underestimated the mercury levels in many
popular species. The National Marine Fisheries Service is in the process of
testing 2,500 samples of Gulf of Mexico fish for mercury. The fisheries
agency plans to test Pacific and Atlantic fish as well. "If the data
demonstrates that other fish should be put in that category, then I think we
would add more fish to the list," Acheson said. He also said the agency was
reconsidering the advice it gives to women and children regarding how much
canned tuna is safe to eat. The FDA's current advice states that women and
children are safe eating two cans of tuna a week.
Scientists say that two cans of tuna a week would push a 130-pound woman
over the EPA's safe level. In fact, just over one can a week would contain
all the mercury a 130-pound woman could safely handle, according to EPA
calculations. As little as half a can a week could push a 4- or 5-year-old
child over the safe level. "We have these things under consideration right
now in regards to canned tuna," Acheson said. "What FDA is doing is trying
to keep its advisory apace with the science and the data."
FDA Denies Any Change
in its Methylmercury Guidelines, Issues Statement on
Seafood.Com News - [FDA statement] Contrary to some recent news reports, the
Food and Drug Administration (FDA) has not issued a new advisory on
methylmercury consumption. FDA's current advisory regarding methylmercury
and fish consumption still stands. </more> The current advisory, issued
March 2001, recommends that pregnant women and women of childbearing age who
may become pregnant not eat shark, swordfish, king mackerel, and tilefish.
Also, as prudent public health advice, FDA also recommends that nursing
mothers and young children not eat these four varieties of fish because of
the relatively high levels of methylmercury they may contain. The current
advisory acknowledges that seafood can be an important part of a balanced
diet for pregnant women and women of childbearing age who may become
pregnant. Further, the current advisory provides that pregnant women and
women of childbearing age can safely eat 12 ounces per week of a variety of
other kinds of cooked fish (typical serving size of fish is from 3 to 6
FDA's believes that women following FDA's advisory would generally be below
the Environmental Protection Agency's (EPA) reference dose for
methylmercury. FDA received a number of recommendations from its Food
Advisory Committee last summer on how to improve this advisory. FDA will
continue to work closely with EPA and others in developing the best
science-based approaches to dealing with methyl mercury in fish.
* * *
Has fish had its chips?
If you have suddenly lost your appetite for salmon, don't get too fond of
the other options. Trouble is brewing for all farmed seafood, reports
Sunday January 11, 2004
Stacks of salmon steaks and fillets remained on ice at Chapel Street
Market in Islington on Friday. Only weeks ago ago they were disappearing
at a record rate, destined for millions of festive dinner tables. Now
shoppers flashed a concerned glance and passed by. Farmed fish was having
cow moment. Just as BSE research prompted an EU ban and shoppers' boycott
of beef almost eight years ago, now public confidence was being rocked in
the very foodstuff nutritionists have been telling us we must eat more
Salmo salar, the Atlantic salmon, is no stranger to health scares. Rarely
has a month passed in recent years without a television programme or a
feature in a magazine raising concerns about aquaculture, the
fastest-growing sector of the global food economy. But Friday was
This was not some fringe pressure group or band of tree-hugging
environmentalists out to rattle cages. It was some of the world's leading
experts on industrial pollution. And what they had to say was
devastating: farmed salmon was poisonous. What's more, the most dangerous
fish of all were salmon raised in Scotland.
Researchers based at the University of Albany in New York revealed in the
journal Science how they found high levels of contaminants such as PCBs,
dioxins and pesticides in Scottish fish, which is marketed around the
world as a premium product. Eating more than three portions a year, they
warned, risked increasing the consumer's chances of developing cancer.
In Britain, 99 per cent of salmon sold in fishmongers and supermarkets
comes from Scottish farms. They moved swiftly to assuage customer fears
but the impact of the findings already appears to have been powerful.
Across the UK this weekend sides of smoked pink fish 'fresh from the
crystal clear waters of Scotland' sat untouched on shelves alongside
curiosities such as salmon nuggets and tikka bites. Staff in one branch
of Tesco near Glasgow estimated that the store was shifting less than
half its usual stock of farmed fish.
Back at the Islington market in London, Jamie Curtis revealed that sales
had nosedived. 'I've had people coming up to me all day,' he said. 'A lot
of customers have been saying that since hearing the news about the risks
associated with eating salmon they're going to give it up for good.'
On hearing details of the American research, one shopper considered
ditching her purchase. Nicola Burn, a 30-year-old teacher, said: 'If I
had known about it I'm not so sure I would have put this packet of salmon
in my basket. I'll definitely be reading the labels on fish more
Reactions like this will distress Scottish fish farmers as they begin the
mammoth task this week of attempting to rebuild public trust. For them -
and for Britain's baffled consumers - further confusion and uncertainty
The intensity of their reaction to the revelations is a clear indication
of just how worried fish farmers are. In Scotland alone the business is
worth £700 million and supports more than 6,500 jobs - mainly in remote
areas with a history of high unemployment.
The country's 300 salmon farms produce 160,000 tonnes of fish a year.
Industry representatives insisted farmed salmon was safe and claimed the
American team's report was misleading. They called on support from the
Food Standards Agency and politicians, who are well aware that
aquaculture accounts for half of the value of all Scottish food exports.
Much of the blame for the high contamination readings has been heaped on
the feed used to raise the fish. Environmentalists have long criticised
this aspect of the industry as it relies on wild fish being caught and
ground into pellets to feed their captive cousins. They have pointed out
that it takes three tons of wild fish to produce one ton of the farmed
variety. It is, therefore, fundamentally an unsustainable industry.
Now the research published in Science suggests that this feed, harvested
from the polluted waters of the North Sea, results in the fish farmed in
the area being more contaminated than those elsewhere. Aquaculture
critics had already pointed out that the polluted waters of the northern
hemisphere produce farmed fish with contamination levels eight times
greater than those in the southern hemisphere farms of Chile, Australia
The world's largest producer of salmon feed is EWOS, based in Bathgate,
West Lothian. Managing director Neil Spreckley yesterday defended the
business and said it was constantly seeking to improve methods.
'Industrial pollution is not as bad as it was 20 or 30 years ago. The raw
materials going into fish feed have improved. We are trying to formulate
more ingredients which are lower in PCBs and dioxins such as soya and
linseed vegetable oils. The problem is that salmon's natural diet is to
And that, say anti-aquaculture campaigners, is the problem with the
entire industry. What we are witnessing with salmon now will be
replicated across the dozens of other carnivorous species being reared in
captivity around the world.
Projections indicate that by 2020 more farmed fish will be eaten than
those caught in the wild. Already aquaculture is worth more than £30
billion a year globally and the number of species that ate being
developed is rapidly increasing.
Like salmon and trout, the vast majority of sea bass and bream consumed
in Britain comes from farms. Mediterranean countries such as Greece have
raced ahead in the production of such species that require warmer waters.
Tuna is also being developed, and the Japanese have even floated the idea
of a huge minke whale farm.
Here and in Norway, though, all eyes are on halibut and cod - the great
hope of aquaculture. Proponents say that both offer the prospect of
cleaner, more sustainable farming than salmon. One person who won't
be serving any of them, however, is Jackie MacKenzie who worked at
a fish farm in the north-west of Scotland for three years in the 1990s
before quitting over concerns that the chemicals he was using were having
a detrimental effect upon his health.
'There used to be fresh salmon on the table when I was a boy,' he told
The Observer. 'But that was a different fish to what we get now. I
wouldn't feed my children the stuff that comes out of these farms.' He
claimed that the aquaculture industry had taken a quality product and
turned it into 'gunk'. Wild salmon, he said, was a firm, muscular,
healthy fish. What now masqueraded as the king of fish was a flabby,
dyed-pink beast that bore little resemblance to its wild relative.
He warned that it was inevitable that other species would develop
problems in captivity. 'All fish have their diseases, and when you cram
lots of them into a confined space it is inevitable the disease will
spread. Then chemicals are introduced in an attempt to control things.'
Along with feed and chemicals, MacKenzie lists escaping fish as one of
the main, unavoidable problems of sea-cage fish farming. Wherever there
are fish in captivity, there are jailbreaks. Inevitably, wild populations
are affected. A Pacific salmon from farms in contaminated waters off the
north-west coast of Russia was recently found in Scotland.
Diseases are passed on, and cross-breeding has resulted in deformities
and genetic mutations that have seen a stark drop in wild salmon stocks
since farms arrived in Scotland in the late 1970s.
MacKenzie and other anti-aquaculture campaigners welcome the Albany
report, claiming that for years they were seen as crackpots standing in
the way of progress. 'Finally the concerns we have are being recognised
by others,' said the ex-fish farmer.
The revelations in the journal Science come as it is revealed that 27
imports of smoked salmon were last year condemned by the powerful US
government watchdog, the Food and Drug Administration, as unfit for human
consumption following random checks.
These included 15 shipments of smoked salmon which were turned away
because they were contaminated with listeria and a further nine salmon
shipments from Scotland which were classified as 'insanitary'. In
Britain, a million Scottish-farmed salmon a week were sold during the
Christmas period. Thousands more trout, sea bass, sea bream and cod that
lived and died in captivity were also eaten. None, however, passed the
MacKenzie family's lips. It appears that many more families up and down
the country are now following their lead.
· How fish are farmed
Main producers are Norway, Chile and Scotland. Worldwide production
exceeds one million tonnes a year. Between 5,000 and 50,000 fish are held
in sea cages. The colourings astaxanthin and canthaxanthin are used to
dye flesh pink. Fish are treated with antibiotics, injected with vaccines
and fed on fishmeal and oil extracted from 'trash fish' living in
polluted waters. As a result, farmed salmon contain carcinogenic PCBs,
dioxins and mercury as well as pesticides.
Raised in France, Italy, Denmark and the UK. Britain produces 35 million
fish a year. As with salmon, antibiotics, vaccines and colourings are
Norway hopes to farm 10,000 tonnes this year. Like salmon, the fishmeal
fed to cod contains PCBs, dioxins and other pollutants. Stocking
densities in cages are similar to salmon, with higher mortality rates.
Production in its infancy, led by Norway followed by Iceland and
Scotland. Reared on a diet of live plankton, followed by fishmeal
pellets, they are exposed to the same drugs, pollutants.
Sea bass/sea bream
Greece accounts for 60 per cent of European production. A temperatures of
20C is required, hence the proliferation of warm-water bugs.
Mainly farmed in Spain, Croatia, Italy and Malta to supply Japan. In
2001, just 12 Mediterranean farms produced 11,000 tonnes of bluefin -
half the global total.
Production is centred on France, Spain, Ireland and Scotland and totals
6,000 tonnes. The breeding cycle of turbot is similar to that of halibut,
and farmers use similar technology. Viral haemorrhagic septicaemia led to
the closure of a farm on Gigha in 1994.
· Other food health scares
Despite its famed health benefits, it was found to make two-thirds of
children ill when they ate it for the first time. According to a report
published in May 2003, symptoms ranged from a tingling in the throat to
severe wheezing and collapse. The Food Standards Agency advised parents
to be alert.
Fried and oven-baked potatoes were reported to contain dangerously high
levels of acrylamide, a substance that might cause cancer. In April 2002,
researchers in Sweden reported that the chemical was formed when foods
that contain carbohydrate, such as potatoes and cereals, a re-fried or
baked at high temperatures (above 120C).
In addition to the known risks of a high caffeine intake, pregnant women
were reported to suffer an increased danger of having a stillborn baby if
they drank coffee. Women who drank more than eight cups of coffee a day
had a 300 per cent greater risk of stillbirth, compared with those who
drank none during pregnancy, according to a report by a Danish
Even ice cubes could not avoid the wrath of the health inspectors. The
Health Protection Agency found almost half the ice cubes that it tested
in London bars contained bugs found in human faeces, with 5 per cent
containing the lethal E.coli
Mercury study shows permanent damage to kids
Saturday, February 7, 2004 Posted: 9:34 AM EST (1434 GMT)
WASHINGTON (Reuters) -- Children whose mothers eat seafood high in
mercury while pregnant can suffer irreparable brain damage, new research
shows. The report comes the same week as the Environmental
Protection Agency doubled its estimate of how many newborns had unsafe
levels of mercury in their blood.
Warning on mercury in tuna criticized
Groups say not enough done to fight pollution
Tuesday March 23, 2004
By Aaron Kuriloff
St. Bernard/Plaquemines bureau
Louisiana sport and commercial fishing associations joined
environmentalists Monday in expressing regret about a new federal
advisory warning children and pregnant women to avoid eating more than
small amounts of canned albacore tuna because of high levels of mercury
in the fish.
Albacore contains more mercury than smaller tuna species, such as
skipjack or "chunk light" tuna, more commonly sold in cans, said
officials with the Food and Drug Administration and the Environmental
Protection agency. They also warned young children and women of
childbearing age to avoid eating shark, king mackerel and swordfish
because of high mercury levels.
Those warnings sound familiar to sport and commercial fishers in a state
where health officials have advised residents to avoid regular
consumption of fish caught in nearly 30 waterways. But while fishing and
environmental groups said federal officials aren't doing enough to combat
mercury pollution, commercial fishing organizations said that, for most
consumers, the benefits of eating almost all kinds fish far exceed the
"There's nothing new here. Mackerel and tuna have always been hot," said
Randy Lanctot, referring to mercury levels in the fish. Lanctot,
executive director of the Louisiana Wildlife Federation, an umbrella
organization of local hunting and fishing groups said, "It seems like
we're going backward and not forward."
Mercury, a heavy metal found in soils and rock, often gets into the food
chain through coal-fired power plant emissions, which enter the
atmosphere and fall back to earth in rain, ending up in rivers and lakes,
state officials and environmentalists said.
Bacteria transform the element into methylmercury, a form toxic to
humans, which accumulates in fish. Predator species such as tuna and
swordfish contain more mercury than prey such as shrimp or crabs,
Because tuna is the second-most-popular seafood in the United States,
according to federal statistics, the consequences of mercury
contamination remain hotly debated. Health officials say that eating
mercury in fish can cause birth defects, nerve and kidney damage, and
developmental problems in children younger than 7.
But officials with the U.S. Tuna Foundation, the lobbying group
representing Star Kist Foods, Chicken of the Sea International and
Bumblebee Seafood -- which has an office in Violet -- pointed to sections
of the report emphasizing that heart-friendly omega-3 fatty acids
contained in canned tuna promote healthy fetal development, prevent
postpartum depression and can reduce the risks of premature births.
"While almost all ocean fish and seafood naturally contain trace levels
of mercury, seafood including canned tuna provides a number of heath
benefits during pregnancy," Dr. Lillian Beard, an industry spokeswoman
and an associate clinical professor of pediatrics at the George
Washington University School of Medicine and Health Sciences, said in a
Sensible consumption will prevent most health risks, said Aaron Viles,
Gulf States field organizer for the U.S. Public Interest Research Group.
But along with issuing warnings and educating seafood consumers, the
federal government should work harder to prevent mercury from reaching
the atmosphere, he said.
"Here in Sportsman's Paradise, we have 30 mercury-in-fish advisories and
four plants pumping out 1,500 pounds of mercury every year," Viles said.
"There are mercury advisories for every single water body running into"
But most fish in those waterways aren't particularly vulnerable to
mercury contamination, said Ewell Smith, executive director of the
Louisiana Seafood Promotion and Marketing Board. While Louisiana anglers
do catch tuna and king mackerel in the Gulf, he said, shrimp, crabs and
oysters form the backbone of the state's commercial seafood industry, and
those species are unlikely to contain high levels of mercury.
Even the game species preferred by local anglers are relatively safe, he
"We want people to be safe; that's just good business," he said. "But
none of the fish mentioned are really our fisheries. Black drum, redfish,
sheepshead and trout are all fish that we have no problems with."
Aaron Kuriloff can be reached at firstname.lastname@example.org or (504)
With Sales Plummeting, Tuna Strikes Back
FOR much of the last three decades, canned tuna fish has been America's
favorite seafood and a trusted staple of children's lunches. Those days,
however, are over.
As awareness has increased about the high levels of mercury in some
kinds of canned tuna fish, tuna has taken on an image problem. Some
consumers are shunning the product in favor of other kinds of fish or
are avoiding fish altogether. Now 21 percent of consumers say they are
"extremely concerned" about mercury in fish, up from 17 percent two
years ago, according to the NPD Group research firm.
As a result, industry sales are sagging. Since March 2004, when the
federal government issued a new advisory about seafood consumption and
mercury, sales of canned tuna in the United States swung from modest
growth to a steady decline. Sales are down 10 percent in the last year,
causing a revenue loss of $150 million for the $1.5 billion industry,
according to ACNielsen.
The joint Food and Drug Administration and Environmental Protection
Agency advisory was the first time canned tuna fish was mentioned in
such warnings. Previously, the agencies has warned only about mercury in
swordfish, king mackerel, shark and tilefish.
Hoping to stem the decline and repair tuna's reputation, the industry
is trying to arrange a government program to oversee an advertising
campaign promoting the benefits of tuna. Called "Tuna - A Smart Catch,"
the ad campaign would not directly address the mercury issue, but
instead would highlight the various health benefits of tuna fish.
In one TV ad, moms proclaim that tuna has "way less fat than beef and
pork," contains no carbs and is "good for us."
But the ads, which have been created by Marriner Marketing in
Columbia, Md., will not appear on TV screens any time soon. The tuna
industry is waiting for government approval of its ad program, to be
administered by a group to be called the American Council for Tuna.
David G. Burney, executive director of the United States Tuna
Foundation, which is overseeing the creation of the council, says the
industry already has the support of the National Marine Fisheries
Service, a division of the Department of Commerce, but is waiting for
approval from the Office of Management and Budget, which oversees all
government regulatory programs.
John Stiker, an executive vice president at Bumble Bee, said he was
hoping the ad campaign would start next spring.
The American Council for Tuna follows in the footsteps of Department
of Agriculture "checkoff" programs that have financed the "Got Milk"
campaign and the "Beef. It's What's for Dinner" ads. Like these ad
campaigns, the tuna program will not receive any government funding and
will be supported through a fee imposed on all tuna producers.
Mr. Burney of the United States Tuna Foundation says he is hoping to
raise $25 million in the first year, the majority of which will go
toward advertising and the rest to other marketing efforts, like
payments to public relations agencies. Contributing to the pot would be
not only the three largest tuna companies - Bumble Bee, Chicken of the
Sea and StarKist, which together account for roughly 85 percent of the
tuna sold in the United States - but also dozens of small family-owned
companies that operate fishing boats, and import companies that sell
private-label tuna fish to supermarkets.
Mr. Stiker of Bumble Bee says he hopes the ads will reassure
consumers that tuna is a "wonder food."
"It's got these great omega 3's that you really can't get in any
other typical lunch food, but we found that Americans just don't think
of it as being very contemporary," Mr. Stiker said.
Mr. Stiker and Mr. Burney do not dispute that tuna is laced with
mercury, which is a known toxin, but they say that, despite government
warnings, the levels are still small enough that they do not pose a
The F.D.A. and E.P.A. guidelines issued in March 2004 advised
pregnant women, women of childbearing age and young children not to
consume more than six ounces, or one can, of "chunk white" albacore tuna
a week. For "chunk light" tuna, which comes from the smaller skipjack
fish and contains less mercury, the recommended consumption limit is 12
ounces a week.
Mercury is of particular concern for fetuses because scientists
believe that mercury in the mother's body passes to the fetus and may
accumulate there. Young children are vulnerable because mercury can have
a damaging effect on developing brains. Scientists at the National
Academy of Sciences have said that adults can also be at risk if mercury
levels are high enough. Symptoms of mercury toxicity include kidney
troubles, irritability, tremors, changes in vision or hearing, and
Mr. Burney says he is convinced that getting mercury toxicity from
tuna is impossible. While his wife was pregnant, he said, she consumed a
can of albacore tuna almost every day. Mr. Stiker says his three boys,
9-year-old triplets, eat several cans of albacore a week.
Mr. Burney says that studies funded by the Tuna Foundation show
mercury levels in a variety of types of tuna have not increased in the
last 30 years. "It takes many, many years before mercury in the
atmosphere reaches areas of the ocean where it can enter the food
chain," Mr. Burney said.
Environmentalists believe that higher mercury levels in the
atmosphere, much of which come from the emissions of coal-powered
electricity plants, work their way into water sources and then into the
food chain. Mr. Burney contends that because tuna are deepwater ocean
fish, it takes many years for atmospheric mercury to find its way into
Posted on Tue, Aug. 23, 2005
Monster tuna found to contain high level of mercury
BY TOM AVRIL
Knight Ridder Newspapers
PHILADELPHIA - (KRT) - The monster bluefin tuna that Dan Dillon caught off
Delaware was a serious fish - at 873 pounds, more than double the previous
state record. But the government says he should go easy with the knife and
fork. The mighty fish contained 2.5 parts per million of mercury, the
environmental group Oceana reported Tuesday - a level so high it would be
illegal to sell.
The U.S. Food and Drug Administration can block the commercial sale of fish
containing more than 1 part per million. At levels above 1.9 parts per
million, the U.S. Environmental Protection Agency recommends eating less
than six meals a year.
Dillon, 39, of Herndon, Va., who caught the tuna July 2 after a 90-minute
struggle, split the big fish among family and friends. Delaware officials
urged him to proceed cautiously, and Dillon said Tuesday that he heeded the
advice. "I haven't really eaten that much myself," said Dillon, who donated
a 5-ounce sample to Oceana, based in Washington, D.C., for testing. "We
spread it around."
Rick Greene, head of the water toxics program for the Delaware Department of
Natural Resources and Environmental Control, said he expected the mercury
level to be high. Tuna are large fish at the top of the food chain,
accumulating mercury from the smaller fish they eat, and this tuna was far
larger and likely far older than most, he noted. "Quite frankly, I'm not
surprised by this result," said Greene, who is conducting his own mercury
tests on the fish.
The mercury level in Dillon's fish is not the highest reported; Japanese
researchers have found bluefin with more than 6 parts per million of
mercury. Canned tuna has much lower levels of mercury, but health experts
urge pregnant women and small children to limit consumption of that product,
too. Scientists believe mercury can harm fetal brain development.
Bert Adams, owner of the shop where the big fish was carved into 500 pounds
of steaks, said his customers didn't seem too concerned.
"They want their tuna fish cleaned."
But when Dillon threw a giant tuna party, the pregnant woman there wasn't
Sobering estimate from EPA that 630,000 babies are
born with mercury exposure
that could affect intelligence...
For pregnant moms, low-mercury fish is intelligent choice
By Jim McQuiggin
In a newly released Harvard study, doctors have concluded that women who eat
fish at least twice a week can boost the intelligence of their newborn. The
study, conducted among 135 Boston-area women, showed that women who ate fish
at least twice a week during the second trimester had babies with the
highest intelligence scores. It is important to note that the fish consumed
among the mothers in the test had mercury levels below 1.2 parts per
Although nearly all fish contain trace amounts of mercury but larger species
such as swordfish, shark, and albacore tuna accumulate the highest levels.
In fact, the US Food and Drug Administration entirely rules out those
species, as well as mackerel and tilefish taken off the Atlantic Coast and
Gulf of Mexico, for pregnant and nursing women and young children. Some
white and albacore tuna, canned and fresh, also have high mercury levels.
Generally, the darker the fish meat, the higher the mercury content. About
630,000 babies a year are born with mercury exposure that could reduce their
mental abilities, the U.S. Environmental Protection Agency estimates.
For each additional weekly serving of fish, the babies' intelligence scores
increased by 4 points, or an average of almost 7%. But for every increase of
1 part per million of mercury, the babies' intelligence scores dropped by
7.5 points, or 12.5%. A woman could raise her mercury level by 1 ppm if she
ate an average-sized serving of swordfish once a week, said Dr. Emily Oken
of Harvard Medical School, the study's lead researcher. In tests designed by
neuropsychologists to study early signs of intelligence and memory, the
Boston-area babies were shown photographs of new faces and ones they had
been shown before, and the researchers recorded how much time they spent
studying each one. Babies score higher on the test if they move quickly from
the familiar face, indicating recognition, to exploring the new face.
On call: Tuna on white; hold the mercury
By Dana Whitten
BELFAST (Feb 21): Parents of youngsters exploring solid foods sometimes ask
if fish, particularly tuna fish, is safe for them. Most of us are aware that
there is a concern about mercury contamination with harmful side effects in
many species of fish; remember when swordfish was unavailable because of
mercury? This article will briefly survey what is known of the environmental
dangers of mercury, particularly how it is related to us in Maine, a state
in which mercury levels in fish, loons and eagles are among the highest in
the country. Mercury is an environmental toxin, found everywhere, that
causes a wide range of adverse health effects in humans. Three forms of
mercury (elemental, inorganic and organic) exist, each with its own type of
toxicity. Exposure to this heavy metal occurs after inhalation or ingestion,
and everyone is exposed to at least small amounts. It occurs naturally in
ore and fossil fuels such as coal and petroleum. Environmental contamination
results from the actions of man, mining, smelting and industrial
discharges. Elemental mercury or quicksilver is that funny silvery, beady
substance we were entranced with as kids, rolling it around in our palms
after a thermometer broke. (If you ever see a kid playing with liquid
mercury, intervene and find out from a toxicology expert how to safely
dispose of the substance; poisoning can occur from inhaling invisible
vapors.) It is the liquid form of the metal and was once used in other
medical instruments and is now used in dental fillings, fluorescent light
bulbs and button batteries.
Indiscriminate disposal of these items in landfills or waste incinerators is
a major source of environmental contamination as the substance readily
vaporizes, is inhaled and passes from the lungs to the red blood cells and
deposits in the brain, spinal cord and kidneys. It easily crosses the
placenta and accumulates in the fetus. Elemental mercury can cause acute,
life-threatening illness and chronic brain disease such as occurred with hat
makers who used liquid mercury in processing felt hats. (Hence the "Mad
Hatter" from "Alice in Wonderland.") It is presently believed that dental
fillings do not pose a threat as elemental mercury is poorly absorbed from
the gut. We didn't worry too much when a child bit off the end of a
thermometer and swallowed some. Inorganic mercury compounds (salts) have
long been used for their antibacterial properties. They were also used a
century ago in teething powders, all of these being long-banned from use in
this country. Ingestion can be very toxic and was a not-uncommon form of
suicide. A long forgotten childhood illness, pink disease, was seen in
infants exposed to teething powders and organic mercury compounds in latex
paint and diaper fungicides. Inorganic mercury compounds are still available
on the world market. Organic mercury compounds, primarily methyl mercury
and ethyl mercury, have been produced as biocides and pesticides and were
once found in two common household antiseptics: mercurochrome and
merthiolate. Methyl mercury is a predominant form of mercury in our
environment and is formed by microorganisms from elemental mercury dropped
out of the air in precipitation, originating mainly from incineration and
discarded household products evaporating into the atmosphere. It is
estimated that 650 tons of mercury escape into the environment and are
formed in microorganisms each year. Methyl mercury produced by
microorganisms when atmospheric mercury hits water is ingested by small fish
and shellfish and bioaccumulates up the food chain as larger fish eat
smaller ones. Methyl mercury is a permanent resident in these small
animals and others that eat them (loons, eagles, sharks, whales, humans) and
cannot be removed by processing. It is slowly excreted as consumption levels
continue to rise. There is an alarming rate of death in loons in Maine due
to methyl mercury; fatality rates in other animals are unknown. Methyl
mercury is 95 percent absorbed by the bowel in man and passes through the
placenta, into the brain and breast milk. It is most toxic to the developing
brain of the fetus, causing
destruction of certain cell types; after birth, retardation, blindness,
deafness and seizures may develop. There have been two large human-produced
disasters, in Mina Mata Bay, Japan and in Iraq.
While most of the mothers were mainly unaffected, unborn children were
severely affected. Interestingly, already born, exposed children had a
good capacity to recover from neurological involvement. Their symptoms
included behavior changes and learning
problems. There are two ongoing large studies in the world regarding the
development of children in saltwater fish-eating populations. In older
children and adults, larger amounts of mercury ingested from eating fish are
required to produce symptoms; these include
tingling, prickling or numbness of the hands and feet, or visual changes.
All fish in Maine lakes, ponds and rivers have methyl mercury in them. We
receive the industrial waste that blows west to east across the country,
bringing to coastal states our increased rates of asthma and mercury
exposure. Fish-eating fish, such as pickerel and bass, and older fish have
the highest levels. Brook trout and landlocked salmon are the safest.
"Safe Eating Guidelines" produced by the Bureau of Health states that
pregnant and nursing women, women who may get pregnant, and children under 8
should not eat freshwater fish, and one meal per week of the trout and
salmon is safe. That is pretty sad, as fish is a nutritious, low-fat and
otherwise healthy food. Other contaminants such as PCBs, dioxins or DDT are
found at high levels in certain freshwater bodies preventing any safe eating
of any fish. In this part of Maine that includes the Kennebec River from
Augusta to the Chops. As for saltwater fish, the guidelines say no
swordfish, shark or tilefish or king mackerel for pregnant or nursing women,
women who may become pregnant, or children under 8. The same group should
only eat one can of "white" (albacore) or two cans of light tuna per week.
Consumption of striped bass and bluefish should be
limited to two meals per month for everyone. Lobster tomalley is high in
environmental contaminants and should not be eaten by anyone. Lastly, I
need to mention that ethyl mercury in the form of thimerosal was used in
routine childhood immunizations prior to 1999. Less is known of the toxic
effects of ethyl mercury than methyl mercury, but the FDA questioned whether
infants receiving thimerosal-containing vaccines might be exposed to
higher-than-acceptable levels of mercury. Studies have not been completed,
but so far there is no consensus that this form of mercury in the doses used
caused neurotoxicity that is detectable. Based on a joint recommendation by
the American Academy of Pediatrics and the U.S. Public Health Service, none
of the routine childhood vaccines contain thimerosal. Phenyl mercury was
removed from interior latex paints in 1991. Mercury in all forms is toxic
to fetuses and children. There is no effective method of treating mercury
poisoning, so prevention is essential. In our state, where fishing is a
popular pastime and an important form of livelihood, all of us who are
consumers and providers of this generally healthy food need to be aware and
up to date on the safety issues of what goes on our plates. Pass the lemons,
Dr. Dana Whitten practices at Belfast Pediatrics.
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