By Eric Pianin, Washington Post Staff Writer
Farm-raised salmon, a growing staple of American diets, contains
significantly higher concentrations of PCBs, dioxin and other
cancer-causing contaminants than salmon caught in the wild, and should
be eaten infrequently, according to a new study of commercial fish sold
in North America, South America and Europe.
The study, using Environmental Protection Agency (news - web sites)
health guidelines, concluded that although consumers can safely eat four
to eight meals of wild salmon a month, consumption of more than one
eight-ounce portion of farmed salmon a month in most cases poses an
"unacceptable cancer risk."
Food and Drug Administration (news - web sites) and fishing industry
officials immediately took issue with the findings. They said the
contaminant levels in salmon have declined by 90 percent since the
1970s, and that the remaining threat -- when balanced against the high
protein and cardiovascular health benefits of eating salmon -- do not
warrant shunning the food.
"We've looked at the levels found . . . and they do not represent a
health concern," said Terry C. Troxell, director of the FDA's Office of
Plant and Dairy Foods and Beverages. "In the end, our advice is not to
alter consumption of farmed or wild salmon."
The two-year, $2.4 million study, funded by the Pew Charitable Trust and
published yesterday in the journal Science, is the latest blow to the
commercial fish industry, already suffering from growing concerns about
elevated levels of mercury in tuna and shellfish.
The study found that salmon contamination varied by geography.
Store-bought samples from Frankfurt, Edinburgh, Paris, London and Oslo
were generally the most contaminated, while samples from stores in New
Orleans and Denver were the least. Cities including Washington, New
York, Los Angeles, Chicago and Seattle ranked somewhere in the middle,
and their residents were advised to eat farmed salmon no more than once
or twice a month.
EPA guidelines say that if a person eats fish twice a week, it should
contain no more than 4 to 6 parts per billion of PCBs. The study found
that PCB levels in farmed salmon sold in the United States and Canada
averaged about five times that amount: 30 parts per billion. On average,
farmed salmon had concentrations of health-threatening contaminants 10
times greater than those found in wild salmon.
Consumers may have difficulty distinguishing between farmed and wild
salmon, because many stores and restaurants do not clearly label them.
Wild salmon is three to four times more expensive, but some retailers
confuse the issue by identifying farmed salmon as "Atlantic salmon." The
study called for labels differentiating wild from farmed and noting the
country of origin.
Ninety percent of the fresh salmon consumed in the United States is
farm-raised, industry officials say. More than half of that salmon comes
from Chile, however, where the pollutant level of farmed salmon is less
than that of most other regions but still higher than in wild fish,
according to the study.
Farmed fish contain higher concentrations of contaminants than wild fish
largely because they are fed meal that consists of ground-up fish
tainted with the contaminants. Wild salmon eat tiny fish and aquatic
organisms that are less contaminated.
Salmon of the Americas, a group representing farmed salmon producers in
the United States, Canada and Chile, described salmon as an unparalleled
source of omega-3 fatty acids for prevention of coronary heart disease,
and noted that contaminant levels for North and South American wild and
farmed salmon are well below FDA and World Health Organization (news -
web sites) limits. Alex Trent, executive director of Salmon of the
Americas, said his industry does not discount some of the health
problems associated with PCB contamination of farmed salmon. But meat
and dairy products consumed in large quantities pose similar problems,
he said, and consumers would be foolish to deny themselves the health
benefits of salmon.
"Scaring people away from farm salmon presents more of a health risk
than letting them eat PCBs at these trace levels," Trent said.
However, the study's chief author said the FDA consumer health
guidelines for eating salmon need to be updated.
"We are not saying people shouldn't eat farmed salmon," said David. O.
Carpenter, director of the Institute for Health and the Environment at
the University at Albany-SUNY and chief author of the study. "We're
telling them to reduce their frequency of consumption until the industry
can develop a food source for omega-3 fatty acids that does not have
these contaminants."
Diet- and health-conscious Americans have turned to salmon in recent
years, and about 23 million eat the fish more than once a month. The
annual global production of farmed salmon has increased fortyfold in two
decades.
Some producers of farmed fish have taken steps to improve the quality of
the meal fed to their fish, although critics say far more needs to be
done to eliminate PCBs and other contaminants.
PCBs, or polychlorinated biphenyls, have been banned in the United
States since the late 1970s and are among a dozen chemical contaminants
targeted for worldwide phaseout under a U.N. treaty. PCBs, which were
used as industrial insulators, persist in the environment and have been
linked to cancer and impaired fetal brain development. Dioxins, a
byproduct of high-temperature industrial and waste treatment, have been
linked to cancer, reproductive and developmental problems and altered
immune functions.
Jane Houlihan, vice president for research at the Environmental Working
Group, said the study "leaves little room for the farmed fish industry
to argue away the problems of polluted farmed seafood."
But Mike Bolger, director of FDA's division of risk assessment, said his
agency is identifying sources of PCBs and other dioxin-like contaminants
in fish and working with the industry on ways to reduce their presence
in salmon feed. "We're convinced [this is] the most effective, efficient
and quickest way of reducing exposure," he said.
vielleicht noch eine handvoll antibiotika-shrimps dazu?
